Claude Code in CI/CD Pipelines

Updated May 2026 · GitHub Actions, GitLab CI, Docker

Claude Code is a CLI tool — it runs anywhere bash runs. That means you can use it in GitHub Actions, GitLab CI, CircleCI, or any Docker-based pipeline to automate code review, PR summaries, test generation, and changelog updates without human intervention.

Prerequisites

• An Anthropic API key (set as a CI secret — never hardcode it)
• Node.js 18+ on your runner (most GitHub Actions runners include it)
• The --no-interactive flag on all claude commands (required in non-TTY environments)

GitHub Actions: Automated PR Review

This workflow runs Claude Code review on every pull request and posts the summary as a PR comment.

# .github/workflows/claude-review.yml
name: Claude Code PR Review

on:
  pull_request:
    types: [opened, synchronize]

permissions:
  contents: read
  pull-requests: write

jobs:
  review:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
        with:
          fetch-depth: 0   # full history for accurate diff

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

      - name: Run Claude review
        env:
          ANTHROPIC_API_KEY: ${{ secrets.ANTHROPIC_API_KEY }}
        run: |
          git diff origin/${{ github.base_ref }}...HEAD > /tmp/pr.diff
          claude --no-interactive \
            "Review this pull request diff for correctness, security issues, and style. Output a structured markdown review with sections: Summary, Issues (severity: high/medium/low), Suggestions. Be concise." \
            < /tmp/pr.diff > /tmp/review.md

      - name: Post review comment
        env:
          GH_TOKEN: ${{ github.token }}
        run: |
          gh pr comment ${{ github.event.pull_request.number }} \
            --body "$(cat /tmp/review.md)"

GitHub Actions: PR Summary on Merge

Auto-generate a human-readable changelog entry when a PR merges to main.

# .github/workflows/claude-changelog.yml
name: Generate Changelog Entry

on:
  pull_request:
    types: [closed]
    branches: [main]

jobs:
  changelog:
    if: github.event.pull_request.merged == true
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
        with:
          fetch-depth: 0

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

      - name: Generate changelog entry
        env:
          ANTHROPIC_API_KEY: ${{ secrets.ANTHROPIC_API_KEY }}
        run: |
          git log --oneline origin/main~1..HEAD > /tmp/commits.txt
          git diff origin/main~1..HEAD -- '*.ts' '*.js' '*.py' > /tmp/diff.txt
          claude --no-interactive \
            "Given these commits and code changes, write one concise changelog entry (1-3 sentences, plain language, user-facing focus). No bullet points. Start with a verb." \
            < <(cat /tmp/commits.txt /tmp/diff.txt) >> CHANGELOG.md

      - name: Commit changelog
        run: |
          git config user.email "ci@example.com"
          git config user.name "Claude Code Bot"
          git add CHANGELOG.md
          git commit -m "chore: add changelog entry for PR #${{ github.event.pull_request.number }}" || true
          git push

GitHub Actions: Test Generation on New Functions

Detect new functions in a PR and auto-generate test stubs.

name: Claude Test Generation

on:
  pull_request:
    types: [opened]

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

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

      - name: Generate test stubs
        env:
          ANTHROPIC_API_KEY: ${{ secrets.ANTHROPIC_API_KEY }}
        run: |
          # Extract only new/changed source files (not test files)
          git diff origin/${{ github.base_ref }}...HEAD \
            --name-only \
            --diff-filter=AM \
            | grep -E '\.(ts|js|py)$' \
            | grep -v '__tests__\|\.test\.\|\.spec\.' \
            > /tmp/changed_files.txt

          if [ -s /tmp/changed_files.txt ]; then
            while IFS= read -r file; do
              claude --no-interactive \
                "Generate Jest test stubs for all exported functions in this file. Use describe/it blocks, include happy path and one edge case per function. Output only the test file content." \
                < "$file" > "${file%.ts}.test.ts"
            done < /tmp/changed_files.txt
          fi

      - name: Commit generated tests
        run: |
          git config user.email "ci@example.com"
          git config user.name "Claude Code Bot"
          git add -A
          git diff --staged --quiet || git commit -m "test: add generated test stubs"
          git push origin HEAD:${{ github.head_ref }}

GitLab CI: Equivalent Setup

# .gitlab-ci.yml
stages:
  - review

claude-review:
  stage: review
  image: node:20
  only:
    - merge_requests
  script:
    - npm install -g @anthropic-ai/claude-code
    - git diff origin/$CI_MERGE_REQUEST_TARGET_BRANCH_NAME..HEAD > /tmp/pr.diff
    - claude --no-interactive
        "Review this diff for bugs, security issues, and code quality. Output markdown."
        < /tmp/pr.diff > /tmp/review.md
    - |
      curl --request POST \
        --header "PRIVATE-TOKEN: $GITLAB_API_TOKEN" \
        --header "Content-Type: application/json" \
        --data "{\"body\": \"$(cat /tmp/review.md | jq -Rs .)\"}" \
        "$CI_API_V4_URL/projects/$CI_PROJECT_ID/merge_requests/$CI_MERGE_REQUEST_IID/notes"
  variables:
    ANTHROPIC_API_KEY: $ANTHROPIC_API_KEY  # set in GitLab CI/CD variables

CI Cost Estimation

Enable prompt caching on your CLAUDE.md content to cut repeated-context costs by ~90%. The cache write is a one-time cost per session; all subsequent calls in the same CI job reuse it at $0.003/1K tokens (vs $0.003 base rate — full read is $0.015/1K).

Best Practices for CI Use

• Always use --no-interactive — CI has no TTY and will hang without it
• Set a --max-tokens limit on review output to control costs and keep comments readable
• Cache the npm install -g step using GitHub Actions cache to avoid the install delay on every run
• Store ANTHROPIC_API_KEY as a repository secret — never hardcode it in workflow files
• Use --output json when piping output to other tools — structured JSON is more reliable than parsing prose
• Create a CLAUDE.md in your repo root — it's automatically loaded and tells Claude your coding conventions, avoiding generic suggestions
• Scope the review diff to changed files only — pipe git diff --name-only before running Claude to avoid processing unchanged code

Frequently Asked Questions

→ Full GitHub integration guide

→ Claude Code vs GitHub Copilot

→ Claude Code best practices for teams

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