---
title: Update Session
url: https://platform.claude.com/docs/en/api/http/beta/sessions/update
---

# Update Session

**POST** `/v1/sessions/{session_id}`

Update Session

## Path parameters

- `session_id: string`

## Headers

- `"anthropic-version": optional string`

  The version of the Claude API you want to use.

  Read more about versioning and our version history [here](https://platform.claude.com/docs/en/api/versioning?sdk_languages=http).

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

  This endpoint is in beta: requests must send `managed-agents-2026-04-01` in this header.

  - `string`

  - `"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"`

  - `"user-profiles-2026-08-18"`

  - `"user-profiles-2026-09-04"`

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

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

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

  - `"dreaming-2026-04-21"`

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

  - `"server-side-fallback-2026-06-01"`

  - `"server-side-fallback-2026-07-01"`

  - `"fallback-credit-2026-06-01"`

  - `"fallback-credit-2026-07-01"`

  - `"agent-memory-2026-07-22"`

  - `"mid-conversation-tool-changes-2026-07-01"`

  - `"compact-2026-01-12"`

  - `"computer-use-2025-11-24"`

  - `"mcp-tunnels-2026-06-22"`

  - `"structured-outputs-2025-11-13"`

  - `"task-budgets-2026-03-13"`

  - `"thinking-display-updates-2026-08-18"`

  - `"ce-user-management-2026-07-13"`

  - `"mid-conversation-output-config-2026-07-01"`

  - `"thinking-binding-controls-2026-08-01"`

  - `"mid-conversation-system-clear-at-2026-08-21"`

  - `"compact-2026-09-04"`

  - `"inline-tools-2026-09-15"`

  - `"mcp-client-2026-09-15"`

  - `"ce-plugins-2026-09-01"`

  - `"spend-limit-reads-2026-09-26"`

  - `"telemetry-destinations-2026-08-11"`

- `"anthropic-workspace-id": optional string`

  Optional header to select the Workspace for this request. The value is a Workspace ID (for example, `wrkspc_011CZkZaBF1tNoB5wlCeusgy`).

  Only needed for credentials that can act on more than one Workspace. A credential that belongs to a specific Workspace may omit it; if sent, it must match that Workspace.

## Body parameters

- `agent: optional BetaManagedAgentsSessionAgentUpdate`

  Agent configuration update. Only `tools` and `mcp_servers` are updatable mid-session. Only valid for sessions created from an agent or deployment reference. The session must not be running.

  - `mcp_servers: optional array of BetaManagedAgentsURLMCPServerParams`

    Replacement MCP server list. Full replacement: the provided array becomes the new value. Send an empty array to clear; omit to preserve.

    - `type: "url"`

    - `name: string`

      Unique name for this server, referenced by mcp_toolset configurations. 1-255 characters.

      minLength: 1, maxLength: 255

    - `url: string`

      Endpoint URL for the MCP server.

      maxLength: 2048

  - `tools: optional array of BetaManagedAgentsAgentToolset20260401Params or BetaManagedAgentsMCPToolsetParams or BetaManagedAgentsCustomToolParams`

    Replacement tool list. Full replacement: the provided array becomes the new value. Send an empty array to clear; omit to preserve.

    - `BetaManagedAgentsAgentToolset20260401Params object`

      Configuration for built-in agent tools. Use this to enable or disable groups of tools available to the agent.

      - `type: "agent_toolset_20260401"`

      - `configs: optional array of BetaManagedAgentsAgentToolConfigParams`

        Per-tool configuration overrides.

        - `BetaManagedAgentsBashToolConfigParams object`

          Configuration override for the bash tool.

          - `type: optional "bash"`

          - `name: "bash"`

            Must be "bash".

          - `enabled: optional boolean or null`

            Whether this tool is enabled and available to Claude. Overrides the default_config setting.

          - `permission_policy: optional BetaManagedAgentsAlwaysAllowPolicy or BetaManagedAgentsAlwaysAskPolicy or BetaManagedAgentsAutoPolicy or null`

            Permission policy for this tool. Controls whether tool calls are auto-approved or require confirmation.

            - `BetaManagedAgentsAlwaysAllowPolicy object`

              Tool calls are automatically approved without user confirmation.

              - `type: "always_allow"`

            - `BetaManagedAgentsAlwaysAskPolicy object`

              Tool calls require user confirmation before execution.

              - `type: "always_ask"`

            - `BetaManagedAgentsAutoPolicy object`

              The server decides each tool call individually: it judges, from the tool, its input, and the session content so far, whether the call is safe to execute or high-risk, and evaluates it to allow when judged safe and to deny when judged high-risk. A call the server cannot reach a judgement on evaluates to ask.

              - `type: "auto"`

        - `BetaManagedAgentsEditToolConfigParams object`

          Configuration override for the edit tool.

          - `type: optional "edit"`

          - `name: "edit"`

            Must be "edit".

          - `enabled: optional boolean or null`

            Whether this tool is enabled and available to Claude. Overrides the default_config setting.

          - `permission_policy: optional BetaManagedAgentsAlwaysAllowPolicy or BetaManagedAgentsAlwaysAskPolicy or BetaManagedAgentsAutoPolicy or null`

            Permission policy for this tool. Controls whether tool calls are auto-approved or require confirmation.

            - `BetaManagedAgentsAlwaysAllowPolicy object`

              Tool calls are automatically approved without user confirmation.

            - `BetaManagedAgentsAlwaysAskPolicy object`

              Tool calls require user confirmation before execution.

            - `BetaManagedAgentsAutoPolicy object`

              The server decides each tool call individually: it judges, from the tool, its input, and the session content so far, whether the call is safe to execute or high-risk, and evaluates it to allow when judged safe and to deny when judged high-risk. A call the server cannot reach a judgement on evaluates to ask.

        - `BetaManagedAgentsReadToolConfigParams object`

          Configuration override for the read tool.

          - `type: optional "read"`

          - `name: "read"`

            Must be "read".

          - `enabled: optional boolean or null`

            Whether this tool is enabled and available to Claude. Overrides the default_config setting.

          - `permission_policy: optional BetaManagedAgentsAlwaysAllowPolicy or BetaManagedAgentsAlwaysAskPolicy or BetaManagedAgentsAutoPolicy or null`

            Permission policy for this tool. Controls whether tool calls are auto-approved or require confirmation.

            - `BetaManagedAgentsAlwaysAllowPolicy object`

              Tool calls are automatically approved without user confirmation.

            - `BetaManagedAgentsAlwaysAskPolicy object`

              Tool calls require user confirmation before execution.

            - `BetaManagedAgentsAutoPolicy object`

              The server decides each tool call individually: it judges, from the tool, its input, and the session content so far, whether the call is safe to execute or high-risk, and evaluates it to allow when judged safe and to deny when judged high-risk. A call the server cannot reach a judgement on evaluates to ask.

        - `BetaManagedAgentsWriteToolConfigParams object`

          Configuration override for the write tool.

          - `type: optional "write"`

          - `name: "write"`

            Must be "write".

          - `enabled: optional boolean or null`

            Whether this tool is enabled and available to Claude. Overrides the default_config setting.

          - `permission_policy: optional BetaManagedAgentsAlwaysAllowPolicy or BetaManagedAgentsAlwaysAskPolicy or BetaManagedAgentsAutoPolicy or null`

            Permission policy for this tool. Controls whether tool calls are auto-approved or require confirmation.

            - `BetaManagedAgentsAlwaysAllowPolicy object`

              Tool calls are automatically approved without user confirmation.

