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.

Langtrace AI publishes 3 API contracts indexed on the APIs.io network: Projects API, Prompt Registry API, and Traces API. Tagged areas include Artificial Intelligence, LLM, Observability, OpenTelemetry, and Tracing.

The Langtrace AI catalog on APIs.io includes 1 Spectral governance ruleset.

Langtrace AI’s developer surface includes authentication, documentation, and 9 more developer resources.

🌐 Visit website 📡 Profile data on GitHub

27.0/100 thin ▬ flat Agent 25/100 agent aware open core · AGPL-3.0 Full breakdown ↓
scored 2026-11-13 · rubric v0.28.0 · Show this score on your site →

AccessFreemiumSelf serve⚡ Free to try

1 published contract

Artificial Intelligence LLM Observability OpenTelemetry Tracing Open Source

What this lets a business do 1

Business capabilities this provider's published APIs can perform, derived from its own contracts. Browse all capabilities →

SaaS Platform Operations Management

BC-4220

Traces

POST /trace POST /traces

Kin Score

Kin Score How this is scored →
scored 2026-11-13 · rubric v0.28.0

Composite quality — 27.0/100 · thin

Contract Quality 9.1 / 19

Developer Ergonomics 4.5 / 15

Access Clarity 1.0 / 15

Operational Transparency 1.2 / 10

Contract Governance 1.2 / 9

Discoverability 5.0 / 8

Regulatory Posture 0.8 / 15

Create-or-Update Ergonomics 0.0 / 10

Agent readiness — 25/100 · agent aware

Machine-Readable Contract 18 / 18

Agentic Access Contract 10 / 10

Documented Reversibility 0 / 6

MCP Server 0 / 12

Machine-Readable Auth 10 / 10

Idempotency 0 / 9

Stable Error Semantics 8 / 8

Request/Response Examples 0 / 7

Rate-Limit Signaling 7 / 7

Typed Event Surface 0 / 6

Agent Skills 0 / 5

Well-Known Catalog 0 / 4

Consent & Bot Identity 0 / 3

A2A Agent Card 0 / 8

Dry-Run / Simulate Mode 0 / 4

Delegated User Identity 0 / 6

Protected Resource Metadata 0 / 5

Registration Without a Human 0 / 6

Agentic Commerce Well-Known Document 0 / 5

Pagination 5 / 5

Distinct Operations 3 / 3

MCP Tool Quality 6 / 6

Regulatory Posture applies to this provider. Its tags matched the Horizontal (data, software, accessibility, platform) regime, so Regulatory Posture carries 15 points of the composite. If this regime is wrong for your business, say so on your provider repo — the applicability map is public and we will correct it.

Create-or-Update Ergonomics applies to this provider. This API accepts writes, so it carries 10 points of the composite. It is scored from the published contracts themselves: whether a caller can create-or-update in one call, whether the write accepts a key the caller already holds, and whether the response says which branch ran. Without that, every write needs a search-and-branch in front of it, and the first time that check is skipped a duplicate record is created. Scored against the observed mean rather than raw — a provider at the catalog average is unchanged by this facet, not penalised by it.

The six quality facets above are damped to 75 points between them, because the conditional facet above carries the other 25. That is why each facet's contribution is shown against a damped maximum: raising a quality facet moves the composite by 75% of its nominal weight, not 100%. The full arithmetic is at apis.io/rating/.

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Agent readiness — checks not met, largest first (exact, from this profile):

MCP Server +12 pts — deployment.mode + probe verdict on the mcp/ manifest, not the pointer; an unprobed slug falls back to authorship Ask about this →
Idempotency +9 pts — OpenAPI mutating operations declare an idempotency key — a header, a request-body property, or a named de-duplication token whose own description says so (verified); else common[].type matches /idempoten/i (documented) Ask about this →
A2A Agent Card +8 pts — a2a/-a2a.yml manifest, graded on conformance.grade against A2A 1.0.0 Ask about this →
Request/Response Examples +7 pts — share of operations carrying request/response examples; else an Examples / Code Samples link Ask about this →
Registration Without a Human +6 pts — a `registration_endpoint` in the served RFC 8414 / OIDC discovery document Ask about this →
Delegated User Identity +6 pts — a served discovery document listing authorization_code in grant_types_supported (served), else an oauth2 authorizationCode flow or openIdConnect declared in an OpenAPI (documented) Ask about this →

8 more unmet checks in the Agent Readiness table above.

