DiffLog Documentation

On this page: generate · config · tags · Configuration · GitHub Actions · Development

■ generate

Generate release notes from git history.

difflog generate [options]

Options
Flag	Description
`-p\|--path <PATH>`	Repository path (default `.`).
`-f\|--from <REF>`	Start reference (tag/branch/commit).
`-t\|--to <REF>`	End reference (default `HEAD`).
`-a\|--audience <AUDIENCE>`	Developers, EndUsers, SocialMedia, Executive.
`--format <FORMAT>`	Markdown, Html, PlainText, Json.
`-o\|--output <FILE>`	Output file path.
`--from-date <DATE>`	Include commits from date (yyyy-MM-dd).
`--to-date <DATE>`	Include commits until date (yyyy-MM-dd).
`--no-links`	Exclude issue/PR links.
`--no-contributors`	Exclude contributor list.
`--repo-url <URL>`	Repository URL override.
`--exclude <CATEGORIES>`	Comma-separated categories to exclude.
`--system-prompt <PROMPT>`	Override the system prompt for this run.
`--system-prompt-file <FILE>`	Read system prompt from file.
`-i\|--interactive`	Guided interactive mode.

Examples

difflog generate --from v1.0.0 --to v1.1.0 --format Markdown
difflog generate -a EndUsers --format Html --output release-notes.html
difflog generate --system-prompt-file prompts/social.txt

■ config

Store OpenAI settings and optional audience-specific system prompts.

difflog config [options]

Options
Flag	Description
`--api-key <KEY>`	OpenAI API key.
`--base-url <URL>`	Base URL for OpenAI-compatible APIs.
`--model <MODEL>`	Model name (default `gpt-4o`).
`--audience <AUDIENCE>`	Audience to set a custom system prompt for.
`--system-prompt <PROMPT>`	Prompt to store for that audience.
`--system-prompt-file <FILE>`	Read the prompt from a file.
`-i\|--interactive`	Prompt for missing values.

Examples

difflog config --api-key sk-... --model gpt-4o
difflog config --audience Developers --system-prompt-file prompts/dev.txt

■ tags

List tags in a repository.

difflog tags --path .

■ Configuration

DiffLog reads configuration from environment variables or the saved config file:

OPENAI_API_KEY
OPENAI_BASE_URL
OPENAI_MODEL

The difflog config command saves values to a config file (location is printed after saving). Environment variables always take precedence.

System prompt resolution order:

--system-prompt / --system-prompt-file
Stored prompt for the selected audience
Built-in defaults

■ GitHub Actions

Use DiffLog in your CI/CD pipeline to automatically generate release notes. Add your OpenAI API key as a repository secret (OPENAI_API_KEY).

.github/workflows/release-notes.yml

name: Generate Release Notes

on:
  push:
    tags:
      - 'v*'

jobs:
  release-notes:
    runs-on: ubuntu-latest
    steps:
      - uses: actions/checkout@v4
        with:
          fetch-depth: 0  # Required for full git history

      - name: Setup .NET
        uses: actions/setup-dotnet@v4
        with:
          dotnet-version: '10.0.x'

      - name: Install DiffLog
        run: dotnet tool install -g DiffLog

      - name: Generate Release Notes
        env:
          OPENAI_API_KEY: ${{ secrets.OPENAI_API_KEY }}
          # Optional: override model or base URL
          # OPENAI_MODEL: gpt-4o
          # OPENAI_BASE_URL: https://your-endpoint.openai.azure.com
        run: |
          # Get the previous tag
          PREV_TAG=$(git describe --tags --abbrev=0 HEAD^ 2>/dev/null || echo "")
          CURRENT_TAG=${GITHUB_REF#refs/tags/}

          if [ -n "$PREV_TAG" ]; then
            difflog generate --from $PREV_TAG --to $CURRENT_TAG --format Markdown -o release-notes.md
          else
            difflog generate --to $CURRENT_TAG --format Markdown -o release-notes.md
          fi

      - name: Create GitHub Release
        uses: softprops/action-gh-release@v2
        with:
          body_path: release-notes.md

For scheduled changelog generation or PR-based workflows:

- name: Generate Weekly Changelog
  env:
    OPENAI_API_KEY: ${{ secrets.OPENAI_API_KEY }}
  run: |
    difflog generate --from-date $(date -d '7 days ago' +%Y-%m-%d) --format Markdown -o changelog.md

■ Development

Build and pack locally:

dotnet build src/DiffLog.csproj -c Release
dotnet pack src/DiffLog.csproj -c Release -o ./artifacts

or use test-local-tool.ps1 to pack and install the tool from source.

Dependencies

.NET 10 SDK
Spectre.Console / Spectre.Console.Cli
Microsoft.Extensions.AI + OpenAI client

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