ralph-loop
Ralph Loop — Python Orchestrator
⚠️ IMPORTANT: This skill uses a Python orchestrator script. Do NOT execute arbitrary bash commands. Use Bash ONLY to run ralph_loop.py. All task commands (like /developer-kit-specs:specs.task-implementation) are shown to the user to execute manually.
Overview
The Ralph Loop applies Geoffrey Huntley's "Ralph Wiggum as a Software Engineer" technique to specification-driven development. It uses a Python orchestrator script that manages a state machine: one invocation = one step, state persisted in fix_plan.json.
Key insight: Implementing + reviewing + syncing in one invocation explodes the context window. Solution: each loop iteration does exactly one step, saves state to fix_plan.json, and stops. The next iteration resumes from saved state.
Key improvement: The Python script ralph_loop.py handles all state management, task selection, and command generation. It does NOT execute task commands directly — it shows you the correct command to execute in your CLI.
When to Use
- User runs
/loopcommand for recurring automation - User asks to "automate implementation" or "run tasks in loop"
- User wants to "iterate through tasks step-by-step" or "run workflow automation"
- User needs "context window management" across multiple SDD commands
- User wants to "process task range" from TASK-N to TASK-M
- User needs multi-agent support (different CLIs for different tasks)
Architecture
┌─────────────────┐ ┌─────────────────┐ ┌─────────────────┐
│ ralph_loop.py │────▶│ fix_plan.json │────▶│ User executes │
│ (orchestrator)│ │ (state file) │ │ command in CLI │
└─────────────────┘ └─────────────────┘ └─────────────────┘
│ │
│ ▼
│ ┌─────────────────┐
└──────────────────────────────────────│ Task result │
│ (success/ │
│ failure) │
└─────────────────┘
One Step Flow:
- Run
ralph_loop.py --action=loop - Script reads
fix_plan.jsonand determines current step - Script shows the command to execute (e.g.,
/developer-kit-specs:specs.task-implementation) - User executes the command in their CLI
- User runs
ralph_loop.py --action=loopagain - Script updates state based on result and shows next command
State Machine
fix_plan.json state machine:
┌─────────────────────────────────────────────────────────────┐
│ state: "init" │
│ → --action=start: Initialize fix_plan.json │
│ → Load tasks from tasks/TASK-*.md files │
│ → Apply task_range filter │
│ │
│ state: "choose_task" │
│ → Pick next pending task (within range, deps satisfied)│
│ → No tasks in range → state: "complete" │
│ → Task found → state: "implementation" │
│ │
│ state: "implementation" │
│ → Show /developer-kit-specs:specs.task-implementation command │
│ → User executes, then runs loop again │
│ → Next state: "review" │
│ │
│ state: "review" │
│ → Show /developer-kit-specs:specs.task-review command │
│ → User reviews results, then runs loop again │
│ → Issues found → state: "fix" (retry ≤ 3) │
│ → Clean → state: "cleanup" │
│ │
│ state: "fix" │
│ → Show commands to fix issues │
│ → User applies fixes, then runs loop again │
│ → Next state: "review" │
│ │
│ state: "cleanup" │
│ → Show /developer-kit-specs:specs-code-cleanup command│
│ → Next state: "sync" │
│ │
│ state: "sync" │
│ → Show /developer-kit-specs:specs.spec-sync-with-code command │
│ → Next state: "update_done" │
│ │
│ state: "update_done" │
│ → Mark task done, commit git changes │
│ → Re-evaluate dependencies │
│ → state: "choose_task" │
│ │
│ state: "complete" | "failed" │
│ → Print result, stop │
└─────────────────────────────────────────────────────────────┘
File Location Requirements
⚠️ CRITICAL: The fix_plan.json file MUST ALWAYS be located in:
docs/specs/[ID-feature]/_ralph_loop/fix_plan.json
This is enforced by the script to prevent LLMs from creating files in wrong locations.
Migration: If you have an old fix_plan.json in the root of your spec folder, the script will automatically migrate it to _ralph_loop/ on first run.
