--- name: graphql-inspector-diff-8c18fd9e0de7 user-invocable: false description: Use when detecting breaking changes between GraphQL schema versions, comparing schemas across branches, or validating schema migrations. allowed-tools: [Read, Write, Edit, Bash, Glob, Grep] --- # GraphQL Inspector - Schema Diff Expert knowledge of GraphQL Inspector's diff command for detecting breaking, non-breaking, and dangerous changes between GraphQL schema versions. ## Overview GraphQL Inspector's diff command compares two GraphQL schemas and outputs a precise list of changes. Each change is categorized as breaking, non-breaking, or dangerous, helping teams prevent API regressions. ## Core Commands ### Basic Diff ```bash # Compare two schema files npx @graphql-inspector/cli diff old-schema.graphql new-schema.graphql # Compare against git branch npx @graphql-inspector/cli diff 'git:origin/main:schema.graphql' schema.graphql # Compare against specific commit npx @graphql-inspector/cli diff 'git:abc123:schema.graphql' schema.graphql # Compare against tag npx @graphql-inspector/cli diff 'git:v1.0.0:schema.graphql' schema.graphql ``` ### URL-Based Comparison ```bash # Compare local schema against remote endpoint npx @graphql-inspector/cli diff 'https://api.example.com/graphql' schema.graphql # Compare two remote endpoints npx @graphql-inspector/cli diff 'https://staging.api.com/graphql' 'https://prod.api.com/graphql' ``` ### Command Options ```bash # Only show breaking changes npx @graphql-inspector/cli diff old.graphql new.graphql --onlyBreaking # Fail on dangerous changes npx @graphql-inspector/cli diff old.graphql new.graphql --failOnDangerous # Custom rules npx @graphql-inspector/cli diff old.graphql new.graphql --rule suppressRemovalOfDeprecatedField # Output as JSON npx @graphql-inspector/cli diff old.graphql new.graphql --json ``` ## Change Categories ### Breaking Changes Changes that will break existing clients: | Change Type | Example | |-------------|---------| | Field removed | `User.email` removed | | Type removed | `UserType` deleted | | Required argument added | New `id: ID!` on query | | Type changed | `User.age: Int` → `User.age: String` | | Non-null constraint added | `email: String` → `email: String!` | | Union member removed | `SearchResult` loses `Product` type | | Enum value removed | `Status.PENDING` removed | | Interface field removed | `Node.id` removed from interface | ### Dangerous Changes Changes that may break some clients: | Change Type | Example | |-------------|---------| | Argument default changed | `limit = 10` → `limit = 20` | | Enum value added | New `Status.ARCHIVED` | | Optional argument added | New `User.name(format: String)` | | Union member added | `SearchResult` gains `Article` type | | Interface added to type | `User` implements `Timestampable` | | Nullable field becomes non-null | `email: String` → `email: String!` on output | ### Non-Breaking Changes Safe changes that won't break clients: | Change Type | Example | |-------------|---------| | Field added | New `User.avatar` field | | Type added | New `Comment` type | | Optional argument added | New `users(filter: String)` | | Deprecation added | `@deprecated(reason: "Use newField")` | | Description changed | Updated field documentation | | Directive added | `@cacheControl(maxAge: 60)` | ## Configuration ### Rules Configuration Create `.graphql-inspector.yaml`: ```yaml diff: rules: - suppressRemovalOfDeprecatedField - considerUsage failOnBreaking: true failOnDangerous: false ``` ### Available Rules ```yaml # Suppress rules - suppressRemovalOfDeprecatedField # Deprecated fields can be removed - suppressCommonPrefixChanges # Ignore prefix renames # Usage-based rules - considerUsage # Check if breaking change affects real usage ``` ### Schema Sources ```yaml # Local file old: ./old-schema.graphql # Git reference old: git:origin/main:schema.graphql # URL with headers old: url: https://api.example.com/graphql headers: Authorization: Bearer ${API_TOKEN} # Glob pattern new: ./**/*.graphql ``` ## CI/CD Integration ### GitHub Actions ```yaml name: Schema Diff user-invocable: false on: pull_request: paths: - 'schema.graphql' - '**/*.graphql' jobs: diff: runs-on: ubuntu-latest steps: - uses: actions/checkout@v4 with: fetch-depth: 0 - name: Install Inspector run: npm install -g @graphql-inspector/cli - name: Check for breaking changes run: | graphql-inspector diff \ 'git:origin/main:schema.graphql' \ schema.graphql \ --onlyBreaking ``` ### GitLab CI ```yaml schema-diff: image: node:20 script: - npm install -g @graphql-inspector/cli - graphql-inspector diff "git:origin/main:schema.graphql" schema.graphql rules: - changes: - "**/*.graphql" ``` ## Usage-Based Diffing Check if breaking changes affect actual operations: ```bash # Provide operations to check against npx @graphql-inspector/cli diff old.graphql new.graphql \ --rule considerUsage \ --documents "src/**/*.graphql" ``` Benefits: - Only flags breaking changes