Add tool: Gesso — OpenAPI 3.0/3.1/3.2 contract testing for PHP

Tool details

• Name: Gesso
• Homepage: https://studio-design.github.io/gesso/
• Source repository: https://github.com/studio-design/gesso
• License: MIT
• Language: PHP
• OpenAPI versions supported: 3.0, 3.1, 3.2
• Suggested categories: Testing, Data Validators
• Commercial: No (fully open source)

Description

Gesso — OpenAPI 3.0/3.1/3.2 contract testing for PHP. Framework-independent core with Laravel, Symfony, Pest, and PSR-7 adapters. Provides PHPUnit endpoint-coverage tracking at (method, path, status, content-type) granularity, request and response validation, schema-driven fuzzing with deterministic replay, and enum + schema drift detection.

Why it belongs on tools.openapis.org

Fills a gap in the PHP row of the Testing and Data Validators categories: the closest current entries (Spectator, league/openapi-psr7-validator, kirschbaum-development/laravel-openapi-validator, osteel/openapi-httpfoundation-testing) each cover a slice — Gesso is the only PHP entry that covers OpenAPI 3.1/3.2, framework-agnostic core + Laravel/Symfony/Pest/PSR-7 adapters, endpoint coverage, and schema-driven fuzzing in one library.

Notes for maintainers

The repo already carries the relevant GitHub topics (openapi3, openapi31, openapi, openapi-validator, contract-testing, api-testing, plus the PHP/framework tags). We noticed the weekly Full build workflow has been failing since at least 2026-07-12, so topic-based auto-ingest hasn't fired — happy to also open a direct PR to src/_data/tools.yaml if that's preferred.

Start with src/_data/tools.yaml and compare existing PHP and OpenAPI tool entries for the expected fields and categories. Review the Full build workflow or run its available validation to check the links and metadata. Done means Gesso appears in the catalog with accurate details, links, and Testing/Data Validators categorization.