## Archive Session Thread

**post** `/v1/sessions/{session_id}/threads/{thread_id}/archive`

Archive Session Thread

### Path Parameters

- `session_id: string`

- `thread_id: string`

### Header Parameters

- `"anthropic-beta": optional array of AnthropicBeta`

  Optional header to specify the beta version(s) you want to use.

  - `string`

  - `"message-batches-2024-09-24" or "prompt-caching-2024-07-31" or "computer-use-2024-10-22" or 23 more`

    - `"message-batches-2024-09-24"`

    - `"prompt-caching-2024-07-31"`

    - `"computer-use-2024-10-22"`

    - `"computer-use-2025-01-24"`

    - `"pdfs-2024-09-25"`

    - `"token-counting-2024-11-01"`

    - `"token-efficient-tools-2025-02-19"`

    - `"output-128k-2025-02-19"`

    - `"files-api-2025-04-14"`

    - `"mcp-client-2025-04-04"`

    - `"mcp-client-2025-11-20"`

    - `"dev-full-thinking-2025-05-14"`

    - `"interleaved-thinking-2025-05-14"`

    - `"code-execution-2025-05-22"`

    - `"extended-cache-ttl-2025-04-11"`

    - `"context-1m-2025-08-07"`

    - `"context-management-2025-06-27"`

    - `"model-context-window-exceeded-2025-08-26"`

    - `"skills-2025-10-02"`

    - `"fast-mode-2026-02-01"`

    - `"output-300k-2026-03-24"`

    - `"user-profiles-2026-03-24"`

    - `"advisor-tool-2026-03-01"`

    - `"managed-agents-2026-04-01"`

    - `"cache-diagnosis-2026-04-07"`

    - `"thinking-token-count-2026-05-13"`

### Returns

- `BetaManagedAgentsSessionThread object { id, agent, archived_at, 8 more }`

  An execution thread within a `session`. Each session has one primary thread plus zero or more child threads spawned by the coordinator.

  - `id: string`

    Unique identifier for this thread.

  - `agent: BetaManagedAgentsSessionThreadAgent`

    Resolved `agent` definition for a single `session_thread`. Snapshot of the agent at thread creation time. The multiagent roster is not repeated here; read it from `Session.agent`.

    - `id: string`

    - `description: string`

    - `mcp_servers: array of BetaManagedAgentsMCPServerURLDefinition`

      - `name: string`

      - `type: "url"`

        - `"url"`

      - `url: string`

    - `model: BetaManagedAgentsModelConfig`

      Model identifier and configuration.

      - `id: BetaManagedAgentsModel`

        The model that will power your agent.

        See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.

        - `"claude-opus-4-8" or "claude-opus-4-7" or "claude-opus-4-6" or 7 more`

          The model that will power your agent.

          See [models](https://docs.anthropic.com/en/docs/models-overview) for additional details and options.

          - `"claude-opus-4-8"`

            Frontier intelligence for long-running agents and coding

          - `"claude-opus-4-7"`

            Frontier intelligence for long-running agents and coding

          - `"claude-opus-4-6"`

            Most intelligent model for building agents and coding

          - `"claude-sonnet-4-6"`

            Best combination of speed and intelligence

          - `"claude-haiku-4-5"`

            Fastest model with near-frontier intelligence

          - `"claude-haiku-4-5-20251001"`

            Fastest model with near-frontier intelligence

          - `"claude-opus-4-5"`

            Premium model combining maximum intelligence with practical performance

          - `"claude-opus-4-5-20251101"`

            Premium model combining maximum intelligence with practical performance

          - `"claude-sonnet-4-5"`

            High-performance model for agents and coding

          - `"claude-sonnet-4-5-20250929"`

            High-performance model for agents and coding

        - `string`

      - `speed: optional "standard" or "fast"`

        Inference speed mode. `fast` provides significantly faster output token generation at premium pricing. Not all models support `fast`; invalid combinations are rejected at create time.

        - `"standard"`

        - `"fast"`

    - `name: string`

    - `skills: array of BetaManagedAgentsAnthropicSkill or BetaManagedAgentsCustomSkill`

      - `BetaManagedAgentsAnthropicSkill object { skill_id, type, version }`

        A resolved Anthropic-managed skill.

