Diffler

diffler

magit, without Emacs.

I like magit a lot, and I wanted it as its own program. That's diffler: one binary with Doom Emacs keys for staging, committing, branching and reading diffs. You can review pull requests from GitHub, GitLab or Forgejo without checking them out. And if you work with a coding agent like Claude Code, it can read the comments you leave in the diff and reply right there, while you watch it fix the code.

Features

• Stage, commit, branch, push and pull with magit's keys
• Comment on lines and ranges, mark files as viewed
• Review pull requests without checking them out
• Let your agent answer your comments and walk you through its changes (optional)
• Open several projects as tabs; your agent sees all of them through one connection
• Open, create and remove git worktrees (jj workspaces), each as its own tab
• Works in git and jj repos
• Shows changed images in the terminal, before and after

Install

cargo install diffler

No compiling, and no Rust toolchain needed.

cargo binstall diffler

Or download it straight from the releases page: macOS, Linux and Windows, x86_64 and arm64. Any GitHub-release installer (eget, ubi, ...) works against it too.

macOS and Linux. The tap is this repository.

brew tap matheusfillipe/diffler https://github.com/matheusfillipe/diffler
brew install diffler

Windows. The bucket is this repository.

scoop bucket add diffler https://github.com/matheusfillipe/diffler
scoop install diffler

diffler-bin on the AUR ships the prebuilt binary, so it installs without building.

yay -S diffler-bin

The flake serves the prebuilt binary. nix run tries it without installing anything, nix profile install keeps it.

nix run github:matheusfillipe/diffler
nix profile install github:matheusfillipe/diffler

A wrapper that fetches the prebuilt binary. The package name is scoped, the command it installs is plain diffler.

npx @mattfillipe/diffler
npm install -g @mattfillipe/diffler

Quick start

diffler                 # open the status screen in the current repo
diffler path/to/repo    # or in another one

Inside diffler, <cr> opens a file's diff, s stages, cc commits, and c comments a line. For pull requests, b p lists the open ones and <cr> opens one's page: its description and conversation, where c comments on the pull request as a whole and R requests a reviewer. <cr> again reviews its diff, and S submits your line comments as a single review. b P opens a new pull request from the current branch.

With a coding agent

Connect your agent once:

claude mcp add diffler -- npx -y diffler-mcp
# or, as a plugin (MCP server plus the /df, /dfa and /dfr commands):
claude plugin marketplace add matheusfillipe/diffler && claude plugin install diffler@diffler
# or, over HTTP, reaching the first diffler you started (it takes port 8417):
claude mcp add --transport http diffler http://127.0.0.1:8417/mcp

Once connected, the server's prompts show up as /diffler:review, /diffler:walkthrough and /diffler:critique. The plugin adds /df, to answer your comments, /dfa, to walk you through a change, and /dfr, to review a change and leave comments.

Add the server to opencode.json in the project, or globally in ~/.config/opencode/opencode.json:

{
  "mcp": {
    "diffler": {
      "type": "local",
      "command": ["npx", "-y", "diffler-mcp"],
      "enabled": true
    }
  }
}

And install the /df, /dfa and /dfr commands (opencode has no package mechanism for commands, so this fetches the ones maintained in this repo):

mkdir -p ~/.config/opencode/commands
for c in df dfa dfr; do curl -fsSLo ~/.config/opencode/commands/$c.md \
  https://raw.githubusercontent.com/matheusfillipe/diffler/main/.opencode/commands/$c.md; done

Run npx -y diffler-mcp as a stdio server. It finds the port of the diffler running in your repo, since each diffler writes its own to .diffler/mcp.json. Or point it at http://127.0.0.1:8417/mcp (streamable HTTP), the port the first diffler you started takes. The server also ships review, walkthrough and critique prompts that prompt-aware clients surface as commands.

Comment on the agent's changes and press Z to send them. The agent answers in the thread and you resolve it once you're happy. Ask it for a walkthrough of its change and open it from the status screen. More in docs/walkthroughs.md, and the MCP tools are listed in docs/mcp.md. Don't need it? Set enabled = false under [mcp] in the config, or run diffler --no-mcp.

How it compares

¹ GitHub, GitLab and Forgejo. ² GitHub, GitLab, Gitea, Bitbucket, Azure DevOps and Gerrit. ³ tuicr exports your comments as markdown for you to paste into the agent.

Keys

Vim motions everywhere (j/k, gg/G, /, <c-d>/<c-u>). ? shows the full keymap of the screen you're on, and <c-k> fuzzy-finds any action.

Every binding is remappable in docs/config.example.toml. The mouse works, over tmux too: click to select or fold, and right-click (or press and hold) a line, file or comment for what you can do with it.

Configuration

Layered TOML: defaults, then ~/.config/diffler/config.toml, then <repo>/.diffler/config.toml, then CLI flags. Every option is documented in docs/config.example.toml. See the merged result and where each value came from:

diffler config --dump

Themes

Switch live with T, or set ui.theme. See every theme in the gallery. Add your own as a TOML file in ~/.config/diffler/themes/: docs/themes lists every key.

Development

just ci     # fmt + clippy + tests
just e2e    # PTY end-to-end suite (needs uv)

Requires Rust 1.90+, just, cargo-nextest. Hooks: prek install.

License

MIT or Apache-2.0, at your option.