Testing an agent that pays

The other commands test a service that sells. wasit serve tests the other side, an agent that pays: it runs a local x402 paywall that misbehaves in one chosen way, so you can point your agent at it and watch what the agent does.

bash

wasit serve --mode no-settle

Mode	What the paywall does	What a careful agent does
`no-settle`	Issues an honest challenge, then serves the resource for any payment without settling it and without a `PAYMENT-RESPONSE` header	Finds no `PAYMENT-RESPONSE` and does not count the payment as made
`wrong-settlement`	Issues an honest challenge, then serves the resource with a `PAYMENT-RESPONSE` reporting success for a transaction that is not this payment	Looks the transaction up on-chain before trusting it
`wrong-network`	Asks to be paid on `stellar:pubnet` (mainnet) instead of `stellar:testnet`	Refuses before signing anything
`overprice`	Asks for one million USDC (`10000000000000` base units)	Refuses a price above its spending limit

Option	Default	Notes
`--mode <mode>`	required	One of the four above
`--port <port>`	`4020`	The server answers on every path
`--host <host>`	`127.0.0.1`	Local only unless you bind another interface
`--network <id>`	`stellar:testnet`	`stellar:testnet` or `eip155:84532` (Base Sepolia). On Base Sepolia the paywall uses the SDK's USDC, `wrong-network` asks for Base mainnet (`eip155:8453`), and `overprice` one million USDC in its 6 decimals
`--pay-to <address>`	`STELLAR_PAYEE_ADDRESS`, or `EVM_PAYEE_ADDRESS` on Base Sepolia	A testnet account (`G...`) with a trustline for the asset, or an EVM address (`0x...`)
`--amount <units>`	`10000`	Price in base units, for every mode except `overprice`
`--asset <contract>`	testnet USDC	`CBIELTK6YBZJU5UP2WWQEUCYKLPU6AUNZ2BQ4WWFEIE3USCIHMXQDAMA`
`--settlement-tx <hash>`	a random hash	`wrong-settlement` only. The default cites a transaction that exists nowhere; pass a real, unrelated transaction to test an agent that finds it on-chain but must notice it is not this payment

Nothing is settled or forwarded in any mode, so no payment the server receives can move funds. Your agent still needs a funded testnet wallet: payment clients build and simulate the transfer to --pay-to before signing, which is also why the payee must exist on testnet with a trustline for the asset.

The server prints one line per request: the challenge it sent, or the payment it received and what that says about the agent:

text

wasit serve: no-settle on http://127.0.0.1:4020/ (any path)
01:02:46  GET /paid: payment received for 10000 base units on stellar:testnet.
          Served 200 without settling and without PAYMENT-RESPONSE. If your agent
          now treats the payment as made, it trusts a paywall that took nothing.

Every mode's challenge is a well-formed x402 v2 challenge (wasit test --read-only passes it), so an agent that falls for one fell for the misbehaviour, not for a malformed message. Pointing wasit test itself at no-settle or wrong-settlement shows what a non-conformant paywall looks like from the checks' side: X402-06 and X402-07 fail.