crit

Crit

Review your coding agent's plans, diffs and running apps in the browser. Click a line, leave a comment, and the agent gets it.

Adaptive UI for each type of output

To an agent, plans and code are both just text. To you, reviewing a plan and reviewing a web app are different jobs.

Crit gives each type of output its own review UI. Point at the exact thing that's wrong and leave a comment for the agent:

• crit plan.md renders a markdown file with review comments.
• crit finds your git changes and shows them as syntax-highlighted diffs.
• crit http://localhost:3000 proxies your running app and adds a review layer on top.
• crit landing.html renders a static HTML file you can click and comment on.

Everything runs locally from a single binary.

Quickstart

1. Install Crit binary

Brew:

brew install crit

Go:

go install github.com/tomasz-tomczyk/crit/cmd/crit@latest

Nix:

nix profile install github:tomasz-tomczyk/crit

Arch Linux:

yay -S crit.md-bin

AUR package, maintained outside this project. Any AUR helper works in place of yay.

Windows:

iwr https://github.com/tomasz-tomczyk/crit/releases/latest/download/crit-windows-amd64.exe -OutFile crit.exe

Note: Then move crit.exe somewhere on your PATH. ARM64 users: swap amd64 for arm64. WSL users: use the Linux binary instead.

Or download the latest release from GitHub.

2. Integrate with your agent

Claude Code:

claude plugin marketplace add tomasz-tomczyk/crit
claude plugin install crit@crit

Crit also works with Cursor, GitHub Copilot, OpenCode, OMO, omp, Codex, Gemini, Qwen, Hermes, Windsurf, Cline, Grok, Aider, and Pi — any agent that can read a file and run a command. See integrations/ for all install methods and details.

3. Tell your agent to use crit

Most integrations include a /crit slash command that automates the full review loop. The agent launches Crit, waits for your review, then acts on the feedback. Repeat until you approve.

Here's a 2-minute demo walkthrough of plan review and branch review:

Usage

The recommended way is to run the /crit command in your agent after any piece of work, whether it wrote a plan or changed code. You can also launch Crit yourself in a terminal and paste the prompt back to your agent when you finish.

crit                              # auto-detect changed files in your repo
crit plan.md                      # review a specific file
crit plan.md api-spec.md          # review multiple files
crit http://localhost:3000        # review a running dev server
crit landing.html                 # review a static HTML file

In your agent chat, run /crit with any of the arguments above. Run it bare and the agent picks what to launch from the conversation.

Story mode

For larger branch, PR, MR, or range reviews, story mode adds a chaptered overview of the diff — thematic chapters, a prologue, and a support bucket for noise — so you can understand the shape of the change before line-by-line review. It is an explainer, not a reviewer.

Recommended: invoke /crit-story (or $crit-story, /skill:crit-story, depending on your agent) after crit install <tool>. Your agent authors the story in-session via crit story --prep / --story-file. Only run it when you explicitly ask — agents will not infer it from a normal /crit review.

Alternative: crit story from the terminal uses your global agent_cmd (separate LLM spend). Generation is LLM-driven exploration — cost depends on change complexity more than raw file/diff size, and does not scale linearly. In our experience, complex PRs (~20–50 files, ~2k–5k lines) land around $1–$1.40 with Claude Opus 5. See the story mode guide for commands, custom prompts, JSON shape, and token-cost notes.

Live mode

crit live <url> (or crit <url>) proxies a running dev server through Crit's review UI. Crit's iframe loads the app on a different origin/port than your browser tab, so host-scoped session cookies are not shared automatically. If the direct URL works but Crit shows a login page or hydration mismatch, forward the upstream cookies:

# one-off
crit live http://localhost:4000/dashboard --cookie "_crit_key=..."

# repeatable (Netscape jar or raw Cookie header lines)
crit live http://localhost:4000/dashboard --cookie-file .crit/live-cookies.txt

# reuse cookies from a Chrome session with remote debugging enabled
crit live http://localhost:4000/dashboard --cdp-url http://127.0.0.1:9222

Getting cookies: log in to the app in your browser, then copy the session cookie from DevTools (Application → Cookies), export a cookie jar, or start Chrome with --remote-debugging-port=9222 and pass --cdp-url so Crit reads cookies for the target origin automatically.

