> ## Documentation Index
> Fetch the complete documentation index at: https://docs.cartesia.ai/llms.txt
> Use this file to discover all available pages before exploring further.

# Provision Cartesia Number

> Provision a new Cartesia-managed US phone number



## OpenAPI

````yaml /latest.yml POST /agents/phone-numbers/provision
openapi: 3.0.1
info:
  title: Cartesia API
  version: 0.0.1
servers:
  - url: https://api.cartesia.ai
    description: Production
security: []
paths:
  /agents/phone-numbers/provision:
    post:
      tags:
        - Phone Numbers
      summary: Provision Cartesia Number
      description: Provision a new Cartesia-managed US phone number
      operationId: phone_numbers_provision
      parameters:
        - $ref: '#/components/parameters/CartesiaVersionHeader'
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/ProvisionPhoneNumberBody'
      responses:
        '201':
          description: Phone number provisioned.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ProvisionPhoneNumberResponse'
              example:
                id: pn_abc123
                label: Support line
                number: '+14155551234'
                agent:
                  id: agent_abc123
                  name: Customer support
                created_at: '2026-03-01T00:00:00Z'
                updated_at: '2026-03-01T00:00:00Z'
        '402':
          description: >-
            Subscription phone number limit reached (`error_code:
            quota_exceeded`). Upgrade your plan or delete existing Cartesia
            numbers.
        '404':
          description: Agent not found.
      security:
        - APIKeyAuth: []
components:
  parameters:
    CartesiaVersionHeader:
      name: Cartesia-Version
      in: header
      description: API version header.
      required: true
      schema:
        type: string
        format: date
        example: '2026-03-01'
        enum:
          - '2026-03-01'
  schemas:
    ProvisionPhoneNumberBody:
      title: ProvisionPhoneNumberBody
      type: object
      description: Request body for provisioning a new Cartesia-managed phone number.
      properties:
        label:
          type: string
          description: A human-readable name for the phone number.
        agent_id:
          type: string
          description: >-
            Optional agent ID to assign. Inbound calls to the number will be
            routed to this agent.
      required:
        - label
    ProvisionPhoneNumberResponse:
      title: ProvisionPhoneNumberResponse
      description: The number supports inbound calls and outbound calls to US numbers only
      allOf:
        - $ref: '#/components/schemas/PhoneNumberBaseResponse'
    PhoneNumberBaseResponse:
      title: PhoneNumberBaseResponse
      type: object
      description: Common phone number fields.
      properties:
        id:
          type: string
          description: Unique identifier for the phone number.
        label:
          type: string
          nullable: true
          description: A human-readable name for the phone number.
        number:
          type: string
          description: The phone number in E.164 format (e.g. +14155551234).
        agent:
          nullable: true
          description: The agent assigned to handle inbound calls, or null if unassigned.
          type: object
          properties:
            id:
              type: string
            name:
              type: string
          required:
            - id
            - name
        created_at:
          type: string
          format: date-time
          description: UTC timestamp when the phone number was created.
        updated_at:
          type: string
          format: date-time
          description: UTC timestamp when the phone number was last updated.
      required:
        - id
        - number
        - agent
        - created_at
        - updated_at
  securitySchemes:
    APIKeyAuth:
      type: http
      scheme: bearer
      bearerFormat: API Key
      description: >-
        Cartesia API key (`sk_car_...`). Get one at
        [play.cartesia.ai/keys](https://play.cartesia.ai/keys).

````