Iterative Runner

Runs Claude in a persistent loop that keeps retrying until tests pass or the task is complete.

When to Use

• Running TDD loops that iterate until all tests pass
• Overnight builds that need to keep trying until successful
• Any task requiring repeated attempts until completion criteria are met
• Automated retry for flaky or complex implementations

Core Concept

while :; do cat PROMPT.md | claude ; done

Keep iterating until task is complete.

Workflow

Step 1: Define Completion Criteria

Specify clear success conditions:

• All tests passing
• No linter errors
• Specific output marker (e.g.,

  <promise>DONE</promise>

  )

Step 2: Set Safety Limits

Always use

--max-iterations

to prevent infinite loops.

Step 3: Run the Loop

# Basic loop
iterative-runner "Build feature X" --completion-promise "DONE" --max-iterations 30

# TDD loop
iterative-runner "Implement feature using TDD.
1. Write failing test
2. Implement to pass
3. Run tests
4. Fix if failing
5. Repeat

Output <promise>DONE</promise> when all tests green." --max-iterations 50

Prompt Best Practices

1. Clear completion criteria - Define what "done" means
2. Incremental goals - Break into phases
3. Self-correction - Include retry logic
4. Escape hatch - Always use --max-iterations

Template

Implement [FEATURE].

Requirements:
- [Requirement 1]
- [Requirement 2]

Success criteria:
- All tests passing
- No linter errors

After 15 failed iterations:
- Document blockers
- List attempted approaches

Output <promise>COMPLETE</promise> when done.