🤖 fix: GPT-5.6 Sol promotional pricing and GPT-6 Astra Codex context cap

[ThomasK33]

Summary

Reconciles two OpenAI catalog entries with their first-party sources: GPT-5.6 Sol now prices at OpenAI's current promotional rates, and GPT-6 Astra's Codex OAuth context cap drops from 372K to the catalog's 272K.

Background

Both discrepancies were found while validating #4259 and tracked in #4347.

Pricing source. OpenAI API pricing, fetched 2026-09-26. GPT-5.6 Sol (per 1M tokens):

	Input	Cached input	Cache writes	Output
Short context (≤272K)	$4.00	$0.40	$5.00	$20.00
Long context (>272K)	$8.00	$0.80	$10.00	$30.00

The page says "GPT-5.6 Sol's promotional pricing is available at least through November 21, 2026." The previous entry ($5/$30/$0.50/$6.25; long context $10/$45/$1/$12.50) was the standard rate. The multipliers (2x input, 1.5x output, 1.25x cache writes, 272K boundary) are unchanged.

Catalog source. openai/codex@04fc75ad models.json, the pin the repo already cites: gpt-6-astra has context_window: 272000 and max_context_window: 872000. openai/codex main (checked 2026-09-26) has the same values.

Implementation

• models-extra.ts: GPT_56_SOL_STATS (shared by gpt-5.6-sol and the bare gpt-5.6 alias) now uses the promo rates.
• Time-limited pricing follows the most recent repo precedent (Gemini 3.7/3.8 Flash intro rates): encode the rate actually billed, with a dated TODO(2026-11-21) that records the standard rates and the source. No new mechanism. The older precedent (Claude Sonnet 5, DeepSeek V4 Pro) listed the standard rate instead. I picked the billed rate because the issue asks for it, the promotion has no fixed end date, and the pricing page no longer shows a standard rate for Sol.
• codexOAuth.ts: gpt-6-astra 372K → 272K, with the pin cited next to Sol/Luna. Public API windows (1.05M) and user-mapped models are unchanged: the cap applies only when a request actually routes through Codex OAuth.

Validation

Tests were changed first and failed on main:

• displayUsage.test.ts › "applies %s pricing only above the 272K boundary" now includes openai:gpt-5.6-sol and openai:gpt-5.6. It checks 272,000 vs 272,001 prompt tokens and now also checks cache writes (1.25x the active input rate), so the boundary is shown to move input, cache-read, cache-write and output rates together.
• codexOAuth.test.ts (Astra override) and contextLimit.test.ts › "caps GPT-6 Astra on the OAuth route but keeps the API window for API-key auth" (272K on OAuth, 1.05M with API-key auth).
• modelStats.test.ts base-rate row for Sol updated. Its long-context assertions are multipliers of the base rates, so they checked the new values unchanged.

Pre-fix failures

Expected: 272000
Received: 372000
(fail) codexOAuth model gating > allows gpt-6-astra through Codex OAuth with a 272000 context cap
Expected: 0.668
Received: 0.8350000000000001
(fail) createDisplayUsage > tiered long-context pricing > applies openai:gpt-5.6-sol pricing only above the 272K boundary [1.00ms]
(fail) createDisplayUsage > tiered long-context pricing > applies openai:gpt-5.6 pricing only above the 272K boundary
(fail) getEffectiveContextLimit > caps GPT-6 Astra on the OAuth route but keeps the API window for API-key auth
 60 pass
 4 fail

After the fix, bun test src/common passes (2380 tests) and make static-check passes.

Risks

Low. Sol cost estimates and goal budgets drop by 20–33% until the promotion ends. The dated TODO marks when to restore them. OAuth-routed Astra now starts limit-driven compaction at 272K instead of 372K.

Deferred

• The GPT-5.6 family Codex caps (372K since [openai] 🤖 fix: use 372K GPT-5.6 OAuth context #3730) also differ from the catalog (272K). Out of scope here: tracked in 🤖 fix: reconcile GPT-5.6 family Codex OAuth context caps with the Codex catalog #4683.

Fixes #4347

---

Generated with xum • Model: anthropic:claude-opus-5-5 • Thinking: high

[ThomasK33]

@codex review

[ThomasK33]

@codex security review

[chatgpt-codex-connector]

Codex Review Summary

This comment shows the latest Codex review activity on this pull request.

Review	Status	Commit	Review trigger
📝 Code Review	✅ Completed 2026-09-26T17:57:16.974835Z	c0204dc	Manual request
🔒 Security Review	✅ Completed 2026-09-26T17:58:06.495335Z	c0204dc	Manual request

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review" or "@codex security review".

Codex reacts with 👀 while any review is running, comments if it has suggestions, and reacts with 👍 once all reviews finish with no findings.

[chatgpt-codex-connector]

Codex Review: Didn't find any major issues. 🚀

Reviewed commit: c0204dc46e

ℹ️ About Codex in GitHub

Your team has set up Codex to review pull requests in this repo. Reviews are triggered when you

• Open a pull request for review
• Mark a draft as ready
• Comment "@codex review".

If Codex has suggestions, it will comment; otherwise it will react with 👍.

Codex can also answer questions or update the PR. Try commenting "@codex address that feedback".

[chatgpt-codex-connector]

🛡️ Codex Security Review

Security review completed. No security issues were found in this pull request.

Reviewed commit: c0204dc46e

View security finding report

Only the user who started this review can view the report in Codex.

ℹ️ About Codex security reviews in GitHub

This is an experimental Codex feature. Security reviews are triggered when:

• You comment "@codex security review"
• A regular code review gets triggered (for example, "@codex review" or when a PR is opened), and you’re opted in so security review runs alongside code review

Once complete, Codex will leave suggestions, or a comment if no findings are found.