Braintrust AI Proxy API

openapi: 3.0.3
info:
  title: Braintrust REST ACL AI Proxy API
  description: The Braintrust REST API for building, evaluating, and observing AI applications. The API is organized around REST, uses predictable resource-oriented URLs under https://api.braintrust.dev/v1, accepts and returns JSON, and authenticates with a Bearer API key. This specification covers the core documented resource surface - projects, experiments, datasets, logs/spans, prompts, functions and scorers, evals, project configuration, organization/ACL management, credentials, and the OpenAI-compatible AI proxy.
  termsOfService: https://www.braintrust.dev/legal/terms-of-service
  contact:
    name: Braintrust Support
    email: support@braintrust.dev
    url: https://www.braintrust.dev/docs
  version: '1.0'
servers:
- url: https://api.braintrust.dev
  description: US data plane (default)
- url: https://api-eu.braintrust.dev
  description: EU data plane
security:
- bearerAuth: []
tags:
- name: AI Proxy
paths:
  /v1/proxy/chat/completions:
    post:
      operationId: proxychatCompletions
      tags:
      - AI Proxy
      summary: Proxy chat/completions
      description: OpenAI-compatible chat completions proxied to the configured model provider, with optional caching and automatic logging. Set stream to true for a Server-Sent Events response.
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/ChatCompletionRequest'
      responses:
        '200':
          description: Returns a chat completion, or an SSE stream when stream is true.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/ChatCompletionResponse'
            text/event-stream:
              schema:
                type: string
                description: Server-Sent Events stream of chat completion chunks.
        '401':
          $ref: '#/components/responses/Unauthorized'
  /v1/proxy/embeddings:
    post:
      operationId: proxyembeddings
      tags:
      - AI Proxy
      summary: Proxy embeddings
      description: OpenAI-compatible embeddings proxied to the configured model provider.
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              required:
              - model
              - input
              properties:
                model:
                  type: string
                input:
                  oneOf:
                  - type: string
                  - type: array
                    items:
                      type: string
      responses:
        '200':
          description: Returns an embeddings response.
          content:
            application/json:
              schema:
                type: object
                properties:
                  object:
                    type: string
                  data:
                    type: array
                    items:
                      type: object
                      properties:
                        index:
                          type: integer
                        embedding:
                          type: array
                          items:
                            type: number
        '401':
          $ref: '#/components/responses/Unauthorized'
  /v1/proxy/credentials:
    post:
      operationId: proxycredentials
      tags:
      - AI Proxy
      summary: Create temporary credential
      description: Mint a temporary credential (JWT) scoped for use with the AI proxy, suitable for handing to browser or untrusted clients.
      requestBody:
        required: true
        content:
          application/json:
            schema:
              type: object
              properties:
                ttl_seconds:
                  type: integer
                  description: Time-to-live for the temporary credential, in seconds.
                logging:
                  type: object
                  additionalProperties: true
                model:
                  type: string
      responses:
        '200':
          description: Returns a temporary credential.
          content:
            application/json:
              schema:
                type: object
                properties:
                  key:
                    type: string
        '401':
          $ref: '#/components/responses/Unauthorized'
components:
  schemas:
    ChatCompletionRequest:
      type: object
      required:
      - model
      - messages
      properties:
        model:
          type: string
        messages:
          type: array
          items:
            type: object
            properties:
              role:
                type: string
                enum:
                - system
                - user
                - assistant
                - tool
              content:
                type: string
        temperature:
          type: number
          nullable: true
        max_tokens:
          type: integer
          nullable: true
        stream:
          type: boolean
        tools:
          type: array
          items:
            type: object
            additionalProperties: true
    Error:
      type: object
      properties:
        error:
          type: string
          description: A human-readable error message.
    ChatCompletionResponse:
      type: object
      properties:
        id:
          type: string
        object:
          type: string
        created:
          type: integer
        model:
          type: string
        choices:
          type: array
          items:
            type: object
            properties:
              index:
                type: integer
              message:
                type: object
                properties:
                  role:
                    type: string
                  content:
                    type: string
                    nullable: true
              finish_reason:
                type: string
                nullable: true
        usage:
          type: object
          properties:
            prompt_tokens:
              type: integer
            completion_tokens:
              type: integer
            total_tokens:
              type: integer
  responses:
    Unauthorized:
      description: Authentication failed - missing or invalid API key.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      bearerFormat: API key or JWT
      description: 'Authenticate requests with your Braintrust API key in the Authorization header, e.g. `Authorization: Bearer $BRAINTRUST_API_KEY`.'