Kin Score — facets with the most composite points still available (weight × headroom):

Access Clarity scores 6.4 — up to +18.7 composite points Ask about this →
Developer Ergonomics scores 29.8 — up to +14.0 composite points Ask about this →
Contract Quality scores 48.4 — up to +12.9 composite points Ask about this →

Each check links to what satisfies it. Publish the artifact, or tell us where it already lives, and the score moves on the next scoring run.

Not sure how this applies to your stack? Ask about any one item. Kin Lane reads every question, looks at your profile and your situation, and replies with what a fix would take — scoped to that one area, priced up front, yours whether you ship it or not. Ask a question →

Improve this rating by publishing the missing artifacts — every area above can be raised, and the full rubric is at apis.io/rating/. Every facet and dimension name above is a link: it opens that measurement's own page — what it means, the exact checks that feed it, how the whole catalog distributes on it, and the providers at the top of it. This rating is computed from the provider profile at artifacts.apis.io/langtrace/apis.yml: open an issue on github.com/api-evangelist/langtrace to ask a question or point us at an artifact you publish. Submit an artifact on GitHub — free → Manage your own listing — the Influence plan, $499/mo →

Standards implemented 1

Standards this provider implements or carries. De facto ones are profiled and measured by the API Commons; formal ones come from the standards directory and are linked by the provider's own tags. The evidence column says how each claim was established — not that it was made.

OpenAPI

measured — observed by APIs.io (published)

APIs 3

Individual APIs this provider publishes, each with its own machine-readable definition.

Langtrace AI Projects API

Project and API key management.

Langtrace AI Prompt Registry API

Versioned prompt storage and retrieval.

Langtrace AI Traces API

OpenTelemetry trace ingestion and retrieval.

Open Collections 4

Open, tool-agnostic API collections (OpenAPI-derived and Bruno).

Langtrace AI Projects API

OPEN COLLECTION

Langtrace AI Projects Prompt Registry API

OPEN COLLECTION

Langtrace AI Projects Traces API

OPEN COLLECTION

Langtrace AI API

OPEN COLLECTION

Langtrace AI API pricing

Not yet checked against Langtrace AI's own pricing page. Compiled by API Evangelist on 2026-06-20 from www.langtrace.ai/pricing; confirm before you rely on a figure. A free plan or tier is listed.

Plan	Price
Self-Hosted (Open Source) open_source	—
Free free	Free
Growth paid	—
Enterprise enterprise	—

Plan details, limits and sources →

Rate limits

Trace Retrieval Page Size: 100 traces
Cloud Span Allowance: see plan / provider documentation spans
Ingestion Rate: see provider documentation spans

Compiled by API Evangelist, not yet checked against Langtrace AI's documentation. All 4 limits →

Pricing Plans 1

Published pricing tiers and plan structures.

Langtrace AI Plans Pricing

4 plans

PLANS

Rate Limits 1

Documented rate limits and quota policies.

Langtrace AI Rate Limits

4 limits

RATE LIMITS

FinOps 1

Cost, billing, and metering signals for API financial operations.

Langtrace AI Finops

FINOPS

Spectral Rules 1

Spectral governance rulesets for linting and validating these APIs. Counts are the severity each rule declares, not results of running them.

Langtrace AI API Rules

66 rules · 64 error-severity 1 warn-severity 1 info-severity

SPECTRAL

Security Posture 2

Authentication, domain security, vulnerability disclosure, and trust-center signals.

Langtrace AI Authentication

apiKey · 1 scheme

SECURITY

Langtrace AI Domain Security

TLSv1.3 · HSTS · DMARC

SECURITY

Agentic Access (API Evangelist recommendations) 1

Recommended x-agentic-access execution contracts for AI agents.

