**TL;DR:** The query names an index that does not exist, is the wrong type, or is still building. Check getSearchIndexes before touching the query. Confirm Run db.[collection].getSearchIndexes(). Check three things: 1.

## The error

```text
index not found
```

## The fix

1. The name matches exactly, including case.

2. The `type` is `vectorSearch`, not `search`. A full-text index cannot serve `$vectorSearch`.

3. The `status` is `READY`. `BUILDING` or `FAILED` explains everything.

4. Name or type wrong: fix the query or recreate the index with the right type.

5. Still building: wait. Poll `getSearchIndexes()` until READY. Large collections take a while.

6. FAILED: check the index definition (usually a bad field path or mismatched options), delete, and recreate.

## When to use this

- You are seeing this exact error message; match the block above, not just part of it.
- The failing call matches the scenario in the title: Atlas error.
- You want the fastest verified fix before digging through logs.

## When not to use this

- Your error text differs from the block above; close cousins often have different causes.
- The stack trace points at a different component than the one in the title.
- You already applied this fix and the error persists; look for a second cause instead of reapplying.

## Compatibility

- Not pinned to a specific version; follows current Atlas behavior.

## Also seen as

- `FAILED`