data-contract-migrations
Design and verify data contracts, schema changes, migrations, rollbacks, backfills, compatibility windows, tenant isolation, and API-to-database field mapping. Use when changing database schema, event payloads, persisted documents, analytics tables, multi-tenant data boundaries, or any user-visible data contract where silent fallback or undeclared fields would be dangerous.
git clone --depth 1 https://github.com/majiayu000/spellbook /tmp/data-contract-migrations && cp -r /tmp/data-contract-migrations/skills/data-contract-migrations ~/.claude/skills/data-contract-migrationsSKILL.md
# Data Contract Migrations ## Purpose Use this skill when data shape changes can break reads, writes, reports, tenants, or integrations. The goal is an explicit compatibility and migration plan, not just a SQL diff. ## Preflight Gather these facts before proposing changes: 1. Current schema, models, serializers, API contracts, and persisted samples. 2. Writers and readers of each field. 3. Migration tool and rollback support. 4. Data volume, tenant boundaries, and backfill cost. 5. Required zero-downtime or maintenance-window constraints. 6. Existing tests or fixtures that prove compatibility. If the current data does not contain a field, treat it as absent. Do not invent fallback fields. ## Migration Design Use expand-migrate-contract for production systems: 1. Expand: add nullable columns, new tables, new enum values, or versioned payloads without breaking old readers. 2. Dual-write or adapter: write both old and new forms when needed. 3. Backfill: migrate historical data with batching, checkpoints, and retry behavior. 4. Read switch: move readers to the new contract after verification. 5. Contract: remove old fields only after the compatibility window and rollback risk pass. For small systems, a direct migration is acceptable only when downtime, rollback, and data loss risks are explicitly low. ## Required Checks Every plan must include: - Forward migration command. - Rollback or roll-forward recovery command. - Backfill idempotency and resume behavior. - Data validation query before and after. - Tenant isolation check when tenants exist. - API/serializer compatibility test. - Observability for migration progress and failure. ## Output Shape ```text contract_change: affected_readers_writers: migration_strategy: backfill_plan: rollback_or_recovery: tenant_and_security_checks: verification_queries: test_commands: release_gate: ``` Raise errors for missing critical data rather than warning and falling back to incomplete output.
Audit AND optimize a CLAUDE.md / AGENTS.md instruction file — score it against the five high-leverage patterns, flag anti-patterns, then apply approved fixes in place. Use when the user says 优化 CLAUDE.md / 优化 AGENTS.md / optimize my agent doc / 帮我改 claudemd, or after an audit when they want the fixes applied (not just reported).
Generate or update repository-specific AGENTS.md instruction files from real repo evidence. Use when asked to create, design, scaffold, split, or improve root or scoped AGENTS.md files for Codex/Claude/agent workflows, especially when a repo needs directory-specific rules, validation commands, generated-file boundaries, or a short agent onboarding router.
REST/GraphQL/gRPC API design best practices. Use when designing APIs, defining contracts, handling versioning. Covers OpenAPI 3.2, GraphQL Federation, gRPC streaming.
Mobile app UI design expert for iOS and Android. Use when designing app interfaces, creating design systems, ensuring accessibility, or following platform guidelines. Covers Material Design 3, Human Interface Guidelines, color theory, typography, and 2025 trends.
End-to-end app feature inventory and user-story testing workflow with a canonical tracker. Use when the user asks to audit every feature, derive expected behavior from code, test user journeys, or explicitly fix and retest documented UX or logistical defects.
Design architecture foundations before implementation. Use when asked to design or refactor architecture, choose Rust/Go crate, package, module, runtime, workflow, or service boundaries, compare mature project architecture, prevent stacked one-off PRs, audit migration debt in existing repos, or produce a spec before coding.
Evidence-driven architecture research for understanding real systems and making technical decisions. Use when doing architecture landscape studies, source-backed system archaeology, build-vs-buy or adopt/adapt/build decisions, open-source and commercial comparisons, revisiting an earlier architecture choice, or handling requests such as 架构调研, 架构选型, 竞品架构, 技术尽调, 同类方案, 开源替代, how is X built, and what should we learn from X. Do not use for small mechanical changes, market-only discovery, or detailed design after the technology direction is already fixed.
Ask Grok or Gemini via opencli (browser-session based, no API cost). Use when the user says "问 grok", "问 gemini", "ask grok", "ask gemini", "用 grok 查", "grok 怎么看", "让 gemini 分析", or wants a second opinion from Grok/Gemini without paying API tokens. Routes to opencli which drives the already-logged-in Chrome session.