## TL;DR

Upgrade the Atlas CLI to a release newer than 1.29.0, the maintainers fixed the payload shape for local-deployment vector search indexes right after this was reported, and the reporter confirmed it works on the fixed build.

## Steps

1. Upgrade the Atlas CLI to a release newer than 1.29.0, the maintainers fixed the payload shape for local-deployment vector search indexes right after this was reported, and the reporter confirmed it works on the fixed build. Keep the index definition as in the docs (`type: vectorSearch` with a `definition.fields` array); no JSON reshaping is needed on fixed versions.

## When to use

You are seeing this: Creating a vector search index on an Atlas local deployment with atlas deployments search indexes create fails with Error: (UnknownError) "userCommand.indexes[0].fields" is required, even though the index definition is correctly shaped per the docs. Use this skill when you run into "Atlas CLI: vector search index on local deployments fails with "userCommand.indexes[0].fields is required"".

## When not to use

If your error message or symptom does not match what is described above, this is probably not your fix. Search for your exact error text instead of forcing this one to fit.

## Versions

Versions mentioned in the source: 1.29.0. If you are on something much newer or older, the details may have shifted.

## Why this happens

Creating a vector search index on an Atlas local deployment with atlas deployments search indexes create fails with Error: (UnknownError) "userCommand.indexes[0].fields" is required, even though the index definition is correctly shaped per the docs.