---
title: "Patch message metadata"
method: PATCH
path: "/session/{session_id}/messages/{message_id}/meta"
tags: ["session"]
---

# Patch message metadata

`PATCH /session/{session_id}/messages/{message_id}/meta`

Update message metadata using patch semantics. Only updates keys present in the request. Pass null as value to delete a key.

## Path parameters

- `session_id` string, uuid, required
- `message_id` string, uuid, required

## Request body

- HandlerPatchMessageMetaReq
  - `meta` object, required

## Response `200`

OK

- object
  - `code` integer
  - `error` string
  - `msg` string
  - `data` HandlerPatchMessageMetaResp
    - `meta` object

## Other responses

- `400` — Invalid request
- `404` — Message not found

## Changes

- **2026-02-03** `d9c864d0dc7d` — 1 info
  - endpoint added
- **2025-11-12** `a1c1bcb0e2ee` — 1 breaking
  - api path removed without deprecation

[Change history](https://skmtc.dev/memodb-io/apis/acontext-api/changes/session/:session_id/messages/:message_id/meta/patch.md)

---

[API](https://skmtc.dev/memodb-io/apis/acontext-api.md) · [All operations](https://skmtc.dev/memodb-io/apis/acontext-api/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/memodb-io/acontext-api/revisions/c8775333b1ed/schema)