> ## 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. # Start one evaluation session per target > Resolves a bounded target set, then starts one public evaluation root session per target. All items share an evaluation_batch_id. Each item reports its own session id or start error because a later target can fail after earlier sessions commit. A stopped target workspace is cloned and bound to an unchanged transcript watermark before the evaluator runs; an active or incoherent target is rejected. ## OpenAPI ````yaml /recursion/openapi.yaml post /managed-agents/v1/evaluations openapi: 3.1.0 info: title: Managed Agents API version: 0.15.0 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/evaluations: post: tags: - Evaluations summary: Start one evaluation session per target description: >- Resolves a bounded target set, then starts one public evaluation root session per target. All items share an evaluation_batch_id. Each item reports its own session id or start error because a later target can fail after earlier sessions commit. A stopped target workspace is cloned and bound to an unchanged transcript watermark before the evaluator runs; an active or incoherent target is rejected. operationId: managedAgentsStartEvaluations parameters: - $ref: '#/components/parameters/RecursionTenantId' - $ref: '#/components/parameters/RecursionOrganizationId' requestBody: content: application/json: schema: $ref: '#/components/schemas/StandaloneStartEvaluationsRequest' required: true responses: '200': content: application/json: schema: $ref: '#/components/schemas/EvaluationBatchStartResult' description: OK headers: recursion-organization-id: $ref: '#/components/headers/RecursionOrganizationId' recursion-tenant-id: $ref: '#/components/headers/RecursionTenantId' '400': description: Bad Request. content: application/json: schema: oneOf: - $ref: '#/components/schemas/ManagedAgentsApiErrorInvalidJson' - $ref: '#/components/schemas/ManagedAgentsApiErrorInvalidRequest' discriminator: propertyName: code mapping: invalid_json: '#/components/schemas/ManagedAgentsApiErrorInvalidJson' invalid_request: '#/components/schemas/ManagedAgentsApiErrorInvalidRequest' x-recursion-error-codes: - invalid_json - 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' '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' '415': description: Unsupported Media Type. content: application/json: schema: $ref: '#/components/schemas/ManagedAgentsApiErrorUnsupportedMediaType' x-recursion-error-codes: - unsupported_media_type 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: StandaloneStartEvaluationsRequest: properties: criteria: $ref: '#/components/schemas/EvaluationCriteriaRequest' description: >- The criteria every evaluation in this batch checks, in order: structured criteria, or (deprecated) a keyed markdown rubric. Omit to use the evaluator agent's default criteria. x-recursion-omission: source: evaluator agent default_rubric strategy: derive evaluatorAgentId: description: Agent whose prompt, model and limits judge each target. format: uuid type: string evaluatorAgentVersionId: description: >- Optional immutable evaluator version. Omit to use its latest version. format: uuid type: string x-recursion-omission: source: latest version of evaluatorAgentId strategy: derive projectId: description: >- Project billed for evaluator model calls. Omit to use each target session's project. type: string x-recursion-omission: source: target session project strategy: derive targets: $ref: '#/components/schemas/EvaluationBatchSelectorRequest' description: >- Explicit target session ids, or newest sessions selected by statuses, limit and optional agent_ids. A batch starts at most 20 targets. required: - evaluatorAgentId - targets type: object additionalProperties: false EvaluationBatchStartResult: properties: evaluationBatchId: format: uuid type: string items: items: $ref: '#/components/schemas/EvaluationBatchStartItem' type: array required: - evaluationBatchId - items type: object additionalProperties: false ManagedAgentsApiErrorInvalidJson: type: object properties: code: type: string minLength: 1 description: Stable machine-readable error code. enum: - invalid_json 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. 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. 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. ManagedAgentsApiErrorUnsupportedMediaType: type: object properties: code: type: string minLength: 1 description: Stable machine-readable error code. enum: - unsupported_media_type 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. EvaluationCriteriaRequest: anyOf: - $ref: '#/components/schemas/EvaluationCriteriaList' - type: string EvaluationBatchSelectorRequest: examples: - session_ids: - session-id oneOf: - additionalProperties: false properties: session_ids: description: >- Explicit target session ids. Every id must be an eligible session visible to the caller or no run is created. items: minLength: 1 pattern: >- ^[^\u0009-\u000d\u0020\u0085\u00a0\u1680\u2000-\u200a\u2028\u2029\u202f\u205f\u3000](?:[\s\S]*[^\u0009-\u000d\u0020\u0085\u00a0\u1680\u2000-\u200a\u2028\u2029\u202f\u205f\u3000])?$ type: string maxItems: 20 minItems: 1 type: array uniqueItems: true required: - session_ids type: object - additionalProperties: false properties: agent_ids: description: >- Optional target agent ids with status selection, applied before the newest-first limit. items: minLength: 1 pattern: >- ^[^\u0009-\u000d\u0020\u0085\u00a0\u1680\u2000-\u200a\u2028\u2029\u202f\u205f\u3000](?:[\s\S]*[^\u0009-\u000d\u0020\u0085\u00a0\u1680\u2000-\u200a\u2028\u2029\u202f\u205f\u3000])?$ type: string maxItems: 100 type: array uniqueItems: true x-recursion-omission: strategy: absent limit: description: Maximum newest matching sessions selected by statuses. maximum: 20 minimum: 1 type: integer statuses: description: >- Eligible target statuses. Used with limit to choose the newest matching sessions. items: $ref: '#/components/schemas/SessionStatus' maxItems: 5 minItems: 1 type: array uniqueItems: true required: - statuses - limit type: object EvaluationBatchStartItem: properties: errorCode: enum: - invalid_request - not_found - conflict - forbidden - unavailable - rate_limited - too_large - unprocessable - evaluation_start_failed type: string errorMessage: type: string evaluationSessionId: format: uuid type: string targetSessionId: format: uuid type: string required: - targetSessionId type: object additionalProperties: false 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. EvaluationCriteriaList: description: Structured criteria, in order. They render to at most 256 KiB. items: $ref: '#/components/schemas/CriterionConfig' maxItems: 200 minItems: 1 type: array SessionStatus: description: Coarse session state shared by Managed Agents and imported RL rollouts. enum: - active - awaiting_human - completed - failed - cancelled type: string 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: $ref: '#/components/schemas/PlatformSafeJsonValue' type: object CriterionConfig: description: One keyed rubric criterion. properties: criterion_key: description: >- Stable key of the criterion: a lowercase slug, unique within the rubric. Verdicts and revision feedback cite it, so it keeps identifying the criterion when its text is edited. maxLength: 64 minLength: 1 pattern: ^[a-z][a-z0-9]*(?:[-_][a-z0-9]+)*$ type: string criterion_text: description: >- What the evaluator checks, as one line. Criteria must be independently checkable: 'the CSV has a numeric price column' can be verified, 'the data looks good' cannot. maxLength: 4096 minLength: 1 type: string label: description: >- Short display name of the criterion, as one trimmed line of at most 80 characters, frozen onto every verdict that scores it. Omit to display the key. maxLength: 80 minLength: 1 type: string section: description: Heading the criterion is grouped under, as one line. Omit for none. maxLength: 4096 type: string required: - criterion_key - criterion_text type: object additionalProperties: false 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. ````