Instructions
Phase 1: Initialize
Run the Python script with --action=start to scan task files and create fix_plan.json in the correct location:
python3 plugins/developer-kit-specs/skills/ralph-loop/scripts/ralph_loop.py \
--action=start \
--spec=docs/specs/001-feature/ \
--from-task=TASK-036 \
--to-task=TASK-041
Phase 2: Execute Loop Steps
Run the script with --action=loop to get the current state and the command to execute:
python3 plugins/developer-kit-specs/skills/ralph-loop/scripts/ralph_loop.py \
--action=loop \
--spec=docs/specs/001-feature/
The script will show you the exact command to execute for the current step. Execute it in your CLI, then run the loop command again.
Phase 3: Advance State (Manual)
After executing the shown command, manually advance to the next step:
python3 plugins/developer-kit-specs/skills/ralph-loop/scripts/ralph_loop.py \
--action=next \
--spec=docs/specs/001-feature/
This updates fix_plan.json to the next state (e.g., implementation → review).
Phase 4: Monitor Progress
Check status anytime with --action=status:
python3 plugins/developer-kit-specs/skills/ralph-loop/scripts/ralph_loop.py \
--action=status \
--spec=docs/specs/001-feature/
Quick Start
1. Initialize
python3 plugins/developer-kit-specs/skills/ralph-loop/scripts/ralph_loop.py \
--action=start \
--spec=docs/specs/001-feature/ \
--from-task=TASK-036 \
--to-task=TASK-041 \
--agent=claude
2. Run Loop
python3 plugins/developer-kit-specs/skills/ralph-loop/scripts/ralph_loop.py \
--action=loop \
--spec=docs/specs/001-feature/
The script will show you the command to execute. Run it, then run the loop again.
3. Check Status
python3 plugins/developer-kit-specs/skills/ralph-loop/scripts/ralph_loop.py \
--action=status \
--spec=docs/specs/001-feature/
Arguments
| Argument | Description |
|---|---|
--action |
start (init), loop (run one step), status, resume, next (advance step) |
--spec |
Spec folder path (e.g. docs/specs/001-feature/) |
--from-task |
Start of task range (e.g. TASK-036) |
--to-task |
End of task range (e.g. TASK-041) |
--agent |
Default agent: claude, codex, copilot, kimi, gemini, glm4, minimax |
--no-commit |
Skip git commits (for testing) |
Step Details
Step 1: Initialize (--action=start)
The script:
- Scans
tasks/TASK-*.mdfiles in the spec folder - Extracts metadata from YAML frontmatter (id, title, status, lang, dependencies, agent)
- Applies
--from-taskand--to-taskfilters - Creates
fix_plan.jsonwith full state
Step 2: Choose Task (choose_task)
The script:
- Finds pending tasks within range
- Checks dependencies are satisfied
- Selects next task
- Updates
fix_plan.jsonwithcurrent_task - Shows command to execute
Step 3: Implementation (implementation)
The script shows:
→ Implementation: TASK-037
Execute:
/developer-kit-specs:specs.task-implementation --task=TASK-037
After execution, update state:
python3 ralph_loop.py --action=loop --spec=docs/specs/001-feature/
Step 4: Review (review)
The script shows:
→ Review: TASK-037 | Retry: 0/3
Execute:
/developer-kit-specs:specs.task-review --task=TASK-037
Review the generated review report, then update state:
python3 ralph_loop.py --action=loop --spec=docs/specs/001-feature/
Step 5: Fix (fix) - If Review Failed
If issues found, script shows fix instructions. After fixes, user runs loop again.
Step 6: Cleanup (cleanup)
The script shows:
→ Cleanup: TASK-037
Execute:
/developer-kit-specs:specs-code-cleanup --task=TASK-037
Step 7: Sync (sync)
The script shows:
→ Sync: TASK-037
Execute:
/developer-kit-specs:specs.spec-sync-with-code docs/specs/001-feature/ --after-task=TASK-037
Step 8: Update Done (update_done)
The script:
- Marks task as completed in
fix_plan.json - Commits git changes (unless
--no-commit) - Updates iteration count
- Returns to
choose_task
Multi-Agent Support
Default Agent for All Tasks
python3 ralph_loop.py --action=start --spec=... --agent=codex
Per-Task Agent
Specify agent in task file YAML frontmatter:
---
id: TASK-036
title: Refactor user service
status: pending
lang: java
agent: codex
---
Supported agents: claude, codex, copilot, kimi, gemini, glm4, minimax
Using with /loop (Claude Code)
For automatic scheduling every 5 minutes:
/loop 5m python3 plugins/developer-kit-specs/skills/ralph-loop/scripts/ralph_loop.py \
--action=loop \
--spec=docs/specs/001-feature/
This will repeatedly run the loop, showing you the next command each time.
