Get your OpenRouter key
Takes about 2 minutes. You'll need a credit card for ~$1 in credits.
Create an account
Go to openrouter.ai and click “Get API Key” or sign up with Google / GitHub.
Add credits
Navigate to Settings → Credits. Add $5 — enough for 4-5 reviews with an open-source model or 1 review with Claude. Unused credits don't expire.
Create an API key
Go to Settings → Keys, click “Create Key”, and name it coarse.
Copy the key now — you won't see it again.
Set a spending limit on the key
On the Keys page, click the ⋮ menu next to your new key and choose “Edit”. Set a credit limit (e.g. $5). The key stops working once the limit is hit — zero risk of surprise charges.
Why this matters: coarse is open-source — you can read every line of code. Your key is sent directly to OpenRouter to run the review, then discarded — it is never stored. But you don't have to trust us: the per-key limit guarantees it can never spend more than you allow, even in the worst case.
Paste into coarse
Come back here, paste your key into the form, and upload your PDF.