devlyn-cli

Context Engineering & Harness Engineering Toolkit for Claude Code

Structured prompts, agent orchestration, and automated pipelines — debugging, code review, UI design, product specs, and more.

If devlyn-cli saved you time, give it a star — it helps others find it too.

Install

npx devlyn-cli

That's it. The interactive installer handles everything. Run it again anytime to update.

How It Works — Three Steps, Full Cycle

devlyn-cli turns Claude Code into an autonomous development pipeline. The core loop is simple:

ideate  →  auto-resolve  →  preflight  →  fix gaps  →  ship

Step 1 — Plan with /devlyn:ideate

Turn a raw idea into structured, implementation-ready specs.

/devlyn:ideate "I want to build a habit tracking app with AI nudges"

This produces three documents through interactive brainstorming:

Document	What It Contains
docs/VISION.md	North star, principles, anti-goals
docs/ROADMAP.md	Phased roadmap with links to each spec
docs/roadmap/phase-N/*.md	Self-contained spec per feature — ready for auto-resolve

Need to add features later? Run ideate again — it expands the existing roadmap.

Step 2 — Build with /devlyn:auto-resolve

Point it at a spec (or just describe what you want) and walk away.

/devlyn:auto-resolve "Implement per spec at docs/roadmap/phase-1/1.1-user-auth.md"

It runs a 10-phase pipeline autonomously:

Build → Build Gate → Browser Test → Evaluate → Fix Loop → Simplify → Review → Security → Clean → Docs

• Each phase runs as a separate agent with fresh context
• Git checkpoints at every phase for safe rollback
• Build Gate runs your project's real compilers, typecheckers, and linters — catches type errors, cross-package drift, and Docker build failures that tests alone miss. Auto-detects project type (Next.js, Rust, Go, Solidity, Expo, Swift, and more) and Dockerfiles.
• Browser validation tests your feature end-to-end (clicks, forms, verification)
• Evaluation grades against done-criteria — if it fails, auto-fix and re-evaluate

Skip phases you don't need: --skip-browser, --skip-review, --skip-clean, --skip-docs, --skip-build-gate, --max-rounds 6 Customize the build gate: --build-gate strict (warnings = errors), --build-gate no-docker (skip Docker builds for speed) Use dual-model routing: --engine auto (Codex builds, Claude evaluates — see below)

Step 3 — Verify with /devlyn:preflight

After implementing all roadmap items, run a final alignment check:

/devlyn:preflight

Reads every commitment from your vision, roadmap, and item specs, then audits the codebase evidence-based. Catches what you missed:

Category	What It Finds
MISSING	In roadmap but not implemented
INCOMPLETE	Started but unfinished
DIVERGENT	Implemented differently than spec
BROKEN	Has a bug preventing it from working
STALE_DOC	Docs don't match current code

Confirmed gaps become new roadmap items — feed them back into auto-resolve. Use --autofix to do this automatically, or --phase 2 to check only one phase.

Bonus — Intelligent Model Routing with --engine

Install the Codex MCP server during setup, then:

/devlyn:auto-resolve "fix the auth bug" --engine auto

--engine auto routes each pipeline phase and team role to the optimal model (Claude Opus 4.6 or GPT-5.4) — validated through A/B testing, not just benchmarks.

--engine auto (default, recommended) · --engine codex (force Codex for build) · --engine claude (Claude only)

Works across the full pipeline:

/devlyn:auto-resolve "implement feature" --engine auto
/devlyn:ideate "plan new project" --engine auto
/devlyn:preflight --engine auto

How routing works — A/B tested on 6 roles, 11 integration tests

Pipeline phases — builder and critic are always different models (GAN dynamic):

Phase	Model	Why
Build (implementation)	Codex GPT-5.4	SWE-bench Pro +11.7pp for hard coding tasks
Evaluate	Claude	Long-context (MRCR +28pp) for full-diff grading
Fix Loop	Codex GPT-5.4	Same advantage as Build
Challenge	Claude	Fresh skeptical review needs different model family
Browser Validate	Claude	Chrome MCP session-bound

Team roles — each of 21 roles routes to the best model:

Engine	Roles	Examples
Claude (11)	Analysis, design, architecture	root-cause-analyst, architecture-reviewer, ux-designer, product-analyst
Codex (4)	Code generation, performance	implementation-planner, test-engineer, performance-engineer
Dual (6)	Both models find unique issues	security-auditor, quality-reviewer, api-designer

Key finding: Benchmark predictions were only 33% accurate. 4 of 6 A/B-tested roles needed routing changes after real testing — proving that benchmarks alone are insufficient for optimal routing.

