diff --git a/.ai/plans/apimatic-config.md b/.ai/plans/apimatic-config.md
index 7b98c9772..78a55a86c 100644
--- a/.ai/plans/apimatic-config.md
+++ b/.ai/plans/apimatic-config.md
@@ -151,6 +151,8 @@ Rejected:
   bundled SDK.
   `codegenVersion` stays, inside `publishing`, because the mismatch check
   in `PluginConfig.assertNoCodegenVersionMismatch` depends on it.
+  *(Superseded: the service decides the generator, so the field and its check
+  both left in the v3 retirement. An older file keeps it; nothing reads it.)*
   `packageConfiguration` and `source.repositoryType` from the design sketch are
   not modelled in this release. A hand-written file carrying `packageConfiguration`
   keeps it, because unknown fields in these blocks are preserved. A hand-written
diff --git a/.ai/plans/portal-config.md b/.ai/plans/portal-config.md
index fba85d396..7b3ef0081 100644
--- a/.ai/plans/portal-config.md
+++ b/.ai/plans/portal-config.md
@@ -550,8 +550,9 @@ Following `.ai/instructions.md` and the skills in `.ai/skills/`.
   `"typescript": {}` section 12 recommends validates. Inside `publishing`,
   `source`, `package` (per language, as `plugin-config.ts` types them) and
   `codegenVersion` (`v3`, `v4`) are typed and none is required, matching the
-  plugin path's leniency: `assertNoCodegenVersionMismatch` already reads a
-  missing `codegenVersion` as no mismatch. `languages` is optional in the schema: the "at least one"
+  plugin path's leniency: the mismatch check then read a missing
+  `codegenVersion` as no mismatch. *(Superseded: `codegenVersion` and its
+  check have both since left; the field is no longer typed in the schema.)* `languages` is optional in the schema: the "at least one"
   rule is the portal command's, and a file `sdk publish` alone created is
   valid. The `$schema` URL
   is `https://cdn.jsdelivr.net/npm/@apimatic/cli@2/apimatic.schema.json`.
@@ -745,8 +746,8 @@ verified to build 22 pages with this branch's CLI.
   entry (`"typescript": {}`) is enough, since the portal checks only the key.
   Today a `{}` entry is inert for the plugin commands: `hasPublishedSdks` needs
   `publishing.source` or `publishing.package`, so `plugin generate` still
-  reports no published SDKs, and `assertNoCodegenVersionMismatch` skips an
-  entry with no `publishing` record.
+  reports no published SDKs. *(The mismatch check that also skipped such an
+  entry has since been removed with `codegenVersion`.)*
 - **The hand-written entry is not inert for long.** Since #350 an entry with no
   `publishing` block means "this language is wanted, nothing is published
   yet", which is the state the coming bundling change turns into an SDK
diff --git a/.ai/skills/action.md b/.ai/skills/action.md
index 81bb9774b..b6f04793e 100644
--- a/.ai/skills/action.md
+++ b/.ai/skills/action.md
@@ -93,7 +93,7 @@ Use when creating a new Action class. Choose the variant that matches the action
 ### What to determine
 
 1. **Topic** — action group folder (e.g., `api`, `sdk`, `portal`). Can be nested: `sdk/publish`, `publishing/profile`
-2. **Action name** — file name, lowercase hyphenated (e.g., `validate`, `generate`, `save-changes`)
+2. **Action name** — file name, lowercase hyphenated (e.g., `validate`, `generate`, `record-sdk`)
 3. **Class name** — PascalCase with `Action` suffix (e.g., `ValidateAction`, `PortalNewTocAction`)
 4. **Variant** — one of:
    - `standard` — full constructor with configDir, commandMetadata, authKey; services, withDirPath, prompts
diff --git a/.ai/skills/event.md b/.ai/skills/event.md
index 556467236..587d23f8f 100644
--- a/.ai/skills/event.md
+++ b/.ai/skills/event.md
@@ -7,7 +7,7 @@ Domain events live at `src/types/events/` and represent something that **already
 ### Naming
 
 - **Class name must be past tense** — the event describes something that occurred: `QuickstartCompleted`, `SdkChangesSaved`, `SdkConflictsResolved`. Never present tense (`SdkSaveChanges`) or imperative (`SaveChanges`).
-- **File name** — lowercase hyphenated, matching the class name: `quickstart-completed.ts`, `sdk-changes-saved.ts`.
+- **File name** — lowercase hyphenated, matching the class name: `quickstart-completed.ts`, `sdk-publish-validation-failed.ts`.
 - **Class name suffix** — always `Event`: `QuickstartCompletedEvent`, `SdkChangesSavedEvent`.
 
 ### Structure
@@ -102,9 +102,7 @@ export class {PascalName}Event extends DomainEvent {
 |---|---|
 | Self-contained success event (no payload) | `src/types/events/quickstart-completed.ts` |
 | Self-contained initiation event (no payload) | `src/types/events/quickstart-initiated.ts` |
-| Success event with payload (`language`) | `src/types/events/sdk-changes-saved.ts` |
-| Success event with payload (`language`) | `src/types/events/sdk-conflicts-resolved.ts` |
 | Failure event (dynamic message + flags) | `src/types/events/sdk-publish-validation-failed.ts` |
 | DomainEvent base class | `src/types/events/domain-event.ts` |
 | Firing from Command (success + failure) | `src/commands/quickstart.ts` |
-| Firing from Command (failure only) | `src/commands/sdk/save-changes.ts` |
+| Firing from Command (failure only) | `src/commands/sdk/publish.ts` |
diff --git a/.ai/skills/prompt.md b/.ai/skills/prompt.md
index b3aad2f76..214c7b754 100644
--- a/.ai/skills/prompt.md
+++ b/.ai/skills/prompt.md
@@ -81,7 +81,7 @@ Use when creating a new Prompts class. Choose the variant that matches the comma
 ### What to determine
 
 1. **Topic** — folder path matching the action (e.g., `auth`, `api`, `sdk`, `portal`, `sdk/publish`)
-2. **Name** — file name, lowercase hyphenated (e.g., `login`, `generate`, `save-changes`)
+2. **Name** — file name, lowercase hyphenated (e.g., `login`, `generate`, `record-sdk`)
 3. **Class name** — PascalCase with `Prompts` suffix (e.g., `LoginPrompts`, `SdkGeneratePrompts`)
 4. **Variant** — one of:
    - `simple` — log methods and optional spinner; no interactive prompts
diff --git a/README.md b/README.md
index c60da9843..ef85e4b9e 100644
--- a/README.md
+++ b/README.md
@@ -82,7 +82,6 @@ USAGE
 * [`apimatic quickstart`](#apimatic-quickstart)
 * [`apimatic sdk generate`](#apimatic-sdk-generate)
 * [`apimatic sdk publish`](#apimatic-sdk-publish)
-* [`apimatic sdk save-changes`](#apimatic-sdk-save-changes)
 
 ## `apimatic api transform`
 
@@ -426,9 +425,8 @@ Generate an SDK for your API
 
 ```
 USAGE
-  $ apimatic sdk generate -l csharp|java|php|python|ruby|typescript|go [-d <value>] [--skip-changes]
-    [--api-version <value>] [--zip] [--track-changes] [--codegen-version v3|v4] [--stability stable|beta] [-i <value>]
-    [-f] [-k <value>]
+  $ apimatic sdk generate -l csharp|java|php|python|ruby|typescript|go [-d <value>] [--api-version <value>]
+    [--zip] [--codegen-version v4] [--stability stable|beta] [-i <value>] [-f] [-k <value>]
 
 FLAGS
   -d, --destination=<value>       [default: <input>/sdk/<language> | <input>/sdk/<api-version>/<language>] path where
@@ -440,22 +438,20 @@ FLAGS
   -l, --language=<option>         (required) Programming language for SDK generation
                                   <options: csharp|java|php|python|ruby|typescript|go>
       --api-version=<value>       Version of the API to use for SDK generation (if multiple versions exist)
-      --codegen-version=<option>  [default: v3] Version of the code generator to use
-                                  <options: v3|v4>
-      --skip-changes              Do not apply the saved changes to the generated SDK
-      --stability=<option>        [default: stable] Stability level of the generated SDK
+      --codegen-version=<option>  [default: v4] Version of the code generator to use
+                                  <options: v4>
+      --stability=<option>        Stability level of the generated SDK. Defaults to the level the language offers.
                                   <options: stable|beta>
-      --track-changes             Enable change tracking for SDK generation (only required for initial setup)
       --zip                       Download the generated SDK as a .zip archive
 
 DESCRIPTION
   Generate an SDK for your API
 
-  Generate Software Development Kits (SDKs) from API specifications.
-  Supports multiple programming languages including Java, C#, Python, JavaScript, and more.
+  Generate a Software Development Kit (SDK) from an API specification.
+  C#, TypeScript and Python are available; Java, Ruby, Go and PHP are on their way.
 
 EXAMPLES
-  apimatic sdk generate --language=java
+  apimatic sdk generate --language=typescript
 
   apimatic sdk generate --language=csharp --input=./
 
@@ -470,9 +466,9 @@ Generate and publish an SDK to a package registry and/or source repository
 
 ```
 USAGE
-  $ apimatic sdk publish [-p <value>] [-v <value>] [-d <value>] [-l csharp|java|php|python|ruby|typescript] [-f]
-    [-i <value>] [--publish-type package|sourcecode...] [--dry-run] [--codegen-version v3|v4] [--stability stable|beta]
-    [--update-plugin-config]
+  $ apimatic sdk publish [-p <value>] [-v <value>] [-d <value>] [-l csharp|java|php|python|ruby|typescript|go]
+    [-f] [-i <value>] [--publish-type package|sourcecode...] [--dry-run] [--codegen-version v4] [--stability
+    stable|beta]
 
 FLAGS
   -d, --destination=<value>       [default: <input>/sdk] path where the sdk will be generated.
@@ -480,19 +476,17 @@ FLAGS
   -i, --input=<value>             [default: ./] path to the parent directory containing the 'src' directory, which
                                   includes API specifications and configuration files.
   -l, --language=<option>         Language of the SDK to generate and publish.
-                                  <options: csharp|java|php|python|ruby|typescript>
+                                  <options: csharp|java|php|python|ruby|typescript|go>
   -p, --profile-id=<value>        Id of the publishing profile to use.
   -v, --version=<value>           Semantic version of the SDK to publish (e.g. 1.0.0).
-      --codegen-version=<option>  [default: v3] Version of the code generator to use
-                                  <options: v3|v4>
+      --codegen-version=<option>  [default: v4] Version of the code generator to use
+                                  <options: v4>
       --dry-run                   Generate the SDK locally for review without publishing.
       --publish-type=<option>...  One or more publishing targets: 'package' for a package registry, 'sourcecode' for a
                                   git repository.
                                   <options: package|sourcecode>
-      --stability=<option>        [default: stable] Stability level of the generated SDK
+      --stability=<option>        Stability level of the generated SDK. Defaults to the level the language offers.
                                   <options: stable|beta>
-      --update-plugin-config      Record the published SDK in 'src/apimatic.json', creating the file if it does not
-                                  exist. Interactive runs are asked instead.
 
 DESCRIPTION
   Generate and publish an SDK to a package registry and/or source repository
@@ -506,44 +500,10 @@ EXAMPLES
 
   apimatic sdk publish --profile-id=a1b2c3d4e5f6a1b2c3d4e5f6 --language=typescript --version=1.0.0 --publish-type=package --publish-type=sourcecode
 
-  apimatic sdk publish --profile-id=b2c3d4e5f6a1b2c3d4e5f6a1 --language=java --version=2.0.0 --publish-type=sourcecode
+  apimatic sdk publish --profile-id=b2c3d4e5f6a1b2c3d4e5f6a1 --language=csharp --version=2.0.0 --publish-type=sourcecode
 
   apimatic sdk publish --profile-id=c3d4e5f6a1b2c3d4e5f6a1b2 --language=python --version=1.0.0 --publish-type=package --dry-run
-
-  apimatic sdk publish --profile-id=d4e5f6a1b2c3d4e5f6a1b2c3 --language=csharp --version=1.0.0 --publish-type=package --codegen-version=v4 --stability=beta
 ```
 
 _See code: [src/commands/sdk/publish.ts](https://github.com/apimatic/apimatic-cli/blob/v1.3.1/src/commands/sdk/publish.ts)_
-
-## `apimatic sdk save-changes`
-
-Save customizations made to an auto-generated SDK
-
-```
-USAGE
-  $ apimatic sdk save-changes -l csharp|java|php|python|ruby|typescript|go [--sdk <value>] [--api-version <value>] [-i
-    <value>]
-
-FLAGS
-  -i, --input=<value>        [default: ./] path to the parent directory containing the 'src' directory, which includes
-                             API specifications and configuration files.
-  -l, --language=<option>    (required) Programming language of the SDK
-                             <options: csharp|java|php|python|ruby|typescript|go>
-      --api-version=<value>  Version of the API where changes should be saved (if multiple versions exist).
-      --sdk=<value>          [default: ./sdk/<language> | ./sdk/<api-version>/<language>] path to the folder containing
-                             the updated SDK.
-
-DESCRIPTION
-  Save customizations made to an auto-generated SDK
-
-  Requires an input directory with API specifications, a path to the updated SDK directory, and the programming
-  language.
-
-EXAMPLES
-  apimatic sdk save-changes --language=csharp
-
-  apimatic sdk save-changes --language=java --sdk=./sdk
-```
-
-_See code: [src/commands/sdk/save-changes.ts](https://github.com/apimatic/apimatic-cli/blob/v1.3.1/src/commands/sdk/save-changes.ts)_
 <!-- commandsstop -->
diff --git a/apimatic.schema.json b/apimatic.schema.json
index af6284a85..36079a73e 100644
--- a/apimatic.schema.json
+++ b/apimatic.schema.json
@@ -262,7 +262,7 @@
       "properties": {
         "publishing": {
           "type": "object",
-          "description": "Where the SDK is published, and which generator produced it.",
+          "description": "Where the SDK is published.",
           "additionalProperties": true,
           "properties": {
             "source": {
@@ -279,9 +279,6 @@
             },
             "package": {
               "type": "object"
-            },
-            "codegenVersion": {
-              "enum": ["v3", "v4"]
             }
           }
         }
diff --git a/src/actions/plugin/record-sdk.ts b/src/actions/plugin/record-sdk.ts
deleted file mode 100644
index 6131929cc..000000000
--- a/src/actions/plugin/record-sdk.ts
+++ /dev/null
@@ -1,69 +0,0 @@
-import { PluginRecordSdkPrompts } from '../../prompts/plugin/record-sdk.js';
-import { DirectoryPath } from '../../types/file/directoryPath.js';
-import { buildLanguageEntry } from '../../types/plugin/language-entry.js';
-import { PluginConfigContext } from '../../types/plugin-config-context.js';
-import { PublishType } from '../../types/publish-api/publishing-profile-item.js';
-import { PublishingProfile } from '../../types/publish/publishing-profile.js';
-import { SemVersion } from '../../types/publish/version.js';
-import { Language } from '../../types/sdk/generate.js';
-import { ActionResult } from '../action-result.js';
-
-/**
- * Callers discard the result: this runs after a publish that already succeeded, and no outcome here
- * may change that.
- */
-export class PluginRecordSdkAction {
-  private readonly prompts: PluginRecordSdkPrompts = new PluginRecordSdkPrompts();
-
-  public readonly execute = async (
-    sourceDirectory: DirectoryPath,
-    language: Language,
-    publishingProfile: PublishingProfile,
-    publishTypes: PublishType[],
-    packageVersion: SemVersion
-  ): Promise<ActionResult> => {
-    // The entry describes what this run published, not what the profile enables: a package-only
-    // run claims no repository, and a source-only run records no released version. The package
-    // configuration is written either way — it says how the package is set up, not that one
-    // exists, and the service reads the package's name out of it.
-    const entry = buildLanguageEntry(
-      language,
-      publishTypes.includes(PublishType.SourceCodePublishing)
-        ? publishingProfile.getGitConfigurationForLanguage(language)
-        : undefined,
-      publishingProfile.getPackageConfigurationDataForLanguage(language),
-      publishTypes.includes(PublishType.PackagePublishing) ? packageVersion : undefined
-    );
-
-    const pluginConfigContext = new PluginConfigContext(sourceDirectory);
-    const configState = await pluginConfigContext.getPluginConfigState();
-    if (configState.state === 'unreadable') {
-      this.prompts.pluginConfigUnreadable(configState.reason);
-      return ActionResult.failed();
-    }
-
-    const configExisted = configState.state === 'present';
-
-    if (!entry.publishing?.source && (!configExisted || configState.hasNoSourceRepository(language))) {
-      this.prompts.noSourceRepository(language);
-    }
-
-    const writeResult = await pluginConfigContext.upsertLanguage(language, entry);
-    if (writeResult.isErr()) {
-      switch (writeResult.error) {
-        // Readable a moment ago, so this only happens if the file changed underneath us.
