mb-implement

name	mb-implement
description	Implements a feature end-to-end — spec, plan, build, review, simplify, ship — fully autonomous from a feature description file. Use when you have a feature described in a file and want the full pipeline to run without pausing for input.

mb-implement — End-to-End Feature Implementation

Takes a path to a feature description file and drives the full implementation pipeline autonomously. At every decision point, apply your best judgment and default to the most conservative, idiomatic choice for this codebase. Do not pause for human input between phases.

Input

The feature file path is passed as the skill argument ($ARGUMENTS). Read the file first. If the file does not exist, stop and report the error.

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Phase 1 — Spec

Invoke the agent-skills:spec-driven-development skill.

Derive the spec from the feature file — do not ask clarifying questions. Where ambiguous, default to the minimal scope that satisfies the described goal. Cover all six areas: objective, commands, project structure, code style, testing strategy, and boundaries.

Save to tasks/spec.md (not SPEC.md in root). Announce ✓ Spec → tasks/spec.md and continue.

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Phase 2 — Plan

Invoke the agent-skills:planning-and-task-breakdown skill.

Read tasks/spec.md and relevant codebase sections. Slice work vertically — one complete path per task. Write each task with acceptance criteria and a verification step. Save the plan to tasks/plan.md and the ordered task list to tasks/todo.md.

Do not wait for human review. Announce ✓ Plan → tasks/todo.md and continue.

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Phase 3 — Build

Invoke agent-skills:incremental-implementation alongside agent-skills:test-driven-development.

Work through every task in tasks/todo.md in order. For each task:

1. Read the acceptance criteria
2. Write a failing test (RED)
3. Implement minimum code to pass (GREEN)
4. Run bun run check, bun run lint, bun run test — fix all errors before moving on
5. Commit with a descriptive message
6. Mark the task complete in tasks/todo.md

If any check fails, apply agent-skills:debugging-and-error-recovery and resolve before continuing. Never skip a task or leave failures unresolved.

Announce ✓ Build complete when all tasks pass all checks.

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Phase 4 — Review and fix

Invoke agent-skills:code-review-and-quality.

Review all changes introduced in this session across five axes: correctness, readability, architecture, security, performance. Categorize findings as Critical, Important, or Suggestion.

Fix all Critical and Important findings. Apply Suggestions only when they are unambiguous improvements with no behavior risk. Run bun run preflight after fixes; resolve any new failures.

Announce ✓ Review complete and continue.

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Phase 5 — Simplify

Invoke agent-skills:code-simplification.

Target code introduced in this session. Apply simplifications incrementally — run bun run test after each one. Revert any simplification that breaks tests. Run bun run preflight at the end.

Announce ✓ Simplification complete and continue.

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Phase 6 — Ship

Invoke agent-skills:shipping-and-launch.

Spawn code-reviewer, security-auditor, and test-engineer subagents in parallel (all three Agent tool calls in a single turn). Merge their reports. Fix all blockers. If a Critical finding cannot be fixed, halt and report — do not ship.

Once GO: confirm bun run preflight passes, then output the ship decision with a rollback plan.

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Completion report

Feature: [name from feature file]
Tasks completed: N
Commits: [list]
Review findings fixed: N critical, N important
Final status: GO / NO-GO