ralph-py 0.2.0

Minimal CLI for orchestrating Ralph loops across coding agents

ralph-py

Minimal CLI for orchestrating Ralph loops across coding agents.

Ralph loops solve context rot — the degradation LLMs suffer in long sessions as conversation history fills with noise. Instead of one long session, ralph runs your agent repeatedly with fresh context, using a simple markdown file as memory between iterations.

pip install ralph-py

Quick start

# Run a loop in the foreground (Ctrl+C to stop)
ralph run "implement user authentication with JWT tokens"

# Schedule a loop via system cron (survives reboots)
ralph schedule "run tests and fix failures" --cron "0 */2 * * *"

# Check on your loops
ralph list
ralph show <loop-id>
ralph logs <loop-id>

# Clean up
ralph remove <loop-id>

How it works

┌──────────────────────────────────────────────────────────────┐
│                                                              │
│   ralph run "implement auth"                                 │
│       │                                                      │
│       ├── iteration 1 ─── agent runs ─── updates memory.md   │
│       │       ↓                                              │
│       │   sleep 5s                                           │
│       │       ↓                                              │
│       ├── iteration 2 ─── agent runs ─── updates memory.md   │
│       │       ↓                                              │
│       │   sleep 5s                                           │
│       │       ↓                                              │
│       ├── iteration 3 ─── agent runs ─── prints              │
│       │                                  RALPH_COMPLETE       │
│       │                                                      │
│       └── done.                                              │
│                                                              │
└──────────────────────────────────────────────────────────────┘

Each iteration:

1. Ralph reads your task prompt and the accumulated memory.md
2. Builds a composite prompt (your task + memory + iteration context + instructions)
3. Invokes the agent CLI as a blocking subprocess with fresh context
4. The agent works, updates memory.md, and exits
5. Ralph checks for RALPH_COMPLETE in stdout, updates state, repeats

You only write the task. Memory management, iteration tracking, and completion detection are automatic.

Supported agents

Agent	Provider flag	Non-interactive mode
Claude Code	--provider claude (default)	claude -p "prompt"
Codex CLI	--provider codex	codex exec "prompt"
Aider	--provider aider	aider --message "prompt"
OpenCode	--provider opencode	opencode run "prompt"

ralph run "refactor the database layer" --provider codex --model gpt-4.1
ralph run "add test coverage" --provider aider --model claude-sonnet-4-20250514

Commands

ralph run

Start a foreground loop. The agent runs repeatedly with a configurable delay between iterations.

ralph run "implement auth feature" [options]

Option	Short	Default	Description
--provider	-p	claude	Agent CLI to use
--model	-m	(provider default)	Model name
--max-iter	-n	50	Stop after N iterations
--delay	-d	5	Seconds between iterations
--prompt-file	-f		Read prompt from a file
--name		(auto)	Human-readable loop name
--workdir	-w	.	Working directory for the agent

Ctrl+C gracefully stops — the current iteration finishes, state is saved.

ralph schedule

Install a system cron job. Each tick runs one iteration. Survives reboots.

ralph schedule "run tests and fix failures" --cron "0 */2 * * *"
ralph schedule --prompt-file ./nightly-task.md --cron "0 3 * * *" --name "nightly fixes"

Option	Short	Default	Description
--cron	-c	(required)	Cron expression

All options from ralph run also apply (except --delay).

ralph list

Show all loops.

