Cartesia Knowledge Base API

openapi: 3.0.3
info:
  title: Cartesia Agents Knowledge Base API
  description: 'The Cartesia REST API for real-time voice AI - text-to-speech and voice-changer generation (single-shot bytes or Server-Sent Events), batch speech-to-text transcription, voice management and cloning, audio infill, custom datasets, pronunciation dictionaries, API keys and scoped access tokens, the Voice Agents platform (agents, calls, call batches, phone numbers, telephony providers, webhooks, deployments, knowledge base documents/folders, and evaluation metrics), and usage reporting. All requests require a `Cartesia-Version` header and an `Authorization: Bearer` API key (`sk_car_...`) or short-lived access token. The lowest-latency, streaming surface for TTS and STT is a separate WebSocket protocol documented in the companion AsyncAPI document at asyncapi/cartesia-ai-asyncapi.yml.'
  version: '2026-03-01'
  contact:
    name: Cartesia
    url: https://cartesia.ai
  license:
    name: API documentation - Cartesia Terms of Service
    url: https://cartesia.ai/terms-of-service
servers:
- url: https://api.cartesia.ai
  description: Cartesia production API
security:
- bearerAuth: []
tags:
- name: Knowledge Base
  description: Documents and folders used by agents.
paths:
  /documents:
    get:
      operationId: listDocuments
      tags:
      - Knowledge Base
      summary: List Documents
      description: List all knowledge base documents in your organization.
      parameters:
      - $ref: '#/components/parameters/CartesiaVersion'
      responses:
        '200':
          description: A page of documents.
          content:
            application/json:
              schema:
                type: object
                properties:
                  data:
                    type: array
                    items:
                      $ref: '#/components/schemas/Document'
        '401':
          $ref: '#/components/responses/Unauthorized'
    post:
      operationId: createDocument
      tags:
      - Knowledge Base
      summary: Create Document
      parameters:
      - $ref: '#/components/parameters/CartesiaVersion'
      requestBody:
        required: true
        content:
          multipart/form-data:
            schema:
              type: object
              required:
              - file
              properties:
                file:
                  type: string
                  format: binary
                folder_id:
                  type: string
      responses:
        '200':
          description: The created document.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Document'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '422':
          $ref: '#/components/responses/ValidationError'
  /documents/bulk:
    post:
      operationId: bulkCreateDocuments
      tags:
      - Knowledge Base
      summary: Bulk Create Documents
      description: Upload up to 100 knowledge base documents in a single request.
      parameters:
      - $ref: '#/components/parameters/CartesiaVersion'
      requestBody:
        required: true
        content:
          multipart/form-data:
            schema:
              type: object
              properties:
                files:
                  type: array
                  items:
                    type: string
                    format: binary
                folder_id:
                  type: string
      responses:
        '200':
          description: The created documents.
          content:
            application/json:
              schema:
                type: object
                properties:
                  data:
                    type: array
                    items:
                      $ref: '#/components/schemas/Document'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '422':
          $ref: '#/components/responses/ValidationError'
  /documents/{id}:
    parameters:
    - name: id
      in: path
      required: true
      description: The ID of the document.
      schema:
        type: string
    get:
      operationId: getDocument
      tags:
      - Knowledge Base
      summary: Get Document
      parameters:
      - $ref: '#/components/parameters/CartesiaVersion'
      responses:
        '200':
          description: The requested document.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Document'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '404':
          $ref: '#/components/responses/NotFound'
    patch:
      operationId: updateDocument
      tags:
      - Knowledge Base
      summary: Update Document
      parameters:
      - $ref: '#/components/parameters/CartesiaVersion'
      requestBody:
        content:
          application/json:
            schema:
              type: object
              properties:
                folder_id:
                  type: string
      responses:
        '200':
          description: The updated document.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Document'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '404':
          $ref: '#/components/responses/NotFound'
    delete:
      operationId: deleteDocument
      tags:
      - Knowledge Base
      summary: Delete Document
      parameters:
      - $ref: '#/components/parameters/CartesiaVersion'
      responses:
        '200':
          description: Deletion confirmation.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/DeleteResponse'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '404':
          $ref: '#/components/responses/NotFound'
  /folders:
    get:
      operationId: listFolders
      tags:
      - Knowledge Base
      summary: List Folders
      parameters:
      - $ref: '#/components/parameters/CartesiaVersion'
      responses:
        '200':
          description: A page of folders.
          content:
            application/json:
              schema:
                type: object
                properties:
                  data:
                    type: array
                    items:
                      $ref: '#/components/schemas/Folder'
        '401':
          $ref: '#/components/responses/Unauthorized'
    post:
      operationId: createFolder
      tags:
      - Knowledge Base
      summary: Create Folder
      parameters:
      - $ref: '#/components/parameters/CartesiaVersion'
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              required:
              - name
              properties:
                name:
                  type: string
                parent_folder_id:
                  type: string
      responses:
        '200':
          description: The created folder.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Folder'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '422':
          $ref: '#/components/responses/ValidationError'
  /folders/{id}:
    parameters:
    - name: id
      in: path
      required: true
      description: The ID of the folder.
      schema:
        type: string
    get:
      operationId: getFolder
      tags:
      - Knowledge Base
      summary: Get Folder
      parameters:
      - $ref: '#/components/parameters/CartesiaVersion'
      responses:
        '200':
          description: The requested folder.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Folder'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '404':
          $ref: '#/components/responses/NotFound'
    patch:
      operationId: updateFolder
      tags:
      - Knowledge Base
      summary: Update Folder
      parameters:
      - $ref: '#/components/parameters/CartesiaVersion'
      requestBody:
        content:
          application/json:
            schema:
              type: object
              properties:
                name:
                  type: string
                parent_folder_id:
                  type: string
      responses:
        '200':
          description: The updated folder.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Folder'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '404':
          $ref: '#/components/responses/NotFound'
    delete:
      operationId: deleteFolder
      tags:
      - Knowledge Base
      summary: Delete Folder
      parameters:
      - $ref: '#/components/parameters/CartesiaVersion'
      responses:
        '200':
          description: Deletion confirmation.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/DeleteResponse'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '404':
          $ref: '#/components/responses/NotFound'
components:
  schemas:
    Folder:
      type: object
      properties:
        id:
          type: string
        name:
          type: string
        parent_folder_id:
          type: string
          nullable: true
        created_at:
          type: string
          format: date-time
    DeleteResponse:
      type: object
      properties:
        id:
          type: string
        deleted:
          type: boolean
    Document:
      type: object
      properties:
        id:
          type: string
        name:
          type: string
        folder_id:
          type: string
          nullable: true
        size_bytes:
          type: integer
        created_at:
          type: string
          format: date-time
    Error:
      type: object
      properties:
        title:
          type: string
        message:
          type: string
        error_code:
          type: string
        status_code:
          type: integer
        doc_url:
          type: string
        request_id:
          type: string
  responses:
    Unauthorized:
      description: Missing, invalid, or expired API key / access token.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
    NotFound:
      description: The requested resource was not found.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
    ValidationError:
      description: The request payload failed validation.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
  parameters:
    CartesiaVersion:
      name: Cartesia-Version
      in: header
      required: true
      description: API version date, e.g. 2026-03-01.
      schema:
        type: string
        example: '2026-03-01'
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      bearerFormat: sk_car_... API key or short-lived access token
      description: 'Cartesia API key (sk_car_...) or a short-lived access token minted via POST /access-token, passed as Authorization: Bearer <token>. Every request also requires the Cartesia-Version header.'