            - `BetaManagedAgentsAlwaysAskPolicy object`

              Tool calls require user confirmation before execution.

            - `BetaManagedAgentsAutoPolicy object`

              The server decides each tool call individually: it judges, from the tool, its input, and the session content so far, whether the call is safe to execute or high-risk, and evaluates it to allow when judged safe and to deny when judged high-risk. A call the server cannot reach a judgement on evaluates to ask.

        - `BetaManagedAgentsGlobToolConfigParams object`

          Configuration override for the glob tool.

          - `type: optional "glob"`

          - `name: "glob"`

            Must be "glob".

          - `enabled: optional boolean or null`

            Whether this tool is enabled and available to Claude. Overrides the default_config setting.

          - `permission_policy: optional BetaManagedAgentsAlwaysAllowPolicy or BetaManagedAgentsAlwaysAskPolicy or BetaManagedAgentsAutoPolicy or null`

            Permission policy for this tool. Controls whether tool calls are auto-approved or require confirmation.

            - `BetaManagedAgentsAlwaysAllowPolicy object`

              Tool calls are automatically approved without user confirmation.

            - `BetaManagedAgentsAlwaysAskPolicy object`

              Tool calls require user confirmation before execution.

            - `BetaManagedAgentsAutoPolicy object`

              The server decides each tool call individually: it judges, from the tool, its input, and the session content so far, whether the call is safe to execute or high-risk, and evaluates it to allow when judged safe and to deny when judged high-risk. A call the server cannot reach a judgement on evaluates to ask.

        - `BetaManagedAgentsGrepToolConfigParams object`

          Configuration override for the grep tool.

          - `type: optional "grep"`

          - `name: "grep"`

            Must be "grep".

          - `enabled: optional boolean or null`

            Whether this tool is enabled and available to Claude. Overrides the default_config setting.

          - `permission_policy: optional BetaManagedAgentsAlwaysAllowPolicy or BetaManagedAgentsAlwaysAskPolicy or BetaManagedAgentsAutoPolicy or null`

            Permission policy for this tool. Controls whether tool calls are auto-approved or require confirmation.

            - `BetaManagedAgentsAlwaysAllowPolicy object`

              Tool calls are automatically approved without user confirmation.

            - `BetaManagedAgentsAlwaysAskPolicy object`

              Tool calls require user confirmation before execution.

            - `BetaManagedAgentsAutoPolicy object`

              The server decides each tool call individually: it judges, from the tool, its input, and the session content so far, whether the call is safe to execute or high-risk, and evaluates it to allow when judged safe and to deny when judged high-risk. A call the server cannot reach a judgement on evaluates to ask.

        - `BetaManagedAgentsWebFetchToolConfigParams object`

          Configuration override for the web_fetch tool.

          - `type: optional "web_fetch"`

          - `name: "web_fetch"`

            Must be "web_fetch".

          - `allowed_domains: optional array of string`

            Only fetch URLs whose host is one of these domains or a subdomain of one. Each entry is a plain hostname like "docs.example.com" (no scheme, port, or path). At most 64 entries; an empty list is rejected (omit the field instead). Cannot be combined with blocked_domains.

          - `blocked_domains: optional array of string`

            Never fetch URLs whose host is one of these domains or a subdomain of one. Each entry is a plain hostname like "ads.example.com" (no scheme, port, or path). At most 64 entries; an empty list is rejected (omit the field instead). Cannot be combined with allowed_domains.

          - `enabled: optional boolean or null`

            Whether this tool is enabled and available to Claude. Overrides the default_config setting.

          - `max_content_tokens: optional number or null`

            Maximum number of tokens of fetched text content to include in context per call. Does not apply to binary content such as PDFs.

            format: int32

          - `permission_policy: optional BetaManagedAgentsAlwaysAllowPolicy or BetaManagedAgentsAlwaysAskPolicy or BetaManagedAgentsAutoPolicy or null`

            Permission policy for this tool. Controls whether tool calls are auto-approved or require confirmation.

            - `BetaManagedAgentsAlwaysAllowPolicy object`

              Tool calls are automatically approved without user confirmation.

            - `BetaManagedAgentsAlwaysAskPolicy object`

              Tool calls require user confirmation before execution.

            - `BetaManagedAgentsAutoPolicy object`

              The server decides each tool call individually: it judges, from the tool, its input, and the session content so far, whether the call is safe to execute or high-risk, and evaluates it to allow when judged safe and to deny when judged high-risk. A call the server cannot reach a judgement on evaluates to ask.

          - `url_sources: optional BetaManagedAgentsWebFetchURLSourcesParams or null`

            Which sources contribute URLs the tool may fetch. Omit to allow every source.

            - `client_tool_results: optional BetaManagedAgentsWebFetchURLSourceToolFilterParams or null`

              Which custom tools' results contribute URLs that may be fetched: "all" (the default), "none", or an only or except list. Each name in a list must be a custom tool in the same tools array.

              - `BetaManagedAgentsWebFetchURLSourceShorthand = "all" or "none"`

                String form of a url_sources value that has no field other than its type: "all" means {"type": "all"} and "none" means {"type": "none"}.

                - `"all"`

                - `"none"`

              - `BetaManagedAgentsWebFetchURLSourceToolFilter = BetaManagedAgentsWebFetchURLSourceAll or BetaManagedAgentsWebFetchURLSourceNone or BetaManagedAgentsWebFetchURLSourceOnly or BetaManagedAgentsWebFetchURLSourceExcept`

                Which tools' results contribute URLs that may be fetched.

                - `BetaManagedAgentsWebFetchURLSourceAll object`

                  Every URL from this source may be fetched. This is the default.

                  - `type: "all"`

                - `BetaManagedAgentsWebFetchURLSourceNone object`

                  This source contributes no URLs that may be fetched.

                  - `type: "none"`

                - `BetaManagedAgentsWebFetchURLSourceOnly object`

                  Only the named tools' results contribute URLs that may be fetched.

                  - `type: "only"`

                  - `tools: array of BetaManagedAgentsWebFetchURLSourceToolReference`

                    The tools whose results contribute. Between 1 and 128 entries, each with a different name. An empty list is rejected; use "none" to allow no tool's results.

                    - `type: "tool_reference"`

                      Must be "tool_reference".

                    - `name: string`

                      Name of the tool. Compared exactly, so upper and lower case letters are different.

                      minLength: 1, maxLength: 128

                - `BetaManagedAgentsWebFetchURLSourceExcept object`

                  Every tool's results contribute URLs that may be fetched, except the named tools' results.

                  - `type: "except"`

                  - `tools: array of BetaManagedAgentsWebFetchURLSourceToolReference`

                    The tools whose results do not contribute. Between 1 and 128 entries, each with a different name. An empty list is rejected; use "all" to leave out no tool's results.

                    - `type: "tool_reference"`

                      Must be "tool_reference".

                    - `name: string`

                      Name of the tool. Compared exactly, so upper and lower case letters are different.

                      minLength: 1, maxLength: 128

            - `server_tool_results: optional BetaManagedAgentsWebFetchURLSourceToolFilterParams or null`

              Which of the web_search and web_fetch tools' results contribute URLs that may be fetched: "all" (the default), "none", or an only or except list. Each name in a list must be "web_search" or "web_fetch".

            - `user_input: optional BetaManagedAgentsWebFetchURLSourceUserInputParams or null`

              Whether URLs in the text of user messages may be fetched: "all" (the default) or "none".