$ ralph list
┌──────────────────┬───────────────────┬───────────┬──────┬──────────────┬──────────┐
│ ID               │ NAME              │ STATUS    │ ITER │ SCHEDULE     │ LAST RUN │
├──────────────────┼───────────────────┼───────────┼──────┼──────────────┼──────────┤
│ implement-auth…  │ implement auth    │ running   │ 7/50 │ (foreground) │ 2m ago   │
│ nightly-fixes…   │ nightly fixes     │ running   │ 12/50│ 0 3 * * *    │ 8h ago   │
│ refactor-db…     │ refactor db layer │ completed │ 15/50│ (foreground) │ 1d ago   │
└──────────────────┴───────────────────┴───────────┴──────┴──────────────┴──────────┘

ralph show <loop-id>

Full details: config, memory contents, and latest log tail.

ralph logs <loop-id>

View the output log for an iteration.

ralph logs <loop-id>                # latest iteration
ralph logs <loop-id> --iter 3       # specific iteration
ralph logs <loop-id> --tail 20      # last 20 lines

ralph remove <loop-id>

Stop a loop and delete its files. Use --keep-files to preserve logs and memory.

ralph remove <loop-id>              # remove everything
ralph remove <loop-id> --keep-files # stop cron, keep files

ralph once <loop-id>

Run a single iteration. This is what cron calls — you can also use it manually.

Memory

Memory is a plain markdown file (~/.ralph/loops/<id>/memory.md) that persists across iterations. Ralph injects it into the prompt automatically. The agent is instructed to update it after each iteration.

## Iteration 3
- Implemented JWT token generation and validation
- All auth tests passing (12/12)
- TODO: refresh token endpoint, rate limiting

## Iteration 2
- Created login endpoint, password hashing with bcrypt
- Added test fixtures for auth module

## Iteration 1
- Set up project structure and database models
- Created user registration endpoint

Memory lives outside your project directory (~/.ralph/loops/<id>/), so multiple loops can target the same repo without conflicting, and nothing ralph-related ends up in your git history.

Completion

The loop stops when any of these happen:

Condition	Result status
Agent prints RALPH_COMPLETE on its own line	completed
Iteration count reaches --max-iter	stopped
ralph remove <id>	stopped
Ctrl+C during ralph run	stopped

The agent is automatically instructed to print RALPH_COMPLETE when the task is done — you don't need to include this in your prompt.

Data layout

All state lives under ~/.ralph/:

~/.ralph/
└── loops/
    └── implement-auth-a1b2/
        ├── prompt.md       # Your original task (immutable)
        ├── memory.md       # Agent-maintained memory
        ├── state.json      # Iteration count, status, config
        └── logs/
            ├── 001.log     # stdout from iteration 1
            ├── 002.log
            └── 003.log

No databases. No daemon. Just files.

Foreground vs. scheduled

	ralph run	ralph schedule
Process	Foreground, needs a terminal	No process — cron manages it
Survives reboot	No	Yes
Timing	Fixed delay between iterations	Cron expression
Output	Streamed to terminal	Written to log files
Best for	Active development	Overnight/periodic tasks

Installation

Requires Python 3.11+.

# pip
pip install ralph-py

# uv
uv tool install ralph-py

# pipx
pipx install ralph-py

# From source
git clone https://github.com/SiluPanda/ralph-py.git
cd ralph-py
pip install -e .

Dependencies

One runtime dependency: typer. Cron management uses the system crontab command directly — no extra libraries.

What ralph doesn't do

Ralph is deliberately minimal. It does not:

• Track costs — delegate to the agent CLI (--max-budget-usd on Claude Code)
• Manage git — the agent handles commits, branches, etc.
• Provide a TUI/dashboard — use ralph list and ralph logs
• Rotate agents — one provider per loop
• Retry with backoff — fresh context is the retry mechanism
• Run a daemon — scheduling is the OS's job

Background

The Ralph loop (named by Geoffrey Huntley, mid-2025) is a technique for running coding agents autonomously on long tasks. The insight: LLMs degrade as context fills — past 60-70% capacity, performance collapses. Ralph fixes this by restarting the agent with fresh context each iteration, using files and git as the memory layer instead of conversation history.

# The original Ralph loop is one line of bash:
while :; do cat PROMPT.md | claude -p; done

ralph-py wraps this pattern with scheduling, memory management, iteration tracking, and multi-agent support — while staying true to the philosophy of simplicity.

License

MIT