> ## Documentation Index
> Fetch the complete documentation index at: https://developers.circle.com/llms.txt
> Use this file to discover all available pages before exploring further.

# The keyless trial

> How the Facilitator Service keyless trial lets sellers settle without a Circle account

The Facilitator Service keyless trial lets you settle real x402 payments without
a Circle account. Facilitator Service creates a seller account for your payout
address (`payTo`) on your first
[`/settle`](/api-reference/agent-stack/facilitator-service/settle-payment) call
and keeps settling payments until you hit the trial limit.

## Seller proof

With no API key to authenticate keyless requests, Facilitator Service relies on
a seller proof: an EIP-712 signature from the key controlling `payTo`. The proof
shows Facilitator Service that you own the `payTo` address.

See [Sign a seller proof](/facilitator-service/sign-seller-proof) for how to
construct one.

## The trial allowance

Each `payTo` has its own trial allowance on each supported blockchain, with
testnet and mainnet counted separately. Each
[`/settle`](/api-reference/agent-stack/facilitator-service/settle-payment) call
counts against that allowance until it's exhausted, at which point
[`/settle`](/api-reference/agent-stack/facilitator-service/settle-payment)
responds with `HTTP 403 registration_required`. To continue settling, claim your
seller account.

## Facilitator Service seller accounts

A seller account is the record Facilitator Service keeps for a `payTo`. It
tracks payment history and, during the keyless trial, how much of the trial
allowance you've consumed. Facilitator Service creates one automatically the
first time you settle a payment for a new `payTo`.

A new seller account is unclaimed. It stays unclaimed until you bind it to a
Circle account, at which point
[`/settle`](/api-reference/agent-stack/facilitator-service/settle-payment)
accepts your Circle API key for that `payTo` and the trial allowance no longer
applies. Payment history carries over.

See [Claim your seller account](/facilitator-service/claim-seller-account) for
the procedure. If you don't have a Circle account yet, create one in
[Circle Console](https://console.circle.com/).