Ralph

Ralph — Autonomous PRD-Driven Agent Loop

Ralph is a file-based agent loop that breaks work into stories defined in a prd.json file and executes them one at a time using AI coding agents (OpenCode, Claude Code, Codex, etc.).

Core Concepts

PRD (Product Requirements Document)

A JSON file containing a project name, description, and an ordered list of user stories:

{
  "name": "My Feature",
  "branchName": "ralph/my-feature",
  "description": "What this PRD is about",
  "userStories": [
    {
      "id": "US-001",
      "title": "Add database schema",
      "description": "As a developer, I need...",
      "acceptanceCriteria": ["Column x exists", "Migration runs"],
      "priority": 1,
      "passes": false,
      "dependsOn": []
    }
  ]
}

Stories

Each story must be completable in one agent iteration. Stories have:

• ID: Sequential (US-001, US-002, etc.)
• Priority: Lower number = higher priority
• dependsOn: Story IDs that must complete first
• acceptanceCriteria: Verifiable checks the agent must satisfy
• passes: false until completed, then true

Dependencies

Stories execute in dependency order:

• Schema/database → Backend logic → UI components → Integration
• A story is "blocked" until all its dependsOn stories pass
• Ralph always selects the highest-priority unblocked story

Agent Workflow

When an agent learns this skill, it operates in ralph mode:

1. Create a PRD

Use ralph init or create a prd.json manually:

ralph init "Feature Name" --prd ./tasks/prd.json

2. Check Status

See progress at any time:

ralph status --prd ./tasks/prd.json

3. Run the Agent Loop

Execute stories one at a time:

ralph run --prd ./tasks/prd.json

Or use supercli:

sc ralph run run --prd ./tasks/prd.json

4. Preview Prompts (Dry Run)

See what the agent will receive without executing:

ralph run --prd ./tasks/prd.json --dry-run
ralph story prompt --prd ./tasks/prd.json --story US-001

5. Story Lifecycle

1. Ralph selects the next available story
2. Generates a prompt with story details + acceptance criteria + prerequisites
3. Spawns the agent CLI (openmode, claude, codex, etc.) with the prompt
4. Agent implements the story
5. Ralph marks passes: true in prd.json
6. Ralph commits changes via git
7. Repeat until all stories pass

PRD Best Practices

• One story = one agent iteration: If a story is too big, split it
• Acceptance criteria must be verifiable: Not vague like "works well"
• Order by dependencies: Lower-priority stories that depend on earlier ones
• Include quality gates: Typecheck, lint, test commands in acceptance criteria
• Use ralph/ branch prefix: E.g., ralph/kotlin-migration

Commands Reference

supercli Usage

sc ralph init run "Feature name"         # Create PRD
sc ralph run run --prd ./prd.json        # Run the loop
sc ralph status run --prd ./prd.json     # Check progress
sc ralph story next --prd ./prd.json     # Next story
sc ralph prompt run --prd ./prd.json     # Agent prompt