Hunk

Hunk is an open-source, review-first terminal diff viewer built by Modem and released under the MIT license. It is designed for both human developers and AI coding agents, offering a fast, visually polished interface that works across macOS, Linux, and Windows. The project has accumulated over 7,800 GitHub stars and reached v0.17.6 as of late July 2026.

What It Is

Hunk is a terminal UI (TUI) application that replaces plain-text git diff output with an interactive, multi-file review stream. Rather than scrolling through raw patch text, users navigate a sidebar of changed files, view split or stacked diff layouts, and read syntax-highlighted code changes. It is built on OpenTUI and Pierre diffs, and is distributed as an npm package (hunkdiff), a Homebrew formula, and a Nix flake.

Agent-First Design

What sets Hunk apart from tools like delta, difftastic, or diff-so-fancy is its first-class support for AI coding agents. Agents can connect to a live Hunk review session, navigate hunks, and leave inline comments and annotations that render directly beside the code they describe — keeping AI reasoning in the diff rather than in a separate tab or chat window. The workflow is:

• The developer opens hunk diff or hunk show in one terminal pane.
• The agent runs hunk session review --repo . --json and hunk session comment add to inspect and annotate the live session.
• A skill file (retrieved via hunk skill path) can be loaded by any compatible coding agent to enable this workflow automatically.

Review Workflow and Navigation

Hunk mirrors Git's diff-style commands but opens changesets in an interactive UI:

• hunk diff — review current working tree changes, including untracked files
• hunk diff --watch — auto-reload as the working tree changes
• hunk show — review the latest commit
• hunk diff before.ts after.ts — compare two files directly
• git diff --no-color | hunk patch - — pipe a patch from stdin

It also auto-detects Jujutsu and Sapling version control systems, using native revsets inside those workspaces. Hunk can be set as the Git pager so git diff and git show open in Hunk automatically.

Layouts, Themes, and Configuration

Hunk supports split, stacked, and responsive auto layouts that adapt to terminal width, with runtime toggles for line numbers and line wrapping. Six built-in themes are shown on the homepage (Graphite, Midnight, Ember, Zenburn, Catppuccin Mocha, Catppuccin Latte), and users can define custom themes that inherit from any built-in theme and override specific colors or TextMate syntax scopes. Configuration is stored in ~/.config/hunk/config.toml or a per-repo .hunk/config.toml, covering theme, layout mode, VCS backend, watch mode, tab width, and agent note display.

Extensibility and Embedding

Hunk includes an experimental extension API (Phase 1) that loads plain TypeScript extensions from the user config directory or a trusted repository's .hunk/extensions/ folder. Extensions can contribute themes, add VCS backends, rewrite changesets before review (e.g., collapsing lockfiles), replace the file-navigation sidebar with a custom React component, and react to lifecycle events. Hunk also publishes HunkDiffView and lower-level primitives from hunkdiff/opentui for embedding the same diff renderer in other OpenTUI applications.

Update: v0.17.6

The latest release is v0.17.6, published on July 25, 2026. The repository shows active development with frequent pushes and 100 open issues as of late July 2026. The extension API is marked experimental and may change between minor releases; breaking changes are called out in release notes. The older [custom_theme.syntax] role table is deprecated and will be removed in the next major release, with syntax_scopes as the replacement.