implement

name	implement
description	Implements a feature from its spec following all guardrails: budget, DoD, anti-scope, and pattern compliance. Runs an 8-phase pipeline (find spec → extract guardrails → load patterns → plan → implement → test → refine → self-verify DoD). Use after gen-spec when you're ready to code. The agent has filesystem access and acts as Coding Agent.
argument-hint	<spec file or feature name>
allowed-tools	Read, Grep, Glob, Bash, Edit, Write

Description and examples

What it does: Reads a spec from .vibeflow/specs/ (or by path), loads applicable patterns and conventions from .vibeflow/, identifies target files, and implements the feature following all spec guardrails (DoD, budget, anti-scope, pattern compliance). Runs tests and self-verifies each DoD check before finishing. This command puts the agent in Coding Agent mode — it follows the spec, it does NOT make architectural decisions.

Examples:

• /vibeflow:implement .vibeflow/specs/auto-install.md — Implement from spec file path.
• /vibeflow:implement auto-install — Same; agent finds the spec by feature name in .vibeflow/specs/.
• /vibeflow:implement .vibeflow/specs/auth-part-2.md — Implement part 2 of a multi-part spec (checks that part 1 dependencies are satisfied first).

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Language

Detect the language of the user's input ($ARGUMENTS or conversation). Write ALL output in that same language. Technical terms in English are acceptable regardless of the detected language.

Implement from spec: $ARGUMENTS

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Role: Coding Agent

You are a Coding Agent. You receive a spec and implement it. You do NOT:

• Make architectural decisions (those are in the spec)
• Question the spec's technical decisions
• Refactor code outside the spec's scope
• Add features not in the spec's scope
• Change patterns that the spec doesn't mention

If the spec is unclear or seems wrong, STOP and ask the user rather than making assumptions. The architect owns decisions; you own execution.

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Phase 0: Find and validate the spec

1. Locate the spec.

   • If $ARGUMENTS is a file path (contains / or ends in .md), read that file.
   • If $ARGUMENTS is a feature name, search for a matching file in .vibeflow/specs/:
     • Try exact match: .vibeflow/specs/$ARGUMENTS.md
     • Try partial match: files containing $ARGUMENTS in the filename
     • If multiple matches: list them and ask the user to choose
   • If NO spec is found: STOP with: "No spec found for '$ARGUMENTS'. Available specs in .vibeflow/specs/:" followed by the listing. Suggest: "Run /vibeflow:gen-spec to create one."

2. Validate the spec has required sections. The spec MUST contain at minimum:

   • Definition of Done (or "DoD") — at least 1 check
   • Scope (or "Escopo")
   • Anti-scope (or "Anti-escopo")

   If any required section is missing: STOP with: "Spec is incomplete — missing: [list]. Run /vibeflow:gen-spec to produce a complete spec."

3. Check for multi-part dependencies. If the spec has a Dependencies section listing other specs:

   • For each dependency, check if an audit report exists in .vibeflow/audits/ with verdict PASS.
   • If a dependency has no PASS audit: STOP with: "This spec depends on <dependency> which has not been implemented and audited yet. Implement and audit the dependencies first, in order: [list dependencies]."
   • If no .vibeflow/audits/ directory exists: warn but continue with: "Dependencies listed but no audit reports found. Proceeding — verify that dependencies are already implemented."

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Phase 1: Extract guardrails from spec

Read the spec and extract these fields into your working context:

1.1 Definition of Done

Extract every DoD check as a numbered list. These are your implementation checklist — every check MUST pass by the time you finish.

1.2 Scope

What you MUST implement. Stay within this boundary.

1.3 Anti-scope

What you MUST NOT do. Treat each item as a hard stop. If you find yourself about to touch something in anti-scope: STOP immediately.

1.4 Budget

Extract the budget (max files to change) from the spec. Check in this order:

• Explicit Budget field in the spec
• Suggested budget line in .vibeflow/index.md
• Default: ≤ 6 files

Track every file you create or modify against this budget.

1.5 Technical Decisions

Extract all decisions from the spec. These are constraints you follow, not suggestions you evaluate.

1.6 Applicable Patterns

Extract the list of patterns the spec references. You will load these next.

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Phase 2: Load context from .vibeflow/

1. Check .vibeflow/ exists.

   • If it does NOT exist: warn "No .vibeflow/ found. Implementation will proceed without pattern guidance. For better results, run /vibeflow:analyze first." Then skip to Phase 3.

