Claude Code Ralph Loop Tutorial
Step-by-step walkthrough for installing and using the Ralph Loop plugin with Claude Code, enabling autonomous iterative development through a stop-hook mechanism.
What Ralph Loop Does
Ralph Loop forces Claude Code to operate in a continuous intelligent loop. Instead of stopping when it believes output is "good enough", Claude keeps working until the task meets explicit completion criteria. The plugin uses a stop hook that blocks exit and feeds the same prompt back.
Installation
- Install Claude Code:
curl -fsSL https://claude.ai/code/install | sh - Ensure you're on version 2.0.76+ to access
/plugins - Run:
/plugin install ralph - Verify with
/pluginto see Ralph listed
Usage
/ralph loop "Build me a REST API for todos" done
The five-step cycle:
- Claude attempts the task
- Tries to exit
- Stop hook blocks exit
- Same prompt feeds back
- Repeats until completion criteria met
Prompt Best Practices
Clear completion criteria — Don't say "make it good". Specify exact requirements: crude operations, input validation, tests, etc.
Incremental goals — Break work into phases the agent can achieve step by step.
Self-correction patterns — Instead of "write code for feature X", use: implement feature, write failing test, run test, fix until passing.
Max iterations — Always set a limit to prevent runaway token usage.
Results Demonstrated
A paint tool comparison: standard Claude Code (single pass) produced basic brush/size features. With Ralph Loop enabled, the same prompt generated spray effects, shapes, text, emoji support, image enhancement, and photo imports.
Real-world examples cited:
- $50K outsourcing contract completed for $297 in AI costs
- Created an esoteric programming language ("Gen Z") in 30 hours of autonomous operation
- 6 repositories shipped overnight during a Y Combinator hackathon
Connections
Ralph Loop is the plugin implementation of the ralph-wiggum-as-a-software-engineer technique by Geoffrey Huntley. See stop-chatting-with-ai-start-loops-ralph-driven-development for methodology on structuring prompts for loop-based development. Contrast with 12-factor-agents, which argues for deterministic workflows over "loop until solved" patterns.