A native macOS PDF reader where you converse with what you read — select a passage, capture a diagram, ask anything. Built on Codex, so the AI runs on the ChatGPT plan you already pay for. No API keys. No subscription. No servers.
Every conversation is anchored to the page. Every annotation has a place. Everything stays on your Mac.
One tap chooses what the AI sees: your selection, everything up to your page, or the whole document. Context is never re-sent when it hasn't changed.
Draw a box over any figure or equation and ask. Vision included — captures travel with the conversation as annotations.
A strip beneath the PDF anchors every annotation to its exact line, doubles as your reading-progress bar, and previews before it jumps.
Replies stream token by token. Conversation history lives in threads that resume — fast follow-ups, no re-uploading your document.
A focus timer feeds a GitHub-style activity heatmap — streaks, finished documents, even your AI token usage per project.
Dictate questions with on-device speech recognition; have answers read aloud. Find anything with ⌘F, export everything to Markdown.
Internalize contains no AI of its own — it drives the Codex app you install from OpenAI, on your own plan. That's why it's free.
Get the Codex app and sign in with your ChatGPT account. If you already use Codex, you're done.
Open the DMG, drag to Applications, launch. Signed and notarized — no warnings, no setup, and it updates itself from then on.
Import a PDF, select anything, and ask. Your documents, annotations, and conversations persist in workspaces — locally.
Really free. The expensive part of AI apps is the AI — Internalize sidesteps that by running on the ChatGPT plan you already have, through the Codex app on your machine. There's no catch to monetize; if the app earns a place in your reading life, there'll be a tip jar.
Codex is OpenAI's local agent app, and its app-server protocol is the documented way for third-party software to integrate it. That's what lets Internalize give you frontier-model conversations with zero API keys and zero per-token costs — your plan, your machine, your data.
No. You sign in inside Codex itself — Internalize never handles credentials. It runs Codex in an isolated, read-only profile, so your personal Codex setup is untouched and the app can't perform actions through it, only conversations.
macOS 15 or newer, Apple Silicon and Intel (universal binary). The app is signed with an Apple Developer ID and notarized, and ships its own one-click updates.
The App Store sandbox forbids apps from launching external programs — which is precisely how Internalize drives Codex. Direct distribution with Apple's notarization gives you the same malware-scanned safety without that limitation.
Free. Native. Private. On the plan you already pay for.
Download Internalize