Optimistic entities not cleared after insert

I've validated the bug against the latest version of DB packages

Describe the bug
TLDR: after the onInsert runs, optimistic state passed into collection.insert isn't cleared out

I have a simple onInsert handler

    onInsert: async ({ transaction }) => {
      return Promise.all(
        transaction.mutations.map(async (mutation) => {
          const { modified } = mutation;
          return postApi({
            endpoint: '/locations',
            body: {
              name: modified.name ?? '',
            },
          });
        })
      );
    },

Which is run when I do the following

          const tx = locationCollection.insert({
            created: String(Date.now()),
            deleted: null,
            id: String(Math.random() * 10000),
            name: value.name.trim(),
          });
          await tx.isPersisted.promise;

After onInsert runs, I have both of these entities listed in the collection

Here is the query that I am using to display that collection data

  const locationsQuery = useLiveQuery((q) =>
    q
      .from({ location: locationsCollection })
      .where(({ location }) => isNull(location.deleted))
  );

To Reproduce
Here's the order of events locally

Load the query
Perform an action to add location (the entity I am working with)
onInsert runs
optimistic + new synced entity remain in the collection (or at least the return value from the useLiveQuery)

Expected behavior

"The optimistic state is held until the handler resolves, at which point the data is persisted to the server and synced back" I expect the server data to be synced back, replacing the optimistic data, not appended adjacent to it

Desktop (please complete the following information):

Device: Apple m3 pro
OS: Tahoe 26.3.1
Browser: Brave
Version:
- Brave 1.87.191
- Chromium: 145.0.7632.120

Smartphone (please complete the following information):
n/a

Additional context

This is my getKey function (if relevant)
getKey: (location) => location.id,

I presume it is related to this issue: #1442

If I change getKey to a value that is stable between local and remove versions (like location.name) then I don't see this issue, but based off the following, I should be able to safely set this to an id / should only be relevant for update/delete operations

     * Function to extract the ID from an object
     * This is required for update/delete operations which now only accept IDs
     * @param item The item to extract the ID from
     * @returns The ID string for the item
     * @example
     * // For a collection with a 'uuid' field as the primary key
     * getKey: (item) => item.uuid
     */

I have the same issue 🙁

@samwillis

@samwillis sorry to be a bother, but this is a pretty bad regression. Can we get this looked into today? Seems like there are quite a few people seeing this.

Same issue over here

I think it might have the same root cause as #1442 - which is now fixed by #1547, released in @tanstack/db@0.6.7 on 2026-05-23.

@am1006

Ah thanks @am1006

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Optimistic entities not cleared after insert #1464

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Optimistic entities not cleared after insert #1464

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willbowdler-cc commented on Apr 8, 2026

willbowdler-cc commented on Apr 8, 2026

andorep commented on Apr 14, 2026

willbowdler-cc commented on Apr 14, 2026

n0119566 commented on May 2, 2026

am1006 commented on May 24, 2026

KyleAMathews commented on May 24, 2026

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