openapi: 3.0.1
info:
  title: Langtrace AI Projects Prompt Registry 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: Prompt Registry
  description: Versioned prompt storage and retrieval.
paths:
  /promptset:
    get:
      operationId: getPromptFromRegistry
      tags:
      - Prompt Registry
      summary: Get a prompt from the registry.
      description: Fetches a prompt set from the prompt registry. If no version is provided the live prompt is returned; if there are no live prompts an error is thrown. Dynamic variables may be supplied using variables.<variable_name> query parameters.
      parameters:
      - name: promptset_id
        in: query
        required: true
        description: ID of the prompt registry, found in the Langtrace UI.
        schema:
          type: string
      - name: version
        in: query
        required: false
        description: Prompt version to fetch. Defaults to the live prompt.
        schema:
          type: integer
      responses:
        '200':
          description: Prompt set returned.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/PromptSet'
        '401':
          description: Invalid api key unauthorized.
          content:
            application/json:
              schema:
                $ref: '#/components/schemas/Error'
components:
  schemas:
    Error:
      type: object
      properties:
        message:
          type: string
          description: Human-readable error message.
    PromptSet:
      type: object
      properties:
        id:
          type: string
        name:
          type: string
        description:
          type: string
        projectId:
          type: string
        prompts:
          type: array
          items:
            $ref: '#/components/schemas/Prompt'
        createdAt:
          type: string
          format: date-time
        updatedAt:
          type: string
          format: date-time
    Prompt:
      type: object
      properties:
        id:
          type: string
        value:
          type: string
          description: The prompt string.
        variables:
          type: array
          items:
            type: string
        model:
          type: string
        modelSettings:
          type: object
        version:
          type: integer
        live:
          type: boolean
        tags:
          type: array
          items:
            type: string
        spanId:
          type: string
        note:
          type: string
        createdAt:
          type: string
          format: date-time
        updatedAt:
          type: string
          format: date-time
  securitySchemes:
    ApiKeyAuth:
      type: apiKey
      in: header
      name: x-api-key
      description: Project-level (or team-level for project creation) API key.