Tool Router

Patch a tool router session config (v3.1)

Partially updates the configuration of an existing tool router session. Only the fields provided in the request body will be updated. Uses optimistic concurrency control to prevent lost updates. The previous config is stored in config history.

patch/api/v3.1/tool_router/session/{session_id}

Path parameters

session_idstring toolRouterSessionId required

The unique identifier of the tool router session

Example:trs_1a2b3c4d5e6f

The unique identifier of the tool router session

Request body

auth_configsobject

The auth configs to use for the session. This will override the default behavior and use the given auth config when specific toolkits are being executed

connected_accountsobject nullable

The connected accounts to use for the session, as an array of nano-IDs per toolkit. This overrides the default behaviour and pins specific connected accounts when toolkits are executed. Each account must exist (not deleted or disabled) and belong to the same user_id as the session. Multi-account sessions can pin multiple; non-multi-account sessions are capped at length 1.

toolsobject

Tool-level configuration per toolkit. Allows you to enable, disable, or filter by tags for specific tools within each toolkit. Every slug passed in enable / disable must be a valid Composio tool slug for that toolkit — invalid or typo'd slugs fail session creation with a clear error listing which ones didn't match.

Example request

{
  "toolkits": {
    "enable": [
      "gmail",
      "slack",
      "github"
    ]
  },
  "auth_configs": {
    "gmail": "ac_1a2b3c4d5e6f",
    "slack": "ac_7g8h9i0j1k2l"
  },
  "manage_connections": {
    "enable": true,
    "callback_url": "https://your-app.com/auth/callback"
  },
  "tools": {
    "gmail": {
      "enable": [
        "GMAIL_SEND_EMAIL",
        "GMAIL_FETCH_EMAILS"
      ]
    },
    "slack": {
      "disable": [
        "SLACK_ADD_EMOJI"
      ]
    },
    "slackbot": {
      "tags": {
        "enable": [
          "destructiveHint"
        ],
        "disable": [
          "openWorldHint"
        ]
      }
    }
  },
  "workbench": {
    "enable": true,
    "enable_proxy_execution": true,
    "auto_offload_threshold": 20000,
    "sandbox_size": "large"
  },
  "multi_account": {
    "enable": true,
    "max_accounts_per_toolkit": 5
  }
}

Response

Session config successfully patched.

session_idstring toolRouterSessionId required

The identifier of the session

tool_router_toolsstring[] required

List of available tools in this session

config_versioninteger required

Monotonic version of the config. Incremented on each PATCH. Use for optimistic concurrency control.

Example response

{
  "session_id": "trs_1a2b3c4d5e6f",
  "mcp": {
    "url": "https://app.composio.dev/tool_router/v3/trs_1a2b3c4d5e6f/mcp"
  },
  "warnings": [
    {
      "code": "PRELOAD_TOOLS_HIGH_CONTEXT_USAGE",
      "message": "Session preloads 25 tools; each preloaded tool adds to the agent context window. Consider keeping the list at or under ~20 tools."
    }
  ]
}

Changes

Changed in 4 of the 61 revisions of this API.412

Jun 17, 2026589a7d115a5e2See the full diff
- ○
  the endpoint scheme security CookieAuth was removed from the API
  api-security-removed
- ○
  the endpoint scheme security UserApiKeyAuth was removed from the API
  api-security-removed
May 6, 20266ccbbc3d49b932See the full diff
- ▲
  the connected_accounts/additionalProperties/ request property's minItems was increased to 1
  request-property-min-items-increased
- ▲
  the connected_accounts/additionalProperties/ request property type/format changed from string/connectedAccountId to array/
  request-property-type-changed
- ▲
  the config/connected_accounts/additionalProperties/ response's property type/format changed from string/connectedAccountId to array/ for status 200
  response-property-type-changed
- ○
  added the new optional request property experimental/link_url_overwrite
  new-optional-request-property
- ○
  the request property connected_accounts became nullable
  request-property-became-nullable
May 5, 20265a3709be76a717See the full diff
- ▲
  response property config/preload/tools list-of-types was widened by adding types string to media type application/json of response 200
  response-property-list-of-types-widened
- ○
  added the new optional request property execute
  new-optional-request-property
- ○
  added the new optional request property search
  new-optional-request-property
- ○
  added the new ask_always enum value to the request property experimental/permissions/overrides/additionalProperties/
  request-property-enum-value-added
- ○
  added the new ask_once enum value to the request property experimental/permissions/overrides/additionalProperties/
  request-property-enum-value-added
- ○
  request property preload/tools list-of-types was widened by adding types string to media type application/json
  request-property-list-of-types-widened
- ○
  added the required property config/execute to the response with the 200 status
  response-required-property-added
- ○
  added the required property config/search to the response with the 200 status
  response-required-property-added
This revision also has 1 change that name no endpoint, such as unreferenced schemas being removed. See the revision's changelog
May 5, 202652c71f747c651See the full diff
- ○
  endpoint added
  endpoint-added

Full history