Config (global or project .crit.config.json; project overrides global):

{
  "live_cookie_file": ".crit/live-cookies.txt",
  "live_cdp_url": "http://127.0.0.1:9222"
}

Relative paths resolve from the repo root. Prefer a gitignored file under .crit/ over committing live_cookie inline. Run crit live --help for all flags.

If Comment/Pin stays unavailable, or a framework needs local CSP / iframe tweaks, see the live mode guide (injection model, common failures, Phoenix / Vite / Next.js recipes).

crit status                       # show review file path and daemon status
crit resume                       # pick a previous review to reopen
crit stats                        # show lifetime review statistics
crit cleanup                      # delete stale review files

crit resume lists every review in ~/.crit/reviews, newest first, with its branch or files, directory, age, and open comment count. Choosing one reconnects to its daemon, or restarts the daemon in the directory the review came from when it has stopped — so you can resume a review from anywhere. Pass --list to print the list instead, or a session ID to skip the picker.

Features

Round-to-round diff

After your agent edits the file, Crit shows a split or unified diff of what changed - toggle it in the header.

Split view

Unified view

Inline comments: single lines and ranges

Click a line number to comment. Drag to select a range. Comments are rendered inline after their referenced lines, just like a GitHub PR review.

Programmatic comments

AI agents can use crit comment to add inline review comments without opening the browser UI or constructing JSON manually:

crit comment src/auth.go:42 'Missing null check'
crit comment src/handler.go:15-28 'Error handling issue'
crit comment --selector 'h1' 'Heading is vague'                 # live app or HTML preview
crit comment --selector '#save' --route /settings 'Save stays disabled'
crit comment --session 839f3b4cd5d6 src/auth.go:42 'Target this review'
echo '[{"body":"Overall feedback"}]' | crit comment --session 839f3b4cd5d6 --json
crit comment --output ~/.crit src/auth.go:42 'comment'  # same as default (~/.crit/reviews/<key>/)
crit comment --output .crit src/auth.go:42 'comment'    # in-repo: .crit/reviews/<key>/
crit comment --clear   # remove the review file

Comments are appended to the review file (stored in ~/.crit/reviews/) and created automatically if it doesn't exist. Run crit status to see active review session IDs and paths. If multiple sessions match the same directory and branch, select one with --session <id> on crit comment, crit comments, crit share, crit push, or crit pull; an unqualified command fails instead of guessing.

Share for Async Review

Want a second opinion before handing off to the agent? Click the Share button to upload your review and get a public URL anyone can open in a browser, no install needed. Each reviewer's comments are color-coded by author. Unpublish anytime.

You can also share directly from the CLI without starting the browser UI:

crit share plan.md                    # share files and print the URL
crit share plan.md --qr               # also print a QR code in the terminal
crit share plan.md --org acme         # share under an organization
crit share plan.md --org acme --visibility unlisted  # org share with explicit visibility
crit unpublish                        # remove the shared review

When sharing under an org, visibility defaults to organization (members only). Override with --visibility (organization, unlisted, or public). The browser UI shows an org picker when you're signed in and belong to an organization.

Sharing uses crit.md when no sharing key exists. To use several deployments, configure global share_targets; the browser asks for a destination and each review stays bound to its first destination:

{"share_targets":[
  {"name":"Acme Crit","url":"https://crit.acme.com","default":true,"proxy_auth":true},
  {"name":"crit.md","url":"https://crit.md"}
]}

Run crit auth login --share-url https://crit.acme.com to add or authenticate a target, and add --set-default to make it the CLI default. crit auth status lists every target. An explicit "share_targets": [] disables sharing and never injects crit.md. Legacy share_url remains readable; crit config --migrate converts it atomically. --share-url and CRIT_SHARE_URL are process-only overrides and never persist a new target; an explicitly empty CRIT_SHARE_URL disables sharing for that process.