        - `skill_id: string`

        - `type: "anthropic"`

          - `"anthropic"`

        - `version: string`

      - `BetaManagedAgentsCustomSkill object { skill_id, type, version }`

        A resolved user-created custom skill.

        - `skill_id: string`

        - `type: "custom"`

          - `"custom"`

        - `version: string`

    - `system: string`

    - `tools: array of BetaManagedAgentsAgentToolset20260401 or BetaManagedAgentsMCPToolset or BetaManagedAgentsCustomTool`

      - `BetaManagedAgentsAgentToolset20260401 object { configs, default_config, type }`

        - `configs: array of BetaManagedAgentsAgentToolConfig`

          - `enabled: boolean`

          - `name: "bash" or "edit" or "read" or 5 more`

            Built-in agent tool identifier.

            - `"bash"`

            - `"edit"`

            - `"read"`

            - `"write"`

            - `"glob"`

            - `"grep"`

            - `"web_fetch"`

            - `"web_search"`

          - `permission_policy: BetaManagedAgentsAlwaysAllowPolicy or BetaManagedAgentsAlwaysAskPolicy`

            Permission policy for tool execution.

            - `BetaManagedAgentsAlwaysAllowPolicy object { type }`

              Tool calls are automatically approved without user confirmation.

              - `type: "always_allow"`

                - `"always_allow"`

            - `BetaManagedAgentsAlwaysAskPolicy object { type }`

              Tool calls require user confirmation before execution.

              - `type: "always_ask"`

                - `"always_ask"`

        - `default_config: BetaManagedAgentsAgentToolsetDefaultConfig`

          Resolved default configuration for agent tools.

          - `enabled: boolean`

          - `permission_policy: BetaManagedAgentsAlwaysAllowPolicy or BetaManagedAgentsAlwaysAskPolicy`

            Permission policy for tool execution.

            - `BetaManagedAgentsAlwaysAllowPolicy object { type }`

              Tool calls are automatically approved without user confirmation.

            - `BetaManagedAgentsAlwaysAskPolicy object { type }`

              Tool calls require user confirmation before execution.

        - `type: "agent_toolset_20260401"`

          - `"agent_toolset_20260401"`

      - `BetaManagedAgentsMCPToolset object { configs, default_config, mcp_server_name, type }`

        - `configs: array of BetaManagedAgentsMCPToolConfig`

          - `enabled: boolean`

          - `name: string`

          - `permission_policy: BetaManagedAgentsAlwaysAllowPolicy or BetaManagedAgentsAlwaysAskPolicy`

            Permission policy for tool execution.

            - `BetaManagedAgentsAlwaysAllowPolicy object { type }`

              Tool calls are automatically approved without user confirmation.

            - `BetaManagedAgentsAlwaysAskPolicy object { type }`

              Tool calls require user confirmation before execution.

        - `default_config: BetaManagedAgentsMCPToolsetDefaultConfig`

          Resolved default configuration for all tools from an MCP server.

          - `enabled: boolean`

          - `permission_policy: BetaManagedAgentsAlwaysAllowPolicy or BetaManagedAgentsAlwaysAskPolicy`

            Permission policy for tool execution.

            - `BetaManagedAgentsAlwaysAllowPolicy object { type }`

              Tool calls are automatically approved without user confirmation.

            - `BetaManagedAgentsAlwaysAskPolicy object { type }`

              Tool calls require user confirmation before execution.

        - `mcp_server_name: string`

        - `type: "mcp_toolset"`

          - `"mcp_toolset"`

      - `BetaManagedAgentsCustomTool object { description, input_schema, name, type }`

        A custom tool as returned in API responses.

        - `description: string`

        - `input_schema: BetaManagedAgentsCustomToolInputSchema`

          JSON Schema for custom tool input parameters.

          - `properties: optional map[unknown]`

            JSON Schema properties defining the tool's input parameters.

          - `required: optional array of string`

            List of required property names.

          - `type: optional "object"`

            Must be 'object' for tool input schemas.

