cargo-fuzz vs Schemathesis

cargo-fuzz is a Cargo subcommand for fuzzing Rust code. It invokes libFuzzer through the libfuzzer-sys crate rather than acting as a fuzzer itself. Start a crate with `cargo fuzz init`, add a target with `cargo fuzz add `, then use `cargo fuzz run ` to search for bugs. The tool can reduce a failing input with `cargo fuzz tmin` or trim a corpus with `cargo fuzz cmin`; `cargo fuzz coverage` generates source-based coverage information in version 0.10.0 or newer. Documentation also covers structure-aware fuzzing and Cargo feature options, plus a GitHub Actions workflow for building and running targets in CI. It supports Linux, macOS and Windows, with documented systems including x86-64 Linux, x86-64 and Apple-Silicon macOS, and Windows with LLVM sanitizer support. Windows programs can also be fuzzed with MSVC AddressSanitizer. Installation is documented as `cargo install cargo-fuzz`. It requires nightly Rust and a C++11-capable compiler. The project is free and distributed under the MIT and Apache License 2.0.

Schemathesis generates property-based tests from OpenAPI and GraphQL schemas to help engineers find API bugs. Its cases probe boundary values, type mismatches and constraint violations, and it validates API responses against the OpenAPI specification. For multi-step workflows, it chains operations using links inferred from a schema. During a run, it can learn validation rules, resource IDs and authentication requirements from server responses, then reuse them. Users can add Python checks for business rules alongside built-in checks. It supports OpenAPI 2.0, 3.0, 3.1 and 3.2, plus GraphQL schemas. Authentication options include Bearer tokens, Basic authentication and API keys, with environment variable substitution and Python hooks for dynamic flows. Integrations include a GitHub Action, Docker image, pip or uvx installation, and pytest. Reports can be exported as JUnit, VCR, HAR, NDJSON, JSON or Allure; failures can also be saved with curl commands for replay. The tool is self-hosted and licensed under MIT.