> ## Documentation Index > Fetch the complete documentation index at: https://docs.labelbox.com/llms.txt > Use this file to discover all available pages before exploring further. # Get the agent version a session runs > Returns the version of its agent a root session runs now, the version it is set to run, whether a move is pending or was refused, the agent's latest version, and how far each open thread of the session tree has followed. The state changes as the session works, so read it again rather than keeping a copy. A session that is a member of another session's tree answers 409 conflict; read its root. A session that was not started from an agent has no version to read and answers 409 conflict too. ## OpenAPI ````yaml /recursion/openapi.yaml get /managed-agents/v1/sessions/{sessionId}/agent-version openapi: 3.1.0 info: title: Managed Agents API version: 0.14.0 description: >- The Recursion Managed Agents REST API. Authenticate with a Recursion API key as a bearer token. An organization-scoped key acts in its own organization and needs nothing else; a tenant-scoped key must also send `x-organization-id` with an organization id or `default`. Field names follow each operation's published schema. servers: - url: https://api.recursion.labelbox.com security: - bearerAuth: [] paths: /managed-agents/v1/sessions/{sessionId}/agent-version: get: tags: - Sessions summary: Get the agent version a session runs description: >- Returns the version of its agent a root session runs now, the version it is set to run, whether a move is pending or was refused, the agent's latest version, and how far each open thread of the session tree has followed. The state changes as the session works, so read it again rather than keeping a copy. A session that is a member of another session's tree answers 409 conflict; read its root. A session that was not started from an agent has no version to read and answers 409 conflict too. operationId: managedAgentsGetSessionAgentVersion parameters: - description: >- Session id (UUID) as returned by managedAgentsStartSession or managedAgentsListSessions. in: path name: sessionId required: true schema: description: >- Session id (UUID) as returned by managedAgentsStartSession or managedAgentsListSessions. format: uuid type: string - $ref: '#/components/parameters/RecursionTenantId' - $ref: '#/components/parameters/RecursionOrganizationId' responses: '200': content: application/json: schema: $ref: '#/components/schemas/SessionAgentVersion' description: >- The agent version a root session runs, the move waiting to take effect if any, and how far each member of the session tree has followed. headers: recursion-organization-id: $ref: '#/components/headers/RecursionOrganizationId' recursion-tenant-id: $ref: '#/components/headers/RecursionTenantId' '400': description: Bad Request. content: application/json: schema: $ref: '#/components/schemas/ManagedAgentsApiErrorInvalidRequest' x-recursion-error-codes: - invalid_request headers: recursion-organization-id: $ref: '#/components/headers/RecursionOrganizationId' recursion-tenant-id: $ref: '#/components/headers/RecursionTenantId' '401': description: Unauthorized. content: application/json: schema: $ref: '#/components/schemas/ManagedAgentsApiErrorUnauthorized' x-recursion-error-codes: - unauthorized headers: recursion-organization-id: $ref: '#/components/headers/RecursionOrganizationId' recursion-tenant-id: $ref: '#/components/headers/RecursionTenantId' '403': description: Forbidden. content: application/json: schema: $ref: '#/components/schemas/ManagedAgentsApiErrorForbidden' x-recursion-error-codes: - forbidden headers: recursion-organization-id: $ref: '#/components/headers/RecursionOrganizationId' recursion-tenant-id: $ref: '#/components/headers/RecursionTenantId' '404': description: Not Found. content: application/json: schema: $ref: '#/components/schemas/ManagedAgentsApiErrorNotFound' x-recursion-error-codes: - not_found headers: recursion-organization-id: $ref: '#/components/headers/RecursionOrganizationId' recursion-tenant-id: $ref: '#/components/headers/RecursionTenantId' '409': description: Conflict. content: application/json: schema: $ref: '#/components/schemas/ManagedAgentsApiErrorConflict' x-recursion-error-codes: - conflict headers: recursion-organization-id: $ref: '#/components/headers/RecursionOrganizationId' recursion-tenant-id: $ref: '#/components/headers/RecursionTenantId' '413': description: Payload Too Large. content: application/json: schema: $ref: '#/components/schemas/ManagedAgentsApiErrorPayloadTooLarge' x-recursion-error-codes: - payload_too_large headers: recursion-organization-id: $ref: '#/components/headers/RecursionOrganizationId' recursion-tenant-id: $ref: '#/components/headers/RecursionTenantId' '429': headers: Retry-After: description: When to retry, as delay seconds or an HTTP date. schema: type: string recursion-organization-id: $ref: '#/components/headers/RecursionOrganizationId' recursion-tenant-id: $ref: '#/components/headers/RecursionTenantId' description: Too Many Requests. content: application/json: schema: $ref: '#/components/schemas/ManagedAgentsApiErrorRateLimitExceeded' x-recursion-error-codes: - rate_limit_exceeded '500': description: Internal Server Error. content: application/json: schema: $ref: '#/components/schemas/ManagedAgentsApiErrorInternalError' x-recursion-error-codes: - internal_error headers: recursion-organization-id: $ref: '#/components/headers/RecursionOrganizationId' recursion-tenant-id: $ref: '#/components/headers/RecursionTenantId' '502': description: A dependent service returned an invalid response. content: application/json: schema: $ref: '#/components/schemas/ManagedAgentsApiErrorDependencyFailure' x-recursion-error-codes: - bad_gateway headers: recursion-organization-id: $ref: '#/components/headers/RecursionOrganizationId' recursion-tenant-id: $ref: '#/components/headers/RecursionTenantId' '503': headers: Retry-After: description: When to retry, as delay seconds or an HTTP date. schema: type: string recursion-organization-id: $ref: '#/components/headers/RecursionOrganizationId' recursion-tenant-id: $ref: '#/components/headers/RecursionTenantId' description: Service Unavailable. content: application/json: schema: oneOf: - $ref: >- #/components/schemas/ManagedAgentsApiErrorManagedAgentsUnavailable - $ref: >- #/components/schemas/ManagedAgentsApiErrorServiceUnavailable discriminator: propertyName: code mapping: managed_agents_unavailable: >- #/components/schemas/ManagedAgentsApiErrorManagedAgentsUnavailable service_unavailable: >- #/components/schemas/ManagedAgentsApiErrorServiceUnavailable x-recursion-error-codes: - managed_agents_unavailable - service_unavailable '504': headers: Retry-After: description: When to retry, as delay seconds or an HTTP date. schema: type: string recursion-organization-id: $ref: '#/components/headers/RecursionOrganizationId' recursion-tenant-id: $ref: '#/components/headers/RecursionTenantId' description: A dependent service timed out. content: application/json: schema: $ref: '#/components/schemas/ManagedAgentsApiErrorDependencyTimeout' x-recursion-error-codes: - gateway_timeout components: parameters: RecursionTenantId: name: x-tenant-id in: header required: false description: >- Optional tenant consistency check. When present, it must name the tenant bound to the API key, including when x-organization-id is `default`. schema: type: string minLength: 1 RecursionOrganizationId: name: x-organization-id in: header required: false description: >- Organization in which to act. Required for a tenant-scoped API key. Optional for an organization-scoped key, where it must name that same organization. The value may be an organization id or `default`. schema: type: string minLength: 1 schemas: SessionAgentVersion: additionalProperties: false description: >- The agent version a root session runs, the move waiting to take effect if any, and how far each member of the session tree has followed. properties: agentVersionId: description: >- Version the session is set to run: the pending version while a move is waiting, otherwise the version it runs now. format: uuid type: string currentAgentVersionId: description: Version the session runs now. format: uuid readOnly: true type: string currentVersion: description: >- Number of currentAgentVersionId within its agent. Absent when the number can no longer be read. format: int64 minimum: 1 readOnly: true type: integer maximum: 9007199254740991 lastFailure: anyOf: - type: 'null' - $ref: '#/components/schemas/SessionAgentVersionFailure' description: >- Why the most recent move was refused, or null. Null while a newer move is pending. readOnly: true latestAgentVersion: anyOf: - type: 'null' - $ref: '#/components/schemas/SessionAgentVersionRef' description: The agent's newest version, or null when the agent has been deleted. readOnly: true members: description: >- The root session and every open thread of its tree, root first, with how far each has followed the root. items: $ref: '#/components/schemas/SessionAgentVersionMember' readOnly: true type: array pending: anyOf: - type: 'null' - $ref: '#/components/schemas/SessionAgentVersionPending' description: The move waiting to take effect, or null. readOnly: true state: description: >- current: nothing is waiting. pending: agentVersionId takes effect before the session's next model call. failed: the last move was refused and the session stayed on currentAgentVersionId; lastFailure says why. enum: - current - pending - failed readOnly: true type: string required: - agentVersionId - currentAgentVersionId - state - pending - lastFailure - latestAgentVersion - members type: object ManagedAgentsApiErrorInvalidRequest: type: object properties: code: type: string minLength: 1 description: Stable machine-readable error code. enum: - invalid_request message: type: string minLength: 1 description: Human-readable error message. details: $ref: '#/components/schemas/ManagedAgentsApiErrorDetails' description: >- Optional structured error details. Reserved transport fields are typed; code-specific fields remain forward compatible. required: - code - message additionalProperties: false description: Standard flat error response. ManagedAgentsApiErrorUnauthorized: type: object properties: code: type: string minLength: 1 description: Stable machine-readable error code. enum: - unauthorized message: type: string minLength: 1 description: Human-readable error message. details: $ref: '#/components/schemas/ManagedAgentsApiErrorDetails' description: >- Optional structured error details. Reserved transport fields are typed; code-specific fields remain forward compatible. required: - code - message additionalProperties: false description: Standard