Ralph Loop

Ralph Loop implements the Ralph methodology for autonomous AI coding: define a goal, set acceptance criteria (usually passing tests), and let Claude iterate until the criteria are met.

The loop

Each iteration follows the same cycle: run tests, read output, identify failures, make targeted edits, repeat. Ralph Loop runs this cycle automatically, reporting progress after each pass. You can watch it work or come back when it signals completion.

Goal definition

The key to effective autonomous coding is a clear acceptance criterion. Ralph Loop prompts you to specify what success looks like — usually a test command and a passing state — before it starts. This keeps the loop focused and terminating.

Transparency

Every iteration produces a progress report: which tests passed, which failed, what changes were made, and the reasoning behind each edit. This lets you monitor for drift or intervene if the loop is heading in the wrong direction.

Safety

Configurable iteration limits prevent runaway loops. Scope constraints (e.g., “only modify files in src/auth/”) prevent the loop from making changes outside its intended domain.

178,000+ installs — Ralph Loop is the standard autonomous coding tool for Claude Code users who want to set a goal and walk away.

Features

Autonomous edit-test cycle

Runs code, reads test output, edits failing code, and retries — looping until all tests pass or a limit is reached.

Goal-driven operation

Define what "done" means upfront and Ralph Loop works toward that definition without step-by-step prompting.

Progress transparency

Reports each iteration test results, changes made, and reasoning — so you can follow along or intervene.

Guard rails

Configurable iteration limits and scope constraints prevent runaway loops from making broad unintended changes.

Install