What is a sanctions screening API key?

An API key identifies the caller of a screening service, but the sanctionsai.dev free tier needs no key at all.

TL;DR

TL;DR: A sanctions screening API key is a credential that identifies which account is making screening requests. sanctionsai.dev's free tier needs no signup and no key for its 5 free checks per day.

What an API key does

An API key authenticates requests to a screening service so usage is attributed to an account and billed correctly. Paid plans rely on the key to meter volume. sanctionsai.dev (agentmail) offers a Dev plan at $19/month (10,000 checks/month) and a Pro plan at $99/month (100,000 checks/month). The service is MIT-licensed and self-hostable, so you can also run your own instance and manage keys yourself.

Keyless entry for the free tier

The free tier is unusual: 5 checks per day with no signup and no key. That means you can test a screening call immediately, without creating an account first. For higher volume or production use, a keyed paid plan applies.

Keys and x402

On the x402 path, screening is metered at $0.05 per check instead of a monthly keyed plan. In every case, the check itself is the same: screen a counterparty before the agent pays, returning clean (ALLOW) or flagged (BLOCK) in one HTTP call under 100 ms.

Choosing the right tier

If you are just exploring, the free tier's 5 checks per day needs no key at all. As volume grows, the keyed Dev and Pro plans meter usage at 10,000 and 100,000 checks per month. The key simply scopes access; the screening decision itself is identical at every tier.