> ## Documentation Index > Fetch the complete documentation index at: https://docs.getarbol.com/llms.txt > Use this file to discover all available pages before exploring further. # Get a definition > Returns one tenant-owned Definition under definitions:read with explicitly requested options or usage. It is side-effect free and safe to retry. ## OpenAPI ````yaml https://api.getarbol.com/openapi.json get /definitions/{id} openapi: 3.1.2 info: contact: email: support@getarbol.com name: Arbol url: https://docs.getarbol.com description: >- Provider-neutral API for creating and operating Arbol agents, contacts, conversations, channels, knowledge, integrations, and evaluations. Every request is bound to one Auth0 Organization. title: Arbol API version: 1.0.0 servers: - description: Production url: https://api.getarbol.com/v1 security: [] paths: /definitions/{id}: get: tags: - Definitions summary: Get a definition description: >- Returns one tenant-owned Definition under definitions:read with explicitly requested options or usage. It is side-effect free and safe to retry. operationId: getDefinition parameters: - in: path required: true name: id schema: $ref: '#/components/schemas/ArbolResourceId' - in: query name: expand schema: maxItems: 2 type: array items: type: string enum: - options - usage allowEmptyValue: true allowReserved: true explode: false responses: '200': description: OK content: application/json: schema: $ref: '#/components/schemas/DefinitionOutput' headers: X-Request-Id: $ref: '#/components/headers/RequestId' '400': description: >- Inferable validation failure or a non-inferable malformed transport request. content: application/json: schema: oneOf: - oneOf: - $ref: '#/components/schemas/BadRequest' - $ref: '#/components/schemas/UndefinedError' - $ref: '#/components/schemas/TransportBadRequestError' headers: X-Request-Id: $ref: '#/components/headers/RequestId' '401': description: Authentication is required. content: application/json: schema: oneOf: - $ref: '#/components/schemas/Unauthorized' - $ref: '#/components/schemas/UndefinedError' headers: X-Request-Id: $ref: '#/components/headers/RequestId' '403': description: The caller is not allowed to perform this operation. content: application/json: schema: oneOf: - $ref: '#/components/schemas/Forbidden' - $ref: '#/components/schemas/UndefinedError' headers: X-Request-Id: $ref: '#/components/headers/RequestId' '404': description: Definition not found content: application/json: schema: oneOf: - $ref: '#/components/schemas/NotFound' - $ref: '#/components/schemas/UndefinedError' headers: X-Request-Id: $ref: '#/components/headers/RequestId' security: - userOAuth: - org:use - definitions:read - machineOAuth: - definitions:read components: schemas: ArbolResourceId: type: string maxLength: 64 pattern: >- ^[a-z][a-z0-9]{1,15}_[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12}$ description: >- Opaque Arbol resource identifier; the endpoint and tenant-scoped lookup determine its resource type. examples: - agt_018f47a2-4f4d-7d61-9e2c-1d7b8e9a0c31 title: Arbol resource ID DefinitionOutput: type: object properties: agentIds: maxItems: 50 type: array items: $ref: '#/components/schemas/ArbolResourceId' createdAt: $ref: '#/components/schemas/IsoDatetime' description: anyOf: - type: string maxLength: 2000 - type: 'null' id: $ref: '#/components/schemas/ArbolResourceId' identifier: type: string minLength: 1 maxLength: 100 kind: $ref: '#/components/schemas/DefinitionKind' prompt: anyOf: - type: string maxLength: 4000 - type: 'null' revision: type: integer exclusiveMinimum: 0 maximum: 9007199254740991 schemaVersion: type: integer exclusiveMinimum: 0 maximum: 9007199254740991 status: $ref: '#/components/schemas/DefinitionStatus' subjectKind: $ref: '#/components/schemas/DefinitionSubject' unitCode: anyOf: - type: string maxLength: 40 - type: 'null' updatedAt: $ref: '#/components/schemas/IsoDatetime' valueType: $ref: '#/components/schemas/DefinitionValueType' options: maxItems: 100 type: array items: $ref: '#/components/schemas/DefinitionOption' usage: type: object properties: factCount: type: integer minimum: 0 maximum: 9007199254740991 lastObservedAt: anyOf: - $ref: '#/components/schemas/IsoDatetime' - type: 'null' subjectCount: type: integer minimum: 0 maximum: 9007199254740991 required: - factCount - lastObservedAt - subjectCount additionalProperties: false required: - agentIds - createdAt - description - id - identifier - kind - prompt - revision - schemaVersion - status - subjectKind - unitCode - updatedAt - valueType additionalProperties: false title: Definition BadRequest: type: object properties: defined: const: true inferable: type: boolean code: const: BAD_REQUEST status: const: 400 message: type: string data: type: object properties: issues: maxItems: 20 type: array items: type: object properties: message: type: string maxLength: 500 path: maxItems: 16 type: array items: anyOf: - type: string maxLength: 120 - type: integer minimum: -9007199254740991 maximum: 9007199254740991 required: - message additionalProperties: false truncated: type: boolean required: - issues - truncated additionalProperties: false required: - defined - inferable - code - status - message - data UndefinedError: type: object properties: defined: const: false inferable: type: boolean code: type: string status: type: number message: type: string data: {} required: - defined - inferable - code - status - message TransportBadRequestError: additionalProperties: false properties: code: const: BAD_REQUEST data: {} defined: const: false inferable: const: false message: type: string required: - defined - inferable - code - message type: object Unauthorized: type: object properties: defined: const: true inferable: type: boolean code: const: UNAUTHORIZED status: const: 401 message: type: string data: {} required: - defined - inferable - code - status - message Forbidden: type: object properties: defined: const: true inferable: type: boolean code: const: FORBIDDEN status: const: 403 message: type: string data: type: object properties: missingPermissions: maxItems: 10 type: array items: $ref: '#/components/schemas/AuthPermission' required: - missingPermissions additionalProperties: false required: - defined - inferable - code - status - message NotFound: type: object properties: defined: const: true inferable: type: boolean code: const: NOT_FOUND status: const: 404 message: type: string data: {} required: - defined - inferable - code - status - message IsoDatetime: type: string format: date-time pattern: >- ^(?:(?:\d\d[2468][048]|\d\d[13579][26]|\d\d0[48]|[02468][048]00|[13579][26]00)-02-29|\d{4}-(?:(?:0[13578]|1[02])-(?:0[1-9]|[12]\d|3[01])|(?:0[469]|11)-(?:0[1-9]|[12]\d|30)|(?:02)-(?:0[1-9]|1\d|2[0-8])))T(?:(?:[01]\d|2[0-3]):[0-5]\d:[0-5]\d(?:\.\d+)?(?:Z|([+-](?:[01]\d|2[0-3]):[0-5]\d)))$ description: ISO 8601 timestamp with an explicit UTC offset. examples: - '2026-08-29T14:30:00Z' title: ISO timestamp DefinitionKind: type: string enum: - attribute - assessment - category - metric description: Semantic class of an organization-owned Definition. examples: - attribute title: Definition kind DefinitionStatus: type: string enum: - draft - active - retired description: Lifecycle state of an organization-owned Definition. examples: - active title: Definition status DefinitionSubject: type: string enum: - contact - conversation description: Resource type to which a Definition may be asserted. examples: - contact title: Definition subject DefinitionValueType: type: string enum: - text - number - boolean - date - option description: Validated value representation accepted by a Definition. examples: - option title: Definition value type DefinitionOption: type: object properties: description: anyOf: - type: string maxLength: 1000 - type: 'null' key: type: string minLength: 1 maxLength: 80 pattern: ^[a-z][a-z0-9_]*$ label: type: string minLength: 1 maxLength: 160 sortOrder: type: integer minimum: 0 maximum: 1000 id: $ref: '#/components/schemas/ArbolResourceId' status: $ref: '#/components/schemas/DefinitionOptionStatus' required: - description - key - label - sortOrder - id - status additionalProperties: false description: Persisted revision member of an option-valued Definition. title: Definition option AuthPermission: type: string enum: - agent-evaluations:read - agent-evaluations:run - agent-evaluations:write - agents:read - agents:write - analytics:read - arbi:use - channels:read - channels:write - contacts:read - contacts:write - conversations:read - conversations:transcript - conversations:write - definitions:read - definitions:write - facts:read - facts:write - integrations:read - integrations:write - knowledge:read - knowledge:write - org:manage - org:use description: >- One permission from the closed Arbol API vocabulary accepted from a verified Auth0 token. examples: - agents:read title: API permission DefinitionOptionStatus: type: string enum: - active - retired description: Lifecycle state of one option within a Definition revision. examples: - active title: Definition option status headers: RequestId: description: >- Opaque request correlation identifier. Include it when contacting Arbol support. schema: type: string maxLength: 128 securitySchemes: userOAuth: description: >- Organization-scoped Auth0 user access token issued to an approved first-party client or exchanged by a trusted OBO resource server. flows: authorizationCode: authorizationUrl: https://auth.getarbol.com/authorize scopes: agent-evaluations:read: Read Agent evaluation suites, runs, and results. agent-evaluations:run: Execute and cancel Agent evaluation runs. agent-evaluations:write: Create and update Agent evaluation suites. agents:read: Read Agents and their explicitly requested expansions. agents:write: Create, update, and delete Agents. analytics:read: Read organization analytics. arbi:use: Use the personal Arbi workspace. channels:read: Read Agent channels. channels:write: Create, update, authorize, and delete Agent channels. contacts:read: Read Contacts and their explicitly requested expansions. contacts:write: Create, update, merge, import, and delete Contacts. conversations:read: Read Conversation metadata. conversations:transcript: Read Conversation messages and media evidence. conversations:write: Create and process Conversations. definitions:read: Read Definitions and Definition usage. definitions:write: Create, update, and retire Definitions. facts:read: Read current and historical Facts. facts:write: Assert typed Facts. integrations:read: Discover integrations, tools, accounts, and tool-bearing evidence. integrations:write: Authorize accounts and assign exact tool access. knowledge:read: Read Knowledge documents and search indexed content. knowledge:write: Create, index, update, and delete Knowledge documents. org:manage: Update the Organization and administer its members. org:use: Use Arbol as a member of the selected Auth0 Organization. tokenUrl: https://auth.getarbol.com/oauth/token type: oauth2 machineOAuth: description: >- Organization-bound Auth0 client-credentials token. The client grant must contain every operation scope. flows: clientCredentials: scopes: agent-evaluations:read: Read Agent evaluation suites, runs, and results. agent-evaluations:run: Execute and cancel Agent evaluation runs. agent-evaluations:write: Create and update Agent evaluation suites. agents:read: Read Agents and their explicitly requested expansions. agents:write: Create, update, and delete Agents. analytics:read: Read organization analytics. channels:read: Read Agent channels. channels:write: Create, update, authorize, and delete Agent channels. contacts:read: Read Contacts and their explicitly requested expansions. contacts:write: Create, update, merge, import, and delete Contacts. conversations:read: Read Conversation metadata. conversations:transcript: Read Conversation messages and media evidence. conversations:write: Create and process Conversations. definitions:read: Read Definitions and Definition usage. definitions:write: Create, update, and retire Definitions. facts:read: Read current and historical Facts. facts:write: Assert typed Facts. integrations:read: Discover integrations, tools, accounts, and tool-bearing evidence. integrations:write: Authorize accounts and assign exact tool access. knowledge:read: Read Knowledge documents and search indexed content. knowledge:write: Create, index, update, and delete Knowledge documents. org:manage: Update the Organization and administer its members. tokenUrl: https://auth.getarbol.com/oauth/token type: oauth2 ````