# Jaeger v2.21.0

> Observability · 2026-09-14

A feature-rich release with breaking API and configuration changes, expanded experimental query and storage capabilities, and many correctness fixes. It also includes routine dependency updates.

## Action needed
- **[breaking]** The `searchdepth` constraint
  - Query handling caps `searchdepth` at 10000 and rejects negative values.

## Check if affected
- **[breaking]** Removal of the `v1 http endpoints`
  - Applies if you use `v1 http endpoints`.
  - The query component removes the `v1 http endpoints` that the UI no longer calls.
- **[breaking]** The `ai.enable_mcp` configuration, replaced by `ai.mcp`
  - Applies if you configure `ai.enable_mcp`.
  - The configuration replaces `ai.enable_mcp` with an optional `ai.mcp` config block.
- **[breaking]** Elasticsearch configuration key validation
  - Applicability is not stated in the release notes.
  - Startup now rejects five unsupported Elasticsearch configuration keys.
- **[breaking]** Storage backend query validation
  - Applicability is not stated in the release notes.
  - The query component rejects searches that the storage backend cannot serve.

## Other recorded changes
- 64 (defect_corrected 29, added 18, value_changed 10, constraint_changed 3, renamed 2, removed 1, default_changed 1)

[Full analysis](https://ratatosk.io/en/releases/jaeger/v2.21.0)

[Original release notes](https://github.com/jaegertracing/jaeger/releases/tag/v2.21.0)