-        case 'unreadable':
-          this.prompts.pluginConfigUnreadable();
-          return ActionResult.failed();
-        case 'unwritable':
-          this.prompts.pluginConfigNotWritten();
-          return ActionResult.failed();
-        default:
-          throw writeResult.error satisfies never;
-      }
-    }
-
-    this.prompts.sdkRecorded(language, configExisted);
-    return ActionResult.success();
-  };
-}
diff --git a/src/actions/sdk/generate.ts b/src/actions/sdk/generate.ts
index d1cb89363..13f83452b 100644
--- a/src/actions/sdk/generate.ts
+++ b/src/actions/sdk/generate.ts
@@ -6,10 +6,8 @@ import { SdkContext } from '../../types/sdk-context.js';
 import { SdkGeneratePrompts } from '../../prompts/sdk/generate.js';
 import { CommandMetadata } from '../../types/common/command-metadata.js';
 import { TempContext } from '../../types/temp-context.js';
-import { CodegenOption, Language } from '../../types/sdk/generate.js';
-import { MergeSourceTreeAction } from './merge-source-tree.js';
+import { isAvailableLanguage, Language, Stability } from '../../types/sdk/generate.js';
 import { BuildContext } from '../../types/build-context.js';
-import { SemVersion } from '../../types/publish/version.js';
 
 export class GenerateAction {
   private readonly prompts: SdkGeneratePrompts = new SdkGeneratePrompts();
@@ -28,17 +26,16 @@ export class GenerateAction {
     sourceDirectory: DirectoryPath,
     destinationSdkDirectory: DirectoryPath,
     language: Language,
+    stability: Stability,
     force: boolean,
     zipSdk: boolean,
-    skipChanges: boolean,
-    trackChanges: boolean,
-    codegenOption: CodegenOption,
-    stabilityWasProvided: boolean,
     apiVersion?: string,
-    packageVersion?: SemVersion,
     packageSettingsDirectory?: DirectoryPath
-  ): Promise<ActionResult<{ sourceTreeTrackingInitiated: boolean; conflictsResolved: boolean }>> => {
-    this.prompts.warnIfStabilityIgnored(codegenOption, stabilityWasProvided);
+  ): Promise<ActionResult> => {
+    if (!isAvailableLanguage(language)) {
+      this.prompts.languageNotAvailable(language);
+      return ActionResult.failed();
+    }
 
     if (sourceDirectory.isEqual(destinationSdkDirectory)) {
       this.prompts.sameSourceAndSdkDir(sourceDirectory);
@@ -97,8 +94,7 @@ export class GenerateAction {
       return ActionResult.failed();
     }
 
-    const hasSdkSourceTree = await buildContext.hasSdkSourceTree(language);
-    const sdkContext = new SdkContext(language, destinationSdkDirectory, skipChanges && hasSdkSourceTree, version);
+    const sdkContext = new SdkContext(language, destinationSdkDirectory, version);
     if (!force && (await sdkContext.exists()) && !(await this.prompts.overwriteSdk(destinationSdkDirectory))) {
       this.prompts.destinationDirNotEmpty();
       return ActionResult.cancelled();
@@ -108,39 +104,14 @@ export class GenerateAction {
       const tempContext = new TempContext(tempDirectory);
       const buildZipPath = await buildContext.getBuildZipPath(tempDirectory, packageSettingsDirectory);
 
-      if (codegenOption.isV4()) {
-        this.prompts.sdkCustomizationsNotSupportedForV4();
-
-        const response = await this.prompts.generateV4SDK(
-          this.sdkGenerationService.generateV4Sdk(
-            buildZipPath,
-            language,
-            codegenOption.stabilityLevel(),
-            this.configDir,
-            this.commandMetadata,
-            this.authKey
-          )
-        );
-
-        if (response.isErr()) {
-          this.prompts.sdkGenerationServiceError(response.error);
-          return ActionResult.failed();
-        }
-
-        const responseSdkZipPath = await tempContext.save(response.value);
-        const tempSdk = await sdkContext.loadSdkInTempDirectory(tempDirectory, responseSdkZipPath);
-        this.prompts.sdkGenerated(await sdkContext.save(tempSdk, zipSdk));
-        return ActionResult.success();
-      }
-
-      const response = await this.prompts.generateSDK(
+      const response = await this.prompts.generateSdk(
         this.sdkGenerationService.generateSdk(
           buildZipPath,
           language,
+          stability,
           this.configDir,
           this.commandMetadata,
-          this.authKey,
-          packageVersion
+          this.authKey
         )
       );
 
@@ -149,36 +120,11 @@ export class GenerateAction {
         return ActionResult.failed();
       }
 
-      const responseSdkZipPath = await tempContext.save(response.value.sdk);
+      const responseSdkZipPath = await tempContext.save(response.value);
       const tempSdk = await sdkContext.loadSdkInTempDirectory(tempDirectory, responseSdkZipPath);
+      this.prompts.sdkGenerated(await sdkContext.save(tempSdk, zipSdk));
 
-      if (!trackChanges && !hasSdkSourceTree) {
-        this.prompts.sdkGenerated(await sdkContext.save(tempSdk, zipSdk));
-        return ActionResult.success();
-      }
-
-      const sdkSourceTreeTempFilePath = await tempContext.save(response.value.sdkSourceTree);
-
-      const tempSdkWithSourceTree = await sdkContext.loadSdkWithSourceTreeInTempDirectory(
-        tempDirectory,
-        responseSdkZipPath,
-        sdkSourceTreeTempFilePath
-      );
-      const destinationSourceTreePath = buildContext.getSdkSourceTree(language);
-
-      const mergeSourceTree = new MergeSourceTreeAction();
-      return await mergeSourceTree.execute(
-        tempSdkWithSourceTree,
-        tempSdk,
-        destinationSourceTreePath,
-        trackChanges,
-        skipChanges,
-        hasSdkSourceTree,
-        language,
-        destinationSdkDirectory,
-        version,
-        zipSdk
-      );
+      return ActionResult.success();
     });
   };
 }
diff --git a/src/actions/sdk/merge-source-tree.ts b/src/actions/sdk/merge-source-tree.ts
deleted file mode 100644
index e1422884d..000000000
--- a/src/actions/sdk/merge-source-tree.ts
+++ /dev/null
@@ -1,107 +0,0 @@
-import { DirectoryPath } from "../../types/file/directoryPath.js";
-import { FilePath } from "../../types/file/filePath.js";
-import { LauncherService } from "../../infrastructure/launcher-service.js";
-import { MergeSourceTreePrompts } from "../../prompts/sdk/merge-source-tree.js";
-import { Language } from "../../types/sdk/generate.js";
-import { ActionResult } from "../action-result.js";
-import isInCi from "is-in-ci";
-import { MergeSourceTreeContext } from "../../types/merge-source-tree-context.js";
-import { SdkContext } from "../../types/sdk-context.js";
-
-export class MergeSourceTreeAction {
-  private readonly prompts = new MergeSourceTreePrompts();
-  private readonly launcherService = new LauncherService();
-
-  public readonly execute = async (
-    sdkWithSourceTree: DirectoryPath,
-    sdkWithoutSourceTree: DirectoryPath,
-    destinationSourceTreePath: FilePath,
-    trackChanges: boolean,
-    skipChanges: boolean,
-    hasSdkSourceTree: boolean,
-    language: Language,
-    outputSdkDirectory: DirectoryPath,
-    version: string | undefined,
-    zipSdk: boolean
-  ): Promise<ActionResult<{sourceTreeTrackingInitiated: boolean, conflictsResolved: boolean}>> => {
-    const mergeSourceTreeContext = new MergeSourceTreeContext(
-      sdkWithSourceTree, sdkWithoutSourceTree, destinationSourceTreePath,
-      trackChanges, skipChanges, hasSdkSourceTree
-    );
-    const sdkContext = new SdkContext(language, outputSdkDirectory, skipChanges && hasSdkSourceTree, version);
-    const saveSdk = async () => await sdkContext.save(sdkWithoutSourceTree, zipSdk);
-
-    const { hasSkippedChangesEnabled, hasSkippedCustomizations } = await mergeSourceTreeContext.saveSkippingChanges();
-    if (hasSkippedCustomizations) {
-      this.prompts.successfullySkippedChanges(language);
-      this.prompts.sdkGenerated(await saveSdk());
-      return ActionResult.success();
-    }
-    if (hasSkippedChangesEnabled) {
-      this.prompts.sdkGenerated(await saveSdk());
-      return ActionResult.success();
-    }
-
-    const { hasSourceTreeTracked, hasSourceTreeAlreadyTracked, hasAppliedCustomizations } = await mergeSourceTreeContext.saveWithoutConflicts();
-    if (hasAppliedCustomizations) {
-      this.prompts.successfullyAppliedChanges(language);
-      this.prompts.sdkGeneratedWithSourceTree(await saveSdk(), destinationSourceTreePath);
-      return ActionResult.success();
-    }
-    if (hasSourceTreeAlreadyTracked) {
-      this.prompts.changeTrackingAlreadyEnabled(language);
-      this.prompts.sdkGeneratedWithSourceTree(await saveSdk(), destinationSourceTreePath);
-      return ActionResult.success();
-    }
-    if (hasSourceTreeTracked) {
-      this.prompts.sdkGenerated(await saveSdk());
-      this.prompts.changeTrackingEnabled(language, destinationSourceTreePath);
-      return ActionResult.success({sourceTreeTrackingInitiated: true, conflictsResolved: false});
-    }
-
-    this.prompts.startApplyingConflictedChanges(language);
-    
-    let conflictedFilesDirectory = await mergeSourceTreeContext.getConflictedFilesDirectory();
-
-    if (isInCi) {
-      this.prompts.conflictsDetectedInCi(language, conflictedFilesDirectory);
-      return ActionResult.failed();
-    }
-
-    while (!conflictedFilesDirectory.isEmpty()) {
-      this.prompts.conflictsDetected(conflictedFilesDirectory);
-
-      if (!await this.prompts.resolveNowOrAbandon()) {
-        this.prompts.mergeAbandoned(language);
-        return ActionResult.failed();
-      }
-
-      if (await this.launcherService.isIdeAvailable()) {
-        this.prompts.openingVsCodeForConflictResolution(language);
-        await this.launcherService.openFolderInIdeWithWait(sdkWithSourceTree, conflictedFilesDirectory.getAllFiles())
-      } else {
-        this.prompts.openFilesForConflictResolution(language, sdkWithSourceTree);
-      }
-
-      const response = await this.prompts.confirmConflictsResolved();
-
-      if (response === "cancelled") {
-        this.prompts.mergeAbandoned(language);
-        return ActionResult.failed();
-      }
-
-      if (response === "resolved") {
-        break;
-      }
-
-      conflictedFilesDirectory = await mergeSourceTreeContext.getConflictedFilesDirectory();
-    }
-
-    await mergeSourceTreeContext.saveWithResolvedConflicts();
-    this.prompts.conflictsResolved(language);
-    this.prompts.sdkGeneratedWithSourceTree(await saveSdk(), destinationSourceTreePath);
-
-    await mergeSourceTreeContext.cleanUp(() => this.prompts.directoryStillOpen(sdkWithSourceTree));
-    return ActionResult.success({sourceTreeTrackingInitiated: false, conflictsResolved: true});
-  };
-}
diff --git a/src/actions/sdk/publish.ts b/src/actions/sdk/publish.ts
index e10a987a0..23cae027e 100644
--- a/src/actions/sdk/publish.ts
+++ b/src/actions/sdk/publish.ts
@@ -8,7 +8,7 @@ import { PublishType } from '../../types/publish-api/publishing-profile-item.js'
 import { PublishingInfo } from '../../types/publish-api/publishing-info.js';
 import { ProfileId } from '../../types/publish/profile-id.js';
 import { SemVersion } from '../../types/publish/version.js';
-import { CodegenOption, Language } from '../../types/sdk/generate.js';
+import { Language, Stability } from '../../types/sdk/generate.js';
 import { PublishingProfile } from '../../types/publish/publishing-profile.js';
 import { PackageSettingsContext } from '../../types/package-settings-context.js';
 import { TempContext } from '../../types/temp-context.js';
@@ -34,8 +34,7 @@ export class SdkPublishAction {
     semVersion: SemVersion,
     publishingProfile: PublishingProfile,
     dryRun: boolean,
-    codegenOption: CodegenOption,
-    stabilityWasProvided: boolean,
+    stability: Stability,
     publishingSummary: string,
     onPublishSdkError: (errorMessage: string) => void
   ): Promise<ActionResult> => {
@@ -54,14 +53,10 @@ export class SdkPublishAction {
         sourceDirectory,
         outputDirectory,
         language,
+        stability,
         force,
         false,
-        false,
-        false,
-        codegenOption,
-        stabilityWasProvided,
         undefined,
-        semVersion,
         packageSettingsDirectory
       );
       if (sdkGenerationResult.isFailed()) {
diff --git a/src/actions/sdk/publish/interactive.ts b/src/actions/sdk/publish/interactive.ts
index 30adc4e7d..8fce4d06b 100644
--- a/src/actions/sdk/publish/interactive.ts
+++ b/src/actions/sdk/publish/interactive.ts
@@ -5,10 +5,10 @@ import { DirectoryPath } from '../../../types/file/directoryPath.js';
 import { PublishType } from '../../../types/publish-api/publishing-profile-item.js';
 import { PublishingProfile } from '../../../types/publish/publishing-profile.js';
 import { PublishingProfiles } from '../../../types/publish/publishing-profiles.js';
-import { getCodegenOptions } from '../../../types/sdk/generate.js';
+import { AVAILABLE_LANGUAGES, stabilityLevelsFor } from '../../../types/sdk/generate.js';
 import { formatPublishingDetails } from '../../../prompts/sdk/publish.js';
 import { ActionResult } from '../../action-result.js';
-import { PluginRecordSdkAction } from '../../plugin/record-sdk.js';
+import { RecordPublishedSdkAction } from '../record-published-sdk.js';
 import { SdkPublishAction } from '../publish.js';
 import { BuildContext } from '../../../types/build-context.js';
 import { ProfileId } from '../../../types/publish/profile-id.js';
@@ -75,18 +75,24 @@ export class SdkPublishInteractiveAction {
 
     const publishingProfile = PublishingProfile.create(publishingProfileItem);
 
-    const language = await this.prompts.selectLanguage(publishingProfile);
+    // Offering one v4 cannot render would end the run after the version was already asked for.
+    const offered = publishingProfile.getEnabledLanguages().filter((enabled) => AVAILABLE_LANGUAGES.includes(enabled));
+    if (offered.length === 0) {
+      this.prompts.noAvailableLanguageOnProfile(publishingProfile.getEnabledLanguages());
+      return ActionResult.failed();
+    }
+
+    const language = await this.prompts.selectLanguage(publishingProfile, offered);
     if (!language) {
       this.prompts.noLanguageSelected();
       return ActionResult.cancelled();
     }
 
-    const codegenOptions = getCodegenOptions(language);
-    const codegenOption = codegenOptions.length === 1 ? codegenOptions[0]
-      : await this.prompts.selectCodegenVersion(codegenOptions);
-    if (!codegenOption) {
-        this.prompts.noCodegenVersionSelected();
-        return ActionResult.cancelled();
+    const levels = stabilityLevelsFor(language);
+    const stability = levels.length === 1 ? levels[0] : await this.prompts.selectStability(levels);
+    if (!stability) {
+      this.prompts.noStabilitySelected();
+      return ActionResult.cancelled();
     }
 
     const version = await this.prompts.inputVersion();
@@ -102,7 +108,7 @@ export class SdkPublishInteractiveAction {
       language,
       version,
       publishType: publishTypes,
-      codegenOption: codegenOptions.length === 1 ? undefined : codegenOption
+      stability: levels.length === 1 ? undefined : stability
     });
 
     this.prompts.publishingSummary(publishingSummary);
@@ -128,8 +134,7 @@ export class SdkPublishInteractiveAction {
       version,
       publishingProfile,
       false,
-      codegenOption,
-      false,
+      stability,
       publishingSummary,
       onPublishSdkError
     );
@@ -140,15 +145,7 @@ export class SdkPublishInteractiveAction {
       return ActionResult.cancelled();
     }
 
-    if (await this.prompts.confirmRecordSdk()) {
-      await new PluginRecordSdkAction().execute(
-        sourceDirectory,
-        language,
-        publishingProfile,
-        publishTypes,
-        version
-      );
-    }
+    await new RecordPublishedSdkAction().execute(sourceDirectory, language, publishingProfile, publishTypes, version);
 
     return ActionResult.success();
   };
diff --git a/src/actions/sdk/publish/non-interactive.ts b/src/actions/sdk/publish/non-interactive.ts
index 4e885b03c..9cb57fa66 100644
--- a/src/actions/sdk/publish/non-interactive.ts
+++ b/src/actions/sdk/publish/non-interactive.ts
@@ -5,13 +5,14 @@ import { CommandMetadata } from '../../../types/common/command-metadata.js';
 import { DirectoryPath } from '../../../types/file/directoryPath.js';
 import { PublishingProfileItem, PublishType } from '../../../types/publish-api/publishing-profile-item.js';
 import { PublishingProfile } from '../../../types/publish/publishing-profile.js';
-import { CodegenOption, Language } from '../../../types/sdk/generate.js';
+import { Language } from '../../../types/sdk/generate.js';
+import { StabilityChoice } from '../../../types/sdk/stability-choice.js';
 import { ActionResult } from '../../action-result.js';
 import { getDownloadsDirectory } from '../../../infrastructure/os-extensions.js';
 import { SemVersion } from '../../../types/publish/version.js';
 import { ProfileId } from '../../../types/publish/profile-id.js';
 import { BuildContext } from '../../../types/build-context.js';
-import { PluginRecordSdkAction } from '../../plugin/record-sdk.js';
+import { RecordPublishedSdkAction } from '../record-published-sdk.js';
 import { SdkPublishAction } from '../publish.js';
 import { FileService } from '../../../infrastructure/file-service.js';
 
@@ -29,9 +30,7 @@ export class SdkPublishNonInteractiveAction {
     publishTypes: PublishType[],
     force: boolean,
     dryRun: boolean,
-    codegenOption: CodegenOption,
-    stabilityWasProvided: boolean,
-    updatePluginConfig: boolean,
+    stability: StabilityChoice,
     onPublishSdkError: (errorMessage: string) => void,
     profileId?: string,
     version?: string
@@ -112,9 +111,12 @@ export class SdkPublishNonInteractiveAction {
       language,
       version: semVersion,
       publishType: publishTypes,
-      codegenOption
+      // Named only when the user chose it, so a run that took the default reads as the doc does.
+      stability: stability.chosenLevel()
     });
-    const outputDir = dryRun ? await this.fileService.getAvailableDirectoryPath(getDownloadsDirectory('apimatic-sdk')) : sdkDirectory;
+    const outputDir = dryRun
+      ? await this.fileService.getAvailableDirectoryPath(getDownloadsDirectory('apimatic-sdk'))
+      : sdkDirectory;
     const publishResult = await new SdkPublishAction(this.configDir, this.commandMetadata).execute(
       sourceDirectory,
       outputDir,
@@ -125,8 +127,7 @@ export class SdkPublishNonInteractiveAction {
       semVersion,
       publishingProfile,
       dryRun,
-      codegenOption,
-      stabilityWasProvided,
+      stability.stabilityLevel(),
       publishingSummary,
       onPublishSdkError
     );
@@ -138,18 +139,10 @@ export class SdkPublishNonInteractiveAction {
     }
 
     // A dry run publishes nothing, so recording it would claim an SDK that does not exist anywhere.
-    if (updatePluginConfig) {
-      if (dryRun) {
-        this.prompts.dryRunPluginConfigNotice();
-      } else {
-        await new PluginRecordSdkAction().execute(
-          sourceDirectory,
-          language,
-          publishingProfile,
-          publishTypes,
-          semVersion
-        );
-      }
+    if (dryRun) {
+      this.prompts.dryRunPluginConfigNotice();
+    } else {
+      await new RecordPublishedSdkAction().execute(sourceDirectory, language, publishingProfile, publishTypes, semVersion);
     }
 
     return ActionResult.success();
diff --git a/src/actions/sdk/record-published-sdk.ts b/src/actions/sdk/record-published-sdk.ts
new file mode 100644
index 000000000..845d9e991
--- /dev/null
+++ b/src/actions/sdk/record-published-sdk.ts
@@ -0,0 +1,108 @@
+import { RecordPublishedSdkPrompts } from '../../prompts/sdk/record-published-sdk.js';
+import { ApimaticConfigContext } from '../../types/apimatic-config-context.js';
+import { ApimaticConfigDocument, ConfigBlockName, findingClause } from '../../types/apimatic-config/document.js';
+import { DirectoryPath } from '../../types/file/directoryPath.js';
+import { buildLanguageEntry } from '../../types/plugin/language-entry.js';
+import { PluginLanguageEntry, PluginLanguages } from '../../types/plugin/plugin-config.js';
+import { PublishType } from '../../types/publish-api/publishing-profile-item.js';
+import { PublishingProfile } from '../../types/publish/publishing-profile.js';
+import { SemVersion } from '../../types/publish/version.js';
+import { Language } from '../../types/sdk/generate.js';
+import { ActionResult } from '../action-result.js';
+
+/** A publish writes where its SDK went, and nothing else in the file is its business. */
+const RECORDED_BLOCKS: readonly ConfigBlockName[] = ['languages'];
+
+const languagesOf = (document: ApimaticConfigDocument): PluginLanguages =>
+  (document.languages() ?? {}) as PluginLanguages;
+
+/**
+ * What a run published is added to what the entry already holds: a package-only run leaves the
+ * repository a previous source publish recorded, and the other way about.
+ */
+function withLanguage<L extends Language>(
+  languages: PluginLanguages,
+  language: L,
+  entry: PluginLanguageEntry<L>
+): PluginLanguages {
+  const existingEntry = languages[language];
+  const existingPublishing = existingEntry?.publishing;
+  const publishing = entry.publishing
+    ? {
+        ...existingPublishing,
+        ...entry.publishing,
+        source: entry.publishing.source ?? existingPublishing?.source,
+        package: entry.publishing.package ?? existingPublishing?.package
+      }
+    : existingPublishing;
+
+  return { ...languages, [language]: { ...existingEntry, ...entry, ...(publishing ? { publishing } : {}) } };
+}
+
+/**
+ * Callers discard the result: this runs after a publish that already succeeded, and no outcome here
+ * may change that.
+ */
+export class RecordPublishedSdkAction {
+  private readonly prompts: RecordPublishedSdkPrompts = new RecordPublishedSdkPrompts();
+
+  public readonly execute = async (
+    sourceDirectory: DirectoryPath,
+    language: Language,
+    publishingProfile: PublishingProfile,
+    publishTypes: PublishType[],
+    packageVersion: SemVersion
+  ): Promise<ActionResult> => {
+    // A package-only run claims no repository, and a source-only run records no released version.
+    // The configuration is written either way: it says how the package is set up, not that one is.
