Ralph Loop

1) Draft a PRD (validator-required sections)

Ralph validates the prompt file. These headings are required and must be non-empty:

• Goal
• Acceptance Criteria
• Verification
• Progress

Below is a template. Copy it and fill it out replace with your details. Leave the Progress section alone.

# PRD: <Feature name>

## TL;DR

- One sentence: what are we shipping?

## Goal

- What outcome should exist when done?

## Constraints

- Tech constraints, deadlines, guardrails.

## Acceptance Criteria

- [ ] Observable success conditions
- [ ] Edge cases you care about

## Verification

- Tests or manual checks that prove it works

## Notes

- Anything the loop should remember each iteration

## Progress

It's your job to update the progress field every time you make a change. The purpose of this is to ensure the next developer knows what you did, what's done, any decisions or assumptions you made, and is able to continue working. If you've made changes, please copy and paste this template to the bottom of the progress and edit to add your notes.

```template
### {{Title}} - {{Date}}

- {{Summary}}
- {{Decisions}}
- {{Assumptions}}
- {{Risks}}
- {{Status}}
- Best guess at what comes next & why:
  - {{Next}}
  - {{Next?}}
```

Add entries below this line:

2) Set the model

Pick a model that can grind:

• gpt-5.2-codex (extra high reasoning)
• Opus 4.5

3) Switch to the Ralph agent

Tab through agents until the status reads ralph.

4) Run the loop

The Ralph commands has two parameters:

1. The path to the PRD file
2. The max number of iterations to run (default 25)

Start with 5 iterations until you get the hang of it:

/ralph @docs/feature-x.prd.md 5

Then up as needed:

/ralph @docs/feature-x.prd.md 50

5) How the loop behaves

It will keep smashing your prompt back into the loop until it outputs RALPH_DONE or hits the max iteration cap. That is the point: run the happy path for hours without babysitting. Each iteration writes Progress back into the PRD. So the next turn picks up where the last left off.

The configs auto accept everything, but stop git push and attemp to stop any destructive actions.

6) Need to steer every once and a while?

Because this is in Opencode UI, you can interact with the loop while it's running.

Just type a message and hit enter. OpenCode will insert it at the next available moment nudging the agent in the right direction.

However, I find the models eventually get there so try to resist the urg.

7) Stop the loop

• Press Ctrl+C
• Or run /ralph stop

Restart OpenCode after installing to register the /ralph command. Prefer file-based prompts (use @path) for long instructions and multi-line edits.