A review saved before share_base_url existed does not guess a deployment from the share link, and it does not fall back to the current default. Re-bind it with crit share --share-url https://crit.acme.com plan.md, where that URL is still a configured target. If a saved base URL is no longer in your config, Crit names that missing instance instead of sending the review somewhere else.

If a target sits behind an SSO reverse proxy, set proxy_auth: true on that target. Browser-driven Share / Pull / Re-share / Unpublish then use its popup relay; terminal operations remain unavailable for that target.

Authentication

You can share anonymously or you can create a free crit.md account (using GitHub oAuth). To authenticate with crit-web (for sharing and other features that require an account):

crit auth login                    # opens browser to log in
crit auth login --share-url https://crit.acme.com --set-default
crit auth status                   # list targets and identities
crit auth logout --share-url https://crit.md

crit auth login uses the OAuth Device Flow - it opens your browser, you confirm, and the CLI receives a token automatically. The token is stored in your global config (~/.crit.config.json).

GitHub PR and GitLab MR Sync

Crit can review and sync comments bidirectionally with GitHub pull requests and GitLab merge requests. Install and authenticate the CLI for your forge: GitHub CLI (gh auth login) or GitLab CLI (glab auth login). GitLab.com, self-managed GitLab hosts, nested groups, and cross-project merge requests are supported.

Crit auto-detects GitHub or GitLab from the repository remote. Set "forge": "github" or "forge": "gitlab" in config to override ambiguous/self-managed remotes, or pass --forge to crit pull and crit push. GitLab's base URL is configured once with gitlab_url and defaults to https://gitlab.com; set it to your self-managed instance in .crit.config.json. MR URLs remain valid change identifiers, but their host must match the configured gitlab_url.

Open a remote change for review

crit pr 42                                  # GitHub pull request
crit mr 42                                  # GitLab MR in the current project
crit mr https://gitlab.com/group/sub/project/-/merge_requests/42
crit review --mr 42 --remote                # read MR files via GitLab instead of local git

Pull comments

crit pull                                  # auto-detect from current branch and remote
crit pull 42                               # explicit PR number or MR IID
crit pull --forge gitlab 42                # explicit provider
crit pull https://gitlab.com/group/project/-/merge_requests/42

Push comments and review outcomes

crit push                                      # auto-detect PR/MR from current branch
crit push --dry-run                            # preview without posting
crit push --message "Round 2"                  # add a review summary
crit push --event approve 42                   # approve
crit push --event request-changes --forge gitlab 42

Sync viewed files with GitHub

When you review with crit --pr, files you mark as viewed can be ticked in the PR's "Files changed" tab, and the other way round:

crit push --viewed             # tick your viewed files on the PR
crit push --viewed --dry-run   # preview what would change
crit pull --viewed             # bring in files ticked on GitHub

Push skips files that changed since you viewed them, files marked by auto_viewed_patterns, and marks made outside the PR's own diff. Unticking a file in Crit unticks it on GitHub. Your marks stay available after you finish a review, so you can push them afterwards. Pull adds GitHub's ticks but keeps any file you unticked in Crit; an open review page shows them after a reload. GitLab has no equivalent, so --viewed is an error there.

GitLab inline comments are published as a single review using Draft Notes. request-changes requires GitLab support for the reviewer_state=requested_changes bulk-publish option; Crit reports an error instead of silently downgrading the outcome. Pulling again imports replies, edits, deletes, and discussion resolution without duplicating local comments.

Send to agent (experimental)

Click "Send now" on any comment during a review to get an AI agent response in real-time. This feature only appears when agent_cmd is configured. The agent reads the comment context, addresses it (editing code if needed), and replies inline - all while you continue reviewing.

Configure in ~/.crit.config.json (global config only):

{
  "agent_cmd": "claude --dangerously-skip-permissions -p"
}

Security note: agent_cmd is read exclusively from your global ~/.crit.config.json. Project-level .crit.config.json files cannot set it. This prevents a malicious repository from executing arbitrary commands when you trigger "Send to agent".

