Dependadocs

Dependabot for your documentation. Dependadocs runs inside GitHub Actions and automatically opens a PR with AI-generated documentation updates whenever a code PR changes something that makes your docs stale.

• Zero infrastructure — pure GitHub Actions, no servers
• BYOK — bring your own Gemini API key (free tier works)
• Human-in-the-loop — always opens a separate PR for review; never auto-merges
• Conservative — only flags factually incorrect docs (renamed APIs, changed flags, etc.), ignores style/typos

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How it works

Your PR opened/updated, or on schedule, or manually triggered
  → fetch diff via GitHub API
  → discover .md / .rst / .txt files in your repo
  → send diff + docs to Gemini 2.5 Flash (for primary, diff-focused analysis)
  → (if READMEs are present and not updated by primary analysis) send READMEs to Gemini for a holistic correctness check
  → if *any* docs are stale:
      open a new PR  →  dependadocs/pr-{number}  →  targeting your base branch
  → if docs look fine:
      exit cleanly, no PR opened

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Quick start

1. Add your Gemini API key as a secret

In your repo: Settings → Secrets and variables → Actions → New repository secret

Name: GEMINI_API_KEY Value: your key from Google AI Studio

2. Create the workflow file

.github/workflows/dependadocs.yml:

on:
  pull_request:
    types: [opened, synchronize]
  schedule:
    - cron: '0 9 * * 1'
  workflow_dispatch:

permissions:
  contents: write
  pull-requests: write

jobs:
  dependadocs:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
      - uses: usr-wwelsh/dependadocs@main
        with:
          gemini-api-key: ${{ secrets.GEMINI_API_KEY }}

3. Allow Actions to open pull requests

In your repo: Settings → Actions → General → Workflow permissions

Enable "Allow GitHub Actions to create and approve pull requests".

That's it. The next time someone opens a PR, Dependadocs will run.

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Inputs

Input	Required	Default	Description
gemini-api-key	Yes	—	Your Gemini API key
docs-path	No	"" (whole repo)	Restrict doc discovery to a subdirectory, e.g. "docs/"
github-token	No	${{ github.token }}	Override the default GitHub token
lookback-days	No	7	Number of days of commits to diff on scheduled/manual runs

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What Gemini looks for

Dependadocs instructs Gemini to flag documentation that is factually stale due to code changes:

• Function or method renames
• Changed CLI flags or config keys
• Updated API signatures
• Removed or added features referenced in docs

It is explicitly told to ignore typos, grammar, and style improvements.

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Ignoring files

You can exclude files from Dependadocs by creating a .docignore file in your repo root. Each line is a glob pattern — files matching any pattern will be skipped.

# Example .docignore
CHANGELOG.md
ADR/
docs/internal/*
*.generated.md

Patterns with a trailing / match any file inside that directory (e.g. ADR/ excludes all files under ADR/). Patterns without a / match by filename anywhere in the repo.

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Permissions

The workflow needs:

permissions:
  contents: write       # create branches + commit files
  pull-requests: write  # open the doc-update PR

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Development

pip install -r requirements.txt
pytest tests/ -v
ruff check src/ tests/

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License

MIT