+    const entry = buildLanguageEntry(
+      language,
+      publishTypes.includes(PublishType.SourceCodePublishing)
+        ? publishingProfile.getGitConfigurationForLanguage(language)
+        : undefined,
+      publishingProfile.getPackageConfigurationDataForLanguage(language),
+      publishTypes.includes(PublishType.PackagePublishing) ? packageVersion : undefined
+    );
+
+    const config = new ApimaticConfigContext(sourceDirectory);
+    const state = await config.read();
+    if (state.state === 'unparseable') {
+      this.prompts.configUnreadable(findingClause(state.findings));
+      return ActionResult.failed();
+    }
+
+    const configExisted = state.state === 'parsed';
+    if (configExisted) {
+      const findings = state.document.findingsFor('root', ...RECORDED_BLOCKS);
+      if (findings.length > 0) {
+        this.prompts.configUnreadable(findingClause(findings));
+        return ActionResult.failed();
+      }
+    }
+
+    const recorded = configExisted ? languagesOf(state.document)[language] : undefined;
+    if (!entry.publishing?.source && !recorded?.publishing?.source) {
+      this.prompts.noSourceRepository(language);
+    }
+
+    const written = await config.merge(RECORDED_BLOCKS, (document) =>
+      document.with('languages', withLanguage(languagesOf(document), language, entry))
+    );
+    if (written.isErr()) {
+      switch (written.error) {
+        // Readable a moment ago, so this only happens if the file changed underneath us.
+        case 'unreadable':
+          this.prompts.configUnreadable();
+          return ActionResult.failed();
+        case 'unwritable':
+          this.prompts.configNotWritten();
+          return ActionResult.failed();
+        default:
+          throw written.error satisfies never;
+      }
+    }
+
+    this.prompts.sdkRecorded(language, configExisted);
+    return ActionResult.success();
+  };
+}
diff --git a/src/actions/sdk/save-changes.ts b/src/actions/sdk/save-changes.ts
deleted file mode 100644
index 547f31502..000000000
--- a/src/actions/sdk/save-changes.ts
+++ /dev/null
@@ -1,122 +0,0 @@
-import { DirectoryPath } from "../../types/file/directoryPath.js";
-import { ActionResult } from "../action-result.js";
-import { withDirPath } from "../../infrastructure/tmp-extensions.js";
-import { Language } from "../../types/sdk/generate.js";
-import { SaveChangesPrompts } from "../../prompts/sdk/save-changes.js";
-import { SaveChangesContext } from "../../types/save-changes-context.js";
-import { BuildContext } from "../../types/build-context.js";
-import { LauncherService } from "../../infrastructure/launcher-service.js";
-
-export class SaveChangesAction {
-  private readonly prompts = new SaveChangesPrompts();
-  private readonly launcherService = new LauncherService();
-
-  public readonly execute = async (
-    workingDirectory: DirectoryPath,
-    sourceDirectory: DirectoryPath,
-    sdkDirectory: DirectoryPath | undefined,
-    language: Language,
-    apiVersion?: string
-  ): Promise<ActionResult> => {
-    const rootBuildContext = new BuildContext(sourceDirectory);
-    if (!(await rootBuildContext.exists())) {
-      this.prompts.sourceDirectoryEmpty(sourceDirectory);
-      return ActionResult.failed();
-    }
-
-    const versionedContextGetter = async () => {
-      if (!await rootBuildContext.isVersionedBuild()) {
-        if (apiVersion) this.prompts.apiVersionOnlyApplicableWithVersionedBuild();
-        return { version: undefined, buildContext: rootBuildContext };
-      }
-
-      const versionedSourceDirectory = await rootBuildContext.getVersionedSourceDirectory();
-      if (!versionedSourceDirectory) {
-        this.prompts.invalidVersionedDocsDirectory(sourceDirectory);
-        return ActionResult.failed();
-      }
-
-      const singleVersionedSourceDirectory = await rootBuildContext.getSingleVersionedSourceDirectory();
-      if (!apiVersion && singleVersionedSourceDirectory) {
-        return {
-          version: singleVersionedSourceDirectory.leafName(),
-          buildContext: new BuildContext(singleVersionedSourceDirectory)
-        };
-      }
-
-      const selectedVersionedSourceDirectory = await rootBuildContext.getSelectedVersionedSourceDirectory(
-        apiVersion ? async () => apiVersion : this.prompts.selectVersion
-      );
-      if (!selectedVersionedSourceDirectory) {
-        this.prompts.versionNotFound();
-        return ActionResult.failed();
-      }
-
-      return {
-        version: selectedVersionedSourceDirectory.leafName(),
-        buildContext: new BuildContext(selectedVersionedSourceDirectory)
-      };
-    };
-    
-    const versionedContext = await versionedContextGetter();
-    if (versionedContext instanceof ActionResult) {
-      return versionedContext;
-    }
-
-    if (!(await versionedContext.buildContext.hasSdkSourceTree(language))) {
-      this.prompts.sdkSourceTreeNotFound(language);
-      return ActionResult.failed();
-    }
-
-    return await withDirPath(async (tempDirectory) => {
-      const sdkReviewDirectory = tempDirectory.join(language);
-      const sdkSourceTree = versionedContext.buildContext.getSdkSourceTree(language);
-      const saveChangesContext = new SaveChangesContext(
-        sdkSourceTree,
-        sdkReviewDirectory,
-        sdkDirectory,
-        workingDirectory,
-        language,
-        versionedContext.version
-      );
-
-      if (await saveChangesContext.isSdkInputDirectoryMissing(this.prompts.invalidSdkDirectory)) {
-        return ActionResult.failed();
-      }
-
-      const updatedFilesDirectory = await saveChangesContext.getChangesForReviewDirectory();
-      if (updatedFilesDirectory.isEmpty()) {
-        this.prompts.noChangesDetected();
-        return ActionResult.cancelled();
-      }
-
-      this.prompts.modifiedFilesDetected(updatedFilesDirectory);
-
-      if (!await this.prompts.confirmReviewChanges()) {
-        await saveChangesContext.saveSourceTree();
-        this.prompts.changesSaved(sdkSourceTree);
-        return ActionResult.success();
-      }
-
-      if (await this.launcherService.isIdeAvailable()) {
-        this.prompts.openingDirectoryToReviewChanges();
-        const nonDeletedFilesDirectory = await updatedFilesDirectory.mapFilesInDirectory(async (_, fileItem) => {
-          return fileItem.description === "# Deleted" ? undefined : fileItem;
-        });
-        await this.launcherService.openFolderInIdeWithWait(sdkReviewDirectory, nonDeletedFilesDirectory.getAllFiles());
-      } else {
-        this.prompts.reviewChangesManually(sdkReviewDirectory);
-      }
-
-      if (await this.prompts.confirmSaveChanges()) {
-        await saveChangesContext.saveSourceTree();
-        this.prompts.changesSaved(sdkSourceTree);
-        await saveChangesContext.cleanUpSdkReviewDirectory(() => this.prompts.directoryStillOpen(sdkReviewDirectory));
-        return ActionResult.success();
-      }
-      
-      this.prompts.operationCancelled();
-      return ActionResult.cancelled();
-    });
-  };
-}
diff --git a/src/commands/sdk/generate.ts b/src/commands/sdk/generate.ts
index e64f95840..fb2ef4aee 100644
--- a/src/commands/sdk/generate.ts
+++ b/src/commands/sdk/generate.ts
@@ -1,125 +1,98 @@
-import { Command, Flags } from "@oclif/core";
-import { DirectoryPath } from "../../types/file/directoryPath.js";
-import { FlagsProvider } from "../../types/flags-provider.js";
-import { GenerateAction } from "../../actions/sdk/generate.js";
-import { CodeGenerationVersion, CodegenOption, Language, Stability } from "../../types/sdk/generate.js";
-import { CommandMetadata } from "../../types/common/command-metadata.js";
-import { format, intro, outro } from "../../prompts/format.js";
-import { SdkChangesTrackedEvent } from "../../types/events/sdk-changes-tracked.js";
-import { TelemetryService } from "../../infrastructure/services/telemetry-service.js";
-import { SdkConflictsResolvedEvent } from "../../types/events/sdk-conflicts-resolved.js";
+import { Command, Flags } from '@oclif/core';
+import { DirectoryPath } from '../../types/file/directoryPath.js';
+import { FlagsProvider } from '../../types/flags-provider.js';
+import { GenerateAction } from '../../actions/sdk/generate.js';
+import { CodeGenerationVersion, Language, Stability } from '../../types/sdk/generate.js';
+import { StabilityChoice } from '../../types/sdk/stability-choice.js';
+import { CommandMetadata } from '../../types/common/command-metadata.js';
+import { format, intro, outro } from '../../prompts/format.js';
 
 export default class SdkGenerate extends Command {
-  static readonly summary = "Generate an SDK for your API";
+  static readonly summary = 'Generate an SDK for your API';
 
-  static readonly description = `Generate Software Development Kits (SDKs) from API specifications.
-Supports multiple programming languages including Java, C#, Python, JavaScript, and more.`;
+  static readonly description = `Generate a Software Development Kit (SDK) from an API specification.
+C#, TypeScript and Python are available; Java, Ruby, Go and PHP are on their way.`;
 
-  static readonly cmdTxt = format.cmd("apimatic", "sdk", "generate");
+  static readonly cmdTxt = format.cmd('apimatic', 'sdk', 'generate');
 
   static flags = {
+    // Every language stays here so one that is coming back is answered by the command rather than
+    // rejected as an unknown value; the action says which are available.
     language: Flags.string({
-      char: "l",
+      char: 'l',
       required: true,
-      description: "Programming language for SDK generation",
-      options: Object.values(Language).map((p) => p.valueOf()),
+      description: 'Programming language for SDK generation',
+      options: Object.values(Language).map((p) => p.valueOf())
     }),
     destination: Flags.string({
-      char: "d",
-      description: "[default: <input>/sdk/<language> | <input>/sdk/<api-version>/<language>] path where the SDK will be generated"
+      char: 'd',
+      description:
+        '[default: <input>/sdk/<language> | <input>/sdk/<api-version>/<language>] path where the SDK will be generated'
     }),
-    "skip-changes": Flags.boolean({
-      default: false,
-      description: "Do not apply the saved changes to the generated SDK"
-    }),
-    "api-version": Flags.string({
-      description: "Version of the API to use for SDK generation (if multiple versions exist)"
+    'api-version': Flags.string({
+      description: 'Version of the API to use for SDK generation (if multiple versions exist)'
     }),
     zip: Flags.boolean({
       default: false,
-      description: "Download the generated SDK as a .zip archive"
+      description: 'Download the generated SDK as a .zip archive'
     }),
-    "track-changes": Flags.boolean({
-      default: false,
-      description: "Enable change tracking for SDK generation (only required for initial setup)"
-    }),
-    "codegen-version": Flags.string({
-      description: "Version of the code generator to use",
+    'codegen-version': Flags.string({
+      description: 'Version of the code generator to use',
       options: Object.values(CodeGenerationVersion).map((v) => v.valueOf()),
-      default: CodeGenerationVersion.V3
+      default: CodeGenerationVersion.V4
     }),
-    "stability": Flags.string({
-      description: "Stability level of the generated SDK",
-      options: Object.values(Stability).map((s) => s.valueOf()),
-      default: Stability.STABLE
+    stability: Flags.string({
+      description: 'Stability level of the generated SDK. Defaults to the level the language offers.',
+      options: Object.values(Stability).map((s) => s.valueOf())
     }),
     ...FlagsProvider.input,
     ...FlagsProvider.force,
-    ...FlagsProvider.authKey,
+    ...FlagsProvider.authKey
   };
 
   static examples = [
-    `${SdkGenerate.cmdTxt} ${format.flag("language", "java")}`,
-    `${SdkGenerate.cmdTxt} ${format.flag("language", "csharp")} ${format.flag("input", "./")}`,
-    `${SdkGenerate.cmdTxt} ${format.flag("language", "python")} ${format.flag("destination", "./sdk")} ${format.flag(
-      "zip"
+    `${SdkGenerate.cmdTxt} ${format.flag('language', 'typescript')}`,
+    `${SdkGenerate.cmdTxt} ${format.flag('language', 'csharp')} ${format.flag('input', './')}`,
+    `${SdkGenerate.cmdTxt} ${format.flag('language', 'python')} ${format.flag('destination', './sdk')} ${format.flag(
+      'zip'
     )}`
   ];
 
   async run() {
     const {
-      flags: { language,
+      flags: {
+        language,
         input,
         destination,
         force,
         zip: zipSdk,
-        "auth-key": authKey,
-        "skip-changes": skipChanges,
-        "track-changes": trackChanges,
-        "api-version": apiVersion,
-        "codegen-version": codegenVersion,
-        stability
-      },
-      metadata
+        stability,
+        'auth-key': authKey,
+        'api-version': apiVersion
+      }
     } = await this.parse(SdkGenerate);
 
     const workingDirectory = DirectoryPath.createInput(input);
-    const sourceDirectory = input ? new DirectoryPath(input, "src") : workingDirectory.join("src");
-    const sdkDirectory = destination ? new DirectoryPath(destination) : workingDirectory.join("sdk");
+    const sourceDirectory = input ? new DirectoryPath(input, 'src') : workingDirectory.join('src');
+    const sdkDirectory = destination ? new DirectoryPath(destination) : workingDirectory.join('sdk');
 
     const commandMetadata: CommandMetadata = {
       commandName: SdkGenerate.id,
       shell: this.config.shell
     };
-    const telemetryService = new TelemetryService(this.getConfigDir());
 
-    intro("Generate SDK");
+    intro('Generate SDK');
     const action = new GenerateAction(this.getConfigDir(), commandMetadata, authKey);
     const result = await action.execute(
       sourceDirectory,
       sdkDirectory,
       language as Language,
+      StabilityChoice.for(language as Language, stability).stabilityLevel(),
       force,
       zipSdk,
-      skipChanges,
-      trackChanges,
-      CodegenOption.create(codegenVersion as CodeGenerationVersion, stability as Stability),
-      metadata.flags.stability?.setFromDefault !== true,
       apiVersion
     );
     outro(result);
-    await result.mapAll(
-      async (res) => {
-        if (res?.sourceTreeTrackingInitiated) {
-          await telemetryService.trackEvent(new SdkChangesTrackedEvent(language), commandMetadata.shell);
-        }
-        if (res?.conflictsResolved) {
-          await telemetryService.trackEvent(new SdkConflictsResolvedEvent(language), commandMetadata.shell);
-        }
-      },
-      async () => {},
-      async () => {}
-    );
   }
 
   private readonly getConfigDir = () => {
diff --git a/src/commands/sdk/publish.ts b/src/commands/sdk/publish.ts
index 59219da20..8d02647d4 100644
--- a/src/commands/sdk/publish.ts
+++ b/src/commands/sdk/publish.ts
@@ -1,7 +1,8 @@
 import { Command, Flags } from '@oclif/core';
 import { DirectoryPath } from '../../types/file/directoryPath.js';
 import { FlagsProvider } from '../../types/flags-provider.js';
-import { CodeGenerationVersion, CodegenOption, Language, Stability } from '../../types/sdk/generate.js';
+import { CodeGenerationVersion, Language, Stability } from '../../types/sdk/generate.js';
+import { StabilityChoice } from '../../types/sdk/stability-choice.js';
 import { CommandMetadata } from '../../types/common/command-metadata.js';
 import { format, intro, outro } from '../../prompts/format.js';
 import { PublishType } from '../../types/publish-api/publishing-profile-item.js';
@@ -30,9 +31,7 @@ export default class SdkPublish extends Command {
     language: Flags.string({
       char: 'l',
       description: 'Language of the SDK to generate and publish.',
-      options: Object.values(Language)
-        .filter((l) => l !== Language.GO)
-        .map((l) => l.valueOf())
+      options: Object.values(Language).map((l) => l.valueOf())
     }),
     ...FlagsProvider.force,
     ...FlagsProvider.input,
@@ -50,17 +49,11 @@ export default class SdkPublish extends Command {
     'codegen-version': Flags.string({
       description: 'Version of the code generator to use',
       options: Object.values(CodeGenerationVersion).map((v) => v.valueOf()),
-      default: CodeGenerationVersion.V3
+      default: CodeGenerationVersion.V4
     }),
     stability: Flags.string({
-      description: 'Stability level of the generated SDK',
-      options: Object.values(Stability).map((s) => s.valueOf()),
-      default: Stability.STABLE
-    }),
-    'update-plugin-config': Flags.boolean({
-      default: false,
-      description:
-        "Record the published SDK in 'src/apimatic.json', creating the file if it does not exist. Interactive runs are asked instead."
+      description: 'Stability level of the generated SDK. Defaults to the level the language offers.',
+      options: Object.values(Stability).map((s) => s.valueOf())
     })
   };
 
@@ -75,21 +68,14 @@ export default class SdkPublish extends Command {
     )}`,
     `${SdkPublish.cmdTxt} ${format.flag('profile-id', 'b2c3d4e5f6a1b2c3d4e5f6a1')} ${format.flag(
       'language',
-      'java'
+      'csharp'
     )} ${format.flag('version', '2.0.0')} ${format.flag('publish-type', PublishType.SourceCodePublishing)}`,
     `${SdkPublish.cmdTxt} ${format.flag('profile-id', 'c3d4e5f6a1b2c3d4e5f6a1b2')} ${format.flag(
       'language',
       'python'
     )} ${format.flag('version', '1.0.0')} ${format.flag('publish-type', PublishType.PackagePublishing)} ${format.flag(
       'dry-run'
-    )}`,
-    `${SdkPublish.cmdTxt} ${format.flag('profile-id', 'd4e5f6a1b2c3d4e5f6a1b2c3')} ${format.flag(
-      'language',
-      'csharp'
-    )} ${format.flag('version', '1.0.0')} ${format.flag('publish-type', PublishType.PackagePublishing)} ${format.flag(
-      'codegen-version',
-      'v4'
-    )} ${format.flag('stability', 'beta')}`
+    )}`
   ];
 
   async run() {
@@ -103,11 +89,9 @@ export default class SdkPublish extends Command {
         input,
         'publish-type': publishType,
         'dry-run': dryRun,
-        'codegen-version': codegenVersion,
         stability,
-        'update-plugin-config': updatePluginConfig
-      },
-      metadata
+        'codegen-version': codegenVersion
+      }
     } = await this.parse(SdkPublish);
 
     const publishTypes = [...new Set(publishType)] as PublishType[];
@@ -137,8 +121,8 @@ export default class SdkPublish extends Command {
               language,
               ...(force && { force }),
               'publish-type': publishTypes,
-              'codegen-version': codegenVersion,
-              stability
+              stability,
+              'codegen-version': codegenVersion
             }),
             commandMetadata.shell
           );
@@ -153,9 +137,7 @@ export default class SdkPublish extends Command {
           publishTypes,
           force,
           dryRun,
-          CodegenOption.create(codegenVersion as CodeGenerationVersion, stability as Stability),
-          metadata.flags.stability?.setFromDefault !== true,
-          updatePluginConfig,
+          StabilityChoice.for(language as Language, stability),
           onPublishSdkError,
           profileId,
           version
diff --git a/src/commands/sdk/save-changes.ts b/src/commands/sdk/save-changes.ts
deleted file mode 100644
index c5e3e7774..000000000
--- a/src/commands/sdk/save-changes.ts
+++ /dev/null
@@ -1,76 +0,0 @@
-import { Command, Flags } from "@oclif/core";
-import { format, intro, outro } from "../../prompts/format.js";
-import { DirectoryPath } from "../../types/file/directoryPath.js";
-import { SaveChangesAction } from "../../actions/sdk/save-changes.js";
-import { Language } from "../../types/sdk/generate.js";
-import { FlagsProvider } from "../../types/flags-provider.js";
-import { TelemetryService } from "../../infrastructure/services/telemetry-service.js";
-import { CommandMetadata } from "../../types/common/command-metadata.js";
-import { SdkChangesSavedEvent } from "../../types/events/sdk-changes-saved.js";
-
-export default class SaveChanges extends Command {
-  static readonly summary = "Save customizations made to an auto-generated SDK";
-
-  static readonly description =
-    "Requires an input directory with API specifications, a path to the updated SDK directory, and the programming language.";
-
-  static readonly cmdTxt = format.cmd("apimatic", "sdk", "save-changes");
-
-  static flags = {
-    language: Flags.string({
-      char: "l",
-      required: true,
-      description: "Programming language of the SDK",
-      options: Object.values(Language).map((p) => p.valueOf())
-    }),
-    "sdk": Flags.string({
-      description: "[default: ./sdk/<language> | ./sdk/<api-version>/<language>] path to the folder containing the updated SDK."
