fast-loop-coding

Speed-tuned cousin of loop-coding. For small, well-scoped tasks where the full 7-phase pipeline is overkill. Target: 3-4x faster than loop-coding.

Core principle

Single critic for plan, dual for review. Loop-coding (full) is dual on Audit/Plan/Review (defence in depth on big surface). Fast-loop drops Audit entirely, keeps Plan single-model (Codex GPT-5.5 — strong enough alone for small scope), and keeps Review dual (Codex+Opus parallel — cheap insurance once the code exists). If surface is small, one Codex plan converges; if not, escape valve to loop-coding. Aligns with core/rules.md > Model role split: Codex for critique/architecture, Opus for code, dual only on Review.

Decision tree (run BEFORE starting)

Use fast-loop-coding if ALL true:

• Estimated LOC <= 300
• Files touched <= 3
• Single subsystem (no cross-service coupling)
• Tests fit in one file
• No production deploy (staging OK)
• No RED file edits
• No external API contract changes

If ANY false -> use loop-coding (full 7-phase).

If ALL clearly micro (<= 20 LOC, 1 file, no test) -> just edit. No skill needed.

If unsure -> fast-loop-coding. Easy to upgrade mid-task; hard to downgrade.

4 phases (vs loop-coding 7)

Phase 1: Plan (5 min cap) — Codex GPT-5.5

• Single Codex pass: scope, files, est LOC, test cases, rollback
• codex exec --skip-git-repo-check "<task brief + relevant file paths>" — Codex reads code itself
• Write loop-coding-runs/<date>-fast-<slug>/PLAN.md (template at bottom)
• NO parallel research (Sonar+Sonnet) — task is small, agent context is enough
• NO audit phase (Codex plan covers risk surface inline)
• Opus is NOT used here — saves subscription tokens for Implement and Review

Phase 2: Implement

• Direct Edit/Write
• Inline tests as you go (or right after)
• Run tests before review (do not punt)

Phase 3: Review (dual pass — Codex + Opus parallel)

• TWO reviewers in parallel:

- Codex GPT-5.5: codex exec --skip-git-repo-check "review uncommitted diff: ..." (security, architecture, corner cases) - Opus code-reviewer subagent (readability, consistency, patterns, test quality)

• Merge findings: CRITICAL + HIGH applied inline immediately
• Defer MEDIUM + LOW unless trivial (note in PLAN.md)
• ONE fix iteration max (apply both reviewers' criticals together)
• If review still red after 1 fix -> escape to loop-coding

Phase 4: Ship

• Commit + push (after review green)
• No staging dance for <= 300 LOC backend changes (unless deploy.sh requires)
• Update core/hot/handoff.md if non-obvious decision made
• No decisions.md entry unless architectural trade-off

Escape valve (mid-task upgrade)

ABORT fast and switch to loop-coding if:

• Scope balloons past 300 LOC (during implement)
• 4th file needed
• Architectural concern surfaces
• Review found 2+ CRITICALs (signal: under-researched)
• Discovered multi-subsystem coupling
• Test scope explodes (3+ test files)

How to escape:

1. Stop implementation
2. bash skills/loop-coding/scripts/init-run.sh <slug> (full run dir)
3. Copy current PLAN.md content into Phase 3 input of full pipeline
4. Restart from loop-coding Phase 1 (Research)
5. Mark the fast-run dir as aborted in PLAN.md

What this skill does NOT do (vs loop-coding)

When to choose what

fast-loop-coding examples:

• Add a PostToolUseFailure hook (~80 LOC, 2 files)
• Write a one-shot validation script (~150 LOC)
• Refactor one function (extract helper, simplify)
• Add CLI subcommand to existing tool
• New shell helper + bash test
• Tighten one regex pattern + regression test

loop-coding examples:

• Migration (cognee, OpenRouter switch, backend swap)
• Auth/permission rewrite (cross-cutting)
• New skill with sub-skills + scripts
• Anything touching CLAUDE.md / rules.md / USER.md
• Multi-service change (gateway + bot + frontend)
• Phase-gated rollout (dual-write windows, safety gates)

No skill needed (just edit):

• Typo fix
• Single comment add
• Constant tweak
• Single-line bugfix
• Renaming one variable

PLAN.md template (abbreviated)

# <slug> — fast-loop

Goal: <one sentence>
Files: <list, absolute paths>
Est LOC: <number>
Tests: <how — file + cases>
Rollback: <command or revert hash>

## Steps
1. <step>
2. <step>
3. <step>

## Risks
- <risk> -> <mitigation>

## Review verdict
(filled after Phase 3)

## Ship
(filled after Phase 4: commits, push, handoff entry)

Init

bash ~/.claude/skills/fast-loop-coding/scripts/init-fast-run.sh <slug>
# prints run-dir path