flat error response. ManagedAgentsApiErrorForbidden: type: object properties: code: type: string minLength: 1 description: Stable machine-readable error code. enum: - forbidden message: type: string minLength: 1 description: Human-readable error message. details: $ref: '#/components/schemas/ManagedAgentsApiErrorDetails' description: >- Optional structured error details. Reserved transport fields are typed; code-specific fields remain forward compatible. required: - code - message additionalProperties: false description: Standard flat error response. ManagedAgentsApiErrorNotFound: type: object properties: code: type: string minLength: 1 description: Stable machine-readable error code. enum: - not_found message: type: string minLength: 1 description: Human-readable error message. details: $ref: '#/components/schemas/ManagedAgentsApiErrorDetails' description: >- Optional structured error details. Reserved transport fields are typed; code-specific fields remain forward compatible. required: - code - message additionalProperties: false description: Standard flat error response. ManagedAgentsApiErrorConflict: type: object properties: code: type: string minLength: 1 description: Stable machine-readable error code. enum: - conflict message: type: string minLength: 1 description: Human-readable error message. details: $ref: '#/components/schemas/ManagedAgentsApiErrorDetails' description: >- Optional structured error details. Reserved transport fields are typed; code-specific fields remain forward compatible. required: - code - message additionalProperties: false description: Standard flat error response. ManagedAgentsApiErrorPayloadTooLarge: type: object properties: code: type: string minLength: 1 description: Stable machine-readable error code. enum: - payload_too_large message: type: string minLength: 1 description: Human-readable error message. details: $ref: '#/components/schemas/ManagedAgentsApiErrorDetails' description: >- Optional structured error details. Reserved transport fields are typed; code-specific fields remain forward compatible. required: - code - message additionalProperties: false description: Standard flat error response. ManagedAgentsApiErrorRateLimitExceeded: type: object properties: code: type: string minLength: 1 description: Stable machine-readable error code. enum: - rate_limit_exceeded message: type: string minLength: 1 description: Human-readable error message. details: $ref: '#/components/schemas/ManagedAgentsApiErrorDetails' description: >- Optional structured error details. Reserved transport fields are typed; code-specific fields remain forward compatible. required: - code - message additionalProperties: false description: Standard flat error response. ManagedAgentsApiErrorInternalError: type: object properties: code: type: string minLength: 1 description: Stable machine-readable error code. enum: - internal_error message: type: string minLength: 1 description: Human-readable error message. details: $ref: '#/components/schemas/ManagedAgentsApiErrorDetails' description: >- Optional structured error details. Reserved transport fields are typed; code-specific fields remain forward compatible. required: - code - message additionalProperties: false description: Standard flat error response. ManagedAgentsApiErrorDependencyFailure: type: object properties: code: type: string minLength: 1 description: Stable machine-readable error code. enum: - bad_gateway message: type: string minLength: 1 description: Human-readable error message. details: $ref: '#/components/schemas/ManagedAgentsApiErrorDetails' description: >- Optional structured error details. Reserved transport fields are typed; code-specific fields remain forward compatible. required: - code - message additionalProperties: false description: Standard flat error response. ManagedAgentsApiErrorManagedAgentsUnavailable: type: object properties: code: type: string minLength: 1 description: Stable machine-readable error code. enum: - managed_agents_unavailable message: type: string minLength: 1 description: Human-readable error message. details: $ref: '#/components/schemas/ManagedAgentsApiErrorDetails' description: >- Optional structured error details. Reserved transport fields are typed; code-specific fields remain forward compatible. required: - code - message additionalProperties: false description: Standard flat error response. ManagedAgentsApiErrorServiceUnavailable: type: object properties: code: type: string minLength: 1 description: Stable machine-readable error code. enum: - service_unavailable message: type: string minLength: 1 description: Human-readable error message. details: $ref: '#/components/schemas/ManagedAgentsApiErrorDetails' description: >- Optional structured error details. Reserved transport fields are typed; code-specific fields remain forward compatible. required: - code - message additionalProperties: false description: Standard flat error response. ManagedAgentsApiErrorDependencyTimeout: type: object properties: code: type: string minLength: 1 description: Stable machine-readable error code. enum: - gateway_timeout message: type: string minLength: 1 description: Human-readable error message. details: $ref: '#/components/schemas/ManagedAgentsApiErrorDetails' description: >- Optional structured error details. Reserved transport fields are typed; code-specific fields remain