GraphQL Schema Change Comparison

How to use GraphQL Schema Change Comparison

Compare two local GraphQL SDL schemas and statically validate optional saved operations against both versions. Review structural breaking and potentially dangerous changes with the pinned GraphQL.js classifier. Keep actual saved-query validation results separate from assumptions about deployed clients, resolvers or federation.

1. Provide before: complete graphql sdl schema, after: complete graphql sdl schema, optional saved operations and fragments.
2. Choose the supported mode and run the tool. Review its assumptions and any reported errors.
3. Copy the result or download a separate output; reset to clear the current form.

Good to know

• Each schema and optional operation document is at most 100 KB UTF-8, 15,000 tokens, 32 delimiter levels and 500 definitions. A schema has at most 500 named types including built-ins and 3,000 fields; the report retains at most 5,000 changes.
• Complete ordinary SDL schemas only. Executable definitions in SDL, federation composition, remote introspection, custom resolver/scalar implementations and deployed endpoint behavior are outside the profile. Invalid schemas receive diagnostics and are not compared.
• Schema-change classification follows existing GraphQL.js 17.0.2. Potentially dangerous includes categories retained by that library; other changes are not a guarantee of runtime safety. Client traffic and business semantics are not observed.
• Optional saved documents contain executable operations/fragments only and are statically validated against each valid schema, with 20 validation errors per schema plus the library limit notice. No operation, resolver, endpoint or external reference is executed.
• Library and module preparation has a separate 10-second deadline; computation is terminated after 2 seconds. Schema diagnostics are capped at 50 displayed errors per input and report output at 500,000 characters.
• Inputs are processed on this device and are not automatically saved or uploaded.