Context Reader

Setup

Your free Gemini API key, in about a minute

Context Reader has no server. Your browser asks Google's Gemini directly, with a key that belongs to you. That is why it is free with no account and nothing that can collect your reading, and it is the only setup step there is. Here it is, start to finish.

28 seconds, no sound. Recorded on a clean profile; the key in the film was a throwaway and has been deleted. Same video on YouTube if you prefer.

The same thing, written down

  1. Open aistudio.google.com/apikey and sign in with any Google account. Press Create API key, give it a name if you like, and press Create key. It is free and asks for no card.
  2. Press Copy. It is a long string of letters and numbers. Older keys start with AIza, newer ones with AQ., and both work. Treat it like a password.
  3. Open Context Reader's Settings. Right-click the extension icon and choose Options, or open the welcome page's Paste it in Settings button.
  4. Paste the key into the Gemini API Key field (⌘V or Ctrl+V) and press Save. It is checked once against Google, then kept on this device. You should see Saved and verified.
  5. Select a word on any page. A small amber mark appears beside it. Click the mark, and the meaning for that sentence arrives in the language you chose.

What the key does, and does not, allow

It stays on your device

The key is kept in your browser's local storage, never in Chrome's sync storage, and is read only by the extension's background worker. It is sent to exactly one place: Google's Gemini API, on each lookup. Nothing reaches us, because there is no us to reach.

You can encrypt it

In Settings, under At rest, you can set a passphrase. The key is then encrypted with AES-GCM and unlocked for the browser session. The passphrase is never stored, so there is no recovery: forget it and you paste the key again.

It is yours to revoke

Press Revoke in Settings to delete it from the device, and delete the key itself in Google AI Studio to stop it working anywhere. Removing the extension removes the stored key too.

Google's terms apply to the lookups

Because the key is yours, your lookups are covered by Google's Gemini API terms, not by anything of ours. On the free tier Google says it may use submitted content to improve its products.

If something goes wrong

"API key not valid"

That sentence comes from Google. The key was mistyped, or it has been deleted in AI Studio. Create a new one and paste it again.

"Could not reach Gemini"

The check could not run: a blocked network, or Google having a bad minute. Press Save without checking and the key is stored anyway; the next lookup will tell you if it is wrong.

"That model isn't available"

Google renames and retires models. The extension tries another one by itself and says which answered. Settings shows what it is using and offers Check now to go back to your choice.

Nothing happens when I select a word

Some pages block extensions outright: the Chrome Web Store, chrome:// pages and PDF viewers other than the browser's own. Try a normal article first. If it still does nothing, tell us.

Questions

Why does Context Reader need an API key at all?

Because there is no server. The extension calls Google's Gemini API straight from your browser with your own key, so there is nothing to pay for monthly, nothing to keep running, and nowhere your reading can pile up. The cost is this one minute of setup.

Is the Gemini API key free?

Yes, on Google's free tier, and it needs no card. You create it at aistudio.google.com/apikey with a Google account. Heavy use can hit Google's rate limits, at which point the extension falls back to another free model and says so.

Where is my key stored?

In your browser's local storage on that device only, never in Chrome's sync storage, and never sent anywhere except Google. You can also encrypt it with a passphrase in Settings, in which case it is unlocked for the browser session and the passphrase is never stored.

It says “API key not valid”. What now?

That message comes from Google, not from the extension, and it means the key was mistyped or has been deleted. Create a new one and paste it again. If instead it says it could not reach Gemini, your network is blocking the check: press Save without checking, and the key is stored anyway.

How do I remove the key?

Settings, then Revoke. It is deleted from the device immediately. Removing the extension removes it too.

Add to Chrome Add to Firefox

Free. Chrome, Brave and Edge install from the Chrome Web Store; Firefox from addons.mozilla.org.