Langtrace AI Agentic Access

5 operations · 4 acting

AGENTIC

Resources

Documentation 1

Reference material describing how the API behaves

Documentation

Documentation

Agent Surfaces 1

MCP servers, agent skills, and machine-readable catalogs

AgenticAccess

AgenticAccess

Build 1

SDKs, sample code, and the tooling you integrate with

GitHubOrganization

GitHubOrganization

Access & Security 2

Authentication, authorization, and security posture

DomainSecurity

DomainSecurity

Authentication

Authentication

Operate 1

Status, limits, changes, and where to get help

RateLimits

RateLimits

Commercial 2

Pricing, plans, and the legal terms of use

Plans

Plans

FinOps

FinOps

Company 2

The organization behind the API

LinkedIn

Website

Website

Other 1

Properties that don't map to a standard resource type

CapabilityMap

CapabilityMap

Source (apis.yml)

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.
deliveryModel:
  model: open-core
  license: AGPL-3.0
  license_evidence:
    repo: scale3-labs/langtrace
    spdx: AGPL-3.0
    stars: 1232
  open_source: true
  commercial: true
  callable_host: true
  label: Open core · an OSS project plus a commercial hosted product
  confidence: medium
  source:
  - openapi
  - pricing
  - repository-license
  generated: '2026-09-25'
  method: derived
accessModel:
  pricing: freemium
  onboarding: self-serve
  trial: false
  try_now: true
  public: false
  gated: none
  gated_source:
  - onboarding
  label: Freemium · Self-serve signup
  confidence: medium
  source:
  - plans
  - authentication
  - security
  generated: '2026-11-13'
  method: derived
image: https://kinlane-images.s3.amazonaws.com/shared/apis-json/icons/langtrace.png
x-docs-platform: mintlify
x-docs-platform-confidence: medium
x-docs-platform-checked: 2026-10-03
tags:
- Artificial Intelligence
- LLM
- Observability
- OpenTelemetry
- Tracing
- Open Source
tags_raw:
- AI
- LLM
- Observability
- OpenTelemetry
- Tracing
- Open Source
- Open-Source
created: '2026-06-20'
modified: '2026-06-20'
specificationVersion: '0.23'
apis:
- aid: langtrace:langtrace-projects-api
  name: Langtrace AI Projects API
  description: Project and API key management.
  humanURL: https://docs.langtrace.ai/api-reference/traces/POST-trace
  baseURL: https://app.langtrace.ai/api
  tags:
  - Project
  tags_raw:
  - Projects
  properties:
  - type: OpenAPI
    url: openapi/langtrace-projects-api-openapi.yml
  - type: Documentation
    url: https://docs.langtrace.ai/supported-integrations/otel-support/otel-configuration
  - type: APIReference
    url: https://docs.langtrace.ai/api-reference/traces/POST-trace
  - type: PostmanCollection
    url: collections/langtrace.postman_collection.json
  - type: OpenCollection
    url: collections/langtrace.opencollection.json
  - type: GitHub
    url: https://github.com/Scale3-Labs/langtrace
  - type: Documentation
    url: https://docs.langtrace.ai/api-reference/project/POST-project
  - type: APIReference
    url: https://docs.langtrace.ai/api-reference/project/POST-project-api-key
  - type: Documentation
    url: https://docs.langtrace.ai/api-reference/prompt-registry/GET-prompt-registry
  - type: APIReference
    url: https://docs.langtrace.ai/api-reference/prompt-registry/GET-prompt-registry
  - type: Documentation
    url: https://docs.langtrace.ai/api-reference/traces/POST-traces
  - type: APIReference
    url: https://docs.langtrace.ai/api-reference/traces/POST-traces
- aid: langtrace:langtrace-prompt-registry-api
  name: Langtrace AI Prompt Registry API
  description: Versioned prompt storage and retrieval.
  humanURL: https://docs.langtrace.ai/api-reference/traces/POST-trace
  baseURL: https://app.langtrace.ai/api
  tags:
  - Prompt Registry
  properties:
  - type: OpenAPI
    url: openapi/langtrace-prompt-registry-api-openapi.yml
