How I built 62 free tools in a month using Claude Code + a loop script

The system in a nutshell

Each tool lives in its own folder with two plan files before any code is written:

• BRIEF.md — the spec: keyword, pain point, H1, meta description, CTA, FAQ topics (~30 lines).
• PLAN_L1.md — step-by-step build instructions for the agent.

Folder structure example:

app-factory/ bpm-finder/ BRIEF.md PLAN_L1.md app/ ← Vite source
lyric-rhyme-finder/ BRIEF.md PLAN_L1.md app/

The 3-layer build

Layer 1 — SEO Shell (under 1 hour): static HTML with real FAQ content, proper meta/OG tags, a placeholder for the tool. Crawlable before JavaScript loads.

Layer 2 — Minimum Viable Tool (1-3 hours): one input → one output. Core functionality only, no polish, no edge cases.

Layer 3 — only after Google Search Console confirms search impressions. No point polishing something nobody searches for.

Ralph — the autonomous agent loop

Ralph is a shell script that runs Claude Code in a loop. It reads the plan file, executes step by step, and stops when it sees RALPH_DONE in the progress file.

# Run one tool autonomously
ralph ./bpm-finder/PLAN_L1.md

Ralph logs everything to PROGRESS.md. You can leave it running and check in later.

Ralph loop scripts are available from GitHub: portableralph and the original concept at how-to-ralph-wiggum.

cook.sh — run multiple tools in parallel

Once you have 3-5 tools briefed and planned, run cook.sh. It launches a separate Ralph instance for each tool in the background.

./cook.sh
🍳 Starting cook — 5 tools in parallel
🔥 Starting bpm-finder... PID 8421 — logs at bpm-finder/cook.log
🔥 Starting lyric-rhyme-finder... PID 8422 — logs at lyric-rhyme-finder/cook.log

Next morning, check progress: grep 'layer1_done: true' app-factory/*/BRIEF.md

Deploy

Each tool is a Vite build. Deploy individually to Vercel, then wire them into a hub via vercel.json rewrites. The hub proxies the tool at /tool-name/ — both domains get SEO credit.

Example live tool: Drum Machine

Results

• Layer 1 shell: ~45 minutes agent-time
• Layer 2 working tool: ~2 hours agent-time
• Personal time per tool: ~15 minutes (reviewing, not writing)
• 30-day stats: 2,140 views, 254 users, 69 CTA clicks (~1 click per 31 visits)

Tools built

Music tools (BPM finder, Suno metatag explorer, lyric rhyme finder), design tools (background remover, color palette generator, QR code generator). All free, all live.