              - `BetaManagedAgentsWebFetchURLSourceShorthand = "all" or "none"`

                String form of a url_sources value that has no field other than its type: "all" means {"type": "all"} and "none" means {"type": "none"}.

              - `BetaManagedAgentsWebFetchURLSourceUserInput = BetaManagedAgentsWebFetchURLSourceAll or BetaManagedAgentsWebFetchURLSourceNone`

                Whether URLs in the text of user messages may be fetched.

                - `BetaManagedAgentsWebFetchURLSourceAll object`

                  Every URL from this source may be fetched. This is the default.

                - `BetaManagedAgentsWebFetchURLSourceNone object`

                  This source contributes no URLs that may be fetched.

        - `BetaManagedAgentsWebSearchToolConfigParams object`

          Configuration override for the web_search tool.

          - `type: optional "web_search"`

          - `name: "web_search"`

            Must be "web_search".

          - `allowed_domains: optional array of string`

            Only return search results whose host is one of these domains or a subdomain of one. Each entry is a plain hostname like "docs.example.com" (no scheme or port; an optional path suffix is accepted). At most 64 entries; an empty list is rejected (omit the field instead). Cannot be combined with blocked_domains.

          - `blocked_domains: optional array of string`

            Never return search results whose host is one of these domains or a subdomain of one. Each entry is a plain hostname like "ads.example.com" (no scheme or port; an optional path suffix is accepted). At most 64 entries; an empty list is rejected (omit the field instead). Cannot be combined with allowed_domains.

          - `enabled: optional boolean or null`

            Whether this tool is enabled and available to Claude. Overrides the default_config setting.

          - `permission_policy: optional BetaManagedAgentsAlwaysAllowPolicy or BetaManagedAgentsAlwaysAskPolicy or BetaManagedAgentsAutoPolicy or null`

            Permission policy for this tool. Controls whether tool calls are auto-approved or require confirmation.

            - `BetaManagedAgentsAlwaysAllowPolicy object`

              Tool calls are automatically approved without user confirmation.

            - `BetaManagedAgentsAlwaysAskPolicy object`

              Tool calls require user confirmation before execution.

            - `BetaManagedAgentsAutoPolicy object`

              The server decides each tool call individually: it judges, from the tool, its input, and the session content so far, whether the call is safe to execute or high-risk, and evaluates it to allow when judged safe and to deny when judged high-risk. A call the server cannot reach a judgement on evaluates to ask.

          - `user_location: optional BetaManagedAgentsUserLocation or null`

            Approximate user location for search result localization.

            - `type: "approximate"`

              Location precision. Only "approximate" is supported.

            - `city: optional string or null`

              City name.

              minLength: 1, maxLength: 255

            - `country: optional string or null`

              Two-letter ISO 3166-1 country code, uppercase.

            - `region: optional string or null`

              Region or state name.

              minLength: 1, maxLength: 255

            - `timezone: optional string or null`

              IANA timezone identifier, e.g. "America/Los_Angeles".

              minLength: 1, maxLength: 255

      - `default_config: optional BetaManagedAgentsAgentToolsetDefaultConfigParams or null`

        Default configuration applied to all tools in this set.

        - `enabled: optional boolean or null`

          Whether tools are enabled and available to Claude by default. Defaults to true if not specified.

        - `permission_policy: optional BetaManagedAgentsAlwaysAllowPolicy or BetaManagedAgentsAlwaysAskPolicy or BetaManagedAgentsAutoPolicy or null`

          Default permission policy for tools. Controls whether tool calls are auto-approved or require confirmation.

          - `BetaManagedAgentsAlwaysAllowPolicy object`

            Tool calls are automatically approved without user confirmation.

          - `BetaManagedAgentsAlwaysAskPolicy object`

            Tool calls require user confirmation before execution.

          - `BetaManagedAgentsAutoPolicy object`

            The server decides each tool call individually: it judges, from the tool, its input, and the session content so far, whether the call is safe to execute or high-risk, and evaluates it to allow when judged safe and to deny when judged high-risk. A call the server cannot reach a judgement on evaluates to ask.

    - `BetaManagedAgentsMCPToolsetParams object`

      Configuration for tools from an MCP server defined in `mcp_servers`.

      - `type: "mcp_toolset"`

      - `mcp_server_name: string`

        Name of the MCP server. Must match a server name from the mcp_servers array. 1-255 characters.

        minLength: 1, maxLength: 255

      - `configs: optional array of BetaManagedAgentsMCPToolConfigParams`

        Per-tool configuration overrides.

        - `name: string`

          Name of the MCP tool to configure. 1-128 characters.

          minLength: 1, maxLength: 128

        - `enabled: optional boolean or null`

          Whether this tool is enabled. Overrides the `default_config` setting.

        - `permission_policy: optional BetaManagedAgentsAlwaysAllowPolicy or BetaManagedAgentsAlwaysAskPolicy or BetaManagedAgentsAutoPolicy or null`

          Permission policy for this tool. Overrides the `default_config` setting.

          - `BetaManagedAgentsAlwaysAllowPolicy object`

            Tool calls are automatically approved without user confirmation.

          - `BetaManagedAgentsAlwaysAskPolicy object`

            Tool calls require user confirmation before execution.

          - `BetaManagedAgentsAutoPolicy object`

            The server decides each tool call individually: it judges, from the tool, its input, and the session content so far, whether the call is safe to execute or high-risk, and evaluates it to allow when judged safe and to deny when judged high-risk. A call the server cannot reach a judgement on evaluates to ask.

      - `default_config: optional BetaManagedAgentsMCPToolsetDefaultConfigParams or null`

        Default configuration for all tools from this server.

        - `enabled: optional boolean or null`

          Whether tools are enabled by default. Defaults to true if not specified.

        - `permission_policy: optional BetaManagedAgentsAlwaysAllowPolicy or BetaManagedAgentsAlwaysAskPolicy or BetaManagedAgentsAutoPolicy or null`

          Default permission policy for tools from this server.

          - `BetaManagedAgentsAlwaysAllowPolicy object`

            Tool calls are automatically approved without user confirmation.

          - `BetaManagedAgentsAlwaysAskPolicy object`

            Tool calls require user confirmation before execution.

          - `BetaManagedAgentsAutoPolicy object`

            The server decides each tool call individually: it judges, from the tool, its input, and the session content so far, whether the call is safe to execute or high-risk, and evaluates it to allow when judged safe and to deny when judged high-risk. A call the server cannot reach a judgement on evaluates to ask.

    - `BetaManagedAgentsCustomToolParams object`

      A custom tool that is executed by the API client rather than the agent. When the agent calls this tool, an `agent.custom_tool_use` event is emitted and the session goes idle, waiting for the client to provide the result via a `user.custom_tool_result` event.

      - `type: "custom"`

      - `description: string`

        Description of what the tool does, shown to the agent to help it decide when to use the tool.

        minLength: 1

      - `input_schema: BetaManagedAgentsCustomToolInputSchema`

        JSON Schema defining the expected input parameters for the tool.

        - `type: "object"`

        - `properties: optional map[unknown] or null`

        - `required: optional array of string or null`

      - `name: string`

        Unique name for the tool. 1-128 characters; letters, digits, underscores, and hyphens.

        minLength: 1, maxLength: 128

- `budget: optional BetaManagedAgentsBudgetLimit or null`

  Enforced spend ceiling for the session. Set an object to replace the budget of a session that was created with one, or `null` to remove it; omit to preserve. A budget cannot be added to a session created without one (rejected with reason `budget_create_only`), and a removed budget cannot be re-added. Allowed in any non-terminated status. Lowering `max_list_cost` to at or below the session's consumed list cost is rejected with reason `budget_not_raised`, and every model the session can run must have a public list price or the request is rejected with reason `model_not_budgetable`.

