seams

1. get the extension. download seams-extension.zip from the latest release and unzip it somewhere it can stay.
2. load it. open chrome://extensions (or edge://extensions), turn on developer mode, click load unpacked and pick the folder.
3. open any pull request. an open in seams button sits next to the title. it opens the whole pull request in a new tab, every file at its exact commit.
4. add a token (optional) in the extension's options: a fine-grained token with contents: read and pull requests: read and write. it opens private repositories, lets you comment, and checks for changes every 10 seconds instead of every 2 minutes.

1. download from the latest release: seams-linux-x86_64.tar.gz (one static binary), seams-windows-x86_64.zip, or seams-macos-x86_64.tar.gz (apple silicon runs it through rosetta).
2. diff two files. the output is a unified diff, like diff -u.

seams old.txt new.txt                 # unified diff
seams --minimal old.txt new.txt       # the exact smallest diff, however long it takes
seams patch old new > change.seams    # a patch that carries its own lines
seams apply old change.seams > new    # refused if old isn't the file it was made from
seams merge base ours theirs          # three-way merge, git's conflict markers

as git's diff tool: GIT_EXTERNAL_DIFF=tools/seams-git git diff. windows may warn the first time you run seams.exe, because the binary isn't signed yet.

1. clone seams once. you need node 18 or newer.
2. run it inside any git repository with a range, the way you'd give it to git diff. it reads both sides straight from git and opens your browser.

git clone https://github.com/Cintu07/seams
cd your-repo
node ../seams/tools/seams-review.mjs main..my-branch

renames are followed, binary files are skipped, and the server only listens on your machine. this is the one to use for an agent's branch before it becomes a pull request.

1. import it by url. no package manager: about 100 kb of plain modules and a 5 kb wasm file. for your own server, unpack seams-web.tar.gz from the release and serve the folder.
2. or diff ahead of time. seams-pack diffs on your server or in ci and writes a pack; the browser opens it with nothing left to compute. --page also writes a page whose first screen is already in the html.

import { createDiffViewer } from 'https://cintu07.github.io/seams/lib/index.mjs';

const viewer = createDiffViewer(el, { theme: 'sage' });
await viewer.setFiles(before, after, { name: 'main.ts' });

// diffed ahead of time:  node tools/seams-pack.mjs old new -o pr.seamspack
await viewer.setPack('/pr.seamspack');

seven themes: sage, dusk, paper, clay, ink, harbor, and clear, which uses orange and blue instead of red and green for red-green colour blindness. or pass your own colours with the same keys as THEMES.sage.

react: <SeamsDiff oldFile={a} newFile={b} name="main.ts" /> from react.mjs. a whole pull request with a file list: createReview(el).setFiles([{ path, old, new }]).

n p

next and previous change

v

unified or side by side

ctrl f

find in the whole diff, not just what's on screen

drag, ctrl c

select and copy, across as many lines as you like

] [

next and previous file in a pull request

type in the box

filter a pull request's files by path

hover a line number

+ to comment on that line (github, with a token)

space page down home end

what you'd expect