# crates.io

**Canonical:** https://apis.io/providers/crates-io/  
**Website:** https://crates.io  
**APIs profiled:** 5

crates.io is the official package registry for the Rust programming language, operated by the crates.io team under the Rust Foundation with infrastructure support from Amazon Web Services and Fastly. It exposes a Web API at /api/v1 used by Cargo and the website for search, publishing, yanking, and owner management, plus a sparse HTTP index at index.crates.io that has been Cargo's default registry protocol since Rust 1.70 (June 2023). The legacy git index is still mirrored. Every published version is checksummed with SHA-256 and companion documentation is auto-built on docs.rs. The crates.io source code is dual-licensed under Apache-2.0 and MIT and runs on Rust (axum, diesel) with a SvelteKit frontend.

## Kin Score — 40.0 / 100 (developing)

Scored 2026-08-20 under rubric 0.12.0. Trend: flat (+0.0 from 40.0).

| Facet | Score |
|---|---|
| Discoverability | 64.8 |
| Contract Quality | 64.6 |
| Governance | 9.8 |
| Contract Governance | 9.8 |
| Operational Transparency | 47.4 |
| Developer Ergonomics | 50.0 |
| Commercial Clarity | 0.0 |
| Access Clarity | 0.0 |

## Agent readiness — 29.1 (agent-aware)

| Dimension | Value |
|---|---|
| Spec Presence | yes |
| Agentic Access | derived |
| Reversibility Documented | no |
| MCP Server | no |
| Auth Clarity | yes |
| Idempotency | no |
| Error Semantics | no |
| OpenAPI Examples | partial |
| Rate Limit Signal | no |
| Event Surface Described | no |
| Agent Skills | no |
| Well Known Catalog | no |
| Consent Identity | no |
| Agent Card | no |
| Dry Run Mode | no |

## Access

Self-serve signup — onboarding: self-serve, pricing: unknown, trial: no (confidence: medium).

## APIs (5)

- **crates.io Config API** — Registry configuration document
- **crates.io Crates API** — Search and manage Rust crates
- **crates.io Index API** — Per-crate index metadata files served over HTTP
- **crates.io Owners API** — List, add, and remove crate owners
- **crates.io Versions API** — Yank and unyank crate versions

## Agentic access (1)

- **Crates Io Agentic Access** — 15 operations · 5 acting

## Security (3)

- **Crates Io Authentication** — apiKey · 1 scheme
- **Crates Io Domain Security** — TLSv1.3 · DMARC
- **Crates Io Vulnerability Disclosure** — security.txt · contact published

## Tags

Rust, Package Registry, Crates, Cargo, Open-Source, Developer Tools, Rust Foundation

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Profiled by [API Evangelist](https://apievangelist.com) and published on [APIs.io](https://apis.io/providers/crates-io/). Scores are computed from the provider's own public artifacts under a published rubric.