  - `type: "limit"`

  - `max_list_cost: BetaMonetaryAmount`

    Maximum list cost the session may accrue. List price is used regardless of any negotiated discount, so the cap fires at or before the actual charge.

    - `amount: string`

      Amount in minor units of the currency, as an integer decimal string with no leading zeros: "2500" is $25.00 and "50" is fifty cents. A string rather than a number so no float rounding is ever applied.

    - `currency: BetaCurrency`

      Uppercase ISO-4217 currency code. `USD` is the only currency currently supported; the accepted set is closed and grows only when a new currency is priced.

- `metadata: optional map[string] or null`

  Metadata patch. Set a key to a string to upsert it, or to null to delete it. Omit the field to preserve.

- `title: optional string or null`

  Human-readable session title.

  minLength: 1, maxLength: 500

- `vault_ids: optional array of string`

  Vault IDs (`vlt_*`) to attach to the session. Not yet supported; requests setting this field are rejected. Reserved for future use.

## Returns

- `BetaManagedAgentsSession object`

  A Managed Agents `session`.

  - `type: "session"`

  - `id: string`

  - `agent: BetaManagedAgentsSessionAgent`

    Resolved `agent` definition for a `session`. Snapshot of the `agent` at `session` creation time.

    - `type: "agent"`

    - `id: string`

    - `description: string or null`

    - `execution_identity: BetaManagedAgentsExecutionIdentity`

      Execution principal snapshotted from the agent at session creation. Always present; `{"type": "service_account"}` when runs carry no customer-named principal.

      - `BetaManagedAgentsAWSRoleExecutionIdentity object`

        An AWS IAM role principal as returned in API responses.

        - `type: "aws_role"`

        - `role_arn: string`

          The IAM role's ARN.

      - `BetaManagedAgentsServiceAccountExecutionIdentity object`

        The Anthropic-managed service account as returned in API responses.

        - `type: "service_account"`

    - `mcp_servers: array of BetaManagedAgentsMCPServerURLDefinition`

      - `type: "url"`

      - `name: string`

      - `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-haiku-5-5"`

          Fastest model for high-volume, real-time tasks

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

          Efficient model for coding and agents

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

          Powerful intelligence for coding, knowledge work, and long-running agents

        - `"claude-fable-5-1"`

          Frontier intelligence for ambitious tasks across coding, scientific discovery, and enterprise workflows

        - `"claude-sonnet-5"`

          Efficient model for coding and agents

        - `"claude-fable-5"`

          Next generation of intelligence for the hardest knowledge work and coding problems

        - `"claude-opus-5"`

          Powerful intelligence for long-running agents and coding

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

          Powerful intelligence for long-running agents and coding

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

          Powerful intelligence for long-running agents and coding

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

          Powerful intelligence for long-running agents and coding

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

          Best combination of speed and intelligence

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

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

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

          Powerful intelligence for long-running agents and coding

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

          Powerful intelligence for long-running agents and coding

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

          **Deprecated**: Will reach end-of-life on November 30, 2026. Please migrate to claude-sonnet-5-5. Visit https://docs.anthropic.com/en/docs/resources/model-deprecations for more information.

          High-performance model for agents and coding

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

          **Deprecated**: Will reach end-of-life on November 30, 2026. Please migrate to claude-sonnet-5-5. Visit https://docs.anthropic.com/en/docs/resources/model-deprecations for more information.

          High-performance model for agents and coding

        - `string`

      - `effort: optional BetaManagedAgentsEffortLow or BetaManagedAgentsEffortMedium or BetaManagedAgentsEffortHigh or 2 more`

        How hard Claude works on each inference call. One of `low`, `medium`, `high`, `xhigh`, `max`. Always present; resolved to the per-model default at save time when not supplied.

        - `BetaManagedAgentsEffortLow object`

          Low effort. Favors latency over reasoning depth.

          - `type: "low"`

        - `BetaManagedAgentsEffortMedium object`

          Medium effort. Balances latency and reasoning depth.

          - `type: "medium"`

        - `BetaManagedAgentsEffortHigh object`

          High effort. Favors reasoning depth.

          - `type: "high"`

        - `BetaManagedAgentsEffortXhigh object`

          Extra-high effort. Not all models accept this level.

          - `type: "xhigh"`

        - `BetaManagedAgentsEffortMax object`

          Maximum effort. Favors reasoning depth over latency.

          - `type: "max"`

      - `inference_geo: optional string`

        Geographic region for model inference. When unset, requests fall through to the workspace's default_inference_geo.

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

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

        - `"standard"`

        - `"fast"`

    - `multiagent: BetaManagedAgentsSessionMultiagent or null`

      Resolved multiagent orchestration configuration. Null when the agent is single-threaded.

      - `BetaManagedAgentsSessionMultiagentCoordinator object`

        Resolved coordinator topology with full agent definitions for each roster member.

        - `type: "coordinator"`

        - `agents: array of BetaManagedAgentsSessionThreadAgent or BetaManagedAgentsAdvisor`

          Full `agent` definitions the coordinator may spawn as session threads.

          - `BetaManagedAgentsSessionThreadAgent object`

            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`.

            - `type: "agent"`

            - `id: string`

            - `description: string or null`

            - `execution_identity: BetaManagedAgentsExecutionIdentity`

              Execution principal snapshotted from the agent at session creation. Always present; `{"type": "service_account"}` when runs carry no customer-named principal.

            - `mcp_servers: array of BetaManagedAgentsMCPServerURLDefinition`

              - `type: "url"`

              - `name: string`

              - `url: string`

            - `model: BetaManagedAgentsModelConfig`

              Model identifier and configuration.

            - `name: string`

            - `skills: array of BetaManagedAgentsAnthropicSkill or BetaManagedAgentsCustomSkill`

              - `BetaManagedAgentsAnthropicSkill object`

                A resolved Anthropic-managed skill.

                - `type: "anthropic"`

                - `skill_id: string`

                - `version: string`

              - `BetaManagedAgentsCustomSkill object`

                A resolved user-created custom skill.

                - `type: "custom"`

                - `skill_id: string`

                - `version: string`

            - `system: string or null`

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

              - `BetaManagedAgentsAgentToolset20260401 object`

                - `type: "agent_toolset_20260401"`

                - `configs: array of BetaManagedAgentsAgentToolConfig`

                  - `BetaManagedAgentsBashToolConfig object`

                    Configuration for the bash tool.

                    - `type: "bash"`

                    - `enabled: boolean`

                    - `name: "bash"`

                    - `permission_policy: BetaManagedAgentsAlwaysAllowPolicy or BetaManagedAgentsAlwaysAskPolicy or BetaManagedAgentsAutoPolicy`

                      Permission policy for tool execution.

                      - `BetaManagedAgentsAlwaysAllowPolicy object`

                        Tool calls are automatically approved without user confirmation.

                        - `type: "always_allow"`

                      - `BetaManagedAgentsAlwaysAskPolicy object`

                        Tool calls require user confirmation before execution.