            - `"object"`

        - `name: string`

        - `type: "custom"`

          - `"custom"`

    - `type: "agent"`

      - `"agent"`

    - `version: number`

  - `archived_at: string`

    A timestamp in RFC 3339 format

  - `created_at: string`

    A timestamp in RFC 3339 format

  - `parent_thread_id: string`

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

  - `session_id: string`

    The session this thread belongs to.

  - `stats: BetaManagedAgentsSessionThreadStats`

    Timing statistics for a session thread.

    - `active_seconds: optional number`

      Cumulative time in seconds the thread spent actively running. Excludes idle time.

    - `duration_seconds: optional number`

      Elapsed time since thread creation in seconds. For archived threads, frozen at the final update.

    - `startup_seconds: optional number`

      Time in seconds for the thread to begin running. Zero for child threads, which start immediately.

  - `status: BetaManagedAgentsSessionThreadStatus`

    SessionThreadStatus enum

    - `"running"`

    - `"idle"`

    - `"rescheduling"`

    - `"terminated"`

  - `type: "session_thread"`

    - `"session_thread"`

  - `updated_at: string`

    A timestamp in RFC 3339 format

  - `usage: BetaManagedAgentsSessionThreadUsage`

    Cumulative token usage for a session thread across all turns.

    - `cache_creation: optional BetaManagedAgentsCacheCreationUsage`

      Prompt-cache creation token usage broken down by cache lifetime.

      - `ephemeral_1h_input_tokens: optional number`

        Tokens used to create 1-hour ephemeral cache entries.

      - `ephemeral_5m_input_tokens: optional number`

        Tokens used to create 5-minute ephemeral cache entries.

    - `cache_read_input_tokens: optional number`

      Total tokens read from prompt cache.

    - `input_tokens: optional number`

      Total input tokens consumed across all turns.

    - `output_tokens: optional number`

      Total output tokens generated across all turns.

### Example

```http
curl https://api.anthropic.com/v1/sessions/$SESSION_ID/threads/$THREAD_ID/archive \
    -X POST \
    -H 'anthropic-version: 2023-06-01' \
    -H 'anthropic-beta: managed-agents-2026-04-01' \
    -H "X-Api-Key: $ANTHROPIC_API_KEY"
```

#### Response

```json
{
  "id": "sthr_011CZkZVWa6oIjw0rgXZpnBt",
  "agent": {
    "id": "agent_011CZkYqphY8vELVzwCUpqiQ",
    "description": "A focused research subagent.",
    "mcp_servers": [
      {
        "name": "example-mcp",
        "type": "url",
        "url": "https://example-server.modelcontextprotocol.io/sse"
      }
    ],
    "model": {
      "id": "claude-sonnet-4-6",
      "speed": "standard"
    },
    "name": "Researcher",
    "skills": [
      {
        "skill_id": "xlsx",
        "type": "anthropic",
        "version": "1"
      }
    ],
    "system": "You are a research subagent that gathers and summarises sources for the coordinating agent.",
    "tools": [
      {
        "configs": [
          {
            "enabled": true,
            "name": "bash",
            "permission_policy": {
              "type": "always_allow"
            }
          }
        ],
        "default_config": {
          "enabled": true,
          "permission_policy": {
            "type": "always_ask"
          }
        },
        "type": "agent_toolset_20260401"
      }
    ],
    "type": "agent",
    "version": 1
  },
  "archived_at": null,
  "created_at": "2026-03-15T10:00:00Z",
  "parent_thread_id": null,
  "session_id": "sesn_011CZkZAtmR3yMPDzynEDxu7",
  "stats": {
    "active_seconds": 0,
    "duration_seconds": 0,
    "startup_seconds": 0
  },
  "status": "idle",
  "type": "session_thread",
  "updated_at": "2026-03-15T10:00:00Z",
  "usage": {
    "cache_creation": {
      "ephemeral_1h_input_tokens": 0,
      "ephemeral_5m_input_tokens": 0
    },
    "cache_read_input_tokens": 0,
    "input_tokens": 0,
    "output_tokens": 0
  }
}
```