deltoids

Warning

This project is under active development. Diff output may still be broken. In case of doubt, verify changes with another pager.

Tools for reviewing code in the agentic era.

git diff	deltoids

Hunks expand to show the enclosing function, so you always know where you are.

Overview

Deltoids diffs have language-aware syntax highlighting and word-level highlighting within changed lines. They also expand to include relevant context, usually the enclosing function or struct up to 200 lines. This allows you to quickly view the entire context without having to switch to an editor.

Tools:

• deltoids pager: ANSI diff filter for less / core.pager
• deltoids review: review tool
• deltoids edit: file edit tool (used by coding agents)
• deltoids write: file write tool (used by coding agents)
• deltoids traces: trace browser to follow agents in real-time

edit and write are CLI versions of AI coding agent tools. By providing these custom CLIs, we can tell coding agents to generate summaries for each change and visualize them with deltoids traces separately from the coding agent UI.

Installation

Homebrew:

brew install juanibiapina/taps/deltoids

Prebuilt binaries (shell installer):

curl --proto '=https' --tlsv1.2 -LsSf https://github.com/juanibiapina/deltoids/releases/latest/download/deltoids-cli-installer.sh | sh

From source (cargo):

cargo install --git https://github.com/juanibiapina/deltoids deltoids-cli

Usage

Standalone

Pipe any unified diff through deltoids:

git diff | deltoids | less -R
git show HEAD~1 | deltoids | less -R
git log -p | deltoids | less -R

Git Integration

Set deltoids as your default pager:

git config --global core.pager 'deltoids | less -R'

Or for a specific command:

git config --global pager.diff 'deltoids | less -R'
git config --global pager.show 'deltoids | less -R'
git config --global pager.log 'deltoids | less -R'

Lazygit Integration

Add to ~/.config/lazygit/config.yml:

git:
  paging:
    pager: deltoids

Configuration

Deltoids reads $XDG_CONFIG_HOME/deltoids/config.toml (falling back to ~/.config/deltoids/config.toml).

Custom commands

Bind a key in deltoids tui to a shell command that runs against the selected file. {{filename}} expands to the selected file's absolute path (shell-quoted, so paths with spaces work):

# Background (default): dispatches elsewhere and returns immediately.
# The TUI never touches the terminal, so there is no flicker.
[[commands]]
key = "e"
command = "dev tmux edit {{filename}}"
description = "edit file in a tmux pane"

# Subprocess: takes over the terminal for an inline editor. The TUI
# suspends, hands the terminal to the child, then restores and repaints.
[[commands]]
key = "E"
command = "nvim {{filename}}"
subprocess = true
description = "edit file inline in neovim"

subprocess defaults to false. command is a shell line (run via sh -c), not an argv. Custom keys work in both Files and Traces mode against the current selection; they cannot override the built-in keys (q, [, ], <, >, ?) but can shadow a mode's own keys. Press ? to see the configured bindings in the help popup.

Coding Agent Integrations

pi

Install the deltoids plugin for pi to override built-in edit and write tools with the traced versions:

pi install https://github.com/juanibiapina/deltoids

Requires the deltoids binary on PATH. See plugins/pi/README.md for details.

Then run deltoids traces in the same directory as pi to see real-time diffs with summaries.

Claude Code

Install the deltoids plugin to record every Write and Edit call as a trace, grouped by Claude session:

claude plugin marketplace add juanibiapina/deltoids
claude plugin install deltoids@deltoids

Or, from inside an interactive session, run /plugin marketplace add juanibiapina/deltoids then /plugin install deltoids@deltoids.

The Claude session_id is used directly as the deltoids trace id, so continuing a session (claude --continue) keeps appending to the same trace. Requires the deltoids binary on PATH. See plugins/claude-code/README.md for details, including a ~/.claude/settings.json snippet that bypasses the known plugin hook delivery bug.

Unlike the pi integration, Claude Code edits are recorded without a per-edit summary. Claude's PostToolUse hook does not expose one.