Legacy: --with-codex (superseded by --engine)

/devlyn:auto-resolve "fix the auth bug" --with-codex

--with-codex evaluate (default) · --with-codex review · --with-codex both

--engine auto subsumes --with-codex both with broader coverage — Codex is used for build, fix, and 4 team roles, not just evaluate/review.

Manual Commands

When you want step-by-step control instead of the full pipeline.

Debugging & Resolution

Command	Use When
/devlyn:resolve	Simple bugs (1-2 files)
/devlyn:team-resolve	Complex issues — spawns root-cause analyst, test engineer, security auditor
/devlyn:browser-validate	Test a web feature in a real browser (Chrome MCP → Playwright → curl fallback)

Code Review & Quality

Command	Use When
/devlyn:review	Solo review — security, quality, best practices checklist
/devlyn:team-review	Multi-reviewer team — security, testing, performance, product perspectives
/devlyn:evaluate	Grade work against done-criteria with calibrated skepticism
/devlyn:clean	Remove dead code, unused deps, complexity hotspots

UI Design Pipeline

Step	Command	What It Does
1	/devlyn:design-ui	Generate 5 distinct style explorations
2	/devlyn:design-system	Extract design tokens from chosen style
3	/devlyn:implement-ui	Team builds it — component architect, UX, accessibility, responsive, visual QA

Use /devlyn:team-design-ui for step 1 with a full creative team.

Planning & Docs

Command	What It Does
/devlyn:preflight	Verify codebase matches vision/roadmap — gap analysis with evidence
/devlyn:product-spec	Generate or update product specs
/devlyn:feature-spec	Turn product spec → implementable feature spec
/devlyn:discover-product	Scan codebase → auto-generate product docs
/devlyn:recommend-features	Prioritize top 5 features to build next
/devlyn:update-docs	Sync all docs with current codebase

Auto-Activated Skills

These activate automatically — no commands needed. They shape how Claude thinks during relevant tasks.

Skill	Activates During
root-cause-analysis	Debugging — enforces 5 Whys, evidence standards
code-review-standards	Reviews — severity framework, approval criteria
ui-implementation-standards	UI work — design fidelity, accessibility, responsiveness
code-health-standards	Maintenance — dead code prevention, complexity thresholds
workflow-routing	Any task — guides you to the right command

Optional Add-ons

Selected during install. Run npx devlyn-cli again to add more.

Skills — copied to .claude/skills/

Skill	Description
asset-creator	AI pixel art game asset pipeline — generate, chroma-key, catalog
cloudflare-nextjs-setup	Cloudflare Workers + Next.js with OpenNext
generate-skill	Create Claude Code skills following Anthropic best practices
prompt-engineering	Claude 4 prompt optimization
better-auth-setup	Better Auth + Hono + Drizzle + PostgreSQL
pyx-scan	Check if an AI agent skill is safe before installing
dokkit	Document template filling for DOCX/HWPX
devlyn:pencil-pull	Pull Pencil designs into code
devlyn:pencil-push	Push codebase UI to Pencil canvas

Community Packs — installed via skills CLI

Pack	Description
vercel-labs/agent-skills	React, Next.js, React Native best practices
supabase/agent-skills	Supabase integration patterns
coreyhaines31/marketingskills	Marketing automation and content skills
anthropics/skills	Official Anthropic skill-creator with eval framework
Leonxlnx/taste-skill	Premium frontend design skills

MCP Servers — installed via claude mcp add

Server	Description
codex-cli	Codex MCP server — enables --engine auto/codex intelligent model routing and legacy --with-codex mode
playwright	Playwright MCP — powers browser-validate Tier 2

Want to add a pack? Open a PR adding it to the OPTIONAL_ADDONS array in bin/devlyn.js.

Requirements

• Node.js 18+
• Claude Code installed and configured

Contributing

• Add a command — .md file in config/commands/
• Add a skill — directory in config/skills/ with SKILL.md
• Add optional skill — add to optional-skills/ and OPTIONAL_ADDONS
• Suggest a pack — PR to the pack list

Star History

License

MIT — Nocodecat @ Donut Studio