forward compatible. required: - code - message additionalProperties: false description: Standard flat error response. SessionAgentVersionFailure: additionalProperties: false properties: agentVersionId: description: >- Version that was refused. For a member of the tree that names no version of its own, the version the session moved to. format: uuid type: string at: description: When the move was refused. format: date-time type: string code: description: >- Stable reason for the refusal. Current values: agent_unavailable, agent_version_unavailable, agent_changed, session_not_eligible, evaluation_toolset, model_not_allowed, model_unavailable, model_config_invalid, project_required, configuration_invalid, and temporarily_unavailable (send the request again). The list may grow; clients must accept values not listed here. type: string message: description: One fixed sentence explaining code. type: string version: description: >- Number of that version within its agent. Absent when it is not known. format: int64 minimum: 1 type: integer maximum: 9007199254740991 required: - agentVersionId - code - message - at type: object SessionAgentVersionRef: additionalProperties: false properties: agentVersionId: description: Agent version id. format: uuid type: string version: description: >- Number of the version within its agent. Absent when the version has been deleted. format: int64 minimum: 1 type: integer maximum: 9007199254740991 required: - agentVersionId type: object SessionAgentVersionMember: additionalProperties: false properties: adoption: description: >- How far the member has followed the root. current: nothing to adopt. pending: it is running and adopts before its next model call. idle: it is not running and adopts when it is next given work. failed: its move was refused; failure says why. retained: it keeps the configuration it has, because its parent is closed or could not adopt, or its roster entry was removed. enum: - current - pending - idle - failed - retained type: string agentVersionId: description: >- Version the member runs now. Absent for a member with no agent of its own. format: uuid type: string failure: $ref: '#/components/schemas/SessionAgentVersionFailure' description: >- Why the member's move was refused. Present only when adoption is failed. name: description: Name the thread was given when it was created. Empty for the root. type: string role: description: >- What the member's configuration comes from. root: the session itself. self: a copy of its parent's own agent. worker: a thread with no agent of its own, which takes its parent's model and tools. roster: another agent named by the parent's roster. enum: - root - self - worker - roster type: string sessionId: description: The member's session id. format: uuid type: string version: description: >- Number of agentVersionId within its agent. Absent when agentVersionId is, or when the member runs a version of another agent. format: int64 minimum: 1 type: integer maximum: 9007199254740991 required: - sessionId - name - role - adoption type: object SessionAgentVersionPending: additionalProperties: false properties: agentVersionId: description: Version the session moves to. format: uuid type: string requestedAt: description: When the move was requested. format: date-time type: string requestedByUserId: description: User who requested the move. Absent when no user made the request. type: string version: description: >- Number of that version within its agent. Absent when the version has been deleted. format: int64 minimum: 1 type: integer maximum: 9007199254740991 required: - agentVersionId - requestedAt type: object ManagedAgentsApiErrorDetails: type: object properties: field: description: >- Request field or header responsible for the error, when one can be identified. type: string issues: description: >- Boundary-validation failures as path-prefixed human-readable messages. type: array items: type: string requestId: description: Request correlation identifier for support and log lookup. type: string retryable: description: >- Server advice about failure transience. `true` means transient, `false` means non-transient, and absence gives no advice. Automatic replay is allowed only when this field is not `false` and the operation-specific retry and idempotency contract permits replay. type: boolean additionalProperties: $ref: '#/components/schemas/PlatformSafeJsonValue' description: >- Optional structured error details. Reserved transport fields are typed; code-specific fields remain forward compatible. PlatformSafeJsonValue: description: >- A JSON value whose integer members stay within the exact ECMAScript safe-integer range at every nesting level. oneOf: - type: 'null' - type: boolean - type: string - type: integer minimum: -9007199254740991 maximum: 9007199254740991 - type: number not: type: integer - type: array items: $ref: '#/components/schemas/PlatformSafeJsonValue' - additionalProperties: $ref: '#/components/schemas/PlatformSafeJsonValue' type: object headers: RecursionOrganizationId: description: Organization id resolved for this request. schema: type: string minLength: 1 RecursionTenantId: description: Tenant id resolved for this request. schema: type: string minLength: 1 securitySchemes: bearerAuth: type: http scheme: bearer description: A Recursion API key, created in the console under API keys. ````