> ## Documentation Index > Fetch the complete documentation index at: https://docs.mixpeek.com/docs/llms.txt > Use this file to discover all available pages before exploring further. # Return distinct values for a single field. > Return the set of unique values for one document field across a collection, together with a per-value document count sorted desc. Thin wrapper over `/aggregate` for the common `SELECT DISTINCT ` case — use this when a UI needs a facet list (e.g. `brand_slug`) without loading every document. Null/missing values are excluded. ## OpenAPI ````yaml post /v1/collections/{collection_identifier}/documents/distinct openapi: 3.1.0 info: title: Mixpeek API description: >- This is the Mixpeek API, providing access to various endpoints for data processing and retrieval. termsOfService: https://mixpeek.com/terms contact: name: Mixpeek Support url: https://mixpeek.com/contact email: info@mixpeek.com version: '0.82' servers: - url: https://api.mixpeek.com description: Production security: [] paths: /v1/collections/{collection_identifier}/documents/distinct: post: tags: - Collection Documents summary: Return distinct values for a single field. description: >- Return the set of unique values for one document field across a collection, together with a per-value document count sorted desc. Thin wrapper over `/aggregate` for the common `SELECT DISTINCT ` case — use this when a UI needs a facet list (e.g. `brand_slug`) without loading every document. Null/missing values are excluded. operationId: >- distinct_document_values_v1_collections__collection_identifier__documents_distinct_post parameters: - name: collection_identifier in: path required: true schema: type: string description: The unique identifier of the collection. title: Collection Identifier description: The unique identifier of the collection. requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/DistinctValuesRequest' description: Field + optional filters/limit for the distinct query. responses: '200': description: Successful Response content: application/json: schema: $ref: '#/components/schemas/DistinctValuesResponse' '400': description: Bad Request content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' '401': description: Unauthorized content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' '403': description: Forbidden content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' '404': description: Not Found content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' '422': description: Validation Error content: application/json: schema: $ref: '#/components/schemas/HTTPValidationError' '500': description: Internal Server Error content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' components: schemas: DistinctValuesRequest: properties: field: type: string title: Field description: >- Document field whose distinct values should be returned. Dotted paths are supported (e.g. `metadata.brand_slug`). Null/missing values are excluded. examples: - brand_slug - metadata.category filters: anyOf: - additionalProperties: true type: object - type: 'null' title: Filters description: >- Optional pre-aggregation filters, same syntax as the standard aggregation endpoint. Applied before distinct values are computed. limit: anyOf: - type: integer maximum: 10000 minimum: 1 - type: 'null' title: Limit description: >- Maximum number of distinct values to return (sorted by count desc). Defaults to no limit on the server side; for high-cardinality fields always set a limit to keep the response bounded. type: object required: - field title: DistinctValuesRequest description: >- Return the set of unique values for a single field across a collection. Thin wrapper over the aggregation framework for the common `SELECT DISTINCT ` use case. Callers don't need to build a `group_by` + COUNT pipeline by hand — pass a field name and (optionally) pre-aggregation filters and get back a flat list of values plus per-value counts. DistinctValuesResponse: properties: field: type: string title: Field description: The field that was queried. values: items: $ref: '#/components/schemas/DistinctValue' type: array title: Values description: >- Distinct values sorted by descending count. Respects the `limit` argument; use the length of this list as the returned count. total_distinct: type: integer title: Total Distinct description: >- Number of distinct values in the response (== len(values)). When `limit` is set this can be less than the true cardinality. type: object required: - field - values - total_distinct title: DistinctValuesResponse description: Flat list of distinct values for a single field. ErrorResponse: properties: success: type: boolean title: Success description: Always false for error responses default: false status: type: integer title: Status description: HTTP status code for this error error: $ref: '#/components/schemas/ErrorDetail' description: Error details payload type: object required: - status - error title: ErrorResponse description: Error response model. examples: - error: details: id: ns_123 resource: namespace message: Namespace not found type: NotFoundError status: 404 success: false HTTPValidationError: properties: detail: items: $ref: '#/components/schemas/ValidationError' type: array title: Detail type: object title: HTTPValidationError DistinctValue: properties: value: title: Value description: The distinct field value. count: type: integer title: Count description: Number of documents with this exact value. type: object required: - value - count title: DistinctValue description: One distinct value and how many documents carry it. ErrorDetail: properties: message: type: string title: Message description: Human-readable error message type: type: string title: Type description: Stable error type identifier (machine-readable) code: anyOf: - type: string - type: 'null' title: Code description: >- Fine-grained error code for programmatic handling (e.g., namespace_name_taken, feature_extractor_not_found). Present only when consumers may need to branch on a specific error condition. details: anyOf: - additionalProperties: true type: object - type: 'null' title: Details description: >- Optional structured details to help debugging (validation errors, IDs, etc.) type: object required: - message - type title: ErrorDetail description: Error detail model. ValidationError: properties: loc: items: anyOf: - type: string - type: integer type: array title: Location msg: type: string title: Message type: type: string title: Error Type type: object required: - loc - msg - type title: ValidationError ````