Migrate

Migrate

Execute a structural migration, dependency upgrade, or large-scale codebase reorganization with a verified, step-by-step approach.

Process

1. Understand the migration from $ARGUMENTS:

   • What is changing (dependency version, file structure, API pattern, etc.)
   • If unclear, ask the user for specifics before proceeding.

2. Audit the current state:

   • Read CLAUDE.md for project conventions.
   • Identify all files/patterns affected by the migration.
   • Use grep/glob to find every instance of the old pattern.
   • Count the total scope (e.g., "47 files use the old import path").

3. Read the migration guide (if applicable):

   • For dependency upgrades, check the changelog or migration docs.
   • For structural moves, understand the target layout.
   • Identify breaking changes, deprecated APIs, and required codemods.

4. Build a migration plan:

   • Enter plan mode using EnterPlanMode.
   • Present the plan to the user:
     • Total scope (how many files/patterns)
     • Step-by-step execution order
     • Breaking changes and how they'll be handled
     • Verification strategy (tests, type-checking, build)
   • Wait for user approval.

5. Execute in batches after approval:

   • If Claude Code already returned to normal mode after approval, do not call ExitPlanMode again; continue directly with migration. Only use the plan-mode exit tool when the session is still visibly in plan mode.
   • Process files in logical groups (by package, by directory, by pattern).
   • After each batch:
     • Run type-checking (tsc --noEmit or equivalent) to catch breakage early.
     • Run tests for the affected area.
     • Report progress.
   • If a batch fails, stop and report — do not continue blindly.

6. Final verification:

   • Run the full test suite.
   • Run the build.
   • Check for any remaining instances of the old pattern.
   • Report any manual follow-ups needed.

Output Format

Migration Summary

• Scope: X files across Y packages
• Pattern: old → new
• Status: complete / partial (with details)

Changes Made

• Batch-by-batch summary

Verification

• Type-check: pass/fail
• Tests: pass/fail (X passed, Y failed)
• Build: pass/fail
• Remaining old pattern instances: 0 or list

Manual Follow-ups

• Any items that couldn't be automated

Constraints

• Always enter plan mode and get approval before making changes.
• Do not call ExitPlanMode from normal mode. If Claude Code reports "You are not in plan mode" after approval, treat approval as complete and continue implementation.
• Process in verifiable batches — never change everything at once without checking.
• If the migration affects multiple monorepo packages, process one package at a time.
• Do not change behavior — migrations should be purely structural unless the upgrade requires API changes.
• Preserve git history readability — keep migration commits separate from feature work.

Alignment Page

When this skill produces durable deliverables (research, specs, plans, reports, prototypes, or any document output), build a full-depth HTML alignment page at alignment/migrate-{topic}.html. Use a normalized topic slug derived from the app, feature, research subject, report subject, or output filename.

Full content requirement. The alignment page must contain the complete content of every proposed markdown deliverable -- every section, every finding, every detail, every list item. It is a thorough interactive review document, not a summary. Render the full deliverable content in clean, readable HTML with appropriate hierarchy, styling, and navigation. If the skill writes multiple scoped deliverables in one run, build one alignment page that contains all deliverables with anchor-linked navigation. Durable tracker artifacts, such as research/assumption-tracker.md, remain canonical markdown outputs but must also be fully rendered into the alignment page before approval.

Dark-mode styling. Use a dark color scheme by default. Base CSS variables: --bg: #0d1117; --surface: #161b22; --border: #30363d; --text: #c9d1d9; --text-muted: #8b949e; --accent: #58a6ff; --green: #3fb950; --red: #f85149; --orange: #d29922; --purple: #bc8cff;. Apply background: var(--bg); color: var(--text); on body. Use --surface for cards, nav, and table headers. Use --border for all borders. Use --purple for question blocks and gate headings. Use --accent for links and section headings. Keep headings color: #fff or var(--accent) for hierarchy. Question block backgrounds should use #1c2333.

Alignment gates. Treat gates as explicit review sections inside the HTML page. A gate blocks finalization until its required inline questions are answered and compiled into YAML. Include every gate that applies to the skill output, and include these gate types whenever relevant: evidence coverage, assumptions/confidence, scope/non-goals, candidate/verdict decisions, artifact destination, proposed file changes, coverage checkpoint, and post-approval route.

Report-only research gates. For report-only or pre-approval research skills, the alignment page must explicitly contain evidence coverage, assumptions/confidence, recommended path, proposed file changes, and approval gates before any canonical research, spec, or task file is created or updated.

Required inline questions. Each gate must contain at least one required inline question placed directly under the content it governs, inside a visually distinct question block. Each question must use radio-button inputs and include two standing options after the skill-generated choices: "Other / None of the above" backed by a multi-line text box for free-form input, and "Need clarification" backed by an optional notes box where the user can explain what is unclear. When any radio option other than "Other" or "Need clarification" is selected, show an optional "Additional notes" text box beneath it so the user can qualify their choice. Generate questions based on what genuinely needs user input -- do not add filler questions. Do not create a separate bottom "Decisions & Clarifications" section.

Gate YAML contract. At the bottom of the page, include a "Compile Answers" button that aggregates answers from all inline gate questions throughout the page, including free-text notes. The button remains disabled until every required question has a selection, shows a count of remaining unanswered questions, and scrolls to the first unanswered question if clicked early. When every question is answered, generate a structured YAML block with one item per gate answer using this stable shape: section, gate_type, status (answered, other, or needs-clarification), answer, optional notes, and optional target_artifact or target_path when the gate controls file output. After successful compilation, automatically attempt to copy the YAML to the clipboard with the Clipboard API, display copy status, and display the YAML in a read-only textarea with an explicit "Copy YAML" button. The copy button must retry clipboard copy when supported and fall back to selecting the textarea contents when clipboard access is unavailable or blocked.

Pre-approval stop. Before user approval, the next action is review of the HTML alignment page, not downstream routing. Ask the user to review the page and provide the compiled YAML answers. Do not include Recommended next skill, Recommended next command, or downstream routing language until after compiled YAML has been provided and the approved artifacts have been written or updated.

Diff highlighting on updates. When the agent updates an existing alignment page after receiving compiled answers, highlight what changed since the previous version. The agent chooses inline annotation or side-by-side layout per situation.

Archiving. Before replacing an existing alignment page, archive it to docs/history/archive/YYYY-MM-DD/HHMMSS/alignment/migrate-{topic}.html.

Browser open. Attempt to open the resulting HTML page in the browser and report whether the open succeeded or was blocked. A blocked browser-open attempt does not make the skill fail when the files were written correctly.

Default Shipping Contract

• Default next-step routing: when reporting completion, include either Recommended next skill: <command> or the two-line pair **Next work:** <specific task or "none"> and **Recommended next command:** <one command or route> so the next operator has a concrete handoff.
• If this skill creates or modifies tracked repository files, finish by committing and pushing all intended changes to the repository primary branch (main when present, otherwise master) before stopping, even if the user did not explicitly ask for commit/push.
• Do not leave tracked changes or unpushed commits behind. If unrelated tracked work is already present, either include it in sensible commits too or stop and explain the blocker.
• This contract does not override stricter safety rules about secrets, destructive history changes, release publication/tag confirmation, or production deploy confirmation.