> ## Documentation Index > Fetch the complete documentation index at: https://traceroot.ai/docs/llms.txt > Use this file to discover all available pages before exploring further. # List Trace Filter Values > Distinct values for an open-ended categorical filter field. The values-discovery companion to the typed ``filters`` parameter on the trace list: the filterable field catalog lives in the generated schema, while a field's current values are dynamic per project. Only fields the registry marks as distinct-query (model_name, environment) are listable; the field is resolved through the registry before it reaches SQL, so it can never be a raw client-supplied column name. Args: auth (DualStampedAuth): Resolved credential context (API key or user session token); scopes the read to its project and stamps the rate-limit identity. field (str): The categorical field to enumerate. start_after (datetime | None): Lower bound on span start time (active window). end_before (datetime | None): Upper bound on span start time (active window), symmetric with ``start_after`` so options match the list's window. Returns: FilterValuesResponse: Distinct values ordered by descending frequency. Raises: HTTPException: 400 if the field is unknown or not a distinct-query categorical, 500 on a reader failure. ## OpenAPI ````yaml /api-reference/openapi.json get /api/v1/public/traces/filter-values/{field} openapi: 3.1.0 info: title: TraceRoot Public API version: 0.1.0 servers: - description: TraceRoot Cloud url: https://app.traceroot.ai - description: Self-hosted url: '{baseUrl}' variables: baseUrl: default: http://localhost:8000 description: Your TraceRoot backend URL security: [] paths: /api/v1/public/traces/filter-values/{field}: get: tags: - Traces summary: List Trace Filter Values description: >- Distinct values for an open-ended categorical filter field. The values-discovery companion to the typed ``filters`` parameter on the trace list: the filterable field catalog lives in the generated schema, while a field's current values are dynamic per project. Only fields the registry marks as distinct-query (model_name, environment) are listable; the field is resolved through the registry before it reaches SQL, so it can never be a raw client-supplied column name. Args: auth (DualStampedAuth): Resolved credential context (API key or user session token); scopes the read to its project and stamps the rate-limit identity. field (str): The categorical field to enumerate. start_after (datetime | None): Lower bound on span start time (active window). end_before (datetime | None): Upper bound on span start time (active window), symmetric with ``start_after`` so options match the list's window. Returns: FilterValuesResponse: Distinct values ordered by descending frequency. Raises: HTTPException: 400 if the field is unknown or not a distinct-query categorical, 500 on a reader failure. operationId: list_trace_filter_values parameters: - in: path name: field required: true schema: title: Field type: string - description: Only consider spans starting at or after this timestamp in: query name: start_after required: false schema: anyOf: - format: date-time type: string - type: 'null' description: Only consider spans starting at or after this timestamp title: Start After - description: Only consider spans starting before this timestamp in: query name: end_before required: false schema: anyOf: - format: date-time type: string - type: 'null' description: Only consider spans starting before this timestamp title: End Before - description: >- Target project for the request. Required when authenticating with a user session token (a user credential is only meaningful scoped to a project); for an API key it is optional and, if given, must match the key's project. in: query name: project_id required: false schema: anyOf: - type: string - type: 'null' description: >- Target project for the request. Required when authenticating with a user session token (a user credential is only meaningful scoped to a project); for an API key it is optional and, if given, must match the key's project. title: Project Id responses: '200': content: application/json: schema: $ref: '#/components/schemas/FilterValuesResponse' description: Successful Response '400': content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' description: Field is not filterable by distinct values '401': content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' description: Authentication failed '422': content: application/json: schema: $ref: '#/components/schemas/HTTPValidationError' description: Validation Error '500': content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' description: Failed to list filter values '503': content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' description: Authentication service unavailable security: - BearerAuth: [] components: schemas: FilterValuesResponse: description: Distinct values for one categorical filter field, by frequency. properties: field: title: Field type: string values: items: $ref: '#/components/schemas/FilterValueCount' title: Values type: array required: - field - values title: FilterValuesResponse type: object ErrorResponse: description: >- The canonical public error envelope (matches the gateway's normalized shape). properties: detail: title: Detail type: string required: - detail title: ErrorResponse type: object HTTPValidationError: properties: detail: items: $ref: '#/components/schemas/ValidationError' title: Detail type: array title: HTTPValidationError type: object FilterValueCount: description: A distinct categorical value and how often it occurs. properties: count: title: Count type: integer value: title: Value type: string required: - value - count title: FilterValueCount type: object ValidationError: properties: ctx: title: Context type: object input: title: Input loc: items: anyOf: - type: string - type: integer title: Location type: array msg: title: Message type: string type: title: Error Type type: string required: - loc - msg - type title: ValidationError type: object securitySchemes: BearerAuth: scheme: bearer type: http ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.