Permission modes

Agents need tool permissions to edit files on your behalf. How you grant them depends on your trust level:

Mode	Command	What the agent can do
Full access	claude --dangerously-skip-permissions -p	Read, write, and run any tool. Simplest option - recommended for trusted repos.
Selective access	claude --allowedTools Edit,Read,Bash,Write,Glob,Grep -p	Only the listed tools are permitted. Good middle ground.
No permissions	claude -p	The agent can respond to comments but cannot edit files. Useful for Q&A-only workflows.

How it works

1. The agent receives the comment text, quoted text (if text was selected), file path, and line range on stdin.
2. The agent's stdout is captured and posted as a reply to the comment automatically.
3. If the agent edits files, Crit detects the changes via file watching and updates the UI.

Live threads

After the first agent interaction, the comment becomes a live thread:

• Further replies you post in the thread are automatically sent to the agent - no need to click "Send to agent" again.
• The agent sees the full conversation history, so it can build on previous context.
• Live threads show a ⚡ live badge and green glow - the agent will respond immediately to further replies.

Supported agents

Agent	agent_cmd value
Claude Code	claude -p
OpenCode	opencode run
Cline	cline --pipe
Aider	aider --message-file -
Cursor (experimental)	cursor --pipe

Tip: Claude Code still prompts for permission in -p mode. To let it edit files freely, use claude --dangerously-skip-permissions -p instead. The other agents already operate without permission prompts in their pipe/non-interactive modes.

You can also specify a model with --model (e.g. claude --model sonnet -p).

Everything else

• Per-branch review isolation. Each branch gets its own review file — switch branches freely without losing comments. Review data lives in ~/.crit/reviews/, not your repo.
• Draft autosave. Close your browser mid-review and pick up exactly where you left off.
• Vim keybindings. j/k to navigate, c to comment, Shift+F to finish. ? for the full reference.
• Concurrent reviews. Each instance runs on its own port - review multiple plans at once.
• Syntax highlighting. Code blocks are highlighted and split per-line, so you can comment on individual lines inside a fence.
• Diagrams and custom renderers. Mermaid fences render as diagrams, and .mermaid / .mmd files get a Diagram / Source toggle. In a Mermaid file, click a diagram node to comment on the line that defines it. See the renderers guide.
• Live file watching. Each new round loads the latest files. If a file under review changes during a round (in files and plan mode), Crit offers to reload the files in place, keeping your place and any comment you're writing. Comments move to their new lines at the next round, so until then one below an added or removed line can sit slightly off, as after a browser refresh.
• Paired UI and code themes. Choose light and dark Shiki-based palettes in Settings; code, rendered markdown and review UI share their colours. System/Light/Dark selects the active palette. Preferences persist in a cookie across ports.
• Configurable code font. Code-review Settings → Display → Code font lists coding/monospace fonts detected by the local Crit daemon, plus Default, System monospace, and a custom font-family fallback. Applies to code and diffs, and persists across sessions.
• Local by default. Server binds to 127.0.0.1. Your files stay on your machine unless you explicitly share. Non-loopback listen hosts and public_url require --allow-unauthenticated-network (or CRIT_ALLOW_UNAUTHENTICATED_NETWORK=1) because Crit has no network authentication — prefer SSH forwarding, Tailscale Serve to loopback, or Docker -p 127.0.0.1:….
• Collapsing generated files. Honors linguist-generated in .gitattributes — matching files appear collapsed by default.
• No analytics or tracking. Crit collects zero telemetry. No usage stats, no crash reports, no phone-home. If we ever add anonymous usage statistics in the future, they will be explicitly opt-in.
• Update check. On startup, Crit makes one network request to check for a newer version and prints a notice if one is available. Set CRIT_NO_UPDATE_CHECK=1 to disable it.

Configuration

Crit supports persistent configuration via JSON files so you don't have to pass the same flags every time.

File	Scope	Location
~/.crit.config.json	Global	Applies to all projects
.crit.config.json	Project	Repo root (from git rev-parse --show-toplevel)

Project config overrides global. CLI flags and env vars override both.

crit config --generate > ~/.crit.config.json   # scaffold a starter config file
crit config                                    # view resolved config (merged global + project)

Config keys

All keys are optional — omit any you don't need.

