openapi: 3.0.1
info:
  title: LangDB AI Gateway Analytics API
  description: OpenAI-compatible REST API for the LangDB AI Gateway. A single, project-scoped endpoint routes chat completions, embeddings, and image generation across 250+ models from providers such as OpenAI, Anthropic, Google, Meta, Mistral, and DeepSeek, while adding routing, guardrails, tracing, cost control, and an MCP (Model Context Protocol) gateway. Requests are authenticated with a Bearer API key and scoped to a project either by embedding the project id in the path (`/{project_id}/v1/...`) or by sending an `X-Project-Id` header. Tracing and session headers (`X-Thread-Id`, `X-Run-Id`, `X-Label`) attach observability metadata to each call.
  termsOfService: https://langdb.ai/terms
  contact:
    name: LangDB Support
    url: https://langdb.ai
    email: support@langdb.ai
  version: '1.0'
servers:
- url: https://api.us-east-1.langdb.ai/{project_id}/v1
  description: Project-scoped OpenAI-compatible base (US East 1).
  variables:
    project_id:
      default: your-langdb-project-id
      description: LangDB project id. May instead be supplied via the X-Project-Id header.
- url: https://api.us-east-1.langdb.ai
  description: Root base URL for analytics, usage, and thread management endpoints (US East 1).
security:
- bearerAuth: []
tags:
- name: Analytics
  description: Usage analytics and cost summaries.
paths:
  /analytics:
    post:
      operationId: fetchAnalytics
      tags:
      - Analytics
      summary: Fetch analytics data
      description: Returns time-series analytics for the project, filterable by a preset interval such as last_day, last_week, or last_month.
      parameters:
      - $ref: '#/components/parameters/ProjectIdHeader'
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/AnalyticsRequest'
      responses:
        '200':
          description: Analytics rows for the requested window.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/AnalyticsResponse'
        '401':
          $ref: '#/components/responses/Unauthorized'
  /analytics/summary:
    post:
      operationId: fetchAnalyticsSummary
      tags:
      - Analytics
      summary: Fetch analytics summary
      description: Returns an aggregated analytics summary (totals for requests, tokens, and cost) for the requested window.
      parameters:
      - $ref: '#/components/parameters/ProjectIdHeader'
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/AnalyticsRequest'
      responses:
        '200':
          description: Aggregated analytics summary.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/AnalyticsSummary'
        '401':
          $ref: '#/components/responses/Unauthorized'
  /usage/total:
    post:
      operationId: getTotalUsage
      tags:
      - Analytics
      summary: Get total usage
      description: Returns total usage (cost, input tokens, output tokens) for the project over the requested window.
      parameters:
      - $ref: '#/components/parameters/ProjectIdHeader'
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/AnalyticsRequest'
      responses:
        '200':
          description: Total usage figures.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/UsageTotal'
        '401':
          $ref: '#/components/responses/Unauthorized'
  /usage/models:
    post:
      operationId: getUsageByModel
      tags:
      - Analytics
      summary: Get usage by model
      description: Returns usage broken down per model for the project over the requested window.
      parameters:
      - $ref: '#/components/parameters/ProjectIdHeader'
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/AnalyticsRequest'
      responses:
        '200':
          description: Per-model usage figures.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/UsageByModel'
        '401':
          $ref: '#/components/responses/Unauthorized'
components:
  schemas:
    AnalyticsRequest:
      type: object
      properties:
        interval:
          type: string
          description: Preset reporting window.
          enum:
          - last_day
          - last_week
          - last_month
        start_time:
          type: string
          format: date-time
        end_time:
          type: string
          format: date-time
        group_by:
          type: array
          items:
            type: string
    UsageTotal:
      type: object
      properties:
        total_cost:
          type: number
        input_tokens:
          type: integer
        output_tokens:
          type: integer
    UsageByModel:
      type: object
      properties:
        models:
          type: array
          items:
            type: object
            properties:
              model:
                type: string
              total_cost:
                type: number
              input_tokens:
                type: integer
              output_tokens:
                type: integer
    AnalyticsSummary:
      type: object
      properties:
        total_requests:
          type: integer
        total_tokens:
          type: integer
        total_cost:
          type: number
    Error:
      type: object
      properties:
        error:
          type: object
          properties:
            message:
              type: string
            type:
              type: string
            code:
              type: string
    AnalyticsResponse:
      type: object
      properties:
        rows:
          type: array
          items:
            type: object
            properties:
              timestamp:
                type: string
                format: date-time
              requests:
                type: integer
              total_tokens:
                type: integer
              cost:
                type: number
  responses:
    Unauthorized:
      description: Missing or invalid API key.
      content:
        application/json:
          schema:
            $ref: '#/components/schemas/Error'
  parameters:
    ProjectIdHeader:
      name: X-Project-Id
      in: header
      required: false
      description: LangDB project id. Optional when the project id is embedded in the request path.
      schema:
        type: string
  securitySchemes:
    bearerAuth:
      type: http
      scheme: bearer
      bearerFormat: JWT
      description: 'LangDB API key (project access token) sent as `Authorization: Bearer <token>`.'