Langtrace AI

Langtrace is an open-source, OpenTelemetry-based end-to-end observability platform for LLM applications, built by Scale3 Labs. It captures real-time traces, metrics, and evaluations for popular LLMs, agent frameworks, and vector databases. Traces are ingested via an OTLP/HTTP endpoint and a REST API exposes projects, prompt registry, and trace retrieval. Available as a free self-hosted deployment or as Langtrace Cloud.

4 APIs 0 Features

AILLMObservabilityOpenTelemetryTracingOpen Source

APIs

Langtrace Trace Ingestion (OTEL)

OpenTelemetry-compatible trace ingestion endpoint (POST /api/trace). Accepts JSON-encoded OTLP/HTTP spans authenticated with a project-level x-api-key header, for both Langtrace...

Langtrace Projects and API Keys

REST endpoints to create projects (POST /api/project) under a team and to mint project-level API keys (POST /api/api-key), authenticated with an x-api-key header.

Langtrace Prompt Registry

Fetch versioned prompts from the prompt registry (GET /api/promptset) with optional version selection and dynamic variable substitution, returning the live prompt when no versio...

Langtrace Trace Retrieval and Metrics

Paginated retrieval of stored traces for a project (POST /api/traces), returning span results plus pagination metadata. Underlying spans carry the token, cost, latency, and eval...

Resources

👥

GitHubOrganization

Sources

aid: langtrace
url: https://raw.githubusercontent.com/api-evangelist/langtrace/refs/heads/main/apis.yml
name: Langtrace AI
kind: company
description: Langtrace is an open-source, OpenTelemetry-based end-to-end observability
  platform for LLM applications, built by Scale3 Labs. It captures real-time traces,
  metrics, and evaluations for popular LLMs, agent frameworks, and vector databases.
  Traces are ingested via an OTLP/HTTP endpoint and a REST API exposes projects,
  prompt registry, and trace retrieval. Available as a free self-hosted deployment
  or as Langtrace Cloud.
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
tags:
- AI
- LLM
- Observability
- OpenTelemetry
- Tracing
- Open Source
created: '2026-06-20'
modified: '2026-06-20'
specificationVersion: '0.19'
apis:
- aid: langtrace:trace-ingestion-otel
  name: Langtrace Trace Ingestion (OTEL)
  tags:
  - OpenTelemetry
  - Tracing
  - Ingestion
  - OTLP
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  humanURL: https://docs.langtrace.ai/api-reference/traces/POST-trace
  baseURL: https://app.langtrace.ai/api
  properties:
  - url: https://docs.langtrace.ai/supported-integrations/otel-support/otel-configuration
    type: Documentation
  - url: https://docs.langtrace.ai/api-reference/traces/POST-trace
    type: APIReference
  - url: openapi/langtrace-openapi.yml
    type: OpenAPI
  - url: collections/langtrace.postman_collection.json
    type: PostmanCollection
  - url: collections/langtrace.opencollection.json
    type: OpenCollection
  - url: https://github.com/Scale3-Labs/langtrace
    type: GitHub
  description: OpenTelemetry-compatible trace ingestion endpoint (POST /api/trace).
    Accepts JSON-encoded OTLP/HTTP spans authenticated with a project-level x-api-key
    header, for both Langtrace Cloud and self-hosted deployments.
- aid: langtrace:projects-api-keys
  name: Langtrace Projects and API Keys
  tags:
  - Projects
  - API Keys
  - Management
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  humanURL: https://docs.langtrace.ai/api-reference/project/POST-project
  baseURL: https://app.langtrace.ai/api
  properties:
  - url: https://docs.langtrace.ai/api-reference/project/POST-project
    type: Documentation
  - url: https://docs.langtrace.ai/api-reference/project/POST-project-api-key
    type: APIReference
  - url: openapi/langtrace-openapi.yml
    type: OpenAPI
  - url: collections/langtrace.postman_collection.json
    type: PostmanCollection
  - url: collections/langtrace.opencollection.json
    type: OpenCollection
  - url: https://github.com/Scale3-Labs/langtrace
    type: GitHub
  description: REST endpoints to create projects (POST /api/project) under a team and
    to mint project-level API keys (POST /api/api-key), authenticated with an x-api-key
    header.
- aid: langtrace:prompt-registry
  name: Langtrace Prompt Registry
  tags:
  - Prompt Registry
  - Versioning
  - Prompts
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  humanURL: https://docs.langtrace.ai/api-reference/prompt-registry/GET-prompt-registry
  baseURL: https://app.langtrace.ai/api
  properties:
  - url: https://docs.langtrace.ai/api-reference/prompt-registry/GET-prompt-registry
    type: Documentation
  - url: https://docs.langtrace.ai/api-reference/prompt-registry/GET-prompt-registry
    type: APIReference
  - url: openapi/langtrace-openapi.yml
    type: OpenAPI
  - url: collections/langtrace.postman_collection.json
    type: PostmanCollection
  - url: collections/langtrace.opencollection.json
    type: OpenCollection
  - url: https://github.com/Scale3-Labs/langtrace
    type: GitHub
  description: Fetch versioned prompts from the prompt registry (GET /api/promptset)
    with optional version selection and dynamic variable substitution, returning the
    live prompt when no version is specified.
- aid: langtrace:trace-retrieval
  name: Langtrace Trace Retrieval and Metrics
  tags:
  - Traces
  - Metrics
  - Retrieval
  - Evaluations
  image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/apis-json-logo.jpg
  humanURL: https://docs.langtrace.ai/api-reference/traces/POST-traces
  baseURL: https://app.langtrace.ai/api
  properties:
  - url: https://docs.langtrace.ai/api-reference/traces/POST-traces
    type: Documentation
  - url: https://docs.langtrace.ai/api-reference/traces/POST-traces
    type: APIReference
  - url: openapi/langtrace-openapi.yml
    type: OpenAPI
  - url: collections/langtrace.postman_collection.json
    type: PostmanCollection
  - url: collections/langtrace.opencollection.json
    type: OpenCollection
  - url: https://github.com/Scale3-Labs/langtrace
    type: GitHub
  description: Paginated retrieval of stored traces for a project (POST /api/traces),
    returning span results plus pagination metadata. Underlying spans carry the token,
    cost, latency, and evaluation metrics surfaced in the Langtrace dashboards.
common:
- type: GitHubOrganization
  url: https://github.com/Scale3-Labs
- type: LinkedIn
  url: https://www.linkedin.com/company/langtrace
- type: Website
  url: https://www.langtrace.ai
- type: Documentation
  url: https://docs.langtrace.ai
- type: Plans
  url: plans/langtrace-plans-pricing.yml
- type: RateLimits
  url: rate-limits/langtrace-rate-limits.yml
- type: FinOps
  url: finops/langtrace-finops.yml
maintainers:
- FN: Kin Lane
  email: kin@apievangelist.com