action.yml

name: "Gemini AI Code Reviewer"
description: "This GitHub Action automatically reviews PRs using Google's Gemini AI model."
author: 'emnakhemiri'
branding:
  icon: 'zoom-in'
  color: 'blue'

inputs:
  GITHUB_TOKEN:
    description: 'GitHub token. Scope to contents:read + pull_requests:write (+ checks:write for Checks API).'
    required: true
  GEMINI_API_KEY:
    description: 'Google Gemini API key'
    required: true
  MODEL:
    description: 'Model string (e.g. gemini-2.5-flash, gemini-2.5-pro, or a Claude model). Single swap moves tiers.'
    required: false
    default: 'gemini-2.5-flash'
  EXCLUDE:
    description: 'Comma-separated list of file patterns to exclude'
    required: false
    default: ''
  MAX_ITERATIONS:
    description: 'Max tool-call iterations in the agentic loop.'
    required: false
    default: '6'
  TIMEOUT_MS:
    description: 'Wall-clock budget for the agentic loop, in ms.'
    required: false
    default: '30000'
  SMALL_PR_FILES_THRESHOLD:
    description: 'Below this file count (AND line count), use single-pass.'
    required: false
    default: '5'
  SMALL_PR_LINES_THRESHOLD:
    description: 'Below this changed-line count (AND file count), use single-pass.'
    required: false
    default: '50'
  MAX_CONCURRENT_REVIEWS:
    description: 'Max concurrent PR reviews in the same process.'
    required: false
    default: '3'
  GEMINI_RPM:
    description: 'Max requests per minute to Gemini. Set to 5 for free-tier flash, 60+ for paid.'
    required: false
    default: '5'
  MIN_CONFIDENCE_TO_POST:
    description: 'Minimum finding confidence to post inline (low|medium|high).'
    required: false
    default: 'high'
  PROMPT_CACHE_TTL_SECONDS:
    description: 'Gemini context cache TTL for system prompt + conventions.'
    required: false
    default: '3600'
  CODING_CONVENTIONS:
    description: 'Team conventions block appended to the cached prompt.'
    required: false
    default: ''
  ENABLE_LANGSMITH:
    description: 'Enable LangSmith tracing when truthy.'
    required: false
    default: 'false'
  LANGSMITH_PROJECT:
    description: 'LangSmith project name.'
    required: false
    default: 'gemini-ai-code-reviewer'
runs:
  using: 'composite'
  steps:
    - uses: actions/checkout@v4

    - uses: actions/setup-python@v4
      with:
        python-version: '3.10'

    - name: Install dependencies
      shell: bash
      run: |
        python -m pip install --upgrade pip
        pip install -r ${{ github.action_path }}/requirements.txt

    - name: Run code review
      shell: bash
      env:
        GITHUB_TOKEN: ${{ inputs.GITHUB_TOKEN }}
        GEMINI_API_KEY: ${{ inputs.GEMINI_API_KEY }}
        # MODEL is the single swap point between Gemini tiers / Claude.
        GEMINI_MODEL: ${{ inputs.MODEL }}
        EXCLUDE: ${{ inputs.EXCLUDE }}
        MAX_ITERATIONS: ${{ inputs.MAX_ITERATIONS }}
        TIMEOUT_MS: ${{ inputs.TIMEOUT_MS }}
        SMALL_PR_FILES_THRESHOLD: ${{ inputs.SMALL_PR_FILES_THRESHOLD }}
        SMALL_PR_LINES_THRESHOLD: ${{ inputs.SMALL_PR_LINES_THRESHOLD }}
        MAX_CONCURRENT_REVIEWS: ${{ inputs.MAX_CONCURRENT_REVIEWS }}
        GEMINI_RPM: ${{ inputs.GEMINI_RPM }}
        MIN_CONFIDENCE_TO_POST: ${{ inputs.MIN_CONFIDENCE_TO_POST }}
        PROMPT_CACHE_TTL_SECONDS: ${{ inputs.PROMPT_CACHE_TTL_SECONDS }}
        CODING_CONVENTIONS: ${{ inputs.CODING_CONVENTIONS }}
        ENABLE_LANGSMITH: ${{ inputs.ENABLE_LANGSMITH }}
        LANGSMITH_PROJECT: ${{ inputs.LANGSMITH_PROJECT }}
      run: python ${{ github.action_path }}/review_code_gemini.py