Note: The Ralph Loop is now managed directly through the Python script. The deprecated /developer-kit-specs:specs.ralph-loop command has been removed.
Task File Format
Each task should be a separate file: tasks/TASK-XXX.md
---
id: TASK-036
title: Implement user authentication
status: pending
lang: java
dependencies: []
complexity: medium
agent: claude
---
## Description
Implement JWT-based authentication for the API.
## Acceptance Criteria
- [ ] Login endpoint returns JWT token
- [ ] Token validation middleware
- [ ] Refresh token mechanism
Examples
Example 1: Basic Usage
# Initialize
python3 ralph_loop.py --action=start \
--spec=docs/specs/001-feature/ \
--from-task=TASK-001 \
--to-task=TASK-005
# Loop until complete
while true; do
python3 ralph_loop.py --action=loop --spec=docs/specs/001-feature/
# Execute the shown command manually
# Then continue loop
done
Example 2: With Claude Code /loop
# Start with specific range
/loop 5m python3 plugins/developer-kit-specs/skills/ralph-loop/scripts/ralph_loop.py \
--action=loop \
--spec=docs/specs/002-tdd-command \
--from-task=TASK-001 \
--to-task=TASK-010
Example 3: Multi-Agent Setup
# Initialize with Claude as default
python3 ralph_loop.py --action=start \
--spec=docs/specs/001-feature/ \
--agent=claude
# Some tasks have "agent: codex" in their frontmatter
# Those will show Codex-formatted commands
Best Practices
- One step per invocation: Execute exactly one step, save state, stop
- Trust the state: Read from
fix_plan.json, write tofix_plan.json - No context accumulation: State lives in the file, not in context
- Manual command execution: The script shows commands; you execute them in your CLI
- Retry on review failure: Max 3 retries before failing
- Range filtering: Always filter by
task_range - Dependencies first: Only pick tasks where all dependencies are done
- Git commits: The script auto-commits after each completed task
Constraints and Warnings
- Context explosion: Do NOT implement + review + sync in one invocation — context will overflow
- Max retries: Review failures retry up to 3 times, then fail
- Git state: Ensure clean git state before starting
- Test infrastructure: Loop requires tests to pass — without tests, backpressure is ineffective
- Strict state validation: Valid
state.stepvalues are ONLY:init,choose_task,implementation,review,fix,cleanup,sync,update_done,complete,failed - NO automatic command execution: The script shows commands but does NOT execute them — you must run them in your CLI
Troubleshooting
"fix_plan.json not found"
Run --action=start first:
python3 ralph_loop.py --action=start --spec=docs/specs/001-feature/
The script will create fix_plan.json in the correct location:
docs/specs/001-feature/_ralph_loop/fix_plan.json
"fix_plan.json in wrong location"
If you see a warning about the file being in the wrong location, the script will guide you through migration:
# Manual migration if needed
mkdir -p docs/specs/001-feature/_ralph_loop
mv docs/specs/001-feature/fix_plan.json docs/specs/001-feature/_ralph_loop/fix_plan.json
The script will automatically migrate old files on first run.
"Invalid spec folder"
Run --action=start first:
python3 ralph_loop.py --action=start --spec=docs/specs/001-feature/
Task files not found
Ensure tasks are in tasks/TASK-XXX.md format with YAML frontmatter.
Wrong agent commands
Check --agent parameter or task agent: frontmatter field.
References
references/state-machine.md- Complete state machine documentationreferences/multi-cli-integration.md- Multi-CLI setup guidereferences/loop-prompt-template.md- Prompt template for shell loops