> ## 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. # Add a taxonomy node derived from a document selection > Add a node to an existing **flat** taxonomy from a document selection. The node is an ordinary document in the taxonomy's node (source) collection: its anchor vector is the **centroid of the referenced documents' stored vectors** and its `label` is `node_label`. Future documents enriched through this taxonomy are labeled with the nearest node's `label`. Only stored vectors are read — no re-embedding or GPU work. Documents that can't contribute (missing, no matching vector) are skipped and reported in `documents_skipped`; the call fails only when NO document contributes. Hierarchical taxonomies are not supported here (their nodes are whole collections) — the error points you to the flat-taxonomy path. ## OpenAPI ````yaml post /v1/taxonomies/{taxonomy_identifier}/nodes/from-documents 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: - BearerAuth: [] paths: /v1/taxonomies/{taxonomy_identifier}/nodes/from-documents: post: tags: - Taxonomies summary: Add a taxonomy node derived from a document selection description: >- Add a node to an existing **flat** taxonomy from a document selection. The node is an ordinary document in the taxonomy's node (source) collection: its anchor vector is the **centroid of the referenced documents' stored vectors** and its `label` is `node_label`. Future documents enriched through this taxonomy are labeled with the nearest node's `label`. Only stored vectors are read — no re-embedding or GPU work. Documents that can't contribute (missing, no matching vector) are skipped and reported in `documents_skipped`; the call fails only when NO document contributes. Hierarchical taxonomies are not supported here (their nodes are whole collections) — the error points you to the flat-taxonomy path. operationId: >- create_taxonomy_node_from_documents_v1_taxonomies__taxonomy_identifier__nodes_from_documents_post parameters: - name: taxonomy_identifier in: path required: true schema: type: string description: Taxonomy ID or name title: Taxonomy Identifier description: Taxonomy ID or name requestBody: required: true content: application/json: schema: $ref: '#/components/schemas/CreateNodeFromDocumentsRequest' description: >- Keys this body does not declare are refused with 422 extra_forbidden naming the accepted keys (since 2026-11-02). x-unknown-keys: until: '2026-11-02' then: 422 extra_forbidden responses: '200': description: Successful Response content: application/json: schema: $ref: '#/components/schemas/TaxonomyNodeFromDocumentsResponse' '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: Unprocessable Entity content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' '429': description: Too Many Requests content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' '500': description: Internal Server Error content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' '503': description: Service Unavailable content: application/json: schema: $ref: '#/components/schemas/ErrorResponse' security: - BearerAuth: [] NamespaceHeader: [] components: schemas: CreateNodeFromDocumentsRequest: properties: node_label: type: string minLength: 1 title: Node Label description: >- Label for the new node — the value copied onto documents that classify under it (canonical `label` field). documents: items: $ref: '#/components/schemas/DocumentRef' type: array maxItems: 200 minItems: 1 title: Documents description: >- Documents whose stored vectors define the node's anchor (centroid). 1-200 refs; for large selections send a sample — the centroid converges quickly. node_fields: anyOf: - additionalProperties: true type: object - type: 'null' title: Node Fields description: >- Optional extra fields stored on the node document (e.g. `description`). Only fields listed in the taxonomy's enrichment_fields are copied during enrichment. vector_name: anyOf: - type: string - type: 'null' title: Vector Name description: >- Optional explicit vector (index) name for the anchor. If omitted, it is derived from the taxonomy's node collection vector indexes. provenance: anyOf: - additionalProperties: true type: object - type: 'null' title: Provenance description: >- Optional freeform origin context (e.g. cluster_id, run_id, selection type). Stored on the node document under `metadata.promotion` for auditability. type: object required: - node_label - documents title: CreateNodeFromDocumentsRequest description: >- Create a taxonomy node whose classification anchor derives from documents. Mixpeek taxonomy nodes are documents in the taxonomy's source (node) collection: at enrichment time, an incoming document's embedding queries that collection through the taxonomy's retriever and the best-matching node's fields (canonically `label`) are copied onto it. This endpoint computes the CENTROID of the referenced documents' stored vectors and inserts it as a new node document — so future documents whose embeddings land near the referenced selection are classified under `node_label`. No re-embedding or GPU work happens; only stored vectors are read. TaxonomyNodeFromDocumentsResponse: properties: taxonomy_id: type: string title: Taxonomy Id taxonomy_name: type: string title: Taxonomy Name node_document_id: type: string title: Node Document Id description: ID of the created node document (the taxonomy node). node_collection_id: type: string title: Node Collection Id description: The taxonomy's node (source) collection. node_label: type: string title: Node Label vector_name: type: string title: Vector Name description: Vector index name the anchor was stored under. vector_dimensions: type: integer title: Vector Dimensions documents_used: type: integer title: Documents Used description: How many referenced documents contributed to the anchor. documents_skipped: items: $ref: '#/components/schemas/SkippedDocumentRef' type: array title: Documents Skipped taxonomy_created: type: boolean title: Taxonomy Created description: True when this call also created the taxonomy (one-gesture mode). default: false retriever_id: anyOf: - type: string - type: 'null' title: Retriever Id description: Retriever created for the taxonomy (one-gesture mode only). enrichment_hint: type: string title: Enrichment Hint description: >- Plain-language description of how the new node will be applied to future data. nodes: anyOf: - items: $ref: '#/components/schemas/PromotedNode' type: array - type: 'null' title: Nodes description: >- Every node created, when the source was a `cluster_run` (one per cluster). `node_document_id` and `node_label` name the first. type: object required: - taxonomy_id - taxonomy_name - node_document_id - node_collection_id - node_label - vector_name - vector_dimensions - documents_used - enrichment_hint title: TaxonomyNodeFromDocumentsResponse description: Result of promoting a document selection to a taxonomy node. 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 DocumentRef: properties: collection_id: type: string minLength: 1 title: Collection Id description: Collection the document lives in. document_id: type: string minLength: 1 title: Document Id description: The document's ID. type: object required: - collection_id - document_id title: DocumentRef description: A reference to one document in one collection. SkippedDocumentRef: properties: collection_id: anyOf: - type: string - type: 'null' title: Collection Id document_id: anyOf: - type: string - type: 'null' title: Document Id reason: type: string title: Reason type: object required: - reason title: SkippedDocumentRef description: A document reference that could not contribute to the node anchor. PromotedNode: properties: node_document_id: type: string title: Node Document Id node_label: type: string title: Node Label cluster_id: type: string title: Cluster Id member_count: anyOf: - type: integer - type: 'null' title: Member Count type: object required: - node_document_id - node_label - cluster_id title: PromotedNode description: One taxonomy node created from a cluster run. 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. securitySchemes: BearerAuth: type: http scheme: bearer description: >- Mixpeek API key, sent as `Authorization: Bearer mxp_sk_...`. Create one in Studio under Settings → API Keys, or with an admin key via `POST /v1/organizations/users/{user_email}/api-keys`. A missing, malformed, unknown, revoked, inactive or expired key returns 401; a key without the permission, scope or plan an operation needs returns 403. NamespaceHeader: type: apiKey in: header name: X-Namespace description: >- Namespace id (`ns_...`), not the namespace name. This scopes the request rather than authenticating it, and it is required on every operation marked `x-mixpeek-namespace-scoped`. ```` This documentation is built and hosted on [Mintlify](https://mintlify.com), a developer documentation platform.