                        - `type: "always_ask"`

                      - `BetaManagedAgentsAutoPolicy object`

                        The server decides each tool call individually: it judges, from the tool, its input, and the session content so far, whether the call is safe to execute or high-risk, and evaluates it to allow when judged safe and to deny when judged high-risk. A call the server cannot reach a judgement on evaluates to ask.

                        - `type: "auto"`

                  - `BetaManagedAgentsEditToolConfig object`

                    Configuration for the edit tool.

                    - `type: "edit"`

                    - `enabled: boolean`

                    - `name: "edit"`

                    - `permission_policy: BetaManagedAgentsAlwaysAllowPolicy or BetaManagedAgentsAlwaysAskPolicy or BetaManagedAgentsAutoPolicy`

                      Permission policy for tool execution.

                      - `BetaManagedAgentsAlwaysAllowPolicy object`

                        Tool calls are automatically approved without user confirmation.

                      - `BetaManagedAgentsAlwaysAskPolicy object`

                        Tool calls require user confirmation before execution.

                      - `BetaManagedAgentsAutoPolicy object`

                        The server decides each tool call individually: it judges, from the tool, its input, and the session content so far, whether the call is safe to execute or high-risk, and evaluates it to allow when judged safe and to deny when judged high-risk. A call the server cannot reach a judgement on evaluates to ask.

                  - `BetaManagedAgentsReadToolConfig object`

                    Configuration for the read tool.

                    - `type: "read"`

                    - `enabled: boolean`

                    - `name: "read"`

                    - `permission_policy: BetaManagedAgentsAlwaysAllowPolicy or BetaManagedAgentsAlwaysAskPolicy or BetaManagedAgentsAutoPolicy`

                      Permission policy for tool execution.

                      - `BetaManagedAgentsAlwaysAllowPolicy object`

                        Tool calls are automatically approved without user confirmation.

                      - `BetaManagedAgentsAlwaysAskPolicy object`

                        Tool calls require user confirmation before execution.

                      - `BetaManagedAgentsAutoPolicy object`

                        The server decides each tool call individually: it judges, from the tool, its input, and the session content so far, whether the call is safe to execute or high-risk, and evaluates it to allow when judged safe and to deny when judged high-risk. A call the server cannot reach a judgement on evaluates to ask.

                  - `BetaManagedAgentsWriteToolConfig object`

                    Configuration for the write tool.

                    - `type: "write"`

                    - `enabled: boolean`

                    - `name: "write"`

                    - `permission_policy: BetaManagedAgentsAlwaysAllowPolicy or BetaManagedAgentsAlwaysAskPolicy or BetaManagedAgentsAutoPolicy`

                      Permission policy for tool execution.

                      - `BetaManagedAgentsAlwaysAllowPolicy object`

                        Tool calls are automatically approved without user confirmation.

                      - `BetaManagedAgentsAlwaysAskPolicy object`

                        Tool calls require user confirmation before execution.

                      - `BetaManagedAgentsAutoPolicy object`

                        The server decides each tool call individually: it judges, from the tool, its input, and the session content so far, whether the call is safe to execute or high-risk, and evaluates it to allow when judged safe and to deny when judged high-risk. A call the server cannot reach a judgement on evaluates to ask.

                  - `BetaManagedAgentsGlobToolConfig object`

                    Configuration for the glob tool.

                    - `type: "glob"`

                    - `enabled: boolean`

                    - `name: "glob"`

                    - `permission_policy: BetaManagedAgentsAlwaysAllowPolicy or BetaManagedAgentsAlwaysAskPolicy or BetaManagedAgentsAutoPolicy`

                      Permission policy for tool execution.

                      - `BetaManagedAgentsAlwaysAllowPolicy object`

                        Tool calls are automatically approved without user confirmation.

                      - `BetaManagedAgentsAlwaysAskPolicy object`

                        Tool calls require user confirmation before execution.

                      - `BetaManagedAgentsAutoPolicy object`

                        The server decides each tool call individually: it judges, from the tool, its input, and the session content so far, whether the call is safe to execute or high-risk, and evaluates it to allow when judged safe and to deny when judged high-risk. A call the server cannot reach a judgement on evaluates to ask.

                  - `BetaManagedAgentsGrepToolConfig object`

                    Configuration for the grep tool.

                    - `type: "grep"`

                    - `enabled: boolean`

                    - `name: "grep"`

                    - `permission_policy: BetaManagedAgentsAlwaysAllowPolicy or BetaManagedAgentsAlwaysAskPolicy or BetaManagedAgentsAutoPolicy`

                      Permission policy for tool execution.

                      - `BetaManagedAgentsAlwaysAllowPolicy object`

                        Tool calls are automatically approved without user confirmation.

                      - `BetaManagedAgentsAlwaysAskPolicy object`

                        Tool calls require user confirmation before execution.

                      - `BetaManagedAgentsAutoPolicy object`

                        The server decides each tool call individually: it judges, from the tool, its input, and the session content so far, whether the call is safe to execute or high-risk, and evaluates it to allow when judged safe and to deny when judged high-risk. A call the server cannot reach a judgement on evaluates to ask.

                  - `BetaManagedAgentsWebFetchToolConfig object`

                    Configuration for the web_fetch tool.

                    - `type: "web_fetch"`

                    - `enabled: boolean`

                    - `name: "web_fetch"`

                    - `permission_policy: BetaManagedAgentsAlwaysAllowPolicy or BetaManagedAgentsAlwaysAskPolicy or BetaManagedAgentsAutoPolicy`

                      Permission policy for tool execution.

                      - `BetaManagedAgentsAlwaysAllowPolicy object`

                        Tool calls are automatically approved without user confirmation.

                      - `BetaManagedAgentsAlwaysAskPolicy object`

                        Tool calls require user confirmation before execution.

                      - `BetaManagedAgentsAutoPolicy object`

                        The server decides each tool call individually: it judges, from the tool, its input, and the session content so far, whether the call is safe to execute or high-risk, and evaluates it to allow when judged safe and to deny when judged high-risk. A call the server cannot reach a judgement on evaluates to ask.

                    - `url_sources: BetaManagedAgentsWebFetchURLSources or null`

                      Which sources contribute URLs the tool may fetch, always in the object form. Null when not set, which allows every source.

                      - `client_tool_results: BetaManagedAgentsWebFetchURLSourceToolFilter or null`

                        Which custom tools' results contribute URLs that may be fetched. Null when not set, which allows every custom tool's results.

                        - `BetaManagedAgentsWebFetchURLSourceAll object`

                          Every URL from this source may be fetched. This is the default.

                          - `type: "all"`

                        - `BetaManagedAgentsWebFetchURLSourceNone object`

                          This source contributes no URLs that may be fetched.

                          - `type: "none"`

                        - `BetaManagedAgentsWebFetchURLSourceOnly object`

                          Only the named tools' results contribute URLs that may be fetched.

                          - `type: "only"`

                          - `tools: array of BetaManagedAgentsWebFetchURLSourceToolReference`

                            The tools whose results contribute. Between 1 and 128 entries, each with a different name. An empty list is rejected; use "none" to allow no tool's results.

                            - `type: "tool_reference"`

                              Must be "tool_reference".

                            - `name: string`

                              Name of the tool. Compared exactly, so upper and lower case letters are different.

                              minLength: 1, maxLength: 128

                        - `BetaManagedAgentsWebFetchURLSourceExcept object`

                          Every tool's results contribute URLs that may be fetched, except the named tools' results.

