> ## Documentation Index > Fetch the complete documentation index at: https://docs.ai-baseline.com/llms.txt > Use this file to discover all available pages before exploring further. # List knowledge-base metadata filters > Discover metadata-filter fields, supported operators, bounds, and optional categorical values for the knowledge base selected by the server URL. Fields depend on its domain; values depend on its corpus. ## OpenAPI ````yaml /openapi.json get /metadata-filters openapi: 3.1.0 info: title: AI Baseline API description: >- REST v2 contract for querying a selected knowledge base, discovering metadata filters, and reading corpus orientation. The S&P 500 requests are worked examples; fields and available material depend on the selected base and its domain. version: v2 servers: - url: https://api.ai-baseline.dev/{org}/{base}/v2 description: Knowledge-base REST API (defaults to the S&P 500 example) variables: org: default: baseline description: Exact identifier of the organization that owns the knowledge base. base: default: sandp500 description: >- Exact identifier of the knowledge base within the owning organization. The API key must grant access to this base. security: - ApiKeyAuth: [] paths: /metadata-filters: get: tags: - Metadata summary: List knowledge-base metadata filters description: >- Discover metadata-filter fields, supported operators, bounds, and optional categorical values for the knowledge base selected by the server URL. Fields depend on its domain; values depend on its corpus. operationId: listMetadataFilters parameters: - name: include_values in: query required: false schema: type: boolean description: Include allowed categorical values and alias text when available. default: false title: Include Values description: Include allowed categorical values and alias text when available. - name: field in: query required: false schema: anyOf: - type: string - type: 'null' description: Return one public metadata-filter field by name. title: Field description: Return one public metadata-filter field by name. responses: '200': description: Successful Response content: application/json: schema: $ref: '#/components/schemas/MetadataFiltersResponse' '404': description: Unknown domain content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' '413': description: Request body too large content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' '422': description: Validation error content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' '500': description: Internal server error content: application/json: schema: $ref: '#/components/schemas/RequestFailureResponse' '502': description: An AI upstream returned output that failed validation content: application/json: schema: $ref: '#/components/schemas/RequestFailureResponse' '503': description: Service, AI dependency, or local capacity temporarily unavailable headers: Retry-After: description: Advisory delay in seconds for retryable failures schema: type: integer minimum: 1 content: application/json: examples: capacity_queue_full: summary: The bounded capacity waiting room is full value: status_code: 503 message: Service temporarily at capacity detail: code: CAPACITY_UNAVAILABLE retryable: true reason: queue_full retry_after_seconds: 5 capacity_wait_timeout: summary: Capacity was not acquired before the wait timeout value: status_code: 503 message: Service temporarily at capacity detail: code: CAPACITY_UNAVAILABLE retryable: true reason: wait_timeout retry_after_seconds: 5 dependency_unavailable: summary: A required AI upstream service is unavailable value: status_code: 503 message: >- A required AI upstream service is temporarily unavailable. Please retry. detail: code: DEPENDENCY_UNAVAILABLE retryable: true retry_after_seconds: 10 service_unavailable: summary: Application services are unavailable value: status_code: 503 message: Service unavailable detail: code: SERVICE_UNAVAILABLE retryable: false schema: $ref: '#/components/schemas/RequestFailureResponse' '504': description: The admitted request exceeded its execution deadline headers: Retry-After: description: Advisory delay in seconds before retrying schema: type: integer minimum: 1 content: application/json: schema: $ref: '#/components/schemas/RequestFailureResponse' security: - ApiKeyAuth: [] components: schemas: MetadataFiltersResponse: properties: domain: type: string title: Domain description: >- Configured domain ID of the selected knowledge base, not its base identifier. For the baseline/sandp500 example this is sandp_500. schema_version: type: string title: Schema Version fields: items: $ref: '#/components/schemas/MetadataFilterField' type: array title: Fields additionalProperties: false type: object required: - domain - schema_version - fields title: MetadataFiltersResponse ErrorResponse: properties: status_code: type: integer title: Status Code message: type: string title: Message detail: anyOf: - {} - type: 'null' title: Detail type: object required: - status_code - message title: ErrorResponse RequestFailureResponse: properties: status_code: type: integer enum: - 500 - 502 - 503 - 504 title: Status Code message: type: string title: Message detail: $ref: '#/components/schemas/RequestFailureDetail' additionalProperties: false type: object required: - status_code - message - detail title: RequestFailureResponse MetadataFilterField: properties: name: type: string title: Name description: type: string title: Description value_type: type: string title: Value Type operators: items: type: string type: array title: Operators has_values: type: boolean title: Has Values source_required: anyOf: - type: boolean - type: 'null' title: Source Required constraints: anyOf: - additionalProperties: true type: object - type: 'null' title: Constraints numeric_bounds: anyOf: - $ref: '#/components/schemas/MetadataFilterNumericBounds' - type: 'null' max_values_per_condition: anyOf: - type: integer - type: 'null' title: Max Values Per Condition max_value_length: anyOf: - type: integer - type: 'null' title: Max Value Length allowed_values: anyOf: - items: $ref: '#/components/schemas/MetadataFilterAllowedValue' type: array - type: 'null' title: Allowed Values additionalProperties: false type: object required: - name - description - value_type - operators - has_values - source_required - constraints title: MetadataFilterField RequestFailureDetail: properties: code: $ref: '#/components/schemas/FailureCode' retryable: type: boolean title: Retryable reason: anyOf: - type: string enum: - queue_full - wait_timeout - type: 'null' title: Reason retry_after_seconds: anyOf: - type: integer minimum: 1 - type: 'null' title: Retry After Seconds additionalProperties: false type: object required: - code - retryable title: RequestFailureDetail MetadataFilterNumericBounds: properties: min: type: number title: Min max: type: number title: Max additionalProperties: false type: object required: - min - max title: MetadataFilterNumericBounds MetadataFilterAllowedValue: properties: value: type: string title: Value display_value: type: string title: Display Value aliases: items: type: string type: array title: Aliases additionalProperties: false type: object required: - value - display_value - aliases title: MetadataFilterAllowedValue FailureCode: type: string enum: - CAPACITY_UNAVAILABLE - DEPENDENCY_UNAVAILABLE - SERVICE_UNAVAILABLE - INVALID_UPSTREAM_RESPONSE - EXECUTION_DEADLINE_EXCEEDED - EXECUTION_WORK_LIMIT_EXCEEDED - INTERNAL_SERVER_ERROR title: FailureCode securitySchemes: ApiKeyAuth: type: apiKey in: header name: X-API-Key ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.