Ralph is an autonomous coding loop that repeatedly runs AI coding tools until the items in a product requirements document are complete. Developers use it in Git repositories with tools such as Amp or Claude Code, while progress persists through files and git history. Its catalogue add-ons help create requirements documents and convert them into the format Ralph executes.
Borrowing it
Nothing to install: this file belongs to snarktank/ralph. Take a copy, put it at the same path in your own repository, and replace the rules that are about this project with yours.
curl -O https://raw.githubusercontent.com/snarktank/ralph/main/CLAUDE.mdgit clone --depth 1 https://github.com/snarktank/ralphWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/instructions/snarktank/ralph/claude-md)<a href="https://agentmods.dev/instructions/snarktank/ralph/claude-md"><img src="https://agentmods.dev/badge/instructions/snarktank/ralph/claude-md/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/instructions/snarktank/ralph/claude-md"><img src="https://agentmods.dev/badge/instructions/snarktank/ralph/claude-md.svg" alt="Reviewed on agentmods" width="80" height="20"></a>What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00909 | $0.00909 |
| Opus 5.5 | $0.00364 | $0.00364 |
| Sonnet 5.5 | $0.00182 | $0.00182 |
| Haiku 4.5 | $0.00091 | $0.00091 |
Grade A, and why
ralph CLAUDE.md scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 1mo ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 105 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Ralph Agent Instructions
You are an autonomous coding agent working on a software project.
Your Task
- Read the PRD at
prd.json(in the same directory as this file) - Read the progress log at
progress.txt(check Codebase Patterns section first) - Check you're on the correct branch from PRD
branchName. If not, check it out or create from main. - Pick the highest priority user story where
passes: false - Implement that single user story
- Run quality checks (e.g., typecheck, lint, test - use whatever your project requires)
- Update CLAUDE.md files if you discover reusable patterns (see below)
- If checks pass, commit ALL changes with message:
feat: [Story ID] - [Story Title] - Update the PRD to set
passes: truefor the completed story - Append your progress to
progress.txt
Progress Report Format
APPEND to progress.txt (never replace, always append):
## [Date/Time] - [Story ID]
- What was implemented
- Files changed
- **Learnings for future iterations:**
- Patterns discovered (e.g., "this codebase uses X for Y")
- Gotchas encountered (e.g., "don't forget to update Z when changing W")
- Useful context (e.g., "the evaluation panel is in component X")
---
The learnings section is critical - it helps future iterations avoid repeating mistakes and understand the codebase better.
Consolidate Patterns
If you discover a reusable pattern that future iterations should know, add it to the ## Codebase Patterns section at the TOP of progress.txt (create it if it doesn't exist). This section should consolidate the most important learnings:
## Codebase Patterns
- Example: Use `sql<number>` template for aggregations
- Example: Always use `IF NOT EXISTS` for migrations
- Example: Export types from actions.ts for UI components
Only add patterns that are general and reusable, not story-specific details.
Update CLAUDE.md Files
Before committing, check if any edited files have learnings worth preserving in nearby CLAUDE.md files:
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 1mo ago First seen · 105 lines · 909 tokens per session scan A 4dfe2e6d157d
ralph CLAUDE.md is an instructions file published in the GitHub repository snarktank/ralph (22,078 stars, last pushed 8mo ago), licensed MIT. It adds 909 tokens to every session, about $0.0036 per session on Opus 5.5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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