that affect real operations - Allows safe removal of unused fields - Reduces false positives in large schemas ## Federation Support For Apollo Federation schemas: ```bash # Compare federated schemas npx @graphql-inspector/cli diff \ --federation \ old-subgraph.graphql \ new-subgraph.graphql ``` ## Best Practices 1. **Always diff before deploying** - Run diff in CI on every schema change 2. **Use git references** - Compare against main branch, not arbitrary files 3. **Enable usage checking** - Reduce noise by checking actual usage 4. **Document deprecations** - Add `@deprecated` before removing fields 5. **Review dangerous changes** - They may still break edge cases 6. **Keep deprecation window** - Give clients time to migrate 7. **Automate in PRs** - Comment diff results on pull requests 8. **Version your schema** - Tag releases for easy comparison ## Common Patterns ### Deprecation Workflow ```graphql # Step 1: Add new field and deprecate old type User { fullName: String! name: String @deprecated(reason: "Use fullName instead") } # Step 2: After migration window, remove old field type User { fullName: String! } ``` ### Safe Field Renaming ```graphql # Phase 1: Add alias with deprecated old name type User { displayName: String! name: String @deprecated(reason: "Use displayName") } # Phase 2: Remove after client migration type User { displayName: String! } ``` ## Troubleshooting ### Common Issues **"Schema not found"** - Verify file path is correct - Check git reference syntax: `git:branch:path` - Ensure schema file exists in specified location **"Breaking changes detected" in CI** - Review if changes are intentional - Add deprecation if removing field - Use `--rule suppressRemovalOfDeprecatedField` if field was deprecated **"Introspection query failed"** - Check URL is accessible - Verify authentication headers - Ensure introspection is enabled on endpoint ## When to Use This Skill - Planning schema migrations - Reviewing schema changes in pull requests - Setting up CI/CD for schema validation - Detecting breaking changes before deployment - Comparing production vs development schemas - Auditing schema evolution over time --- Source attribution: TheBushidoCollective Original project: https://github.com/TheBushidoCollective/han/blob/19caa51d5fd144ef6b2764f2332f4c856aa5d1af/plugins/tools/graphql-inspector/skills/graphql-inspector-diff/SKILL.md License: Apache-2.0 License information: https://www.apache.org/licenses/LICENSE-2.0 Original upstream instructions; downloaded from Mega AI Hub. ## Upstream license notice # Functional Source License, Version 1.1, ALv2 Future License ## Abbreviation FSL-1.1-ALv2 ## Notice Copyright 2025 The Bushido Collective ## Terms and Conditions ### Licensor ("We") The party offering the Software under these Terms and Conditions. ### The Software The "Software" is each version of the software that we make available under these Terms and Conditions, as indicated by our inclusion of these Terms and Conditions with the Software. ### License Grant Subject to your compliance with this License Grant and the Patents, Redistribution and Trademark clauses below, we hereby grant you the right to use, copy, modify, create derivative works, publicly perform, publicly display and redistribute the Software for any Permitted Purpose identified below. ### Permitted Purpose A Permitted Purpose is any purpose other than a Competing Use. 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If you make a claim against any party that the Software infringes or contributes to the infringement of any patent, then your patent license to the Software ends immediately. ### Redistribution The Terms and Conditions apply to all copies, modifications and derivatives of the Software. If you redistribute any copies, modifications or derivatives of the Software, you must include a copy of or a link to these Terms and Conditions and not remove any copyright notices provided in or with the Software. ### Disclaimer THE SOFTWARE IS PROVIDED "AS IS" AND WITHOUT WARRANTIES OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING WITHOUT LIMITATION WARRANTIES OF FITNESS FOR A PARTICULAR PURPOSE, MERCHANTABILITY, TITLE OR NON-INFRINGEMENT. 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You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. # Mega AI Hub resource metadata Creator / publisher: TheBushidoCollective Original project: https://github.com/TheBushidoCollective/han/blob/19caa51d5fd144ef6b2764f2332f4c856aa5d1af/plugins/tools/graphql-inspector/skills/graphql-inspector-diff/SKILL.md Attribution basis: Source repository record Fields of work: Data & Analytics, Development & Engineering, Product Management Roles: Backend Developer, Data Analyst, Product Manager Specialties: API Tools: Graphql Inspector Country applicability: Country not specified Classification basis: Source catalog labels Instruction SHA-256: adb2ee06a3cd9394a1c2b12bad67dcdac0bfde8bc5734fa922b5fa25bbea3f98