-    }),
-    "api-version": Flags.string({
-      description: "Version of the API where changes should be saved (if multiple versions exist)."
-    }),
-    ...FlagsProvider.input,
-  };
-
-  static examples = [
-    `${SaveChanges.cmdTxt} ${format.flag("language", "csharp")}`,
-    `${SaveChanges.cmdTxt} ${format.flag("language", "java")} ${format.flag("sdk", "./sdk")}`
-  ];
-
-  async run() {
-    const {
-      flags: { sdk, language, input, "api-version": apiVersion }
-    } = await this.parse(SaveChanges);
-
-    const workingDirectory = DirectoryPath.createInput(input);
-    const sourceDirectory = workingDirectory.join("src");
-    const sdkDirectoryInput = sdk ? new DirectoryPath(sdk) : undefined;
-
-    const commandMetadata: CommandMetadata = {
-      commandName: SaveChanges.id,
-      shell: this.config.shell
-    };
-    const telemetryService = new TelemetryService(this.getConfigDir());
-
-    intro("Save Changes");
-    const action = new SaveChangesAction();
-    const result = await action.execute(
-      workingDirectory,
-      sourceDirectory,
-      sdkDirectoryInput,
-      language as Language,
-      apiVersion
-    );
-    outro(result);
-
-    await result.mapAll(
-      async () => await telemetryService.trackEvent(new SdkChangesSavedEvent(language), commandMetadata.shell),
-      async () => {},
-      async () => {}
-    );
-  }
-
-  private readonly getConfigDir = () => {
-    return new DirectoryPath(this.config.configDir);
-  };
-}
diff --git a/src/infrastructure/services/sdk-generation-service.ts b/src/infrastructure/services/sdk-generation-service.ts
index 8fd76e643..87131185c 100644
--- a/src/infrastructure/services/sdk-generation-service.ts
+++ b/src/infrastructure/services/sdk-generation-service.ts
@@ -1,8 +1,6 @@
 import axios from 'axios';
 import {
-  SdkGenerationAsyncController,
   ContentType,
-  SdkSourceTreeGenerationAsyncController,
   FileWrapper,
   SdkLanguages,
   Status,
@@ -18,23 +16,11 @@ import { CommandMetadata } from '../../types/common/command-metadata.js';
 import { err, ok, Result } from 'neverthrow';
 import { Language, Stability } from '../../types/sdk/generate.js';
 import { handleServiceError, ServiceError } from '../service-error.js';
-import {
-  formatValidationErrors,
-  GENERATION_TIMEOUT_MS,
-  pollUntilCompleted,
-  STATUS_POLL_INTERVAL_MS,
-  ValidationErrorFormatter
-} from '../generation-status-poller.js';
+import { GENERATION_TIMEOUT_MS, pollUntilCompleted, STATUS_POLL_INTERVAL_MS } from '../generation-status-poller.js';
 import { envInfo } from '../env-info.js';
 import { REQUEST_TIMEOUT_MS } from '../../config/axios-config.js';
-import { SemVersion } from '../../types/publish/version.js';
 import { GenerationStatusResponse } from '../../types/api/generation-status.js';
 
-export interface GeneratedSdkResult {
-  sdk: NodeJS.ReadableStream;
-  sdkSourceTree: NodeJS.ReadableStream;
-}
-
 const TIMING_DEFAULTS = {
   pollIntervalMs: STATUS_POLL_INTERVAL_MS,
   generationTimeoutMs: GENERATION_TIMEOUT_MS,
@@ -54,64 +40,7 @@ export class SdkGenerationService {
     this.timings = { ...TIMING_DEFAULTS, ...timings };
   }
 
-  // TODO: Pass stream as parameter instead of file path.
   public async generateSdk(
-    buildPath: FilePath,
-    language: Language,
-    configDir: DirectoryPath,
-    commandMetadata: CommandMetadata,
-    authKey: string | null,
-    version?: SemVersion
-  ): Promise<Result<GeneratedSdkResult, ServiceError>> {
-    const buildFileStream = await this.fileService.getStream(buildPath);
-    const file = new FileWrapper(buildFileStream);
-
-    const authInfo: AuthInfo | null = await getAuthInfo(configDir.toString());
-    const authorizationHeader = this.createAuthorizationHeader(authInfo, authKey);
-    const client = apiClientFactory.createApiClient(authorizationHeader, commandMetadata.shell);
-    const sdkGenerationController = new SdkGenerationAsyncController(client);
-
-    let generationId: string;
-    try {
-      const response = await sdkGenerationController.generateSdkViaBuildInputAsync(
-        this.CONTENT_TYPE,
-        file,
-        this.languageSdk[language],
-        undefined,
-        version?.toString()
-      );
-      generationId = response.result.id;
-    } catch (error) {
-      return err(handleServiceError(error));
-    } finally {
-      buildFileStream.close();
-    }
-
-    const statusResult = await pollUntilCompleted({
-      pollIntervalMs: this.timings.pollIntervalMs,
-      fetchStatus: () =>
-        this.getSdkGenerationStatus(generationId, commandMetadata.shell, this.resolveToken(authInfo, authKey)),
-      timeout: { budgetMs: this.timings.generationTimeoutMs, label: 'SDK generation' },
-      formatValidationError: formatSdkValidationError
-    });
-    if (statusResult.isErr()) {
-      return err(statusResult.error);
-    }
-
-    try {
-      const sdkResponse = await sdkGenerationController.downloadGeneratedSdk(generationId);
-      const sdkSourceTreeController = new SdkSourceTreeGenerationAsyncController(client);
-      const sdkSourceTreeResponse = await sdkSourceTreeController.downloadGeneratedSdkSourceTree(generationId);
-      return ok({
-        sdk: sdkResponse.result as NodeJS.ReadableStream,
-        sdkSourceTree: sdkSourceTreeResponse.result as NodeJS.ReadableStream
-      });
-    } catch (error) {
-      return err(handleServiceError(error));
-    }
-  }
-
-  public async generateV4Sdk(
     buildPath: FilePath,
     language: Language,
     stability: Stability,
@@ -145,7 +74,7 @@ export class SdkGenerationService {
     const statusResult = await pollUntilCompleted({
       pollIntervalMs: this.timings.pollIntervalMs,
       fetchStatus: () =>
-        this.getV4SdkGenerationStatus(generationId, commandMetadata.shell, this.resolveToken(authInfo, authKey)),
+        this.getSdkGenerationStatus(generationId, commandMetadata.shell, this.resolveToken(authInfo, authKey)),
       timeout: { budgetMs: this.timings.generationTimeoutMs, label: 'SDK generation' }
     });
     if (statusResult.isErr()) {
@@ -177,50 +106,6 @@ export class SdkGenerationService {
       return err(ServiceError.UnAuthorized);
     }
 
-    try {
-      const response = await this.axiosInstance(shell, token).get(`/sdk/${requestId}/status`, {
-        headers: { Accept: 'application/json' },
-        maxRedirects: 0,
-        validateStatus: () => true
-      });
-
-      if (response.status === 200) {
-        return ok(response.data as GenerationStatusResponse);
-      }
-
-      // Once generation finishes, the API redirects to the download location.
-      if (response.status === 302) {
-        return ok({ status: Status.Completed });
-      }
-
-      // `validateStatus` above stops axios throwing, so nothing reaches the
-      // catch block — classify the status here, or a mistyped endpoint path and
-      // an expired auth key both surface as a generic "unexpected error".
-      if (response.status === 401) {
-        return err(ServiceError.UnAuthorized);
-      }
-      if (response.status === 404) {
-        return err(ServiceError.NotFound);
-      }
-      if (response.status === 500) {
-        return err(ServiceError.ServerError);
-      }
-
-      return err(ServiceError.InvalidResponse);
-    } catch (error: unknown) {
-      return err(handleServiceError(error));
-    }
-  }
-
-  private async getV4SdkGenerationStatus(
-    requestId: string,
-    shell: string,
-    token: string | undefined
-  ): Promise<Result<GenerationStatusResponse, ServiceError>> {
-    if (!token) {
-      return err(ServiceError.UnAuthorized);
-    }
-
     try {
       const response = await this.axiosInstance(shell, token).get(`/sdk/v2/${requestId}/status`, {
         headers: { Accept: 'application/json' },
@@ -267,6 +152,11 @@ export class SdkGenerationService {
     });
   }
 
+  private readonly stabilityTag: Record<Stability, StabilityLevelTag> = {
+    [Stability.STABLE]: StabilityLevelTag.Stable,
+    [Stability.BETA]: StabilityLevelTag.Beta
+  };
+
   private readonly languageSdk: Record<Language, SdkLanguages> = {
     [Language.CSHARP]: SdkLanguages.Csharp,
     [Language.JAVA]: SdkLanguages.Java,
@@ -276,23 +166,4 @@ export class SdkGenerationService {
     [Language.TYPESCRIPT]: SdkLanguages.Typescript,
     [Language.GO]: SdkLanguages.Go
   };
-
-  private readonly stabilityTag: Record<Stability, StabilityLevelTag> = {
-    [Stability.STABLE]: StabilityLevelTag.Stable,
-    [Stability.BETA]: StabilityLevelTag.Beta
-  };
 }
-
-/**
- * SDK generation reports per-language merge conflicts under a dedicated `sdkMergeFailed`
- * key, which needs its own wording. Everything else falls back to the shared format.
- */
-const formatSdkValidationError: ValidationErrorFormatter = (errors) => {
-  const sdkMergeFailedLanguages = errors.sdkMergeFailed;
-  if (sdkMergeFailedLanguages?.length) {
-    return (
-      'SDK generation failed for these languages due to merge conflict.' + '\n- ' + sdkMergeFailedLanguages.join('\n- ')
-    );
-  }
-  return formatValidationErrors(errors);
-};
diff --git a/src/prompts/format.ts b/src/prompts/format.ts
index 57dfceb3d..12f0da246 100644
--- a/src/prompts/format.ts
+++ b/src/prompts/format.ts
@@ -8,6 +8,8 @@ export const format = {
   // Core element types
   var: (text: string) => pc.magenta(`'${text}'`),
   path: (text: DirectoryPath | FilePath) => pc.cyan(`'${text}'`),
+  relative: (target: DirectoryPath | FilePath) => target.asTypedFrom(DirectoryPath.workingDirectory()),
+  relativePath: (target: DirectoryPath | FilePath) => pc.cyan(`'${format.relative(target)}'`),
   cmd: (cmd: string, ...args: string[]) => `${pc.blueBright(cmd)} ${args.map((arg) => pc.dim(arg)).join(' ')}`,
   cmdAlt: (cmd: string, ...args: string[]) =>
     `${pc.dim(pc.blueBright(cmd))} ${args.map((arg) => pc.blueBright(arg)).join(' ')}`,
diff --git a/src/prompts/plugin/generate.ts b/src/prompts/plugin/generate.ts
index e1554abe8..5e3b1d4e3 100644
--- a/src/prompts/plugin/generate.ts
+++ b/src/prompts/plugin/generate.ts
@@ -8,7 +8,7 @@ import { format as f } from '../format.js';
 import { withSpinner } from '../prompt.js';
 import { APIMATIC_CONFIG_FILE_NAME } from '../../types/apimatic-config/document.js';
 import { PluginConfig, PluginConfigWriteFailure } from '../../types/plugin-config-context.js';
-import { Language, languageLabel, PLUGIN_LANGUAGES } from '../../types/sdk/generate.js';
+import { AVAILABLE_LANGUAGES, Language, languageLabel } from '../../types/sdk/generate.js';
 
 export class PluginGeneratePrompts {
   // The spinner covers the service call only; until the save has run there is no path to name.
@@ -81,7 +81,7 @@ export class PluginGeneratePrompts {
 
     const selected = await multiselect<Language>({
       message: 'Which languages should your plugin include?',
-      options: PLUGIN_LANGUAGES.map((language) => ({
+      options: AVAILABLE_LANGUAGES.map((language) => ({
         value: language,
         label: languageLabel(language),
         hint: published.includes(language) ? 'published' : undefined
diff --git a/src/prompts/plugin/publish.ts b/src/prompts/plugin/publish.ts
index d9523b714..a651457b3 100644
--- a/src/prompts/plugin/publish.ts
+++ b/src/prompts/plugin/publish.ts
@@ -80,10 +80,11 @@ export class PluginPublishPrompts {
 
   /**
    * Double quotes rather than `f.path`: single quotes are not quoting to `cmd.exe`, so a path
-   * containing spaces would break the line the user pastes.
+   * containing spaces would break the line the user pastes. Relative where it can be, because the
+   * reader is standing in the directory above it.
    */
   private changeDirectory(pluginDirectory: DirectoryPath): string {
-    return f.cmdAlt('cd', `"${pluginDirectory}"`);
+    return f.cmdAlt('cd', `"${f.relative(pluginDirectory)}"`);
   }
 
   private createRepository(release: PluginReleaseData): string {
diff --git a/src/prompts/quickstart.ts b/src/prompts/quickstart.ts
index f8129f3a1..ecff570df 100644
--- a/src/prompts/quickstart.ts
+++ b/src/prompts/quickstart.ts
@@ -14,7 +14,7 @@ import { APIMATIC_CONFIG_FILE_NAME } from '../types/apimatic-config/document.js'
 import { PluginConfigWriteFailure } from '../types/plugin-config-context.js';
 import { PortalScaffoldProblem } from '../types/portal/portal-source.js';
 import { GENERATED, GITIGNORE, GitignoreFailure } from '../types/project-context.js';
-import { Language, languageLabel, PLUGIN_LANGUAGES, UPCOMING_LANGUAGES } from '../types/sdk/generate.js';
+import { AVAILABLE_LANGUAGES, Language, languageLabel, UPCOMING_LANGUAGES } from '../types/sdk/generate.js';
 import { noteWrapped, withSpinner } from './prompt.js';
 import { reportAuthorizationFailure } from './portal/authorization.js';
 import { convertToOpenApi3 } from './portal/source.js';
@@ -220,8 +220,8 @@ Let's get started!`);
   public async selectLanguages(): Promise<Language[] | undefined> {
     const selected = await multiselect<Language>({
       message: 'Which languages should your portal include?',
-      options: PLUGIN_LANGUAGES.map((language) => ({ value: language, label: languageLabel(language) })),
-      initialValues: [...PLUGIN_LANGUAGES],
+      options: AVAILABLE_LANGUAGES.map((language) => ({ value: language, label: languageLabel(language) })),
+      initialValues: [...AVAILABLE_LANGUAGES],
       required: false
     });
 
diff --git a/src/prompts/sdk/generate.ts b/src/prompts/sdk/generate.ts
index 0bd4e1674..1e4d4aaf5 100644
--- a/src/prompts/sdk/generate.ts
+++ b/src/prompts/sdk/generate.ts
@@ -4,17 +4,22 @@ import { format as f } from '../format.js';
 import { Result } from 'neverthrow';
 import { withSpinner } from '../prompt.js';
 import { ServiceError } from '../../infrastructure/service-error.js';
-import { GeneratedSdkResult } from '../../infrastructure/services/sdk-generation-service.js';
-import { CodeGenerationVersion, CodegenOption } from '../../types/sdk/generate.js';
+import { AVAILABLE_LANGUAGES, Language, languageLabel, UPCOMING_LANGUAGES } from '../../types/sdk/generate.js';
+
+const names = (languages: readonly Language[]) => languages.map(languageLabel).join(', ');
 
 export class SdkGeneratePrompts {
-  public warnIfStabilityIgnored(codegenOption: CodegenOption, stabilityWasProvided: boolean) {
-    if (stabilityWasProvided && codegenOption.isV3()) {
-      log.warn(
-        `${f.flag('stability')} has no effect with ${f.flag('codegen-version', CodeGenerationVersion.V3)}. ` +
-          `The V3 code generator always produces a stable SDK.`
-      );
-    }
+  /**
+   * Named rather than listed as flag values: a user whose language is on its way back reads
+   * something different from one who mistyped, and neither is told to reach for a generator
+   * version that no longer exists.
+   */
+  public languageNotAvailable(language: Language) {
+    log.error(
+      `${languageLabel(language)} isn't available yet.\n` +
+        `Available now: ${names(AVAILABLE_LANGUAGES)}\n` +
+        `Coming soon: ${names(UPCOMING_LANGUAGES)}`
+    );
   }
 
   public async overwriteSdk(directory: DirectoryPath): Promise<boolean> {
@@ -51,11 +56,7 @@ export class SdkGeneratePrompts {
     log.error(message);
   }
 
-  public generateSDK(fn: Promise<Result<GeneratedSdkResult, ServiceError>>) {
-    return withSpinner('Generating SDK', 'SDK generated successfully.', 'SDK Generation failed.', fn);
-  }
-
-  public generateV4SDK(fn: Promise<Result<NodeJS.ReadableStream, ServiceError>>) {
+  public generateSdk(fn: Promise<Result<NodeJS.ReadableStream, ServiceError>>) {
     return withSpinner('Generating SDK', 'SDK generated successfully.', 'SDK Generation failed.', fn);
   }
 
@@ -91,10 +92,6 @@ export class SdkGeneratePrompts {
   }
 
   public sdkGenerated(sdk: DirectoryPath) {
-    log.info(`The generated SDK can be found at ${f.path(sdk)}.`);
-  }
-
-  public sdkCustomizationsNotSupportedForV4() {
-    log.warn(`The V4 Code Generator does not currently support SDK customizations.`);
+    log.info(`The generated SDK can be found at ${f.relativePath(sdk)}.`);
   }
 }
diff --git a/src/prompts/sdk/merge-source-tree.ts b/src/prompts/sdk/merge-source-tree.ts
deleted file mode 100644
index 7b5b98feb..000000000
--- a/src/prompts/sdk/merge-source-tree.ts
+++ /dev/null
@@ -1,116 +0,0 @@
-import { isCancel, log, confirm } from "@clack/prompts";
-import { format as f, getTree } from "../format.js";
-import { DirectoryPath } from "../../types/file/directoryPath.js";
-import { Language } from "../../types/sdk/generate.js";
-import { Directory } from "../../types/file/directory.js";
-import { noteWrapped } from "../prompt.js";
-import { FilePath } from "../../types/file/filePath.js";
-
-export class MergeSourceTreePrompts {
-  public successfullySkippedChanges(language: Language) {
-    log.info(`Skipped saved changes for ${f.var(language)} SDK.`);
-  }
-
-  public successfullyAppliedChanges(language: Language) {
-    log.info(`Successfully applied saved changes for ${f.var(language)} SDK.`);
-  }
-
-  public changeTrackingEnabled(language: Language, destinationSourceTreePath: FilePath) {
-    log.info(`Change tracking is enabled for ${f.var(language)}. The 'sdk-source-tree' has been saved to ${f.path(destinationSourceTreePath)}.`);
-    
-    const message = `Customize your SDK, then run:
-'${f.cmdAlt("apimatic", "sdk", "save-changes")} ${f.flag("language", language)}'
-This persists your changes so they reapply on every future generation.`;
-    noteWrapped(message, "Next Steps");
-  }
-
-  public changeTrackingAlreadyEnabled(language: Language) {
-    log.warn(`Change tracking is already enabled for ${f.var(language)}. The ${f.flag("track-changes")} flag will be ignored.`);
-  }
-
-  public sdkGenerated(sdk: DirectoryPath) {
-    log.info(`The generated SDK can be found at ${f.path(sdk)}.`);
-  }
-
-  public sdkGeneratedWithSourceTree(sdk: DirectoryPath, sourceTree: FilePath) {
-    log.info(`The generated SDK can be found at ${f.path(sdk)}
-  and the 'sdk-source-tree' can be found at ${f.path(sourceTree)}.`);
-  }
-
-  public startApplyingConflictedChanges(language: Language) {
-    log.info(`Applying saved changes for '${f.var(language)}'...`);
-  }
-
-  public conflictsDetectedInCi(language: Language, directory: Directory) {
-    log.error(`Merge conflicts found while applying saved changes:
-  ${getTree(directory.toTreeNode())}`);
-
-    noteWrapped(`Run the command
-'${f.cmdAlt("apimatic", "sdk", "generate")} ${f.flag("language", language)}'
-interactively to review and resolve the conflicts with SDK generation.`, "Next Steps");
-  }
-
-  public conflictsDetected(directory: Directory) {
-    log.warn(`Merge conflicts found while applying saved changes:
-  ${getTree(directory.toTreeNode())}
-Your SDK may not work until all issues are resolved. Conflict markers have been added to the affected files. Resolve each conflict and remove the markers.`);
-  }
-
-  public async resolveNowOrAbandon() : Promise<boolean> {
-    const continueResolving = await confirm({
-      message: `Resolve now, or abandon SDK generation?`,
-      active: "Resolve now",
-      inactive: "Abandon",
-      initialValue: true
-    });
-
-    if (isCancel(continueResolving)) {
-      return false;
-    }
-
-    return continueResolving;
-  }
-
-  public openingVsCodeForConflictResolution(language: Language) {
-    log.info(`Opening ${f.var(language)} SDK in VS Code for conflicts resolution.