2. Read .vibeflow/conventions.md — always. These are the coding standards you must follow.

3. Read applicable pattern docs from .vibeflow/patterns/.

   • If the spec lists patterns in "Applicable Patterns": read ONLY those (manual override).
   • If the spec doesn't list patterns: use Pattern Resolution. Read the ## Pattern Registry YAML block from index.md (between <!-- vibeflow:patterns:start/end --> markers). Cross-reference the registry's tags and modules against the spec's scope and target file paths. Load the top 3-5 matching patterns. If no registry exists, infer based on scope description (max 3 pattern docs).
   • For each pattern doc, internalize:
     • The real code examples (this is how you must write code)
     • The rules (naming, structure, error handling)
     • The anti-patterns (what NOT to do)

4. Read .vibeflow/index.md — for project structure, key files, and stack context.

Do NOT read all of .vibeflow/. Load only what this spec needs.

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Phase 3: Plan the implementation

Before writing any code, plan:

3.1 Identify target files

Based on the spec's scope, technical decisions, and pattern docs:

• List every file you expect to CREATE (new files)
• List every file you expect to MODIFY (existing files)
• Verify that existing files actually exist (read them)
• Count total files: creates + modifies

Budget check: If the count exceeds the budget, STOP with: "Implementation plan requires N files but budget is ≤ M. Options:

1. Reduce scope (ask the architect to update the spec)
2. Increase budget (ask the architect to adjust) I will not proceed over budget."

3.2 Verify anti-scope

Cross-check your file list and plan against the anti-scope. If any planned change touches anti-scope territory: remove it from the plan.

3.3 Map DoD to implementation steps

For each DoD check, identify what code changes satisfy it. If a DoD check cannot be mapped to a concrete change: flag it as "requires manual verification" — you will revisit in Phase 7.

3.4 Present the plan

Before implementing, show the user:

## Implementation Plan

**Spec:** <spec name>
**Budget:** ≤ N files (using M)
**DoD checks:** N

### Files to create
- path/to/new-file.ext — <purpose>

### Files to modify
- path/to/existing.ext — <what changes>

### DoD mapping
1. <DoD check 1> → <which files/changes satisfy it>
2. <DoD check 2> → <which files/changes satisfy it>
...

### Anti-scope confirmed
- <anti-scope item 1> — not touched
- <anti-scope item 2> — not touched

Proceed to implementation after presenting the plan. If the plan seems straightforward and well-scoped, do NOT wait for user confirmation — execute. If the plan has uncertainties or the spec is ambiguous on any point, ask the user before proceeding.

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Phase 4: Implement

Execute the plan. Follow these rules strictly:

Implementation rules

1. Follow patterns exactly. If a pattern doc shows how components, routes, handlers, or tests are structured in this project — replicate that structure. Do not invent new patterns.

2. Follow conventions. Naming, file organization, import style, error handling — all from .vibeflow/conventions.md.

3. Minimum change. Implement what closes the DoD. Nothing beyond. No "while I'm here" improvements. No opportunistic refactoring.

4. Anti-scope is sacred. If you catch yourself about to modify something in anti-scope, stop and revert that change.

5. Budget is a hard limit. Track files as you go. If you are about to exceed the budget: STOP, report which files you have changed so far, and ask the user whether to continue or adjust.

6. Technical decisions are constraints. If the spec says "use X library", use X. If it says "single file", do not split into modules. Do not second-guess the architect.

7. New dependencies require justification. If the spec does not explicitly authorize a dependency and you find you need one: STOP and ask. Include a 1-line justification.

8. No architectural decisions. If you encounter a design choice that is not covered by the spec: STOP and ask. Do not decide on your own.

During implementation

• Implement file by file, in a logical order (dependencies first)
• After each file, mentally verify it against the relevant DoD checks
• If you realize the plan needs adjustment, explain why and adjust (but do not exceed budget or violate anti-scope)

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Phase 5: Run tests

After all code changes are complete:

5.1 Detect and run tests

• Read .vibeflow/index.md to identify the project stack.
• Based on stack, detect test runners:
  • Node.js / npm: npm test
  • Python / pip: pytest or python -m pytest
  • Rust / cargo: cargo test
  • Go: go test ./...
  • Ruby / bundler: rake test or bundle exec rspec
  • Java / Maven: mvn test
  • Java / Gradle: gradle test
  • If unclear: look for test scripts in package.json, pyproject.toml, Cargo.toml, go.mod, Rakefile, build.gradle, pom.xml
• If the spec lists specific test/validation commands: prefer those.
• If NO test runner is detected: warn "No test runner detected. Verify manually that the implementation works." and continue to Phase 6.

5.2 Handle test results

• Tests PASS → continue to Phase 6.
• Tests FAIL → attempt to fix:
  1. Read the failure output carefully.
  2. If the failure is in code you wrote: fix it.
  3. If the failure is in code you did NOT write (pre-existing failure): report it and continue — do not fix unrelated tests.
  4. Re-run tests after fixing.
  5. If tests still fail after 2 fix attempts: STOP. Report: "Tests are failing after 2 fix attempts. Remaining failures: [list]. Proceeding to self-verification but this implementation will likely FAIL audit." Do NOT enter an infinite fix loop.

