cargo-public-api/cargo-public-api — List and diff the public API of Rust library crates between releases and commits.

Description and use

**Brief Summary (2‑3 sentences)**
cargo-public-api is a Rust‑based tool that extracts the public API surface of a crate, compares it across releases or commits, and flags breaking changes and semver violations. It can be run locally as a CLI or integrated into CI pipelines, giving teams immediate feedback on API stability. The project is actively maintained, well‑starred, and ready for production use.

**Value**

• **Prevent accidental breaking changes** – By automatically diffing the public API, the tool catches incompatibilities before they reach users, reducing costly rollbacks and support tickets.
• **Standardize release hygiene** – Embedding the check in CI enforces a consistent semver policy across all Rust libraries in an organization, improving reliability of internal and external SDKs.
• **Speed up development** – Teams can ship new features faster because they get immediate, actionable reports on API impact without manual code review.

**Practical Adoption Path**

1. **Add to the repository** – Include cargo install cargo-public-api (or add it as a dev‑dependency) in each crate’s workflow.
2. **Integrate into CI** – Add a step that runs cargo public-api diff <old-version> <new-version> and fails the build on detected breaking changes.
3. **Optional CLI usage** – Developers can run cargo public-api locally to preview API changes before committing.
4. **Policy enforcement** – Define an organization‑wide rule (e.g., “no breaking changes without a major version bump”) and use the CI reports to enforce it.

**Production Readiness**

• **Activity & community** – 559 stars, 42 forks, recent commits (as of 2026‑06‑25) and ongoing issue discussion indicate a healthy, active project.
• **Maturity** – The binary is stable, well‑documented, and has been adopted by several open‑source crates, showing real‑world viability.
• **Risk profile** – No major licensing or security concerns have been identified; the remaining checks (license compliance, security audit) are routine.

Overall, cargo-public-api is a production‑ready OSS component that can be safely piloted now and rolled out organization‑wide to enforce API stability in Rust services.

Problem

cargo-public-api/cargo-public-api helps teams reuse service infrastructure instead of rebuilding common backend pieces.

Outcome

High for an OSS candidate: recent activity, adoption, and ecosystem signals are strong enough for a serious pilot.

Workflow

• ship API services faster
• reuse backend infrastructure
• standardize service patterns

Evidence

List and diff the public API of Rust library crates between releases and commits. Detect breaking API changes and semver violations via CI or a CLI.

Source