-  1. Resolve each conflict block.
-  2. Save the files.
-  3. Close the editor.`);
-  }
-
-  public openFilesForConflictResolution(language: Language, sdkDir: DirectoryPath) {
-    log.info(`Open ${f.var(language)} SDK at ${f.path(sdkDir)} in your editor for conflicts resolution.
-  1. Resolve each conflict block.
-  2. Save the files.
-  3. Close the editor.`);
-  }
-
-  public async confirmConflictsResolved(): Promise<"resolved" | "unresolved" | "cancelled"> {
-    const conflictsResolved = await confirm({
-      message: `Have you finished resolving all conflicts?`,
-      initialValue: false
-    });
-
-    if (isCancel(conflictsResolved)) {
-      return "cancelled";
-    }
-
-    return conflictsResolved ? "resolved" : "unresolved";
-  }
-
-  public conflictsResolved(language: Language) {
-    log.info(`Saved the current state of ${f.var(language)} SDK as resolved.`);
-  }
-
-  public mergeAbandoned(language: Language) {
-    log.error(`SDK generation has been abandoned. The generated SDK will be discarded.`);
-    noteWrapped(`Run the command
-'${f.cmdAlt("apimatic", "sdk", "generate")} ${f.flag("language", language)}'
-to regenerate the SDK and resolve merge conflicts.`, "Next Steps");
-  }
-
-  public async directoryStillOpen(directory: DirectoryPath) {
-    log.info(`Please close all applications using the directory ${f.path(directory)} to allow cleanup of temporary files.`);
-  }
-
-}
diff --git a/src/prompts/sdk/publish.ts b/src/prompts/sdk/publish.ts
index 26e3b46ff..ca62810e3 100644
--- a/src/prompts/sdk/publish.ts
+++ b/src/prompts/sdk/publish.ts
@@ -6,7 +6,7 @@ import { PublishLogItem } from '../../types/publish-api/publish-log.js';
 import { PublishingInfo } from '../../types/publish-api/publishing-info.js';
 import { PublishType } from '../../types/publish-api/publishing-profile-item.js';
 import { SemVersion } from '../../types/publish/version.js';
-import { CodegenOption, Language } from '../../types/sdk/generate.js';
+import { Language, Stability } from '../../types/sdk/generate.js';
 import { noteWrapped, withSpinner } from '../prompt.js';
 import { format as f } from '../format.js';
 import { PublishingProfile } from '../../types/publish/publishing-profile.js';
@@ -102,7 +102,7 @@ export interface PublishingDetails {
   language: Language;
   version: SemVersion;
   publishType: PublishType[];
-  codegenOption?: CodegenOption;
+  stability?: Stability;
 }
 
 export function formatPublishingDetails({
@@ -110,12 +110,12 @@ export function formatPublishingDetails({
   language,
   version,
   publishType,
-  codegenOption
+  stability
 }: PublishingDetails): string {
   const targets = [...publishType]
-    .map((t) => (t === PublishType.PackagePublishing ? "Package" : "Source Code"))
-    .join(" + ");
+    .map((t) => (t === PublishType.PackagePublishing ? 'Package' : 'Source Code'))
+    .join(' + ');
 
-  const generator = codegenOption ? `\n  Generator: ${codegenOption}` : "";
-  return `\n\n  Profile:   ${profile}\n  Language:  ${language}\n  Version:   ${version}\n  Targets:   ${targets}${generator}`;
+  const level = stability ? `\n  Stability: ${stability}` : '';
+  return `\n\n  Profile:   ${profile}\n  Language:  ${language}\n  Version:   ${version}\n  Targets:   ${targets}${level}`;
 }
diff --git a/src/prompts/sdk/publish/interactive.ts b/src/prompts/sdk/publish/interactive.ts
index 3cc34639d..cfa9700ed 100644
--- a/src/prompts/sdk/publish/interactive.ts
+++ b/src/prompts/sdk/publish/interactive.ts
@@ -10,7 +10,7 @@ import {
   PublishType
 } from '../../../types/publish-api/publishing-profile-item.js';
 import { PublishingProfile } from '../../../types/publish/publishing-profile.js';
-import { CodegenOption, Language } from '../../../types/sdk/generate.js';
+import { AVAILABLE_LANGUAGES, Language, languageLabel, Stability } from '../../../types/sdk/generate.js';
 import { SemVersion } from '../../../types/publish/version.js';
 import { removeQuotes } from '../../../utils/string-utils.js';
 import { SDK_PUBLISHING_OVERVIEW_URL } from '../../publishing/links.js';
@@ -118,8 +118,11 @@ export class SdkPublishInteractivePrompts {
     log.error('No publishing profile was selected.');
   }
 
-  public async selectLanguage(publishingProfile: PublishingProfile): Promise<Language | undefined> {
-    const options = publishingProfile.getEnabledLanguages().map((language) => ({
+  public async selectLanguage(
+    publishingProfile: PublishingProfile,
+    offered: readonly Language[]
+  ): Promise<Language | undefined> {
+    const options = offered.map((language) => ({
       value: language,
       label: `${language} (${publishingProfile
         .getPublishTypesForLanguage(language)
@@ -143,22 +146,34 @@ export class SdkPublishInteractivePrompts {
     log.error('No language was selected for publishing.');
   }
 
-  public async selectCodegenVersion(options: readonly CodegenOption[]): Promise<CodegenOption | undefined> {
-    const codegenOption = await select({
-      message: 'Select the Code Generator version:',
-      initialValue: options[0],
-      options: options.map((option) => ({ value: option, label: `${option}` }))
+  /**
+   * The profile is configured for languages the CLI cannot generate yet. Named rather than
+   * reported as an empty list, so the reason reads as timing rather than a broken profile.
+   */
+  public noAvailableLanguageOnProfile(enabled: readonly Language[]) {
+    log.error(
+      `This publishing profile is configured for ${enabled.map(languageLabel).join(', ')}, ` +
+        `and none of those can be generated yet.\n` +
+        `Available now: ${AVAILABLE_LANGUAGES.map(languageLabel).join(', ')}`
+    );
+  }
+
+  public async selectStability(levels: readonly Stability[]): Promise<Stability | undefined> {
+    const stability = await select({
+      message: 'Select the stability level of the SDK:',
+      initialValue: levels[0],
+      options: levels.map((level) => ({ value: level, label: `${level}` }))
     });
 
-    if (isCancel(codegenOption)) {
+    if (isCancel(stability)) {
       return undefined;
     }
 
-    return codegenOption;
+    return stability;
   }
 
-  public noCodegenVersionSelected() {
-    log.error('No Code Generator version was selected.');
+  public noStabilitySelected() {
+    log.error('No stability level was selected.');
   }
 
   public async inputVersion(): Promise<SemVersion | undefined> {
@@ -194,16 +209,6 @@ export class SdkPublishInteractivePrompts {
     return result;
   }
 
-  public async confirmRecordSdk(): Promise<boolean> {
-    const message =
-      `Update configuration for context plugin generation?` +
-      f.continuation(`See '${f.cmdAlt('apimatic', 'plugin', 'generate')} ${f.flag('help')}' for more information.`);
-
-    const record = await confirm({ message, initialValue: true });
-    if (isCancel(record)) return false;
-    return record;
-  }
-
   public publishingCancelled() {
     log.error('Publishing cancelled.');
   }
diff --git a/src/prompts/sdk/publish/non-interactive.ts b/src/prompts/sdk/publish/non-interactive.ts
index e14411959..b11455d30 100644
--- a/src/prompts/sdk/publish/non-interactive.ts
+++ b/src/prompts/sdk/publish/non-interactive.ts
@@ -89,10 +89,11 @@ export class SdkPublishNonInteractivePrompts {
     );
   }
 
+  /** A publish records itself, and a dry run is the one publish that has nothing to record. */
   public dryRunPluginConfigNotice() {
     const message =
-      `${f.flag('update-plugin-config')} was ignored because ${f.flag('dry-run')} does not publish the SDK. ` +
-      `Re-run without ${f.flag('dry-run')} to record it in ${f.var(APIMATIC_CONFIG_FILE_NAME)}.`;
+      `Nothing was recorded in ${f.var(APIMATIC_CONFIG_FILE_NAME)} because ${f.flag('dry-run')} does not ` +
+      `publish the SDK. Re-run without ${f.flag('dry-run')} to record it.`;
     log.info(message);
   }
 }
diff --git a/src/prompts/plugin/record-sdk.ts b/src/prompts/sdk/record-published-sdk.ts
similarity index 91%
rename from src/prompts/plugin/record-sdk.ts
rename to src/prompts/sdk/record-published-sdk.ts
index f0020d1c0..0b102b374 100644
--- a/src/prompts/plugin/record-sdk.ts
+++ b/src/prompts/sdk/record-published-sdk.ts
@@ -1,9 +1,9 @@
 import { log } from '@clack/prompts';
+import { APIMATIC_CONFIG_FILE_NAME } from '../../types/apimatic-config/document.js';
 import { Language } from '../../types/sdk/generate.js';
 import { format as f } from '../format.js';
-import { APIMATIC_CONFIG_FILE_NAME } from '../../types/apimatic-config/document.js';
 
-export class PluginRecordSdkPrompts {
+export class RecordPublishedSdkPrompts {
   public sdkRecorded(language: Language, configExists: boolean) {
     const message =
       (configExists
@@ -20,7 +20,7 @@ export class PluginRecordSdkPrompts {
     log.warn(message);
   }
 
-  public pluginConfigUnreadable(reason?: string) {
+  public configUnreadable(reason?: string) {
     const cause = reason ? `: ${reason}` : '';
     const message =
       `${f.var(
@@ -29,7 +29,7 @@ export class PluginRecordSdkPrompts {
     log.warn(message);
   }
 
-  public pluginConfigNotWritten() {
+  public configNotWritten() {
     log.warn(
       `${f.var(APIMATIC_CONFIG_FILE_NAME)} could not be written, so this published SDK's details were not added to it.`
     );
diff --git a/src/prompts/sdk/save-changes.ts b/src/prompts/sdk/save-changes.ts
deleted file mode 100644
index c464cb5bd..000000000
--- a/src/prompts/sdk/save-changes.ts
+++ /dev/null
@@ -1,109 +0,0 @@
-import { log, isCancel, select, confirm } from "@clack/prompts";
-import { DirectoryPath } from "../../types/file/directoryPath.js";
-import { format as f, getTree } from "../format.js";
-import { noteWrapped } from "../prompt.js";
-import { FilePath } from "../../types/file/filePath.js";
-import { Directory } from "../../types/file/directory.js";
-
-export class SaveChangesPrompts {
-  
-  public sourceDirectoryEmpty(directory: DirectoryPath) {
-    const message = `The ${f.var("src")} directory is either empty or invalid: ${f.path(directory)}`;
-    log.error(message);
-  }
-
-  public invalidSdkDirectory(directory: DirectoryPath) {
-    const message = `SDK directory does not exist: ${f.path(directory)}`;
-    log.error(message);
-  }
-
-  public invalidVersionedDocsDirectory(directory: DirectoryPath) {
-    const message = `The ${f.var("versioned_docs")} directory is either empty or invalid: ${f.path(directory)}`;
-    log.error(message);
-  }
-
-  public apiVersionOnlyApplicableWithVersionedBuild() {
-    log.warn(`The ${f.flag("api-version")} is only applicable with a versioned build.`);
-  }
-
-  public versionNotFound() {
-    log.error(`The selected API version is invalid.`);
-  }
-
-  public async selectVersion(versions: string[]): Promise<string | undefined> {
-    const version = await select({
-      message: "Select an API version to save SDK changes into:",
-      options: versions.map((v) => ({ label: v, value: v }))
-    });
-
-    if (isCancel(version)) {
-      return undefined;
-    }
-
-    return version;
-  }
-
-  public sdkSourceTreeNotFound(language: string) {
-    log.error(`No 'sdk-source-tree' found for ${f.var(language)}. You need to generate the SDK with change tracking enabled before you can save changes.`);
-    const message = `Generate the SDK with change tracking by running:
-'${f.cmdAlt("apimatic", "sdk", "generate")} ${f.flag("language", language)} ${f.flag("track-changes")}'
-Then customize your SDK and run ${f.cmdAlt("apimatic", "sdk", "save-changes")} again.`;
-    noteWrapped(message, "Next Steps");
-  }
-
-  public operationCancelled() {
-    log.warn("Exiting without saving any changes.");
-  }
-
-  public async directoryStillOpen(directory: DirectoryPath) {
-    log.info(`Please close all applications using the directory ${f.path(directory)} to allow cleanup of temporary files.`);
-  }
-
-  public modifiedFilesDetected(directory: Directory) {
-    log.info(`Detected changes in the following file(s):
-  ${getTree(directory.toTreeNode())}`);
-  }
-
-  public async confirmReviewChanges(): Promise<boolean> {
-    const confirmed = await confirm({
-      message: `Do you want to review these changes?`,
-      initialValue: false
-    });
-
-    if (isCancel(confirmed)) {
-      return false;
-    }
-
-    return confirmed;
-  }
-
-  public noChangesDetected() {
-    log.info("No changes detected in the SDK.");
-  }
-
-  public openingDirectoryToReviewChanges() {
-    log.info(`Opening the changed files in VS Code for review. Close the editor to proceed.`);
-  }
-
-  public async reviewChangesManually(tempDirectory: DirectoryPath) {
-    log.info(`Review the changes at ${f.path(tempDirectory)} to proceed.`);
-  }
-
-  public async confirmSaveChanges(): Promise<boolean> {
-    const confirmed = await confirm({
-      message: `Do you want to save these changes?`,
-      initialValue: true
-    });
-
-    if (isCancel(confirmed)) {
-      return false;
-    }
-
-    return confirmed;
-  }
-
-  public changesSaved(sourceTreePath: FilePath) {
-    log.success(`Changes saved successfully at ${f.path(sourceTreePath)}.`);
-    log.info(`Your saved changes will reapply automatically the next time you generate this SDK.`);
-  }
-}
diff --git a/src/types/build-context.ts b/src/types/build-context.ts
index e1b527827..6ce79d203 100644
--- a/src/types/build-context.ts
+++ b/src/types/build-context.ts
@@ -53,18 +53,6 @@ export class BuildContext {
     return new SpecContext(this.sourceDirectory.join('spec'));
   }
 
-  public async hasSdkSourceTree(language: string): Promise<boolean> {
-    const sourceTreePath = FilePath.create(this.sourceDirectory.join('sdk-source-tree').join(`.${language}`).toString());
-    if (!sourceTreePath) {
-      return false;
-    }
-    return await this.fileService.fileExists(sourceTreePath);
-  }
-
-  public getSdkSourceTree(language: string): FilePath {
-    return FilePath.create(this.sourceDirectory.join('sdk-source-tree').join(`.${language}`).toString())!;
-  }
-
   public async isVersionedBuild(): Promise<boolean> {
     if (!(await this.validate())) {
       return false;
diff --git a/src/types/events/sdk-changes-saved.ts b/src/types/events/sdk-changes-saved.ts
deleted file mode 100644
index 3b19cd338..000000000
--- a/src/types/events/sdk-changes-saved.ts
+++ /dev/null
@@ -1,13 +0,0 @@
-import { DomainEvent } from "./domain-event.js";
-
-export class SdkChangesSavedEvent extends DomainEvent {
-  protected readonly eventName = SdkChangesSavedEvent.name;
-  private static readonly message = "Save changes completed." as const;
-  private static readonly commandName = "sdk:save-changes" as const;
-  private readonly language: string;
-
-  constructor(language: string) {
-    super(SdkChangesSavedEvent.message, SdkChangesSavedEvent.commandName, {});
-    this.language = language;
-  }
-}
diff --git a/src/types/events/sdk-changes-tracked.ts b/src/types/events/sdk-changes-tracked.ts
deleted file mode 100644
index c9c47e617..000000000
--- a/src/types/events/sdk-changes-tracked.ts
+++ /dev/null
@@ -1,13 +0,0 @@
-import { DomainEvent } from "./domain-event.js";
-
-export class SdkChangesTrackedEvent extends DomainEvent {
-  protected readonly eventName = SdkChangesTrackedEvent.name;
-  private static readonly message = "SDK generated with track changes enabled." as const;
-  private static readonly commandName = "sdk:generate" as const;
-  private readonly language: string;
-
-  constructor(language: string) {
-    super(SdkChangesTrackedEvent.message, SdkChangesTrackedEvent.commandName, {});
-    this.language = language;
-  }
-}
diff --git a/src/types/events/sdk-conflicts-resolved.ts b/src/types/events/sdk-conflicts-resolved.ts
deleted file mode 100644
index 692740678..000000000
--- a/src/types/events/sdk-conflicts-resolved.ts
+++ /dev/null
@@ -1,13 +0,0 @@
-import { DomainEvent } from "./domain-event.js";
-
-export class SdkConflictsResolvedEvent extends DomainEvent {
-  protected readonly eventName = SdkConflictsResolvedEvent.name;
-  private static readonly message = "SDK merge conflicts resolved." as const;
-  private static readonly commandName = "sdk:generate" as const;
-  private readonly language: string;
-
-  constructor(language: string) {
-    super(SdkConflictsResolvedEvent.message, SdkConflictsResolvedEvent.commandName, {});
-    this.language = language;
-  }
-}
diff --git a/src/types/file/directoryPath.ts b/src/types/file/directoryPath.ts
index 7bf6664ba..acd767308 100644
--- a/src/types/file/directoryPath.ts
+++ b/src/types/file/directoryPath.ts
@@ -1,5 +1,18 @@
 import * as path from 'path';
 
+/** How a reader standing in `from` would type `target`: `./sdk` beside them, else the full path. */
+export function asTypedFrom(target: string, from: DirectoryPath): string {
+  const here = path.relative(from.toString(), target);
+  if (here === '') {
+    return '.';
+  }
+  // A sibling starts with `..`, and so does a child called `..cache`: only the segment counts.
