---
title: "Update Thread"
method: PATCH
path: "/v0/inboxes/{inbox_id}/threads/{thread_id}"
tags: ["InboxesThreads"]
---

# Update Thread

`PATCH /v0/inboxes/{inbox_id}/threads/{thread_id}`

Updates thread labels. Cannot add or remove system labels (sent, received, bounced, etc.). Rejects requests with a `422` for threads with 100 or more messages.

## Path parameters

- `inbox_id` string, required — The ID of the inbox.
- `thread_id` string, required — ID of thread.

## Request body

- UpdateThreadRequest
  - `add_labels` string[], nullable — Labels to add to thread. Cannot be system labels.
  - `remove_labels` string[], nullable — Labels to remove from thread. Cannot be system labels. Takes priority over `add_labels` (in the event of duplicate labels passed in).

## Response `200`

- UpdateThreadResponse
  - `thread_id` string, required — ID of thread.
  - `labels` string[], required — Labels of thread.

## Other responses

- `400`
- `404`
- `422`

## Changes

- **2026-07-15** `394ddcdd9c29` — 10 info
  - added the optional property `code` to the response with the `400` status
  - added the optional property `code` to the response with the `404` status
  - added the optional property `code` to the response with the `422` status
  - added the optional property `docs` to the response with the `400` status
  - …6 more
- **2026-03-31** `27965096e618` — 1 info
  - endpoint added

[Change history](https://skmtc.dev/agentmail-to/apis/api/changes/v0/inboxes/:inbox_id/threads/:thread_id/patch.md)

---

[API](https://skmtc.dev/agentmail-to/apis/api.md) · [All operations](https://skmtc.dev/agentmail-to/apis/api/llms.txt) · [OpenAPI document](https://skmtc-service-production.skmtc.workers.dev/v1/apis/agentmail-to/api/revisions/394ddcdd9c29/schema)