                          - `type: "except"`

                          - `tools: array of BetaManagedAgentsWebFetchURLSourceToolReference`

                            The tools whose results do not contribute. Between 1 and 128 entries, each with a different name. An empty list is rejected; use "all" to leave out no tool's results.

                            - `type: "tool_reference"`

                              Must be "tool_reference".

                            - `name: string`

                              Name of the tool. Compared exactly, so upper and lower case letters are different.

                              minLength: 1, maxLength: 128

                      - `server_tool_results: BetaManagedAgentsWebFetchURLSourceToolFilter or null`

                        Which of the web_search and web_fetch tools' results contribute URLs that may be fetched. Null when not set, which allows both.

                      - `user_input: BetaManagedAgentsWebFetchURLSourceUserInput or null`

                        Whether URLs in the text of user messages may be fetched. Null when not set, which allows them.

                        - `BetaManagedAgentsWebFetchURLSourceAll object`

                          Every URL from this source may be fetched. This is the default.

                        - `BetaManagedAgentsWebFetchURLSourceNone object`

                          This source contributes no URLs that may be fetched.

                    - `allowed_domains: optional array of string`

                    - `blocked_domains: optional array of string`

                    - `max_content_tokens: optional number or null`

                      format: int32

                  - `BetaManagedAgentsWebSearchToolConfig object`

                    Configuration for the web_search tool.

                    - `type: "web_search"`

                    - `enabled: boolean`

                    - `name: "web_search"`

                    - `permission_policy: BetaManagedAgentsAlwaysAllowPolicy or BetaManagedAgentsAlwaysAskPolicy or BetaManagedAgentsAutoPolicy`

                      Permission policy for tool execution.

                      - `BetaManagedAgentsAlwaysAllowPolicy object`

                        Tool calls are automatically approved without user confirmation.

                      - `BetaManagedAgentsAlwaysAskPolicy object`

                        Tool calls require user confirmation before execution.

                      - `BetaManagedAgentsAutoPolicy object`

                        The server decides each tool call individually: it judges, from the tool, its input, and the session content so far, whether the call is safe to execute or high-risk, and evaluates it to allow when judged safe and to deny when judged high-risk. A call the server cannot reach a judgement on evaluates to ask.

                    - `allowed_domains: optional array of string`

                    - `blocked_domains: optional array of string`

                    - `user_location: optional BetaManagedAgentsUserLocation or null`

                      Approximate user location for search result localization.

                      - `type: "approximate"`

                        Location precision. Only "approximate" is supported.

                      - `city: optional string or null`

                        City name.

                        minLength: 1, maxLength: 255

                      - `country: optional string or null`

                        Two-letter ISO 3166-1 country code, uppercase.

                      - `region: optional string or null`

                        Region or state name.

                        minLength: 1, maxLength: 255

                      - `timezone: optional string or null`

                        IANA timezone identifier, e.g. "America/Los_Angeles".

                        minLength: 1, maxLength: 255

                - `default_config: BetaManagedAgentsAgentToolsetDefaultConfig`

                  Resolved default configuration for agent tools.

                  - `enabled: boolean`

                  - `permission_policy: BetaManagedAgentsAlwaysAllowPolicy or BetaManagedAgentsAlwaysAskPolicy or BetaManagedAgentsAutoPolicy`

                    Permission policy for tool execution.

                    - `BetaManagedAgentsAlwaysAllowPolicy object`

                      Tool calls are automatically approved without user confirmation.

                    - `BetaManagedAgentsAlwaysAskPolicy object`

                      Tool calls require user confirmation before execution.

                    - `BetaManagedAgentsAutoPolicy object`

                      The server decides each tool call individually: it judges, from the tool, its input, and the session content so far, whether the call is safe to execute or high-risk, and evaluates it to allow when judged safe and to deny when judged high-risk. A call the server cannot reach a judgement on evaluates to ask.

              - `BetaManagedAgentsMCPToolset object`

                - `type: "mcp_toolset"`

                - `configs: array of BetaManagedAgentsMCPToolConfig`

                  - `enabled: boolean`

                  - `name: string`

                  - `permission_policy: BetaManagedAgentsAlwaysAllowPolicy or BetaManagedAgentsAlwaysAskPolicy or BetaManagedAgentsAutoPolicy`

                    Permission policy for tool execution.

                    - `BetaManagedAgentsAlwaysAllowPolicy object`

                      Tool calls are automatically approved without user confirmation.

                    - `BetaManagedAgentsAlwaysAskPolicy object`

                      Tool calls require user confirmation before execution.

                    - `BetaManagedAgentsAutoPolicy object`

                      The server decides each tool call individually: it judges, from the tool, its input, and the session content so far, whether the call is safe to execute or high-risk, and evaluates it to allow when judged safe and to deny when judged high-risk. A call the server cannot reach a judgement on evaluates to ask.

                - `default_config: BetaManagedAgentsMCPToolsetDefaultConfig`

                  Resolved default configuration for all tools from an MCP server.

                  - `enabled: boolean`

                  - `permission_policy: BetaManagedAgentsAlwaysAllowPolicy or BetaManagedAgentsAlwaysAskPolicy or BetaManagedAgentsAutoPolicy`

                    Permission policy for tool execution.

                    - `BetaManagedAgentsAlwaysAllowPolicy object`

                      Tool calls are automatically approved without user confirmation.

                    - `BetaManagedAgentsAlwaysAskPolicy object`

                      Tool calls require user confirmation before execution.

                    - `BetaManagedAgentsAutoPolicy object`

                      The server decides each tool call individually: it judges, from the tool, its input, and the session content so far, whether the call is safe to execute or high-risk, and evaluates it to allow when judged safe and to deny when judged high-risk. A call the server cannot reach a judgement on evaluates to ask.

                - `mcp_server_name: string`

              - `BetaManagedAgentsCustomTool object`

                A custom tool as returned in API responses.

                - `type: "custom"`

                - `description: string`

                - `input_schema: BetaManagedAgentsCustomToolInputSchema`

                  JSON Schema for custom tool input parameters.

                  - `type: "object"`

                  - `properties: optional map[unknown] or null`

                  - `required: optional array of string or null`

                - `name: string`

            - `version: number`

              format: int32

          - `BetaManagedAgentsAdvisor object`

            Platform advisor roster entry: a model the session's primary thread may consult mid-turn.

            - `type: "advisor"`

            - `model: string`

              The advisor model id.

      - `BetaManagedAgentsSessionMultiagent20261001 object`

        Resolved multiagent configuration with three members, as copied to the `session` at creation.

        - `type: "multiagent_20261001"`

        - `advisor: BetaManagedAgentsMultiagentAdvisor`

          Whether the session's primary thread can consult an advisor model.

          - `BetaManagedAgentsMultiagentAdvisorEnabled object`

            The session's primary thread can consult `model` mid-turn.

            - `type: "enabled"`

            - `model: string`

              The advisor model id.

          - `BetaManagedAgentsMultiagentAdvisorDisabled object`

            The agent has no advisor.

            - `type: "disabled"`

        - `subagents: BetaManagedAgentsSessionMultiagentSubagents`

          Whether the agent can spawn session threads.

          - `BetaManagedAgentsSessionMultiagentSubagentsEnabled object`

            The agent can spawn session threads.

            - `type: "enabled"`

            - `inline_agents: BetaManagedAgentsMultiagentInlineAgents`

              Whether the agent can define inline agents, which are not saved, when it spawns session threads.

              - `BetaManagedAgentsMultiagentInlineAgentsEnabled object`

                The agent can define inline agents.