+  if (path.isAbsolute(here) || here === '..' || here.startsWith(`..${path.sep}`)) {
+    return target;
+  }
+  return `./${here.split(path.sep).join('/')}`;
+}
+
 export class DirectoryPath {
   private readonly directoryPath: string;
 
@@ -25,6 +38,10 @@ export class DirectoryPath {
     return this.directoryPath;
   }
 
+  public asTypedFrom(from: DirectoryPath): string {
+    return asTypedFrom(this.directoryPath, from);
+  }
+
   public join(...subPath: string[]) {
     return new DirectoryPath(path.join(this.directoryPath, ...subPath));
   }
diff --git a/src/types/file/filePath.ts b/src/types/file/filePath.ts
index f48d7e615..f19a533bf 100644
--- a/src/types/file/filePath.ts
+++ b/src/types/file/filePath.ts
@@ -1,6 +1,6 @@
 import path from 'path';
 import { FileName } from './fileName.js';
-import { DirectoryPath } from './directoryPath.js';
+import { asTypedFrom, DirectoryPath } from './directoryPath.js';
 
 export class FilePath {
   private readonly fileName: FileName;
@@ -41,6 +41,10 @@ export class FilePath {
     return path.relative(directory.toString(), this.toString()).split(path.sep).join('/');
   }
 
+  public asTypedFrom(from: DirectoryPath): string {
+    return asTypedFrom(this.toString(), from);
+  }
+
   public static create(filePath: string): FilePath | undefined {
     if (!filePath) {
       return undefined;
diff --git a/src/types/merge-source-tree-context.ts b/src/types/merge-source-tree-context.ts
deleted file mode 100644
index 190682e03..000000000
--- a/src/types/merge-source-tree-context.ts
+++ /dev/null
@@ -1,76 +0,0 @@
-import { FileService } from "../infrastructure/file-service.js";
-import { GitService } from "../infrastructure/git-service.js";
-import { ZipService } from "../infrastructure/zip-service.js";
-import { Directory } from "./file/directory.js";
-import { DirectoryPath } from "./file/directoryPath.js";
-import { FileName } from "./file/fileName.js";
-import { FilePath } from "./file/filePath.js";
-
-export class MergeSourceTreeContext {
-  private readonly fileService = new FileService();
-  private readonly zipService = new ZipService();
-  private readonly gitService = new GitService();
-
-  constructor(
-    private readonly sdkWithSourceTree: DirectoryPath,
-    private readonly sdkWithoutSourceTree: DirectoryPath,
-    private readonly sourceTreePath: FilePath,
-    private readonly trackChanges: boolean,
-    private readonly skipChanges: boolean,
-    private readonly hasSdkSourceTree: boolean
-  ) { }
-
-  public async saveSkippingChanges(): Promise<{ hasSkippedChangesEnabled: boolean, hasSkippedCustomizations: boolean }> {
-    if (!this.skipChanges || !await this.gitService.hasCustomBranch(this.sdkWithSourceTree)) {
-      return { hasSkippedChangesEnabled: this.skipChanges, hasSkippedCustomizations: false };
-    }
-    await Promise.all(this.gitService.getMergeFiles(this.sdkWithSourceTree).map((filePath) => this.fileService.deleteFile(filePath)));
-    await this.gitService.forceCheckoutMainBranch(this.sdkWithSourceTree);
-    await this.fileService.cleanDirectory(this.sdkWithoutSourceTree);
-    await this.fileService.copyDirectoryExcluding(this.sdkWithSourceTree, this.sdkWithoutSourceTree, [new FileName(".git")]);
-    return { hasSkippedChangesEnabled: true, hasSkippedCustomizations: true };
-  }
-
-  public async saveWithoutConflicts(): Promise<{ hasSourceTreeTracked: boolean, hasSourceTreeAlreadyTracked: boolean, hasAppliedCustomizations: boolean }> {
-    const mergeFiles = this.gitService.getMergeFiles(this.sdkWithSourceTree);
-    if (await this.fileService.fileExists(mergeFiles[0])) {
-      for (const filePath of mergeFiles) {
-        await this.fileService.deleteFile(filePath);
-      }
-      return { hasSourceTreeTracked: false, hasSourceTreeAlreadyTracked: false, hasAppliedCustomizations: false };
-    }
-
-    if (this.trackChanges || this.hasSdkSourceTree) {
-      await this.saveSourceTree();
-    }
-
-    return {
-      hasSourceTreeTracked: this.trackChanges || this.hasSdkSourceTree,
-      hasSourceTreeAlreadyTracked: this.trackChanges && this.hasSdkSourceTree,
-      hasAppliedCustomizations: await this.gitService.hasCustomBranch(this.sdkWithSourceTree)
-    };
-  }
-
-  public async saveWithResolvedConflicts(): Promise<void> {
-    await this.gitService.commitResolvedConflicts(this.sdkWithSourceTree);
-
-    // Re create the sdkWithoutSourceTree using the updated resolved state of the sdkWithSourceTree
-    await this.fileService.cleanDirectory(this.sdkWithoutSourceTree);
-    await this.fileService.copyDirectoryExcluding(this.sdkWithSourceTree, this.sdkWithoutSourceTree, [new FileName(".git")]);
-    await this.saveSourceTree();
-  }
-
-  private async saveSourceTree(): Promise<void> {
-    await this.fileService.ensurePathExists(this.sourceTreePath);
-    await this.gitService.forceCheckoutMainBranch(this.sdkWithSourceTree);
-    await this.zipService.archive(this.sdkWithSourceTree.join(".git"), this.sourceTreePath);
-  }
-
-  public async getConflictedFilesDirectory(): Promise<Directory> {
-    return await this.gitService.getDirectoryWithUnmergedFiles(this.sdkWithSourceTree);
-  }
-
-  public async cleanUp(onCleanUpFailure: () => Promise<void>): Promise<void> {
-    await this.fileService.pollDeleteDirectory(this.sdkWithSourceTree, onCleanUpFailure);
-  }
-}
diff --git a/src/types/plugin-config-context.ts b/src/types/plugin-config-context.ts
index 8748ae570..ef9ca48f8 100644
--- a/src/types/plugin-config-context.ts
+++ b/src/types/plugin-config-context.ts
@@ -14,7 +14,7 @@ import {
   PluginMetadata
 } from './plugin/plugin-config.js';
 import { SemVersion } from './publish/version.js';
-import { isPluginLanguage, Language, PLUGIN_LANGUAGES } from './sdk/generate.js';
+import { AVAILABLE_LANGUAGES, isAvailableLanguage, Language } from './sdk/generate.js';
 
 export type PluginReleaseData = { pluginId: string; version: SemVersion };
 
@@ -42,7 +42,7 @@ export class PluginConfig {
     const unsupported: string[] = [];
 
     for (const [language, entry] of Object.entries(config.languages)) {
-      if (isPluginLanguage(language)) {
+      if (isAvailableLanguage(language)) {
         entries.push([language, entry as PluginLanguages[Language]]);
       } else {
         unsupported.push(language);
@@ -60,7 +60,7 @@ export class PluginConfig {
   public initialLanguages(): readonly Language[] {
     const requested = this.entries.map(([language]) => language);
 
-    return requested.length > 0 ? requested : PLUGIN_LANGUAGES;
+    return requested.length > 0 ? requested : AVAILABLE_LANGUAGES;
   }
 
   public unsupportedLanguages(): readonly string[] {
@@ -117,10 +117,9 @@ const recorded = (
 
 /** In the user's file a cleared language goes, unless its entry records where an SDK was published. */
 const keepsRecord = (language: string, entry: PluginLanguageEntry<Language> | undefined): boolean =>
-  !isPluginLanguage(language) || isPublished(entry);
+  !isAvailableLanguage(language) || isPublished(entry);
 
-/** In the upload only the covered languages remain, beside the ones a plugin never carries. */
-const isNotPluginLanguage = (language: string): boolean => !isPluginLanguage(language);
+const isUnavailableLanguage = (language: string): boolean => !isAvailableLanguage(language);
 
 export class PluginConfigContext {
   private readonly configContext: ApimaticConfigContext;
@@ -183,7 +182,7 @@ export class PluginConfigContext {
 
     const config = new ApimaticConfigContext(staged);
     const covered = await config.merge(OWNED_BLOCKS, (document) =>
-      document.with('languages', recorded(document, languages, isNotPluginLanguage))
+      document.with('languages', recorded(document, languages, isUnavailableLanguage))
     );
 
     // The merge writes nothing when it changes nothing, so a mark on the copy can outlive it —
@@ -191,27 +190,6 @@ export class PluginConfigContext {
     return await covered.asyncAndThen(() => new ResultAsync(config.removeByteOrderMark())).map(() => staged);
   }
 
-  public async upsertLanguage<L extends Language>(
-    language: L,
-    entry: PluginLanguageEntry<L>
-  ): Promise<Result<PluginConfig, PluginConfigWriteFailure>> {
-    return await this.merge((document) => {
-      const languages: PluginLanguages = { ...(document.languages() as PluginLanguages | undefined) };
-      const existingEntry = languages[language];
-      const existingPublishing = existingEntry?.publishing;
-      const publishing = entry.publishing
-        ? {
-            ...existingPublishing,
-            ...entry.publishing,
-            source: entry.publishing.source ?? existingPublishing?.source,
-            package: entry.publishing.package ?? existingPublishing?.package
-          }
-        : existingPublishing;
-      languages[language] = { ...existingEntry, ...entry, ...(publishing ? { publishing } : {}) };
-      return document.with('languages', languages);
-    });
-  }
-
   private async merge(
     apply: (document: ApimaticConfigDocument) => ApimaticConfigDocument
   ): Promise<Result<PluginConfig, PluginConfigWriteFailure>> {
diff --git a/src/types/save-changes-context.ts b/src/types/save-changes-context.ts
deleted file mode 100644
index 111a65aee..000000000
--- a/src/types/save-changes-context.ts
+++ /dev/null
@@ -1,59 +0,0 @@
-import { FileService } from "../infrastructure/file-service.js";
-import { GitService } from "../infrastructure/git-service.js";
-import { ZipService } from "../infrastructure/zip-service.js";
-import { Directory } from "./file/directory.js";
-import { DirectoryPath } from "./file/directoryPath.js";
-import { FileName } from "./file/fileName.js";
-import { FilePath } from "./file/filePath.js";
-import { Language } from "./sdk/generate.js";
-
-export class SaveChangesContext {
-  private readonly fileService = new FileService();
-  private readonly zipService = new ZipService();
-  private readonly gitService = new GitService();
-  private readonly sdkInputDirectory: DirectoryPath;
-
-  constructor(
-    private readonly sourceTreePath: FilePath,
-    private readonly sdkReviewDirectory: DirectoryPath,
-    sdkInputDirectory: DirectoryPath | undefined,
-    workingDirectory: DirectoryPath,
-    language: Language,
-    version: string | undefined
-  ) {
-    this.sdkInputDirectory = sdkInputDirectory ?? (version
-        ? workingDirectory.join("sdk").join(version).join(language)
-        : workingDirectory.join("sdk").join(language));
-  }
-
-  public async isSdkInputDirectoryMissing(onMissingDirectory: (directory: DirectoryPath) => void) {
-    if (await this.fileService.directoryEmpty(this.sdkInputDirectory)) {
-      onMissingDirectory(this.sdkInputDirectory);
-      return true;
-    }
-    return false;
-  }
-
-  public async getChangesForReviewDirectory(): Promise<Directory> {
-    const sdkGitDir = this.sdkReviewDirectory.join(".git");
-    await this.fileService.createDirectoryIfNotExists(sdkGitDir);
-    await this.zipService.unArchive(this.sourceTreePath, sdkGitDir);
-
-    await this.gitService.checkoutCustomBranch(this.sdkReviewDirectory);
-    await this.fileService.cleanDirectoryExcluding(this.sdkReviewDirectory, [new FileName(".git")]);
-    await this.fileService.copyDirectoryExcluding(this.sdkInputDirectory, this.sdkReviewDirectory, [new FileName(".git")]);
-
-    return this.gitService.getDirectoryWithUpdatedFiles(this.sdkReviewDirectory);
-  }
-
-  public async cleanUpSdkReviewDirectory(onCleanUpFailure: () => void): Promise<void> {
-    await this.fileService.pollDeleteDirectory(this.sdkReviewDirectory, onCleanUpFailure);
-  }
-
-  public async saveSourceTree(): Promise<void> {
-    const sdkGitDir = this.sdkReviewDirectory.join(".git");
-    await this.gitService.commitReviewedChanges(this.sdkReviewDirectory);
-    await this.gitService.forceCheckoutMainBranch(this.sdkReviewDirectory);
-    await this.zipService.archive(sdkGitDir, this.sourceTreePath);
-  }
-}
diff --git a/src/types/sdk-context.ts b/src/types/sdk-context.ts
index 64c4828b3..395c97a1f 100644
--- a/src/types/sdk-context.ts
+++ b/src/types/sdk-context.ts
@@ -1,24 +1,17 @@
-import { FileService } from "../infrastructure/file-service.js";
-import { DirectoryPath } from "./file/directoryPath.js";
-import { FilePath } from "./file/filePath.js";
-import { FileName } from "./file/fileName.js";
-import { Language } from "./sdk/generate.js";
-import { ZipService } from "../infrastructure/zip-service.js";
+import { FileService } from '../infrastructure/file-service.js';
+import { DirectoryPath } from './file/directoryPath.js';
+import { FilePath } from './file/filePath.js';
+import { FileName } from './file/fileName.js';
+import { Language } from './sdk/generate.js';
+import { ZipService } from '../infrastructure/zip-service.js';
 
 export class SdkContext {
   private readonly fileService = new FileService();
   private readonly zipService = new ZipService();
   private readonly sdkDirectory: DirectoryPath;
 
-  constructor(
-    private readonly language: Language,
-    sdkDirectory: DirectoryPath,
-    requireUncustomizedDir: boolean,
-    version?: string
-  ) {
-    const baseDirectory = requireUncustomizedDir ? sdkDirectory.join('uncustomized') : sdkDirectory;
-
-    this.sdkDirectory = version ? baseDirectory.join(version).join(language) : baseDirectory.join(language);
+  constructor(private readonly language: Language, sdkDirectory: DirectoryPath, version?: string) {
+    this.sdkDirectory = version ? sdkDirectory.join(version).join(language) : sdkDirectory.join(language);
   }
 
   private get zipPath(): FilePath {
@@ -45,18 +38,4 @@ export class SdkContext {
     await this.zipService.unArchive(tempSdk, tempSdkDirectory);
     return tempSdkDirectory;
   }
-
-  public async loadSdkWithSourceTreeInTempDirectory(
-    tempDirectory: DirectoryPath,
-    tempSdk: FilePath,
-    tempSdkSourceTree: FilePath
-  ): Promise<DirectoryPath> {
-    const tempSdkDirectory = tempDirectory.join('sdk');
-    await this.fileService.createDirectoryIfNotExists(tempSdkDirectory);
-    await this.zipService.unArchive(tempSdk, tempSdkDirectory);
-    const gitSourceTreeDir = tempSdkDirectory.join('.git');
-    await this.fileService.createDirectoryIfNotExists(gitSourceTreeDir);
-    await this.zipService.unArchive(tempSdkSourceTree, gitSourceTreeDir);
-    return tempSdkDirectory;
-  }
 }
diff --git a/src/types/sdk/generate.ts b/src/types/sdk/generate.ts
index ada9e0770..072ebe6ab 100644
--- a/src/types/sdk/generate.ts
+++ b/src/types/sdk/generate.ts
@@ -1,5 +1,4 @@
 import { NonEmptyArray } from '../utils.js';
-
 export enum Language {
   CSHARP = 'csharp',
   JAVA = 'java',
@@ -10,8 +9,8 @@ export enum Language {
   GO = 'go'
 }
 
+/** An enum, not a constant, so the next generator is a line here and nothing else. */
 export enum CodeGenerationVersion {
-  V3 = 'v3',
   V4 = 'v4'
 }
 
@@ -62,69 +61,73 @@ export const LANGUAGE_CHOICES: ReadonlyArray<{ label: string; value: Language }>
   Language.GO
 ].map((value) => ({ label: LANGUAGE_NAMES[value], value }));
 
-// Only these have a v4 renderer, so a plugin cannot carry the rest whatever the config says.
-export const PLUGIN_LANGUAGES: readonly Language[] = [Language.CSHARP, Language.TYPESCRIPT, Language.PYTHON];
-
-/** The name a language is shown under everywhere, so one reads the same in every message. */
-export const languageLabel = (language: string): string =>
-  LANGUAGE_CHOICES.find((choice) => choice.value === language)?.label ?? language;
-
-export function isPluginLanguage(language: string): language is Language {
-  return PLUGIN_LANGUAGES.includes(language as Language);
-}
-
-/** The rest of the enum, so a language cannot be named by both lists or by neither. */
-export const UPCOMING_LANGUAGES: readonly Language[] = LANGUAGE_CHOICES.map((choice) => choice.value).filter(
-  (language) => !isPluginLanguage(language)
-);
-
+/** What each generator offers for a language. A language absent from it cannot be generated. */
 export class CodegenOption {
-  public static readonly v3 = new CodegenOption(CodeGenerationVersion.V3, Stability.STABLE);
-
   private constructor(private readonly version: CodeGenerationVersion, private readonly stability: Stability) {}
 
   public static create(version: CodeGenerationVersion, stability: Stability): CodegenOption {
-    if (version === CodeGenerationVersion.V3) {
-      return CodegenOption.v3;
-    }
     return new CodegenOption(version, stability);
   }
 
-  public isV3(): boolean {
-    return this.version === CodeGenerationVersion.V3;
-  }
-
-  public isV4(): boolean {
-    return this.version === CodeGenerationVersion.V4;
+  public codeGenerationVersion(): CodeGenerationVersion {
+    return this.version;
   }
 
   public stabilityLevel(): Stability {
     return this.stability;
   }
 
-  public codeGenerationVersion(): CodeGenerationVersion {
-    return this.version;
-  }
-
   public toString(): string {
     return `${this.version.toUpperCase()} (${this.stability})`;
   }
 }
 
-/**
- * For validating only interactive `sdk publish/generate` commands.
- * Non-interactive validation is handled server-side by codegen API.
- */
-export const CODEGEN_OPTIONS: Readonly<Record<Language, Readonly<NonEmptyArray<CodegenOption>>>> = {
-  [Language.CSHARP]: [CodegenOption.v3, CodegenOption.create(CodeGenerationVersion.V4, Stability.BETA)],
-  [Language.GO]: [CodegenOption.v3],
-  [Language.JAVA]: [CodegenOption.v3],
-  [Language.PHP]: [CodegenOption.v3],
-  [Language.PYTHON]: [CodegenOption.v3, CodegenOption.create(CodeGenerationVersion.V4, Stability.BETA)],
-  [Language.RUBY]: [CodegenOption.v3],
-  [Language.TYPESCRIPT]: [CodegenOption.v3, CodegenOption.create(CodeGenerationVersion.V4, Stability.BETA)]
+/** The generator and level together, because neither is a choice the other can be made without. */
+export const CODEGEN_OPTIONS: Readonly<Partial<Record<Language, Readonly<NonEmptyArray<CodegenOption>>>>> = {
+  [Language.CSHARP]: [
+    CodegenOption.create(CodeGenerationVersion.V4, Stability.STABLE),
+    CodegenOption.create(CodeGenerationVersion.V4, Stability.BETA)
+  ],
+  [Language.TYPESCRIPT]: [
+    CodegenOption.create(CodeGenerationVersion.V4, Stability.STABLE),
+    CodegenOption.create(CodeGenerationVersion.V4, Stability.BETA)
+  ],
+  [Language.PYTHON]: [
+    CodegenOption.create(CodeGenerationVersion.V4, Stability.STABLE),
+    CodegenOption.create(CodeGenerationVersion.V4, Stability.BETA)
+  ]
 };
 
-export function getCodegenOptions(language: Language): Readonly<NonEmptyArray<CodegenOption>> {
-  return CODEGEN_OPTIONS[language];
+/** The keys of the table above: a language is available exactly when something can generate it. */
+export const AVAILABLE_LANGUAGES: readonly Language[] = Object.keys(CODEGEN_OPTIONS) as Language[];
+
+/** The rest of the enum, so a language cannot be named by both lists or by neither. */
+export const UPCOMING_LANGUAGES: readonly Language[] = LANGUAGE_CHOICES.map((choice) => choice.value).filter(
+  (language) => !AVAILABLE_LANGUAGES.includes(language)
+);
+
+/** Takes a string because a config file names its own languages, and may name anything. */
+export function isAvailableLanguage(language: string): language is Language {
+  return AVAILABLE_LANGUAGES.includes(language as Language);
+}
+
+export function codegenOptionsFor(language: Language): readonly CodegenOption[] {
+  return CODEGEN_OPTIONS[language] ?? [];
+}
+
+export function stabilityLevelsFor(language: Language): readonly Stability[] {
+  return codegenOptionsFor(language).map((option) => option.stabilityLevel());
+}
+
+/** What a flow that never asks sends: the first level a language offers. */
+export function defaultStability(language: Language): Stability {
+  return stabilityLevelsFor(language)[0] ?? Stability.STABLE;
+}
+
+/**
+ * The name a language is shown under everywhere, so one reads the same in every message.
+ * Takes a string because a config file names its own languages, and may name anything.