  - type: Documentation
    url: https://docs.langtrace.ai/supported-integrations/otel-support/otel-configuration
  - type: APIReference
    url: https://docs.langtrace.ai/api-reference/traces/POST-trace
  - type: PostmanCollection
    url: collections/langtrace.postman_collection.json
  - type: OpenCollection
    url: collections/langtrace.opencollection.json
  - type: GitHub
    url: https://github.com/Scale3-Labs/langtrace
  - type: Documentation
    url: https://docs.langtrace.ai/api-reference/project/POST-project
  - type: APIReference
    url: https://docs.langtrace.ai/api-reference/project/POST-project-api-key
  - type: Documentation
    url: https://docs.langtrace.ai/api-reference/prompt-registry/GET-prompt-registry
  - type: APIReference
    url: https://docs.langtrace.ai/api-reference/prompt-registry/GET-prompt-registry
  - type: Documentation
    url: https://docs.langtrace.ai/api-reference/traces/POST-traces
  - type: APIReference
    url: https://docs.langtrace.ai/api-reference/traces/POST-traces
- aid: langtrace:langtrace-traces-api
  name: Langtrace AI Traces API
  description: OpenTelemetry trace ingestion and retrieval.
  humanURL: https://docs.langtrace.ai/api-reference/traces/POST-trace
  baseURL: https://app.langtrace.ai/api
  tags:
  - Traces
  properties:
  - type: OpenAPI
    url: openapi/langtrace-traces-api-openapi.yml
  - type: Documentation
    url: https://docs.langtrace.ai/supported-integrations/otel-support/otel-configuration
  - type: APIReference
    url: https://docs.langtrace.ai/api-reference/traces/POST-trace
  - type: PostmanCollection
    url: collections/langtrace.postman_collection.json
  - type: OpenCollection
    url: collections/langtrace.opencollection.json
  - type: GitHub
    url: https://github.com/Scale3-Labs/langtrace
  - type: Documentation
    url: https://docs.langtrace.ai/api-reference/project/POST-project
  - type: APIReference
    url: https://docs.langtrace.ai/api-reference/project/POST-project-api-key
  - type: Documentation
    url: https://docs.langtrace.ai/api-reference/prompt-registry/GET-prompt-registry
  - type: APIReference
    url: https://docs.langtrace.ai/api-reference/prompt-registry/GET-prompt-registry
  - type: Documentation
    url: https://docs.langtrace.ai/api-reference/traces/POST-traces
  - type: APIReference
    url: https://docs.langtrace.ai/api-reference/traces/POST-traces
common:
- type: CapabilityMap
  url: capabilities/langtrace-capability-edges.yml
  name: Langtrace AI Business Capability Map
- type: AgenticAccess
  url: agentic-access/langtrace-agentic-access.yml
- type: DomainSecurity
  url: security/langtrace-domain-security.yml
- type: Authentication
  url: authentication/langtrace-authentication.yml
- 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

Langtrace AI API — frequently asked questions

Does Langtrace AI have an API?

Yes. APIs.io lists 3 APIs from Langtrace AI, including Langtrace AI Projects API, Langtrace AI Prompt Registry API and Langtrace AI Traces API.

Is there an OpenAPI specification for the Langtrace AI API?

Yes. APIs.io indexes 3 OpenAPI specifications for Langtrace AI, each linked for download from this page.

How do I authenticate with the Langtrace AI API?

Langtrace AI uses bearer-token authentication (apiKey · 1 scheme). The details are profiled on APIs.io as Langtrace AI Authentication.

How much does the Langtrace AI API cost?

APIs.io lists 4 pricing plans for Langtrace AI, with each plan's price, limits and inclusions under Pricing on this page.

Is the Langtrace AI API ready for AI agents?

Langtrace AI has a Kin Score of 27.0 out of 100 (thin) and an Agent Readiness score of 25.3 (agent-aware), scored by API Evangelist on 2026-11-13.

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