Key	Type	Default	Description
port	int	0 (random)	Port for the local server. 0 picks a random available port.
host	string	"127.0.0.1"	Listen host (global/CLI/env only). Non-loopback values also require --allow-unauthenticated-network / CRIT_ALLOW_UNAUTHENTICATED_NETWORK=1. Prefer loopback + SSH/Tailscale/Docker host-loopback publish.
no_open	bool	false	Don't auto-open the browser when starting a review.
quiet	bool	false	On success, suppress daemon connect/start lines, integration tips, and the session summary. Errors, approved:, and the finish prompt are unchanged.
output	string	~/.crit	Crit data root for reviews. Reviews live in <root>/reviews/<key>/ (same layout as the default).
author	string	VCS user name	Author name shown on comments. Falls back to your configured VCS user name.
forge	string	"auto"	Remote review provider: "auto", "github", or "gitlab". Auto-detection uses the repository remote; set this for ambiguous self-managed hosts.
gitlab_url	string	"https://gitlab.com"	GitLab base URL used for every MR operation. Set once for a self-managed instance; MR URL arguments must use the same host.
base_branch	string	auto-detected	Base branch to diff against (e.g. "main", "develop"). Overrides auto-detection.
ignore_patterns	string[]	[".crit/"]	File patterns to exclude from git-mode file lists. Global and project patterns are merged.
auto_viewed_patterns	string[]	[]	File patterns auto-marked as viewed (collapsed) once when a review opens — e.g. ["*.lock", "generated/", "PLAN.md"]. Manually un-marking a file keeps it open. Global and project patterns are merged.
default_markdown_view	string	"" (diff in git mode)	Initial view for markdown files (Document/Diff toggle) in git mode: "document" opens them in document view, "diff" (or unset) keeps diff view. File mode is always document view. Project overrides global.
cleanup_on_approve	bool	true	Automatically delete the review file when you approve with no unresolved comments. Set to false to preserve review history.
notify_on_round_ready	bool	false	Opt in to a desktop notification when a review round becomes ready for you (after the agent finishes addressing comments). On macOS, install terminal-notifier (brew install terminal-notifier) so clicking the notification opens the review URL — without it, clicking falls back to AppleScript's display notification, which macOS attributes to Script Editor and activates that instead of your browser.
no_update_check	bool	false	Don't check for new versions on startup.
no_integration_check	bool	false	Skip the integration config freshness check on startup.
vcs	string	auto-detected	Preferred VCS backend: "git", "sl", or "jj". When set, crit uses this VCS instead of auto-detecting. Falls back to git if the configured VCS isn't available. Can also be set via --vcs CLI flag (flag takes precedence over config).
live_cookie	string	""	Cookie header value forwarded to the upstream app in live mode (e.g. "_crit_key=..."). Global or project. Prefer live_cookie_file for secrets.
live_cookie_file	string	""	Path to a file with upstream cookies for live mode (raw header lines or Netscape jar). Global or project; relative paths resolve from repo root.
live_cdp_url	string	""	Chrome DevTools URL (e.g. http://127.0.0.1:9222) to reuse browser cookies for the live upstream. Global or project.
prompts	object	{}	Custom finish-hook templates (project overrides global per key). See Agent prompts.
hooks	object	{}	Custom finish-hook commands executed at Finish/Approve (project overrides global per key). Deterministic side effects — crit pipes a JSON payload to stdin and sets CRIT_* env vars. See Command hooks.

Agent prompts

Customize what Crit tells your agent when you Finish Review or Approve. Hooks are templates in global or project config (prompts map) and .crit/prompts/*.md files.

See the agent prompts guide for hook reference, template variables, trust flow, and examples.

Command hooks

Run your own scripts when you Finish Review or Approve — deterministic side effects, no LLM in the loop. Crit pipes a JSON payload to the hook's stdin and sets CRIT_* env vars (review path, session key, mode, unresolved count, files-with-comments, …). Keys and resolution mirror the prompt system (on_finish_unresolved / on_finish_approved, optionally :files / :diff / :live / :preview), and project hooks go through the same trust gate as project prompts.

