Introduction

libregistry provides structured, machine-readable data on libraries, models, MCP servers, Docker images, and IAM services — built for AI agents and developers who need reliable compatibility data.

Base URL:

https://api.libregistry.com

All responses are JSON. All list endpoints return { total, offset, limit, results }.

Authentication

Public read endpoints require no authentication. Pass your API key as a Bearer token when accessing rate-limited or account endpoints.

GET /registry HTTP/1.1
Host: api.libregistry.com
Authorization: Bearer lr_live_<your_key>

Get your key from your account page. Keys begin with lr_live_. The full key is shown once at creation — if lost, regenerate from your account page.

Registry

Library compatibility data. Entries may be empirically verified (install + import tested in a clean venv) or unverified (community-sourced).

GET/registry

List libraries.

qstringSearch by name or description.
languagestringFilter by language: python, javascript, rust, go, …
categorystringFilter by category: ai-ml, llm-agents, web-framework, …
statusstringactive · maintenance · deprecated · abandoned
verified_onlyintegerPass 1 to return only entries with a passing verify run.
sortstringPass hits to sort by 7-day traffic.
limitintegerMax results per page. Default 10, max 100.
offsetintegerPagination offset. Default 0.
curl "https://api.libregistry.com/registry?language=python&category=ai-ml&limit=5"
GET/registry/{library}

Full entry for a single library. library is the slug, e.g. openai, langchain, boto3.

curl "https://api.libregistry.com/registry/openai"

Response includes provenance — verified status, last verified date, and next scheduled check.

GET/registry/{library}/compatibility

Compatibility matrix for a library: per-environment install + import results.

curl "https://api.libregistry.com/registry/openai/compatibility"
{
  "matrix": [
    {
      "py_version": "python:3.10-slim",
      "passing": 1,
      "runs": 1,
      "avg_install_s": 4.21,
      "avg_import_s": 0.34,
      "installed_version": "1.35.3",
      "disk_size": 42.1
    }
  ],
  "traffic": {
    "hits_30d": 18400,
    "hits_7d": 3200,
    "actors": [{ "bot": "ChatGPT-User", "hits": 9100 }]
  }
}

Models

AI model registry: specs, pricing, context windows, capabilities.

GET/models
qstringSearch by title, description, or provider.
providerstringFilter by provider: anthropic, openai, google, …
model_typestringFilter by type: chat, embedding, image, …
statusstringactive · deprecated · retired
limitintegerDefault 100, max 500.
offsetintegerDefault 0.
curl "https://api.libregistry.com/models?provider=anthropic"
GET/models/{slug}

Full model record including pricing, modalities, capabilities, and lifecycle dates.

curl "https://api.libregistry.com/models/claude-sonnet-4-5"

MCP Servers

MCP (Model Context Protocol) server registry.

GET/mcp
qstringSearch by name or description.
categorystringFilter by category.
limitintegerDefault 50, max 200.
offsetintegerDefault 0.
curl "https://api.libregistry.com/mcp?q=filesystem"
GET/mcp/{slug}
curl "https://api.libregistry.com/mcp/filesystem"

Docker Images

Curated Docker base image reference.

GET/docker
qstringSearch by name or description.
categorystringFilter by category.
limitintegerDefault 50, max 200.
offsetintegerDefault 0.
curl "https://api.libregistry.com/docker?q=python"
GET/docker/{slug}
curl "https://api.libregistry.com/docker/python-3-12-slim"

IAM Services

Cloud IAM service reference: permissions, policies, identities.

GET/iam
qstringSearch by name or description.
limitintegerDefault 50, max 200.
offsetintegerDefault 0.
curl "https://api.libregistry.com/iam?q=aws"
GET/iam/{slug}
curl "https://api.libregistry.com/iam/aws-iam-role"

Rate limits

HTML registry pages are never rate-limited. Only the JSON API applies these limits.

Anonymous500 requests / day per IP
With API keyUnlimited — free tier, usage visible on your account page

Errors

Standard HTTP status codes.

200OK
400Bad request — check query parameters.
401Missing or invalid Bearer token.
404Resource not found — check the slug against /registry?q=
422Validation error — malformed parameter value.
429Rate limit exceeded — add an API key or wait for the daily reset.
500Internal server error.

Error body:

{ "detail": "Library not found" }