WPGraphQL Schema Diff Gate

PHP control surface for detecting WPGraphQL schema drift, surfacing breaking changes, and showing which headless consumers will fail before a release goes live.

What this repo proves

Headless WordPress failures often start before runtime. A field disappears, nullability tightens, an argument name changes, or a deprecation lands without a migration path. This repo turns that schema drift into a visible release gate instead of an after-the-fact frontend outage.

Why this repo exists

WPGraphQL teams usually discover breaking change too late. An SEO landing page still expects a removed pricing fragment. A persisted query signature drifts. An answer-engine card fails because content no longer satisfies a newly non-null field.

wpgraphql-schema-diff-gate models that release problem directly. It compares a baseline and candidate schema posture, classifies blocked versus watch changes, and ties every diff to impacted consumers and verification lanes.

Screenshots

What it includes

• PHP control plane with HTML proof surfaces and JSON APIs
• sample WPGraphQL schema snapshots across baseline and release-candidate lanes
• breaking-change summaries for removed fields, nullability shifts, argument renames, and deprecations
• consumer impact posture for marketing, AEO, editorial, and persisted-query surfaces
• starter WordPress plugin export for schema-gate notices and manifest examples
• real browser-rendered README proof assets

Local run

cd wpgraphql-schema-diff-gate
php -S 127.0.0.1:5406 router.php

Open:

• http://127.0.0.1:5406/
• http://127.0.0.1:5406/schema-diffs
• http://127.0.0.1:5406/impact-lane
• http://127.0.0.1:5406/verification
• http://127.0.0.1:5406/docs

Validation

php -l public\index.php
php -l src\Services\SchemaDiffGateService.php
php -l src\Views\render.php
php -l plugin\wpgraphql-schema-diff-gate.php
php scripts\run_demo.php
powershell -ExecutionPolicy Bypass -File .\scripts\smoke_check.ps1
powershell -ExecutionPolicy Bypass -File .\scripts\render_readme_assets.ps1

API routes

• GET /api/dashboard/summary
• GET /api/schema-diffs
• GET /api/impact-lane
• GET /api/verification
• GET /api/sample

Plugin starter

• Starter plugin export

Docs

• Architecture notes
• Why we built this