# ~/.crit.config.json
{
  "hooks": {
    "on_finish_unresolved": "inline:rsync -a \"$CRIT_REVIEW_PATH\" ~/reviews/$CRIT_SESSION_KEY.json",
    "on_finish_approved":   "file:~/.crit/hooks/approved.sh"
  }
}

See the command hooks guide for the full env-var/stdin reference, trust flow, and examples (including the “snapshot commented-on files” recipe). Reference example hook scripts live under docs/example-hooks/ in the repo — they're documentation, not installed by crit install and not tracked among the integrations (hooks are opt-in and not used by default).

Global-only config keys

These keys can only be set in ~/.crit.config.json (global). Project-level .crit.config.json cannot override them — this prevents a malicious repository from hijacking local commands or redirecting share requests.

Key	Type	Default	Description
agent_cmd	string	""	Shell command for "Send to agent" (e.g. "claude -p"). See Send to agent.
open_cmd	string	""	Custom command to open review URLs — receives the URL as its only argument (must be a single executable, no flags). Use when the browser isn't on the machine running crit, e.g. crit runs on a remote host over SSH and a small wrapper script opens the URL on your local machine. When unset, crit uses the platform default opener.
share_targets	array	implicit crit.md when absent	Deployment list with per-target name, url, default, proxy_auth, nested auth, and public share_consented. An explicit empty array disables sharing.
auth_token	string	""	Legacy singleton token; read only while share_targets is absent.
share_url	string	implicit "https://crit.md"	Legacy singleton URL. An explicitly empty value disables sharing; migrate with crit config --migrate.
public_url	string	""	Advertised base URL for stderr and browser-open (e.g. https://machine.ts.net via tailscale serve). Listen address unchanged. Requires --allow-unauthenticated-network / CRIT_ALLOW_UNAUTHENTICATED_NETWORK=1.
share_consented	bool	false	Written automatically to true after you confirm the first-time share prompt. Reset to false to see the prompt again. Not used when share_url is a custom (self-hosted) URL.
proxy_auth	bool	false	When true, share / pull / unpublish / re-share use the browser popup relay instead of the local Go server contacting crit-web directly. Use when crit-web is behind an SSO reverse proxy that the terminal cannot authenticate against. No flag or env var — this is a property of the deployment, not a per-invocation choice.
plan_approve_mode	string	unset	Claude Code permission mode after Crit approves an ExitPlanMode hook: default, manual, acceptEdits, plan, auto, dontAsk, or bypassPermissions. The update uses destination: "session", so it lasts only for the current Claude Code session. See Claude Code plan approval mode.
close_on_approve_after_ms	int	unset (disabled)	Auto-close the review tab this many milliseconds after you Approve with no unresolved comments. Unset means no auto-close (current behavior); negative values are treated as unset. A Cancel button during the countdown skips the close for that approval.
stale_review_days	int	14	Delete reviews untouched for this many days in the background sweep that runs when a review starts. Unset or non-positive values use the default. crit cleanup --days N is unaffected.

CLI flags

Flag	Short	Equivalent config key	Description
--port	-p	port	Port to listen on
--host		host	Listen host (default 127.0.0.1)
--public-url		public_url	Advertised review URL (listen unchanged)
--allow-unauthenticated-network		—	Required with non-loopback --host or any --public-url
--no-open		no_open	Don't auto-open browser
--share-url		share_url	Share service URL
--output	-o	output	Crit data root for reviews (<root>/reviews/<key>/).
--quiet	-q	quiet	On success, suppress connect/start status, tips, and session summary
--base-branch		base_branch	Base branch to diff against
--vcs		vcs	VCS backend (git, sl, or jj)
--no-ignore			Temporarily bypass all ignore patterns
--version	-v		Print version and exit

Live mode only (crit live <url> — see crit live --help):

Flag	Equivalent config key	Description
--cookie	live_cookie	Upstream cookie value (repeatable)
--cookie-file	live_cookie_file	File with upstream cookies
--cdp-url	live_cdp_url	Chrome DevTools URL to reuse browser cookies