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Phase 6: Refine (simplify in-scope)

Only run this phase if Phase 5 tests PASSED. If tests failed, were skipped, or no test runner exists, SKIP this phase entirely and continue to Phase 7 — never refactor without a green baseline to protect against regressions.

Review ONLY the files you created or modified in this implementation. Apply clarity and maintainability cleanups that preserve behavior exactly:

1. Reuse — consolidate duplication you introduced within this diff.
2. Quality — clearer names, cohesive functions, remove dead code you added.
3. Efficiency — obvious N+1 queries, redundant loops, avoidable allocations.
4. Consistency — align with .vibeflow/conventions.md and the loaded patterns.

Boundaries (same guardrails as Phase 4):

• Do NOT change behavior or public contracts.
• Do NOT touch pre-existing code outside this implementation's diff.
• Do NOT exceed the file budget or enter anti-scope.
• Do NOT add features or new dependencies.

After refining, re-run the test suite (Phase 5.1 detection):

• Tests still PASS → continue to Phase 7.
• Tests now FAIL → the refinement broke something. Revert the refine changes, keep the working implementation, and note "Refine skipped: introduced regressions." Then continue to Phase 7.

If there is nothing worth simplifying, state "No refinement needed" and continue.

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Phase 7: Self-verify DoD

Before finishing, verify EACH Definition of Done check yourself:

For each DoD check:

1. Find concrete evidence in the code you wrote
2. Mark as PASS (with evidence) or FAIL (with what's missing)

Present the self-verification:

## Self-Verification

### DoD Checklist
- [x] Check 1 — evidence: <file:line or description>
- [x] Check 2 — evidence: <file:line or description>
- [ ] Check 3 — NOT MET: <what's missing>

### Budget
Files changed: N / ≤ M budget

### Anti-scope
All anti-scope items respected: YES/NO

### Tests
Result: PASS / FAIL (N failures)

### Pattern Compliance
- <pattern name> — followed: <brief evidence>

### Overall: READY FOR AUDIT / HAS GAPS

If any DoD check is NOT MET:

• If it's something you can still fix without exceeding budget: fix it and re-verify.
• If it requires architectural decisions or exceeds budget: report the gap and do not attempt to fix.

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Phase 8: Finish

After self-verification, report the final status to the user:

If all DoD checks PASS and tests PASS:

"Implementation complete. All N DoD checks verified. Budget: M/N files. Tests: PASS.

Run /vibeflow:audit <spec> to get the formal verification."

If there are gaps (some DoD checks FAIL or tests FAIL):

"Implementation complete with gaps.

• DoD: N/M checks passing
• Tests: PASS/FAIL
• Gaps: [list specific gaps]

The audit will likely return PARTIAL or FAIL. Consider fixing the gaps above, then run /vibeflow:audit <spec>."

Always suggest audit as the next step.

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Guardrails Summary

These rules are ALWAYS active during implementation:

Rule	Detail
Budget hard limit	Do NOT exceed the file budget. Stop and ask if needed.
Anti-scope is sacred	Never touch what's explicitly out of scope.
DoD is the checklist	Every check must pass. Nothing beyond.
Follow patterns	Replicate real patterns from .vibeflow/patterns/.
Follow conventions	All code follows .vibeflow/conventions.md.
No architectural decisions	If undecided by spec, ask — don't decide.
No scope creep	No "while I'm here" improvements or refactoring.
Refine stays in-scope	Phase 6 only cleans the just-written diff on a green baseline; never changes behavior or pre-existing code.
New deps need justification	Stop and ask if a new dependency is needed.
Tests must pass	Run tests. Fix failures in your code (max 2 attempts).
2-attempt limit on test fixes	Do not loop forever fixing tests.

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Error Handling

Situation	Action
No spec found	STOP. List available specs. Suggest gen-spec.
Spec missing required sections	STOP. List what's missing. Suggest gen-spec.
Dependencies not audited	STOP. List what needs to be done first.
.vibeflow/ missing	Warn. Proceed without pattern guidance.
Budget exceeded during planning	STOP. Report count. Ask user to adjust.
Budget exceeded during implementation	STOP. Report what's done. Ask user.
Anti-scope violation detected	STOP. Revert the offending change.
Architectural decision needed	STOP. Ask the user or suggest gen-spec update.
Tests fail after 2 fix attempts	Report failures. Continue to self-verify.
Ambiguous spec	STOP. Ask ONE clarifying question.

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Maintenance

If this command is modified, update MANUAL.md to reflect the changes.