+ */
+export function languageLabel(language: string): string {
+  return LANGUAGE_NAMES[language as Language] ?? language;
 }
diff --git a/src/types/sdk/stability-choice.ts b/src/types/sdk/stability-choice.ts
new file mode 100644
index 000000000..c98703a5d
--- /dev/null
+++ b/src/types/sdk/stability-choice.ts
@@ -0,0 +1,22 @@
+import { defaultStability, Language, Stability } from './generate.js';
+
+/** The level a run generates at, and whether the caller named it or took what the language offers. */
+export class StabilityChoice {
+  private constructor(private readonly level: Stability, private readonly chosen: boolean) {}
+
+  /** An absent flag is not a level: what the language offers first is what an unasked run sends. */
+  public static for(language: Language, flagValue: string | undefined): StabilityChoice {
+    return flagValue === undefined
+      ? new StabilityChoice(defaultStability(language), false)
+      : new StabilityChoice(flagValue as Stability, true);
+  }
+
+  public stabilityLevel(): Stability {
+    return this.level;
+  }
+
+  /** The publishing summary names the level only when it was asked for. */
+  public chosenLevel(): Stability | undefined {
+    return this.chosen ? this.level : undefined;
+  }
+}
diff --git a/test/actions/plugin/record-sdk.test.ts b/test/actions/sdk/record-published-sdk.test.ts
similarity index 84%
rename from test/actions/plugin/record-sdk.test.ts
rename to test/actions/sdk/record-published-sdk.test.ts
index 2c646e15a..4262ab97c 100644
--- a/test/actions/plugin/record-sdk.test.ts
+++ b/test/actions/sdk/record-published-sdk.test.ts
@@ -4,10 +4,10 @@ import sinon from 'sinon';
 import { expect } from 'chai';
 import { err } from 'neverthrow';
 import { dir as tmpDir, DirectoryResult } from 'tmp-promise';
-import { PluginRecordSdkAction } from '../../../src/actions/plugin/record-sdk.js';
-import { PluginRecordSdkPrompts } from '../../../src/prompts/plugin/record-sdk.js';
+import { RecordPublishedSdkAction } from '../../../src/actions/sdk/record-published-sdk.js';
+import { RecordPublishedSdkPrompts } from '../../../src/prompts/sdk/record-published-sdk.js';
 import { DirectoryPath } from '../../../src/types/file/directoryPath.js';
-import { PluginConfigContext } from '../../../src/types/plugin-config-context.js';
+import { ApimaticConfigContext } from '../../../src/types/apimatic-config-context.js';
 import { PluginIdentityData, PluginLanguages } from '../../../src/types/plugin/plugin-config.js';
 import { PublishType } from '../../../src/types/publish-api/publishing-profile-item.js';
 import { PublishingProfile } from '../../../src/types/publish/publishing-profile.js';
@@ -42,10 +42,10 @@ interface WrittenDocument {
   languages: PluginLanguages;
 }
 
-describe('PluginRecordSdkAction', () => {
+describe('RecordPublishedSdkAction', () => {
   let tmpDirResult: DirectoryResult;
   let sourceDirectory: string;
-  let action: PluginRecordSdkAction;
+  let action: RecordPublishedSdkAction;
   let noSourceRepository: sinon.SinonStub;
 
   const configPath = () => path.join(sourceDirectory, 'apimatic.json');
@@ -59,9 +59,9 @@ describe('PluginRecordSdkAction', () => {
     tmpDirResult = await tmpDir({ unsafeCleanup: true });
     sourceDirectory = path.join(tmpDirResult.path, 'acme-payments', 'src');
     await fsExtra.ensureDir(sourceDirectory);
-    sinon.stub(PluginRecordSdkPrompts.prototype, 'sdkRecorded');
-    noSourceRepository = sinon.stub(PluginRecordSdkPrompts.prototype, 'noSourceRepository');
-    action = new PluginRecordSdkAction();
+    sinon.stub(RecordPublishedSdkPrompts.prototype, 'sdkRecorded');
+    noSourceRepository = sinon.stub(RecordPublishedSdkPrompts.prototype, 'noSourceRepository');
+    action = new RecordPublishedSdkAction();
   });
 
   afterEach(async () => {
@@ -177,8 +177,8 @@ describe('PluginRecordSdkAction', () => {
   });
 
   it('warns when the config cannot be written', async () => {
-    sinon.stub(PluginConfigContext.prototype, 'upsertLanguage').resolves(err('unwritable'));
-    const notWritten = sinon.stub(PluginRecordSdkPrompts.prototype, 'pluginConfigNotWritten');
+    sinon.stub(ApimaticConfigContext.prototype, 'merge').resolves(err('unwritable'));
+    const notWritten = sinon.stub(RecordPublishedSdkPrompts.prototype, 'configNotWritten');
 
     const result = await execute(profileWith(GIT_CONFIG));
 
@@ -187,39 +187,33 @@ describe('PluginRecordSdkAction', () => {
   });
 
   it('reports a config that became unreadable before the write', async () => {
-    sinon.stub(PluginConfigContext.prototype, 'upsertLanguage').resolves(err('unreadable'));
-    const pluginConfigUnreadable = sinon.stub(PluginRecordSdkPrompts.prototype, 'pluginConfigUnreadable');
+    sinon.stub(ApimaticConfigContext.prototype, 'merge').resolves(err('unreadable'));
+    const configUnreadable = sinon.stub(RecordPublishedSdkPrompts.prototype, 'configUnreadable');
 
     await execute(profileWith(GIT_CONFIG));
 
-    expect(pluginConfigUnreadable.calledOnce).to.be.true;
-  });
-
-  it('records on the --update-plugin-config path', async () => {
-    await execute(profileWith(GIT_CONFIG, { packageId: 'Acme.Payments.Sdk' }));
-
-    expect(Object.keys(writtenConfig().languages)).to.deep.equal(['csharp']);
+    expect(configUnreadable.calledOnce).to.be.true;
   });
 
   it('warns and records nothing when the config cannot be read', async () => {
     await fsExtra.writeFile(configPath(), '{ not json');
-    const pluginConfigUnreadable = sinon.stub(PluginRecordSdkPrompts.prototype, 'pluginConfigUnreadable');
+    const configUnreadable = sinon.stub(RecordPublishedSdkPrompts.prototype, 'configUnreadable');
 
     const result = await execute(profileWith(GIT_CONFIG));
 
     expect(result.isFailed()).to.be.true;
-    expect(pluginConfigUnreadable.called).to.be.true;
+    expect(configUnreadable.called).to.be.true;
     expect(fsExtra.readFileSync(configPath(), 'utf-8')).to.equal('{ not json');
   });
 
   it('tells the user why the config could not be read', async () => {
     const contents = JSON.stringify({ languages: 'csharp' });
     await fsExtra.writeFile(configPath(), contents);
-    const pluginConfigUnreadable = sinon.stub(PluginRecordSdkPrompts.prototype, 'pluginConfigUnreadable');
+    const configUnreadable = sinon.stub(RecordPublishedSdkPrompts.prototype, 'configUnreadable');
 
     await execute(profileWith(GIT_CONFIG));
 
-    expect(pluginConfigUnreadable.firstCall.args[0]).to.equal(`its 'languages' is not a JSON object`);
+    expect(configUnreadable.firstCall.args[0]).to.equal(`its 'languages' is not a JSON object`);
     expect(fsExtra.readFileSync(configPath(), 'utf-8')).to.equal(contents);
   });
 
diff --git a/test/commands/examples-parse.test.ts b/test/commands/examples-parse.test.ts
index 2e0f495eb..e4b2969dd 100644
--- a/test/commands/examples-parse.test.ts
+++ b/test/commands/examples-parse.test.ts
@@ -23,8 +23,7 @@ const COMMANDS: CommandMapping[] = [
   { id: 'publishing profile list', fileParts: ['commands', 'publishing', 'profile', 'list.js'] },
   { id: 'quickstart', fileParts: ['commands', 'quickstart.js'] },
   { id: 'sdk generate', fileParts: ['commands', 'sdk', 'generate.js'] },
-  { id: 'sdk publish', fileParts: ['commands', 'sdk', 'publish.js'] },
-  { id: 'sdk save-changes', fileParts: ['commands', 'sdk', 'save-changes.js'] }
+  { id: 'sdk publish', fileParts: ['commands', 'sdk', 'publish.js'] }
 ];
 
 const BIN_NAME = 'apimatic'; // matches package.json oclif.bin
diff --git a/test/commands/sdk/publish-flags.test.ts b/test/commands/sdk/publish-flags.test.ts
index 50f7e1eaf..23cc24145 100644
--- a/test/commands/sdk/publish-flags.test.ts
+++ b/test/commands/sdk/publish-flags.test.ts
@@ -5,44 +5,82 @@ import { CodeGenerationVersion, Stability } from '../../../src/types/sdk/generat
 
 const parse = (argv: string[]) => Parser.parse(argv, { flags: SdkPublish.flags as never, strict: true } as never);
 
-// `warnIfStabilityIgnored` decides whether to fire from oclif's `setFromDefault` metadata rather
-// than from the flag's value, because `--stability stable` on V3 is ignored just as silently as
-// `--stability beta`. This is the codebase's first use of parse metadata, so the mechanism itself
-// is worth pinning down: if oclif ever stops reporting it, the warning fails open and silently.
-describe('sdk publish codegen flags', () => {
-  it('defaults to v3 and stable when neither flag is passed', async () => {
-    const { flags } = (await parse([])) as never as { flags: Record<string, unknown> };
+const rejects = async (argv: string[]): Promise<Error> => {
+  let thrown: unknown;
+  try {
+    await parse(argv);
+  } catch (error) {
+    thrown = error;
+  }
+  expect(thrown, `expected ${argv.join(' ')} to be rejected`).to.be.an('error');
+  return thrown as Error;
+};
 
-    expect(flags['codegen-version']).to.equal(CodeGenerationVersion.V3);
-    expect(flags.stability).to.equal(Stability.STABLE);
+// Recording a publish is bookkeeping, not a decision, so the flag that asked is gone. A run that
+// still passes it is told it is unknown rather than having it quietly ignored — this pins that it
+// is really gone, not merely undocumented.
+describe('sdk publish flags', () => {
+  it('no longer accepts --update-plugin-config', async () => {
+    expect((await rejects(['--update-plugin-config'])).message).to.contain('update-plugin-config');
   });
 
-  it('accepts the v4 combination', async () => {
-    const { flags } = (await parse(['--codegen-version', 'v4', '--stability', 'beta'])) as never as {
+  // v3 is retired, so v4 is the only value — but the flag stays, because the next generator should
+  // be something a caller asks for rather than something a release changes underneath them.
+  it('accepts the one code generator version there is', async () => {
+    const { flags } = (await parse(['--codegen-version', 'v4'])) as never as {
       flags: Record<string, unknown>;
     };
 
     expect(flags['codegen-version']).to.equal(CodeGenerationVersion.V4);
-    expect(flags.stability).to.equal(Stability.BETA);
   });
 
-  it('rejects a codegen version the CLI does not know', async () => {
-    let thrown: unknown;
-    try {
-      await parse(['--codegen-version', 'v5']);
-    } catch (error) {
-      thrown = error;
-    }
+  it('defaults to that version when the flag is not passed', async () => {
+    const { flags } = (await parse([])) as never as { flags: Record<string, unknown> };
 
-    expect(thrown).to.be.an('error');
-    expect((thrown as Error).message).to.contain('v5');
+    expect(flags['codegen-version']).to.equal(CodeGenerationVersion.V4);
   });
 
-  it('does not filter languages by codegen version, leaving that to the service', async () => {
-    const { flags } = (await parse(['--codegen-version', 'v4', '--language', 'typescript'])) as never as {
+  it('refuses the retired version rather than generating something else', async () => {
+    expect((await rejects(['--codegen-version', 'v3'])).message).to.contain('v3');
+  });
+
+  it('still chooses a stability level, which outlived the generator version', async () => {
+    const { flags, metadata } = (await parse(['--stability', 'beta'])) as never as {
       flags: Record<string, unknown>;
+      metadata: { flags: Record<string, { setFromDefault?: boolean } | undefined> };
     };
 
+    expect(flags.stability).to.equal(Stability.BETA);
+    expect(metadata.flags.stability?.setFromDefault).to.not.equal(true);
+  });
+
+  // What a language offers is per language, so the flag carries no default of its own: absent
+  // means unchosen, and the run resolves it against that language's own levels.
+  it('leaves stability unset when it was not asked for', async () => {
+    const { flags } = (await parse([])) as never as { flags: Record<string, unknown> };
+
+    expect(flags.stability).to.be.undefined;
+  });
+
+  it('keeps a stability the caller did ask for', async () => {
+    const { flags } = (await parse(['--stability', 'beta'])) as never as { flags: Record<string, unknown> };
+
+    expect(flags.stability).to.equal(Stability.BETA);
+  });
+
+  it('still parses the flags a publish is actually made of', async () => {
+    const { flags } = (await parse([
+      '--profile-id',
+      'a1b2c3d4e5f6a1b2c3d4e5f6',
+      '--language',
+      'typescript',
+      '--version',
+      '1.0.0',
+      '--publish-type',
+      'package'
+    ])) as never as { flags: Record<string, unknown> };
+
     expect(flags.language).to.equal('typescript');
+    expect(flags.version).to.equal('1.0.0');
   });
 });
diff --git a/test/infrastructure/services/sdk-generation-service.test.ts b/test/infrastructure/services/sdk-generation-service.test.ts
index 0e1c01ae3..3605b5716 100644
--- a/test/infrastructure/services/sdk-generation-service.test.ts
+++ b/test/infrastructure/services/sdk-generation-service.test.ts
@@ -108,31 +108,16 @@ describe('SdkGenerationService generation status polling', () => {
   const errorFrom = (result: { _unsafeUnwrapErr(): unknown }) => result._unsafeUnwrapErr() as ServiceError;
 
   describe('generateSdk', () => {
-    const generateSdk = () => service.generateSdk(buildPath, Language.TYPESCRIPT, configDir, metadata, AUTH_KEY);
+    const generateSdk = () => service.generateSdk(buildPath, Language.TYPESCRIPT, Stability.BETA, configDir, metadata, AUTH_KEY);
 
-    it('polls the sdk status path and downloads both artifacts once complete', async () => {
+    it('polls the v4 status path and downloads once complete', async () => {
       respondToStatus = (res) => redirectToDownload(res);
 
       const result = await generateSdk();
 
       expect(result.isOk(), 'generation should succeed').to.be.true;
-      const { sdk, sdkSourceTree } = result._unsafeUnwrap();
-      expect(await drain(sdk)).to.be.greaterThan(0);
-      expect(await drain(sdkSourceTree)).to.be.greaterThan(0);
-      expect(statusRequests.map((request) => request.url)).to.deep.equal([`/sdk/${GENERATION_ID}/status`]);
-    });
-
-    it('reports sdk merge conflicts with their own wording', async () => {
-      respondToStatus = statusBody({
-        status: Status.ValidationError,
-        errors: { sdkMergeFailed: ['java', 'python'] }
-      });
-
-      const result = await generateSdk();
-
-      expect(errorFrom(result).errorMessage).to.equal(
-        'SDK generation failed for these languages due to merge conflict.\n- java\n- python'
-      );
+      expect(await drain(result._unsafeUnwrap())).to.be.greaterThan(0);
+      expect(statusRequests.map((request) => request.url)).to.deep.equal([`/sdk/v2/${GENERATION_ID}/status`]);
     });
 
     it('passes through the HTML sdk generation embeds in messages', async () => {
@@ -148,28 +133,8 @@ describe('SdkGenerationService generation status polling', () => {
       expect(errorFrom(result).errorMessage).to.equal('One or more validation errors occurred.\n- ' + message);
     });
   });
-
-  describe('generateV4Sdk', () => {
-    it('polls the v4 sdk status path and downloads once complete', async () => {
-      respondToStatus = (res) => redirectToDownload(res);
-
-      const result = await service.generateV4Sdk(
-        buildPath,
-        Language.CSHARP,
-        Stability.BETA,
-        configDir,
-        metadata,
-        AUTH_KEY
-      );
-
-      expect(result.isOk(), 'generation should succeed').to.be.true;
-      expect(await drain(result._unsafeUnwrap() as NodeJS.ReadableStream)).to.be.greaterThan(0);
-      expect(statusRequests.map((request) => request.url)).to.deep.equal([`/sdk/v2/${GENERATION_ID}/status`]);
-    });
-  });
-
-  // Each flow names itself in the timeout message, so each one's wiring is pinned separately.
-  // Before the shared poller these three polled a stuck generation forever.
+  // The timeout message names the flow it came from, so its wiring is pinned here.
+  // Before the shared poller this polled a stuck generation forever.
   describe('giving up on a generation that never finishes', () => {
     const impatient = () => new SdkGenerationService({ pollIntervalMs: 1, generationTimeoutMs: 15 });
 
@@ -178,21 +143,7 @@ describe('SdkGenerationService generation status polling', () => {
     });
 
     it('bounds sdk generation', async () => {
-      const result = await impatient().generateSdk(buildPath, Language.TYPESCRIPT, configDir, metadata, AUTH_KEY);
-
-      expect(errorFrom(result).code).to.equal(ServiceErrorCode.Timeout);
-      expect(errorFrom(result).errorMessage).to.equal('SDK generation timed out.');
-    });
-
-    it('bounds v4 sdk generation', async () => {
-      const result = await impatient().generateV4Sdk(
-        buildPath,
-        Language.CSHARP,
-        Stability.BETA,
-        configDir,
-        metadata,
-        AUTH_KEY
-      );
+      const result = await impatient().generateSdk(buildPath, Language.TYPESCRIPT, Stability.BETA, configDir, metadata, AUTH_KEY);
 
       expect(errorFrom(result).code).to.equal(ServiceErrorCode.Timeout);
       expect(errorFrom(result).errorMessage).to.equal('SDK generation timed out.');
@@ -205,7 +156,7 @@ describe('SdkGenerationService generation status polling', () => {
 
       const bounded = new SdkGenerationService({ pollIntervalMs: 1, generationTimeoutMs: 5_000, requestTimeoutMs: 30 });
 
-      const result = await bounded.generateSdk(buildPath, Language.TYPESCRIPT, configDir, metadata, AUTH_KEY);
+      const result = await bounded.generateSdk(buildPath, Language.TYPESCRIPT, Stability.BETA, configDir, metadata, AUTH_KEY);
 
       expect(errorFrom(result).code).to.equal(ServiceErrorCode.NetworkError);
     });
diff --git a/test/prompts/format.test.ts b/test/prompts/format.test.ts
new file mode 100644
index 000000000..747b45a92
--- /dev/null
+++ b/test/prompts/format.test.ts
@@ -0,0 +1,40 @@
+import path from 'node:path';
+import { expect } from 'chai';
+import { format } from '../../src/prompts/format.js';
+import { DirectoryPath } from '../../src/types/file/directoryPath.js';
+
+// `DirectoryPath` resolves on construction, so every path the CLI holds is absolute. The commands
+// that print one for a reader to read or paste — `sdk generate`'s destination, the `cd` line in
+// `plugin publish` — want it as that reader would type it from where they are standing.
+describe('format.relative', () => {
+  const here = (...parts: string[]) => new DirectoryPath(path.join(process.cwd(), ...parts));
+
+  it('writes a directory below the current one as a relative path', () => {
+    expect(format.relative(here('plugin'))).to.equal('./plugin');
+  });
+
+  it('keeps posix separators on every platform, because the line is pasted into a shell', () => {
+    expect(format.relative(here('sdk', 'typescript'))).to.equal('./sdk/typescript');
+  });
+
+  // Above or outside the working directory there is no short form worth reading: `../../..` tells
+  // a reader less than the path itself.
+  it('leaves a directory outside the current one absolute', () => {
+    const outside = new DirectoryPath(path.resolve(process.cwd(), '..'));
+
+    expect(format.relative(outside)).to.equal(String(outside));
+  });
+
+  it('names the directory the command was run in as the one you are standing in', () => {
+    const cwd = new DirectoryPath(process.cwd());
+
+    expect(format.relative(cwd)).to.equal('.');
+  });
+
+  // `..cache` is a child, not a sibling: only a whole `..` segment leaves the directory.