                - `type: "enabled"`

              - `BetaManagedAgentsMultiagentInlineAgentsDisabled object`

                The agent cannot define inline agents.

                - `type: "disabled"`

            - `predefined_agents: array of BetaManagedAgentsSessionThreadAgent`

              Full `agent` definitions of the predefined agents, which are saved agents that this agent can spawn as session threads.

              - `type: "agent"`

              - `id: string`

              - `description: string or null`

              - `execution_identity: BetaManagedAgentsExecutionIdentity`

                Execution principal snapshotted from the agent at session creation. Always present; `{"type": "service_account"}` when runs carry no customer-named principal.

              - `mcp_servers: array of BetaManagedAgentsMCPServerURLDefinition`

              - `model: BetaManagedAgentsModelConfig`

                Model identifier and configuration.

              - `name: string`

              - `skills: array of BetaManagedAgentsAnthropicSkill or BetaManagedAgentsCustomSkill`

              - `system: string or null`

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

              - `version: number`

                format: int32

          - `BetaManagedAgentsMultiagentSubagentsDisabled object`

            The agent cannot spawn session threads.

            - `type: "disabled"`

        - `workflows: BetaManagedAgentsSessionMultiagentWorkflows`

          Whether the agent can start workflow runs.

          - `BetaManagedAgentsSessionMultiagentWorkflowsEnabled object`

            The agent can start workflow runs.

            - `type: "enabled"`

            - `inline_agents: BetaManagedAgentsMultiagentInlineAgents`

              Whether a run's plan can define inline agents, which are not saved.

            - `predefined_agents: array of BetaManagedAgentsSessionThreadAgent`

              Full `agent` definitions of the predefined agents, which are saved agents that a run's plan can use.

              - `type: "agent"`

              - `id: string`

              - `description: string or null`

              - `execution_identity: BetaManagedAgentsExecutionIdentity`

                Execution principal snapshotted from the agent at session creation. Always present; `{"type": "service_account"}` when runs carry no customer-named principal.

              - `mcp_servers: array of BetaManagedAgentsMCPServerURLDefinition`

              - `model: BetaManagedAgentsModelConfig`

                Model identifier and configuration.

              - `name: string`

              - `skills: array of BetaManagedAgentsAnthropicSkill or BetaManagedAgentsCustomSkill`

              - `system: string or null`

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

              - `version: number`

                format: int32

          - `BetaManagedAgentsMultiagentWorkflowsDisabled object`

            The agent cannot start workflow runs.

            - `type: "disabled"`

    - `name: string`

    - `skills: array of BetaManagedAgentsAnthropicSkill or BetaManagedAgentsCustomSkill`

      - `BetaManagedAgentsAnthropicSkill object`

        A resolved Anthropic-managed skill.

      - `BetaManagedAgentsCustomSkill object`

        A resolved user-created custom skill.

    - `system: string or null`

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

      - `BetaManagedAgentsAgentToolset20260401 object`

      - `BetaManagedAgentsMCPToolset object`

      - `BetaManagedAgentsCustomTool object`

        A custom tool as returned in API responses.

    - `version: number`

      format: int32

  - `archived_at: string or null`

    When the session was archived. Null if not archived.

    format: date-time

  - `budget: BetaManagedAgentsBudgetLimit or null`

    The session's enforced spend ceiling, or null when no budget is set.

    - `type: "limit"`

    - `max_list_cost: BetaMonetaryAmount`

      Maximum list cost the session may accrue. List price is used regardless of any negotiated discount, so the cap fires at or before the actual charge.

      - `amount: string`

        Amount in minor units of the currency, as an integer decimal string with no leading zeros: "2500" is $25.00 and "50" is fifty cents. A string rather than a number so no float rounding is ever applied.

      - `currency: BetaCurrency`

        Uppercase ISO-4217 currency code. `USD` is the only currency currently supported; the accepted set is closed and grows only when a new currency is priced.

  - `created_at: string`

    A timestamp in RFC 3339 format

    format: date-time

  - `environment_id: string`

  - `metadata: map[string]`

  - `outcome_evaluations: array of BetaManagedAgentsOutcomeEvaluationResource`

    Per-outcome evaluation state. One entry per `define_outcome` event sent to the session.

    - `type: "outcome_evaluation"`

    - `completed_at: string or null`

      When the outcome reached a terminal result. Null while `pending`/`running`/`evaluating`.

      format: date-time

    - `description: string`

      What the agent should produce.

    - `explanation: string or null`

      Grader's verdict text from the most recent evaluation. For `satisfied`, explains why criteria are met; for `needs_revision` (intermediate), what's missing; for `failed`, why unrecoverable.

    - `iteration: number`

      0-indexed revision cycle the outcome is currently on.

      format: int32

    - `outcome_id: string`

      Server-generated outc_ ID for this outcome.

    - `result: string`

      Current evaluation state. `pending` before the agent begins work; `running` while producing or revising; `evaluating` while the grader scores; `satisfied`/`max_iterations_reached`/`failed`/`interrupted` are terminal.

  - `resources: array of BetaManagedAgentsSessionResource`

    - `BetaManagedAgentsGitHubRepositoryResource object`

      - `type: "github_repository"`

      - `id: string`

      - `created_at: string`

        A timestamp in RFC 3339 format

        format: date-time

      - `mount_path: string`

      - `updated_at: string`

        A timestamp in RFC 3339 format

        format: date-time

      - `url: string`

      - `checkout: optional BetaManagedAgentsBranchCheckout or BetaManagedAgentsCommitCheckout or null`

        - `BetaManagedAgentsBranchCheckout object`

          - `type: "branch"`

          - `name: string`

            Branch name to check out.

            minLength: 1, maxLength: 255

        - `BetaManagedAgentsCommitCheckout object`

          - `type: "commit"`

          - `sha: string`

            Full commit SHA to check out.

            minLength: 7, maxLength: 64

    - `BetaManagedAgentsFileResource object`

      - `type: "file"`

      - `id: string`

      - `created_at: string`

        A timestamp in RFC 3339 format

        format: date-time

      - `file_id: string`

      - `mount_path: string`

      - `updated_at: string`

        A timestamp in RFC 3339 format

        format: date-time

    - `BetaManagedAgentsMemoryStoreResource object`

      A memory store attached to an agent session.

      - `type: "memory_store"`

      - `memory_store_id: string`

        The memory store ID (memstore_...). Must belong to the caller's organization and workspace.

      - `access: optional "read_write" or "read_only" or null`

        Access mode for the mounted store. Defaults to `read_write`. `read_only` mounts the store as a read-only filesystem.

        - `"read_write"`

        - `"read_only"`

      - `description: optional string`

        Description of the memory store, snapshotted at attach time. Rendered into the agent's system prompt. Empty string when the store has no description.

      - `instructions: optional string or null`

        Per-attachment guidance for the agent on how to use this store. Rendered into the memory section of the system prompt. Max 4096 chars.

        maxLength: 4096

      - `mount_path: optional string or null`

        Filesystem path where the store is mounted in the session container, e.g. /mnt/memory/user-preferences. Derived from the store's name. Output-only.

      - `name: optional string or null`

        Display name of the memory store, snapshotted at attach time. Later edits to the store's name do not propagate to this resource.

  - `stats: BetaManagedAgentsSessionStats`

    Timing statistics for the session.

