Cartesia Phone Numbers API

openapi: 3.0.3
info:
  title: Cartesia Agents Phone Numbers 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: Phone Numbers
  description: Telephony number provisioning and import.
paths:
  /phone-numbers:
    get:
      operationId: listPhoneNumbers
      tags:
      - Phone Numbers
      summary: List Phone Numbers
      parameters:
      - $ref: '#/components/parameters/CartesiaVersion'
      responses:
        '200':
          description: A page of phone numbers.
          content:
            application/json:
              schema:
                type: object
                properties:
                  data:
                    type: array
                    items:
                      $ref: '#/components/schemas/PhoneNumber'
        '401':
          $ref: '#/components/responses/Unauthorized'
  /phone-numbers/import:
    post:
      operationId: importPhoneNumber
      tags:
      - Phone Numbers
      summary: Import Phone Number
      parameters:
      - $ref: '#/components/parameters/CartesiaVersion'
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              required:
              - provider_id
              - number
              properties:
                provider_id:
                  type: string
                number:
                  type: string
      responses:
        '200':
          description: The imported phone number.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/PhoneNumber'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '422':
          $ref: '#/components/responses/ValidationError'
  /phone-numbers/provision:
    post:
      operationId: provisionPhoneNumber
      tags:
      - Phone Numbers
      summary: Provision Cartesia Number
      description: Provision a new Cartesia-managed US phone number.
      parameters:
      - $ref: '#/components/parameters/CartesiaVersion'
      requestBody:
        content:
          application/json:
            schema:
              type: object
              properties:
                area_code:
                  type: string
      responses:
        '200':
          description: The provisioned phone number.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/PhoneNumber'
        '401':
          $ref: '#/components/responses/Unauthorized'
  /phone-numbers/{id}:
    parameters:
    - name: id
      in: path
      required: true
      description: The ID of the phone number.
      schema:
        type: string
    get:
      operationId: getPhoneNumber
      tags:
      - Phone Numbers
      summary: Get Phone Number
      parameters:
      - $ref: '#/components/parameters/CartesiaVersion'
      responses:
        '200':
          description: The requested phone number.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/PhoneNumber'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '404':
          $ref: '#/components/responses/NotFound'
    patch:
      operationId: updatePhoneNumber
      tags:
      - Phone Numbers
      summary: Update Phone Number
      parameters:
      - $ref: '#/components/parameters/CartesiaVersion'
      requestBody:
        content:
          application/json:
            schema:
              type: object
              properties:
                agent_id:
                  type: string
      responses:
        '200':
          description: The updated phone number.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/PhoneNumber'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '404':
          $ref: '#/components/responses/NotFound'
    delete:
      operationId: deletePhoneNumber
      tags:
      - Phone Numbers
      summary: Delete Phone Number
      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:
    PhoneNumber:
      type: object
      properties:
        id:
          type: string
        number:
          type: string
          description: E.164 phone number.
        provider_id:
          type: string
          nullable: true
        agent_id:
          type: string
          nullable: true
        created_at:
          type: string
          format: date-time
    DeleteResponse:
      type: object
      properties:
        id:
          type: string
        deleted:
          type: boolean
    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.'