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Get Session Thread

get/v1/sessions/{session_id}/threads/{thread_id}?beta=true

Path parameters

session_idstring required

Path parameter session_id

thread_idstring required

Path parameter thread_id

Headers

x-api-keystring
anthropic-versionstring
anthropic-betastring

Response

Successful response (OK)

type'session_thread' required
idstring required

Unique identifier for this thread.

session_idstring required

The session this thread belongs to.

status'running' | 'idle' | 'rescheduling' | 'terminated' required

SessionThreadStatus enum

parent_thread_idstring nullable required

Parent thread that spawned this thread. Null for the primary thread.

created_atstring date-time required

A timestamp in RFC 3339 format

updated_atstring date-time required

A timestamp in RFC 3339 format

archived_atstring date-time required

A timestamp in RFC 3339 format

Example response

{
  "type": "session_thread",
  "id": "sthr_011CZkZVWa6oIjw0rgXZpnBt",
  "session_id": "sesn_011CZkZAtmR3yMPDzynEDxu7",
  "status": "idle",
  "agent": {
    "type": "agent",
    "id": "agent_011CZkYqphY8vELVzwCUpqiQ",
    "version": 1,
    "name": "Researcher",
    "description": "A focused research subagent.",
    "model": {
      "id": "claude-opus-5",
      "speed": "standard"
    },
    "system": "You are a research subagent that gathers and summarises sources for the coordinating agent.",
    "tools": [
      {
        "type": "agent_toolset_20260401",
        "default_config": {
          "enabled": true,
          "permission_policy": {
            "type": "always_ask"
          }
        },
        "configs": []
      }
    ],
    "mcp_servers": [],
    "skills": []
  },
  "parent_thread_id": null,
  "created_at": "2026-03-15T10:00:00Z",
  "updated_at": "2026-03-15T10:00:00Z",
  "archived_at": null,
  "usage": {
    "input_tokens": 0,
    "output_tokens": 0,
    "cache_read_input_tokens": 0,
    "cache_creation": {
      "ephemeral_5m_input_tokens": 0,
      "ephemeral_1h_input_tokens": 0
    }
  },
  "stats": {
    "duration_seconds": 0,
    "startup_seconds": 0,
    "active_seconds": 0
  }
}

Changes

Changed in 12 of the 68 revisions of this API.827

  • d1d189d791d11See the full diff
    • ○

      added subschema #2 to the ////////// response property anyOf list for the response status

      response-property-any-of-added

    This revision also has 1 change that name no endpoint, such as unreferenced schemas being removed. See the revision's changelog

  • a5822939dde42See the full diff
    • ○

      added to the response property allOf list for the response status

      response-property-all-of-added

    • ○

      removed from the response property allOf list for the response status

      response-property-all-of-removed

  • 0042750ea1ee41See the full diff
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      added to the //////////////// response property oneOf list for the response status

      response-property-one-of-added

    • ▲

      removed the required property ///////////////// from the response with the status

      response-required-property-removed

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      removed the required property ///////////////// from the response with the status

      response-required-property-removed

    • ▲

      removed the required property ///////////////// from the response with the status

      response-required-property-removed

    • ○

      added discriminator to //////////////// response property for the response status

      response-property-discriminator-added

  • d2b230555b7f36See the full diff
    • ▲

      response property agent/allOf[BetaManagedAgentsSessionRosterEntry]/oneOf[BetaManagedAgentsSessionThreadAgent]/description list-of-types was widened by adding types null to media type application/json of response 200

      response-property-list-of-types-widened

    • ▲

      response property agent/allOf[BetaManagedAgentsSessionRosterEntry]/oneOf[BetaManagedAgentsSessionThreadAgent]/system list-of-types was widened by adding types null to media type application/json of response 200

      response-property-list-of-types-widened

    • ▲

      response property parent_thread_id list-of-types was widened by adding types null to media type application/json of response 200

      response-property-list-of-types-widened

    • ○

      removed from the response property allOf list for the response status

      response-property-all-of-removed

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      removed from the response property allOf list for the response status

      response-property-all-of-removed

    • ○

      removed from the response property allOf list for the response status

      response-property-all-of-removed

    • ○

      added subschema #2 to the response property anyOf list for the response status

      response-property-any-of-added

    • ○

      added subschema #2 to the response property anyOf list for the response status

      response-property-any-of-added

    • ○

      added subschema #2 to the response property anyOf list for the response status

      response-property-any-of-added

  • 93d8fd7d64935See the full diff
    • ○

      added the optional property ///// to the response with the status

      response-optional-property-added

    • ○

      added the optional property ///// to the response with the status

      response-optional-property-added

    • ○

      added the optional property ///// to the response with the status

      response-optional-property-added

    • ○

      added to the response property allOf list for the response status

      response-property-all-of-added

    • ○

      removed from the response property allOf list for the response status

      response-property-all-of-removed

    This revision also has 1 change that name no endpoint, such as unreferenced schemas being removed. See the revision's changelog

  • a97790bd7f182See the full diff
    • ○

      added subschema #4 subschema #5 subschema #6 subschema #7 subschema #11 subschema #12 to the ////// response property anyOf list for the response status

      response-property-any-of-added

    • ○

      removed subschema #4 subschema #5 subschema #6 subschema #10 subschema #11 from the ////// response property anyOf list for the response status

      response-property-any-of-removed

  • 5e4a8830793b1See the full diff
    • ○

      added the optional property ////// to the response with the status

      response-optional-property-added

    This revision also has 7 changes that name no endpoint, such as unreferenced schemas being removed. See the revision's changelog

  • 7caa9a75ddbc1See the full diff
    • ○

      added subschema #2 to the ////// response property anyOf list for the response status

      response-property-any-of-added

  • 00259327305f1See the full diff
    • ○

      added subschema #2 to the ////// response property anyOf list for the response status

      response-property-any-of-added

  • 546c704d347b15See the full diff
    • ▲

      response property agent/allOf[BetaManagedAgentsSessionThreadAgent]/tools/items/oneOf[BetaManagedAgentsCustomTool]/input_schema/required list-of-types was widened by adding types null to media type application/json of response 200

      response-property-list-of-types-widened

    • ○

      removed from the //////////// response property allOf list for the response status

      response-property-all-of-removed

    • ○

      added subschema #1 subschema #2 to the //////////// response property anyOf list for the response status

      response-property-any-of-added

    • ○

      the response property //////////// became required for the status

      response-property-became-required

    • ○

      the response property const value object was added for the status

      response-property-const-added

    • ○

      removed the object enum value from the //////////// response property for the response status

      response-property-enum-value-removed