Closing the Gap: How Contract-First Testing Solves Rust API Validation

Unit tests in Rust verify code logic but miss critical HTTP-level concerns—response codes, serialization, authentication, and API contracts. This guide explains why contract-first testing with Apidog bridges that gap, enabling teams to validate endpoints without duplicating integration tests per handler, providing stable mocks for frontend parallelization, and generating OpenAPI specifications from request definitions rather than code annotations.