Claude Code Headless Mode: Run Claude in CI/CD and Scripts

# Simple prompt
claude --print "List all TODO comments in src/ with file paths and line numbers"

# Pipe a dynamic prompt
FILE="src/api/users.ts"
echo "Add JSDoc comments to every exported function in $FILE" | claude --print

# Capture output
SUMMARY=$(claude --print "Summarize all changes in the last 5 commits")
echo "$SUMMARY" >> CHANGELOG.md

# Exit code handling
if claude --print "Run tests and report any failures" \
     --permission-mode bypassPermissions; then
  echo "Tests passed"
else
  echo "Claude reported test failures" >&2
  exit 1
fi

# .github/workflows/claude-pr-review.yml
name: Claude PR Review
on:
  pull_request:
    types: [opened, synchronize]

jobs:
  review:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
        with:
          fetch-depth: 0

      - uses: actions/setup-node@v4
        with:
          node-version: '20'

      - name: Install Claude Code
        run: npm install -g @anthropic-ai/claude-code

      - name: Run Claude PR review
        env:
          ANTHROPIC_API_KEY: ${{ secrets.ANTHROPIC_API_KEY }}
          GH_TOKEN: ${{ secrets.GITHUB_TOKEN }}
        run: |
          DIFF=$(git diff origin/main...HEAD -- '*.ts' '*.tsx')
          REVIEW=$(echo "Review this PR diff for bugs, security issues, and missing tests. Be concise.\n\n$DIFF" | \
            claude --print --permission-mode bypassPermissions)
          echo "$REVIEW"

#!/bin/bash
# generate-tests.sh — generate tests for all untested functions

set -euo pipefail

# Find functions without matching test files
UNTESTED=$(grep -rn 'export function' src/ | \
  grep -v '.test.' | \
  awk -F: '{print $1}' | sort -u)

# Build prompt
PROMPT="Write Vitest unit tests for the exported functions in these files:\n"
for f in $UNTESTED; do
  PROMPT+="- $f\n"
done
PROMPT+="\nCreate test files alongside each source file."

# Run Claude
echo -e "$PROMPT" | claude --print \
  --permission-mode dontAsk \
  2>&1 | tee claude-test-generation.log