openapi: 3.0.3
info:
  title: Cartesia Agents Metrics 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: Metrics
  description: LLM-as-a-judge quality metrics for agents.
paths:
  /metrics:
    get:
      operationId: listMetrics
      tags:
      - Metrics
      summary: List Metrics
      description: List of all LLM-as-a-Judge metrics owned by your account.
      parameters:
      - $ref: '#/components/parameters/CartesiaVersion'
      responses:
        '200':
          description: A page of metrics.
          content:
            application/json:
              schema:
                type: object
                properties:
                  data:
                    type: array
                    items:
                      $ref: '#/components/schemas/Metric'
        '401':
          $ref: '#/components/responses/Unauthorized'
    post:
      operationId: createMetric
      tags:
      - Metrics
      summary: Create Metric
      parameters:
      - $ref: '#/components/parameters/CartesiaVersion'
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              required:
              - name
              - prompt
              properties:
                name:
                  type: string
                prompt:
                  type: string
      responses:
        '200':
          description: The created metric.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Metric'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '422':
          $ref: '#/components/responses/ValidationError'
  /metrics/{id}:
    parameters:
    - name: id
      in: path
      required: true
      description: The ID of the metric.
      schema:
        type: string
    get:
      operationId: getMetric
      tags:
      - Metrics
      summary: Get Metric
      parameters:
      - $ref: '#/components/parameters/CartesiaVersion'
      responses:
        '200':
          description: The requested metric.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Metric'
        '401':
          $ref: '#/components/responses/Unauthorized'
        '404':
          $ref: '#/components/responses/NotFound'
    delete:
      operationId: deleteMetric
      tags:
      - Metrics
      summary: Delete Metric
      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'
  /metrics/{id}/results:
    parameters:
    - name: id
      in: path
      required: true
      description: The ID of the metric.
      schema:
        type: string
    get:
      operationId: listMetricResults
      tags:
      - Metrics
      summary: List Metric Results
      parameters:
      - $ref: '#/components/parameters/CartesiaVersion'
      responses:
        '200':
          description: A page of metric results.
          content:
            application/json:
              schema:
                type: object
                properties:
                  data:
                    type: array
                    items:
                      type: object
                      additionalProperties: true
        '401':
          $ref: '#/components/responses/Unauthorized'
        '404':
          $ref: '#/components/responses/NotFound'
  /metrics/{id}/results/export:
    parameters:
    - name: id
      in: path
      required: true
      description: The ID of the metric.
      schema:
        type: string
    get:
      operationId: exportMetricResults
      tags:
      - Metrics
      summary: Export Metric Results as CSV
      parameters:
      - $ref: '#/components/parameters/CartesiaVersion'
      responses:
        '200':
          description: CSV export of metric results.
          content:
            text/csv:
              schema:
                type: string
        '401':
          $ref: '#/components/responses/Unauthorized'
        '404':
          $ref: '#/components/responses/NotFound'
  /agents/{id}/metrics/{metric_id}:
    parameters:
    - $ref: '#/components/parameters/AgentId'
    - name: metric_id
      in: path
      required: true
      schema:
        type: string
    post:
      operationId: addMetricToAgent
      tags:
      - Metrics
      summary: Add Metric to Agent
      parameters:
      - $ref: '#/components/parameters/CartesiaVersion'
      responses:
        '200':
          description: Confirmation the metric was attached.
          content:
            application/json:
              schema:
                type: object
                properties:
                  success:
                    type: boolean
        '401':
          $ref: '#/components/responses/Unauthorized'
        '404':
          $ref: '#/components/responses/NotFound'
    delete:
      operationId: removeMetricFromAgent
      tags:
      - Metrics
      summary: Remove Metric from Agent
      parameters:
      - $ref: '#/components/parameters/CartesiaVersion'
      responses:
        '200':
          description: Confirmation the metric was removed.
          content:
            application/json:
              schema:
                type: object
                properties:
                  success:
                    type: boolean
        '401':
          $ref: '#/components/responses/Unauthorized'
        '404':
          $ref: '#/components/responses/NotFound'
components:
  schemas:
    Metric:
      type: object
      properties:
        id:
          type: string
        name:
          type: string
        prompt:
          type: string
        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:
    AgentId:
      name: id
      in: path
      required: true
      description: The ID of the agent.
      schema:
        type: string
    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.'