    - `active_seconds: optional number`

      Cumulative time in seconds the session spent in `running` status. Excludes idle time.

      format: double

    - `duration_seconds: optional number`

      Elapsed time since session creation in seconds. For terminated sessions, frozen at the final update.

      format: double

  - `status: "rescheduling" or "running" or "idle" or "terminated"`

    - `"rescheduling"`

      Transient error occurred, retrying automatically.

    - `"running"`

      Agent is actively executing.

    - `"idle"`

      Agent is waiting for input, including user messages or tool confirmations. Sessions start in idle.

    - `"terminated"`

      Session has ended, either due to an error or completion.

  - `title: string or null`

  - `updated_at: string`

    A timestamp in RFC 3339 format

    format: date-time

  - `usage: BetaManagedAgentsSessionUsage`

    Cumulative token usage for the session.

    - `active_seconds: optional number`

      Cumulative time in seconds during which the session had at least one thread in running status. Overlapping activity from concurrent threads is counted once, unlike `stats.active_seconds`, which sums each thread's own active time. This is the duration the session's runtime cost is priced on.

      format: double

    - `cache_creation: optional BetaManagedAgentsCacheCreationUsage`

      Tokens used to create prompt cache entries, broken down by cache TTL.

      - `ephemeral_1h_input_tokens: optional number`

        Tokens used to create 1-hour ephemeral cache entries.

        format: int32

      - `ephemeral_5m_input_tokens: optional number`

        Tokens used to create 5-minute ephemeral cache entries.

        format: int32

    - `cache_read_input_tokens: optional number`

      Total tokens read from prompt cache.

      format: int32

    - `input_tokens: optional number`

      Total input tokens consumed across all turns.

      format: int32

    - `list_cost: optional BetaMonetaryAmount or null`

      Cumulative list cost of the session across all turns, priced at public list rates. Absent until cost tracking is available for the session.

    - `output_tokens: optional number`

      Total output tokens generated across all turns.

      format: int32

    - `server_tool_use: optional BetaManagedAgentsServerToolUsage or null`

      Cumulative server-executed tool usage across all turns. Absent until server-tool tracking is available for the session.

      - `web_fetch_requests: optional number`

        Number of server-executed web fetch requests.

        format: int32

      - `web_search_requests: optional number`

        Number of server-executed web search requests.

        format: int32

  - `vault_ids: array of string`

    Vault IDs attached to the session at creation. Empty when no vaults were supplied.

  - `deployment_id: optional string or null`

    Deployment ID when the session was created from a deployment reference. Null otherwise.

## Example

```bash
curl https://api.anthropic.com/v1/sessions/$SESSION_ID \
    -H 'Content-Type: application/json' \
    -H 'anthropic-version: 2023-06-01' \
    -H 'anthropic-beta: managed-agents-2026-04-01' \
    -H "X-Api-Key: $ANTHROPIC_API_KEY" \
    -d '{
          "title": "Order #1234 inquiry"
        }'
```

### Response (200)

```json
{
  "id": "sesn_011CZkZAtmR3yMPDzynEDxu7",
  "agent": {
    "id": "agent_011CZkYpogX7uDKUyvBTophP",
    "description": "A general-purpose starter agent.",
    "execution_identity": {
      "type": "service_account"
    },
    "mcp_servers": [
      {
        "name": "example-mcp",
        "type": "url",
        "url": "https://example-server.modelcontextprotocol.io/sse"
      }
    ],
    "model": {
      "id": "claude-opus-5-5",
      "effort": {
        "type": "low"
      },
      "inference_geo": "inference_geo",
      "speed": "standard"
    },
    "multiagent": {
      "agents": [
        {
          "id": "agent_011CZkYqphY8vELVzwCUpqiQ",
          "description": "A focused research subagent.",
          "execution_identity": {
            "type": "service_account"
          },
          "mcp_servers": [
            {
              "name": "example-mcp",
              "type": "url",
              "url": "https://example-server.modelcontextprotocol.io/sse"
            }
          ],
          "model": {
            "id": "claude-opus-5-5",
            "effort": {
              "type": "low"
            },
            "inference_geo": "inference_geo",
            "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"
                  },
                  "type": "bash"
                }
              ],
              "default_config": {
                "enabled": true,
                "permission_policy": {
                  "type": "always_ask"
                }
              },
              "type": "agent_toolset_20260401"
            }
          ],
          "type": "agent",
          "version": 1
        }
      ],
      "type": "coordinator"
    },
    "name": "My First Agent",
    "skills": [
      {
        "skill_id": "xlsx",
        "type": "anthropic",
        "version": "1"
      },
      {
        "skill_id": "skill_011CZkZFNu9hAbo3jZPRgTmx",
        "type": "custom",
        "version": "2"
      }
    ],
    "system": "You are a general-purpose agent that can research, write code, run commands, and use connected tools to complete the user's task end to end.",
    "tools": [
      {
        "configs": [
          {
            "enabled": true,
            "name": "bash",
            "permission_policy": {
              "type": "always_allow"
            },
            "type": "bash"
          }
        ],
        "default_config": {
          "enabled": true,
          "permission_policy": {
            "type": "always_ask"
          }
        },
        "type": "agent_toolset_20260401"
      }
    ],
    "type": "agent",
    "version": 1
  },
  "archived_at": null,
  "budget": {
    "max_list_cost": {
      "amount": "2500",
      "currency": "USD"
    },
    "type": "limit"
  },
  "created_at": "2026-03-15T10:00:00Z",
  "environment_id": "env_011CZkZ9X2dpNyB7HsEFoRfW",
  "metadata": {},
  "outcome_evaluations": [
    {
      "completed_at": "2026-03-15T10:02:31Z",
      "description": "Produce a 2-page summary as summary.md",
      "explanation": "All five sections present with inline citations.",
      "iteration": 0,
      "outcome_id": "outc_011CZkZRSw2kEfs6ncTVmjxP",
      "result": "satisfied",
      "type": "outcome_evaluation"
    }
  ],
  "resources": [
    {
      "id": "sesrsc_011CZkZBJq5dWxk9fVLNcPht",
      "created_at": "2026-03-15T10:00:00Z",
      "file_id": "file_011CNha8iCJcU1wXNR6q4V8w",
      "mount_path": "/uploads/receipt.pdf",
      "type": "file",
      "updated_at": "2026-03-15T10:00:00Z"
    },
    {
      "id": "sesrsc_011CZkZCKr6eXym1gWMPdQiu",
      "created_at": "2026-03-15T10:00:00Z",
      "mount_path": "/workspace/example-repo",
      "type": "github_repository",
      "updated_at": "2026-03-15T10:00:00Z",
      "url": "https://github.com/example-org/example-repo",
      "checkout": {
        "name": "main",
        "type": "branch"
      }
    }
  ],
  "stats": {
    "active_seconds": 0,
    "duration_seconds": 0
  },
  "status": "idle",
  "title": "Order #1234 inquiry",
  "type": "session",
  "updated_at": "2026-03-15T10:00:00Z",
  "usage": {
    "active_seconds": 0,
    "cache_creation": {
      "ephemeral_1h_input_tokens": 0,
      "ephemeral_5m_input_tokens": 0
    },
    "cache_read_input_tokens": 0,
    "input_tokens": 0,
    "list_cost": {
      "amount": "2500",
      "currency": "USD"
    },
    "output_tokens": 0,
    "server_tool_use": {
      "web_fetch_requests": 0,
      "web_search_requests": 3
    }
  },
  "vault_ids": [
    "vlt_011CZkZDLs7fYzm1hXNPeRjv"
  ],
  "deployment_id": "deployment_id"
}
```