+  it('keeps a child whose name merely begins with dots relative', () => {
+    const dotted = new DirectoryPath(process.cwd()).join('..cache');
+
+    expect(format.relative(dotted)).to.equal('./..cache');
+  });
+});
diff --git a/test/prompts/sdk/generate.test.ts b/test/prompts/sdk/generate.test.ts
index cfe08648a..6f5d75967 100644
--- a/test/prompts/sdk/generate.test.ts
+++ b/test/prompts/sdk/generate.test.ts
@@ -1,38 +1,51 @@
-import { expect } from "chai";
-import sinon from "sinon";
-import { log } from "@clack/prompts";
-import { SdkGeneratePrompts } from "../../../src/prompts/sdk/generate.js";
-import { CodeGenerationVersion, CodegenOption, Stability } from "../../../src/types/sdk/generate.js";
+import { expect } from 'chai';
+import sinon from 'sinon';
+import { log } from '@clack/prompts';
+import { SdkGeneratePrompts } from '../../../src/prompts/sdk/generate.js';
+import { Language } from '../../../src/types/sdk/generate.js';
 
-const v4 = CodegenOption.create(CodeGenerationVersion.V4, Stability.BETA);
-
-describe("SdkGeneratePrompts.warnIfStabilityIgnored", () => {
+describe('SdkGeneratePrompts.languageNotAvailable', () => {
   const prompts = new SdkGeneratePrompts();
-  let warn: sinon.SinonStub;
+  let error: sinon.SinonStub;
 
   beforeEach(() => {
-    warn = sinon.stub(log, "warn");
+    error = sinon.stub(log, 'error');
   });
 
   afterEach(() => {
-    warn.restore();
+    error.restore();
+  });
+
+  const messageFor = (language: Language): string => {
+    prompts.languageNotAvailable(language);
+    return error.firstCall.args[0] as string;
+  };
+
+  // The language the user asked for, under the name the rest of the CLI shows it by — not the
+  // flag value they typed, which is how every other list in this CLI would render it.
+  it('names the language that was asked for', () => {
+    expect(messageFor(Language.RUBY)).to.contain("Ruby isn't available yet.");
   });
 
-  it("warns when the flag was typed alongside codegen version v3", () => {
-    prompts.warnIfStabilityIgnored(CodegenOption.v3, true);
+  it('lists the three that can be generated now', () => {
+    const message = messageFor(Language.JAVA);
 
-    expect(warn.calledOnce).to.equal(true);
+    expect(message).to.contain('Available now: C#, TypeScript, Python');
   });
 
-  it("stays silent when the flag was only filled in from its default", () => {
-    prompts.warnIfStabilityIgnored(CodegenOption.v3, false);
+  // Naming them is the difference between "not yet" and "not ever", and the four that left with
+  // v3 are coming back.
+  it('lists the four that are on their way', () => {
+    const message = messageFor(Language.GO);
 
-    expect(warn.called).to.equal(false);
+    expect(message).to.contain('Coming soon: Ruby, Java, PHP, Go');
   });
 
-  it("stays silent on v4, where stability reaches the generation service", () => {
-    prompts.warnIfStabilityIgnored(v4, true);
+  // There is no version to fall back to any more, so nothing may suggest one.
+  it('offers no code generator to fall back to', () => {
+    const message = messageFor(Language.PHP);
 
-    expect(warn.called).to.equal(false);
+    expect(message).to.not.contain('v3');
+    expect(message).to.not.contain('codegen-version');
   });
 });
diff --git a/test/prompts/sdk/publish/publishing-details.test.ts b/test/prompts/sdk/publish/publishing-details.test.ts
index 08c19e71c..111b94788 100644
--- a/test/prompts/sdk/publish/publishing-details.test.ts
+++ b/test/prompts/sdk/publish/publishing-details.test.ts
@@ -1,53 +1,41 @@
-import { expect } from "chai";
-import { formatPublishingDetails } from "../../../../src/prompts/sdk/publish.js";
-import { PublishType } from "../../../../src/types/publish-api/publishing-profile-item.js";
-import { PublishingProfile } from "../../../../src/types/publish/publishing-profile.js";
-import { SemVersion } from "../../../../src/types/publish/version.js";
-import { CodeGenerationVersion, CodegenOption, Language, Stability } from "../../../../src/types/sdk/generate.js";
+import { expect } from 'chai';
+import { formatPublishingDetails } from '../../../../src/prompts/sdk/publish.js';
+import { PublishType } from '../../../../src/types/publish-api/publishing-profile-item.js';
+import { PublishingProfile } from '../../../../src/types/publish/publishing-profile.js';
+import { SemVersion } from '../../../../src/types/publish/version.js';
+import { Language } from '../../../../src/types/sdk/generate.js';
 
-const profile = { toString: () => "My Profile" } as unknown as PublishingProfile;
-const version = SemVersion.tryCreate("1.2.3")._unsafeUnwrap();
+const profile = { toString: () => 'My Profile' } as unknown as PublishingProfile;
+const version = SemVersion.tryCreate('1.2.3')._unsafeUnwrap();
 
-const details = (publishType: PublishType[], codegenOption?: CodegenOption) =>
+const details = (publishType: PublishType[]) =>
   formatPublishingDetails({
     profile,
     language: Language.CSHARP,
     version,
-    publishType,
-    codegenOption
+    publishType
   });
 
-describe("formatPublishingDetails", () => {
-  it("renders the profile, language, version and targets", () => {
-    const output = details([PublishType.PackagePublishing], CodegenOption.v3);
-
-    expect(output).to.contain("Profile:   My Profile");
-    expect(output).to.contain("Language:  csharp");
-    expect(output).to.contain("Version:   1.2.3");
-    expect(output).to.contain("Targets:   Package");
-  });
-
-  it("omits the generator row when no codegen option is given, leaving pre-existing output unchanged", () => {
+describe('formatPublishingDetails', () => {
+  it('renders the profile, language, version and targets', () => {
     const output = details([PublishType.PackagePublishing]);
 
-    expect(output).to.not.contain("Generator:");
+    expect(output).to.contain('Profile:   My Profile');
+    expect(output).to.contain('Language:  csharp');
+    expect(output).to.contain('Version:   1.2.3');
+    expect(output).to.contain('Targets:   Package');
   });
 
-  it("names the generator once it is no longer the default", () => {
-    const output = details(
-      [PublishType.PackagePublishing],
-      CodegenOption.create(CodeGenerationVersion.V4, Stability.BETA)
-    );
+  it('names both targets when a run publishes both', () => {
+    const output = details([PublishType.SourceCodePublishing, PublishType.PackagePublishing]);
 
-    expect(output).to.contain("Generator: V4 (beta)");
+    expect(output).to.contain('Targets:   Source Code + Package');
   });
 
-  it("reports v3 as stable even when beta was requested", () => {
-    const output = details(
-      [PublishType.PackagePublishing],
-      CodegenOption.create(CodeGenerationVersion.V3, Stability.BETA)
-    );
+  // There is one code generator now, so naming it would be a row that never changes.
+  it('says nothing about the code generator', () => {
+    const output = details([PublishType.PackagePublishing]);
 
-    expect(output).to.contain("Generator: V3 (stable)");
+    expect(output).to.not.contain('Generator');
   });
 });
diff --git a/test/types/apimatic-config/schema.test.ts b/test/types/apimatic-config/schema.test.ts
index 5856f2cf7..e492b6b45 100644
--- a/test/types/apimatic-config/schema.test.ts
+++ b/test/types/apimatic-config/schema.test.ts
@@ -10,7 +10,7 @@ import {
 import { COLOR_MODES } from '../../../src/types/portal/config/brand-config';
 import { PortalConfig } from '../../../src/types/portal/portal-config';
 import { PortalLanguages } from '../../../src/types/portal/portal-languages';
-import { CodeGenerationVersion, Language } from '../../../src/types/sdk/generate';
+import { Language } from '../../../src/types/sdk/generate';
 
 /** As much of a schema object as the walks below read. */
 interface SchemaNode {
@@ -60,12 +60,7 @@ describe('apimatic.schema.json', () => {
 
     const cases: [string, unknown, readonly string[]][] = [
       ['brand.colorMode', brand.colorMode.enum, COLOR_MODES],
-      ['languages', schema.definitions.languages.propertyNames.enum, Object.values(Language)],
-      [
-        'languages.*.publishing.codegenVersion',
-        schema.definitions.languageEntry.properties.publishing.properties.codegenVersion.enum,
-        Object.values(CodeGenerationVersion)
-      ]
+      ['languages', schema.definitions.languages.propertyNames.enum, Object.values(Language)]
     ];
 
     for (const [setting, offered, accepted] of cases) {
@@ -268,7 +263,7 @@ describe('apimatic.schema.json', () => {
       ['a language wanted but not yet published', { typescript: {} }],
       [
         'a published language',
-        { python: { publishing: { package: { name: 'calc', version: '1.0.0' }, codegenVersion: 'v4' } } }
+        { python: { publishing: { package: { version: '1.0.0' }, packageConfiguration: { name: 'calc' } } } }
       ],
       [
         'keys this CLI does not model, beside and inside the record',
@@ -306,7 +301,7 @@ describe('apimatic.schema.json', () => {
 
     // The portal reads only which languages there are; the record is typed for the editor.
     it('types the publishing record, which the portal does not read', () => {
-      const languages = { csharp: { publishing: { codegenVersion: 'v9' } } };
+      const languages = { csharp: { publishing: { source: 'github.com/acme/calc' } } };
 
       expect(languagesAccepted(languages)).to.be.true;
       expect(schemaVerdict({ languages }).valid).to.be.false;
diff --git a/test/types/plugin-config-context.test.ts b/test/types/plugin-config-context.test.ts
index 6606d9221..31643c1e8 100644
--- a/test/types/plugin-config-context.test.ts
+++ b/test/types/plugin-config-context.test.ts
@@ -4,15 +4,8 @@ import path from 'path';
 import { expect } from 'chai';
 import { PluginConfigContext, PluginConfigState } from '../../src/types/plugin-config-context';
 import { DirectoryPath } from '../../src/types/file/directoryPath';
-import {
-  LanguagePublishingEntry,
-  PluginIdentityData,
-  PluginLanguages
-} from '../../src/types/plugin/plugin-config';
-import {
-  CSharpPackageConfiguration,
-  TypeScriptPackageConfiguration
-} from '../../src/types/publish/package-settings-configuration';
+import { LanguagePublishingEntry, PluginIdentityData, PluginLanguages } from '../../src/types/plugin/plugin-config';
+import { CSharpPackageConfiguration } from '../../src/types/publish/package-settings-configuration';
 import { Language } from '../../src/types/sdk/generate';
 
 /** The file as written back, read whole: the plugin blocks and whatever sits around them. */
@@ -299,7 +292,6 @@ describe('PluginConfigContext', () => {
     });
   });
 
-
   describe('upsertMetadata', () => {
     it('creates the file with the plugin block, the metadata and a default licence', async () => {
       expect((await context.upsertMetadata(METADATA)).isOk()).to.be.true;
@@ -408,138 +400,6 @@ describe('PluginConfigContext', () => {
       expect(state.hasMetadata()).to.be.true;
       expect(state.publishedLanguages()).to.be.empty;
     });
-
-    it('reports the language it just wrote, alongside metadata written earlier', async () => {
-      withConfig({ plugin: METADATA, languages: {} });
-
-      const state = (await context.upsertLanguage(Language.CSHARP, CSHARP_ENTRY))._unsafeUnwrap();
-
-      expect(state.publishedLanguages()).to.not.be.empty;
-      expect(state.hasMetadata()).to.be.true;
-      expect(state.hasNoSourceRepository(Language.CSHARP)).to.be.false;
-    });
-  });
-
-  describe('upsertLanguage', () => {
-    it('creates the file with the languages block and no plugin block at all', async () => {
-      expect((await context.upsertLanguage(Language.CSHARP, CSHARP_ENTRY)).isOk()).to.be.true;
-      expect(writtenDocument()).to.deep.equal({
-        schemaVersion: 1,
-        languages: { csharp: CSHARP_ENTRY }
-      });
-    });
-
-    it('adds a second language beside the first', async () => {
-      withConfig({ languages: { csharp: CSHARP_ENTRY } });
-
-      const typescriptEntry = {
-        publishing: {
-          source: { repositoryUrl: 'https://github.com/acme/acme-payments-typescript' },
-          package: { version: '1.2.3' }, packageConfiguration: { name: '@acme/payments-sdk' } as TypeScriptPackageConfiguration
-        }
-      } satisfies NonNullable<PluginLanguages['typescript']>;
-      await context.upsertLanguage(Language.TYPESCRIPT, typescriptEntry);
-
-      expect(writtenDocument().languages).to.deep.equal({ csharp: CSHARP_ENTRY, typescript: typescriptEntry });
-    });
-
-    it('replaces both halves when the run published both', async () => {
-      withConfig({ languages: { csharp: { publishing: { source: { repositoryUrl: 'https://old' } } } } });
-
-      await context.upsertLanguage(Language.CSHARP, CSHARP_ENTRY);
-
-      expect(writtenDocument().languages).to.deep.equal({ csharp: CSHARP_ENTRY });
-    });
-
-    describe('keeps the half the run did not publish', () => {
-      it('carries the recorded package over a source-only publish', async () => {
-        withConfig({ languages: { csharp: CSHARP_ENTRY } });
-
-        await context.upsertLanguage(Language.CSHARP, {
-          publishing: {
-            source: { repositoryUrl: 'https://github.com/acme/renamed' }
-          }
-        });
-
-        expect(writtenDocument().languages?.csharp).to.deep.equal({
-          publishing: {
-            source: { repositoryUrl: 'https://github.com/acme/renamed' },
-            package: CSHARP_PUBLISHING.package,
-            packageConfiguration: CSHARP_CONFIGURATION
-          }
-        });
-      });
-
-      it('carries the recorded source over a package-only publish', async () => {
-        withConfig({ languages: { csharp: CSHARP_ENTRY } });
-
-        await context.upsertLanguage(Language.CSHARP, {
-          publishing: {
-            package: { version: '2.0.0' }, packageConfiguration: { packageId: 'Acme.Payments.Sdk' } as CSharpPackageConfiguration
-          }
-        });
-
-        expect(writtenDocument().languages?.csharp).to.deep.equal({
-          publishing: {
-            source: CSHARP_PUBLISHING.source,
-            package: { version: '2.0.0' }, packageConfiguration: { packageId: 'Acme.Payments.Sdk' } as CSharpPackageConfiguration
-          }
-        });
-      });
-
-      it('records the entry as it stands when the language is new to the config', async () => {
-        withConfig({ languages: {} });
-
-        await context.upsertLanguage(Language.CSHARP, {
-          publishing: {
-            package: { version: '2.0.0' }, packageConfiguration: { packageId: 'Acme.Payments.Sdk' } as CSharpPackageConfiguration
-          }
-        });
-
-        expect(writtenDocument().languages?.csharp).to.deep.equal({
-          publishing: {
-            package: { version: '2.0.0' }, packageConfiguration: { packageId: 'Acme.Payments.Sdk' } as CSharpPackageConfiguration
-          }
-        });
-      });
-
-      it('still takes the codegen version from the run that just published', async () => {
-        withConfig({ languages: { csharp: CSHARP_ENTRY } });
-
-        await context.upsertLanguage(Language.CSHARP, {
-          publishing: {
-            package: { version: '2.0.0' }, packageConfiguration: { packageId: 'Acme.Payments.Sdk' } as CSharpPackageConfiguration
-          }
-        });
-
-        expect(writtenDocument().languages?.csharp?.publishing?.package).to.deep.equal({ version: '2.0.0' });
-      });
-    });
-
-    it('leaves the existing plugin block untouched', async () => {
-      withConfig({ plugin: { ...METADATA, license: 'MIT' }, languages: {} });
-
-      await context.upsertLanguage(Language.CSHARP, CSHARP_ENTRY);
-
-      expect(writtenDocument().plugin).to.deep.equal({ ...METADATA, license: 'MIT' });
-    });
-
-    // A publish that succeeded is recorded whatever state the portal is in.
-    it('records past a portal block it cannot read, leaving it as written', async () => {
-      withConfig({ portal: 'not a portal', languages: {} });
-
-      expect((await context.upsertLanguage(Language.CSHARP, CSHARP_ENTRY)).isOk()).to.be.true;
-      expect(writtenDocument().portal).to.equal('not a portal');
-      expect(writtenDocument().languages).to.deep.equal({ csharp: CSHARP_ENTRY });
-    });
-
-    it('refuses a languages block it cannot merge rather than spreading it into the file', async () => {
-      const original = JSON.stringify({ languages: 'csharp' });
-      withFile(original);
-
-      expect((await context.upsertLanguage(Language.CSHARP, CSHARP_ENTRY))._unsafeUnwrapErr()).to.equal('unreadable');
-      expect(written()).to.equal(original);
-    });
   });
 
   describe('recordLanguages', () => {
diff --git a/test/types/sdk/generate.test.ts b/test/types/sdk/generate.test.ts
index 7ab3ab173..90eaee309 100644
--- a/test/types/sdk/generate.test.ts
+++ b/test/types/sdk/generate.test.ts
@@ -1,21 +1,21 @@
 import { expect } from 'chai';
 import {
-  isPluginLanguage,
+  AVAILABLE_LANGUAGES,
+  isAvailableLanguage,
   Language,
   LANGUAGE_CHOICES,
-  PLUGIN_LANGUAGES,
   UPCOMING_LANGUAGES
 } from '../../../src/types/sdk/generate';
 
 // `UPCOMING_LANGUAGES` is derived from the two lists above it. These are the properties that
 // derivation buys, and the reason neither list is maintained by hand.
-describe('the languages a plugin can carry', () => {
+describe('the languages a generator renders', () => {
   it('accounts for every language exactly once', () => {
-    expect([...PLUGIN_LANGUAGES, ...UPCOMING_LANGUAGES]).to.have.members(Object.values(Language));
+    expect([...AVAILABLE_LANGUAGES, ...UPCOMING_LANGUAGES]).to.have.members(Object.values(Language));
   });
 
-  it('names no language as both carried and upcoming', () => {
-    const both = UPCOMING_LANGUAGES.filter((language) => PLUGIN_LANGUAGES.includes(language));
+  it('names no language as both available and upcoming', () => {
+    const both = UPCOMING_LANGUAGES.filter((language) => AVAILABLE_LANGUAGES.includes(language));
 
     expect(both).to.be.empty;
   });
@@ -30,8 +30,8 @@ describe('the languages a plugin can carry', () => {
   });
 
   it('answers for a language named in a config file, not just one already typed', () => {
-    expect(isPluginLanguage('typescript')).to.be.true;
-    expect(isPluginLanguage('java')).to.be.false;
-    expect(isPluginLanguage('cobol')).to.be.false;
+    expect(isAvailableLanguage('typescript')).to.be.true;
+    expect(isAvailableLanguage('java')).to.be.false;
+    expect(isAvailableLanguage('cobol')).to.be.false;
   });
 });
diff --git a/test/types/sdk/stability.test.ts b/test/types/sdk/stability.test.ts
new file mode 100644
index 000000000..c13b3fedc
--- /dev/null
+++ b/test/types/sdk/stability.test.ts
@@ -0,0 +1,31 @@
+import { expect } from 'chai';
+import {
+  AVAILABLE_LANGUAGES,
+  defaultStability,
+  Language,
+  Stability,
+  stabilityLevelsFor
+} from '../../../src/types/sdk/generate';
+
+// The flag's own default is one string for every language. What a language actually offers is
+// what an unasked run has to send, or the service refuses a request the caller did nothing to
+// shape: v4 renders every language it supports at both levels, and the first is what it sends.
+describe('the stability a language offers', () => {
+  it('offers both levels for every language v4 renders', () => {
+    for (const language of AVAILABLE_LANGUAGES) {
+      expect([...stabilityLevelsFor(language)], language).to.deep.equal([Stability.STABLE, Stability.BETA]);
+    }
+  });
+
+  it('defaults each of them to stable, which is the level a caller who says nothing means', () => {
+    for (const language of AVAILABLE_LANGUAGES) {
+      expect(defaultStability(language), language).to.equal(Stability.STABLE);
+    }
+  });
+
+  // A language with no table entry is not generatable at all, so the fallback only has to be a
+  // level the service knows rather than the right one.
+  it('falls back to stable for a language with no table entry', () => {
+    expect(defaultStability(Language.JAVA)).to.equal(Stability.STABLE);
+  });
+});