Ignore patterns

Patterns from global and project configs are merged. Supported syntax:

Pattern	Matches
*.lock	Files ending in .lock anywhere in tree
vendor/	All files under vendor/
package-lock.json	Exact filename anywhere in tree
generated/*.pb.go	Path prefix with glob (filepath.Match syntax)

Use --no-ignore to temporarily bypass all patterns:

crit --no-ignore

Custom styles

To restyle Crit with your own CSS, create ~/.crit/custom.css. Every Crit page (reviews, live mode and the theme preview) loads it after Crit's own styles, reading it fresh each time, so edit the file and reload the tab to see changes. If the file can't be read, Crit logs why and uses its own styles. In review and live mode, Settings → Configuration shows whether the file exists and its path, and Settings → Display has a "Use custom CSS" switch to turn it off without deleting it.

Crit marks the page with the mode in use, data-crit-mode="light" or "dark" (also when following the system setting), so you can keep everything for one mode in one block. Override theme variables and nest element rules inside it:

:root[data-crit-mode="dark"] {
  /* the block a comment is on, and the exact words it quotes */
  --crit-comment-range-bg: rgba(83, 155, 245, 0.15);
  --crit-quote-highlight-bg: rgba(83, 155, 245, 0.28);

  .line-block.has-comment { box-shadow: inset 3px 0 0 #539bf5; }
}

:root[data-crit-mode="light"] {
  --crit-comment-range-bg: rgba(9, 105, 218, 0.10);
  --crit-quote-highlight-bg: rgba(9, 105, 218, 0.18);

  .line-block.has-comment { box-shadow: inset 3px 0 0 #0969da; }
}

For a single value that differs by mode, light-dark(light, dark) also works.

Code diffs are drawn inside shadow roots, which page CSS cannot reach with selectors; only inherited CSS variables (such as the ones above, or --diffs-* overrides) get through. Override the derived --crit-* variables, as above: the palette's own --crit-palette-* values are set inline on <html>, so they only change with !important. Class names are not a stable API and may change between releases.

Environment variables

Variable	Description
CRIT_PORT	Default port for the local server
CRIT_HOST	Listen host (default 127.0.0.1)
CRIT_PUBLIC_URL	Advertised review URL (e.g. tailscale serve)
CRIT_ALLOW_UNAUTHENTICATED_NETWORK	Allow non-loopback host / public_url (1/true/yes/on)
CRIT_SHARE_URL	Override the share service URL
CRIT_AUTH_TOKEN	Override the auth token (skips crit auth login)
CRIT_NO_UPDATE_CHECK	Disable the update check on startup
CRIT_NO_INTEGRATION_CHECK	Skip integration config freshness checks

Other Install Methods

Build from Source

Requires Go 1.26+:

git clone https://github.com/tomasz-tomczyk/crit.git
cd crit
go build -o crit ./cmd/crit
mv crit /usr/local/bin/

Go

go install github.com/tomasz-tomczyk/crit/cmd/crit@latest

Nix

nix run github:tomasz-tomczyk/crit -- --help

Or add it to a flake.nix:

inputs.crit.url = "github:tomasz-tomczyk/crit";

Download Binary

Grab the latest binary for your platform from Releases.

Windows

Native Windows: download crit-windows-amd64.exe (or crit-windows-arm64.exe) from Releases, rename to crit.exe, and place it on your PATH.

WSL: install the Linux binary as you would on Linux (go install, nix run, or download crit-linux-amd64 from Releases). Crit detects WSL and opens URLs in your Windows host browser via wslview / powershell.exe / cmd.exe.

Docker (sandboxed agents)

For running crit alongside an AI agent inside a container, with the review UI reachable from your host browser, see integrations/docker/. Includes a working Dockerfile + entrypoint.sh that bridges crit's loopback-bound server via socat. Publish with -p 127.0.0.1:8080:8080 so the host mapping stays on loopback.

Acknowledgements

Crit embeds the following open-source libraries:

• markdown-it: Markdown parser
• @pierre/diffs: Diff and code rendering
• Shiki: Syntax highlighting and code themes
• Mermaid: Diagram rendering