Cortex
An in-page AI review copilot for GitHub pull requests.
Highlight code, ask, summarize, review, and post line-anchored comments — on your own Claude subscription or API key. No SaaS middleman; your code never touches a third-party server.
Open source (MIT) · Chrome Web Store listing coming soon
Yours, not theirs
Runs on the Claude subscription or API key you already pay for — no second subscription, no per-token surprise.
No middleman
Code goes only to Anthropic or your local CLI, and to GitHub with your token. Nothing to us. Ever.
Human-in-the-loop
Cortex never reviews or posts on its own. You highlight, you ask, you confirm — every public write is yours.
Everything a reviewer needs
From a quick question to a full, well-labeled review — on demand, never autonomous.
Highlight & ask
Select code in a diff and ask — answers stream in, grounded in the real diff hunk and the PR's stated intent.
PR overview
A deterministic, no-AI change map: churn per file with bars and a by-module rollup, so you see where the weight is.
Whole-PR review
A findings list tagged Blocker / Major / Minor / Nit / Praise, with Security, Performance, Error-handling and Readability lenses.
Suggest a fix
Generate a committable GitHub suggestion block for the selected lines — the author applies it in one click.
Test-gap check
A fast, no-AI heuristic that flags changed source files with no matching test change — before you ask for tests.
Batch review + verdict
Accumulate comments into a pending review and submit them together as Comment, Approve, or Request changes.
Conventional Comments
Prepend semantic labels (suggestion, nit, issue…) with blocking / non-blocking decorations, so intent is unmistakable.
Private by design
Keys stay in your browser. Code goes only to Anthropic or your local CLI — and likely secrets are masked first.
See where the weight is, instantly
One click renders a change map — additions, deletions and net per file with a churn bar, plus a by-module rollup. Fully deterministic: no AI call, no tokens.
A reviewer's findings, triaged
Whole-PR review streams a findings list, each led by a color-blind-safe severity chip and a path:line, ready to post as a real review comment.
Feedback that lands as code
Ask for a fix and get a committable suggestion block anchored to exactly the lines it replaces — the author applies it from GitHub in one click.
Build it up, submit once
Collect comments into a pending review (kept per PR), then submit them together with a verdict — just like GitHub's own review flow, with a confirm + undo.
Two backends, your choice
One interface, with automatic fallback. Pick whichever you already pay for.
Anthropic API
Your own API key, billed to your account. The default — paste your key and go, nothing else to install. Works straight from the Chrome Web Store.
Claude Code CLI
Your Claude subscription, via a local native host that shells out to the claude CLI — no API key needed. An opt-in, build-from-source option for power users.
Make your reviews sharper
Cortex is open source and GitHub-only. Clone it, load it, and bring your own key — or wait for the one-click Chrome Web Store release.