openapi: 3.0.1
info:
  title: Langtrace AI Projects Traces API
  description: REST API for Langtrace, an open-source, OpenTelemetry-based observability platform for LLM applications by Scale3 Labs. Covers OTLP/HTTP trace ingestion, project and API key management, the prompt registry, and paginated trace retrieval. The same endpoints are available on Langtrace Cloud (app.langtrace.ai) and on self-hosted deployments. All requests are authenticated with an x-api-key header.
  termsOfService: https://www.langtrace.ai/terms
  contact:
    name: Langtrace AI Support
    url: https://docs.langtrace.ai
  license:
    name: AGPL-3.0
    url: https://github.com/Scale3-Labs/langtrace/blob/main/LICENSE
  version: '1.0'
servers:
- url: https://app.langtrace.ai/api
  description: Langtrace Cloud
- url: http://localhost:3000/api
  description: Self-hosted Langtrace deployment
security:
- ApiKeyAuth: []
tags:
- name: Traces
  description: OpenTelemetry trace ingestion and retrieval.
paths:
  /trace:
    post:
      operationId: sendTrace
      tags:
      - Traces
      summary: Send OpenTelemetry-compatible traces to Langtrace.
      description: Ingests JSON-encoded OTLP/HTTP spans. Use an OTEL exporter configured for the otlphttp protocol with JSON encoding and no compression, and set the x-api-key header to a project-level API key. Available on Langtrace Cloud and self-hosted instances.
      requestBody:
        required: true
        description: An OTLP/HTTP ExportTraceServiceRequest payload, JSON-encoded.
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/OTLPTraceExportRequest'
      responses:
        '200':
          description: Traces accepted for ingestion.
        '401':
          description: Invalid or missing API key.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
  /traces:
    post:
      operationId: downloadTraces
      tags:
      - Traces
      summary: Download traces for a project.
      description: Retrieves stored traces for a project, paginated. Returns up to 100 traces per page along with pagination metadata.
      requestBody:
        required: true
        content:
          application/json:
            schema:
              $ref: '#/components/schemas/GetTracesRequest'
      responses:
        '200':
          description: Traces returned.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/GetTracesResponse'
        '401':
          description: Invalid api key unauthorized.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
components:
  schemas:
    OTLPTraceExportRequest:
      type: object
      description: OTLP/HTTP ExportTraceServiceRequest. JSON-encoded resource spans as produced by an OpenTelemetry exporter. See the OpenTelemetry protocol specification for the full structure.
      properties:
        resourceSpans:
          type: array
          items:
            type: object
    Error:
      type: object
      properties:
        message:
          type: string
          description: Human-readable error message.
    GetTracesRequest:
      type: object
      required:
      - projectId
      - page
      - pageSize
      properties:
        projectId:
          type: string
          description: ID of your project, found on the Langtrace traces tab.
        page:
          type: integer
          description: Page number to retrieve. Starts from 1.
        pageSize:
          type: integer
          maximum: 100
          description: Number of traces to retrieve per page. Maximum value is 100.
    GetTracesResponse:
      type: object
      properties:
        traces:
          type: object
          properties:
            result:
              type: array
              items:
                type: object
              description: List of retrieved traces.
            metadata:
              type: object
              properties:
                page:
                  type: integer
                page_size:
                  type: integer
                total_pages:
                  type: integer
  securitySchemes:
    ApiKeyAuth:
      type: apiKey
      in: header
      name: x-api-key
      description: Project-level (or team-level for project creation) API key.