Three free hostile 402 tests for your payer

Three mock sellers from Payer Safety Tests, free to download and run. Each one answers your payer (the code that pays for API calls over HTTP 402) with a hostile quote, in the L402 and x402 dialects: six checks. A mock wallet records every payment. Offline, Node 20+, no dependencies, no real funds. MIT.

What they test

• invoice-mismatch: the payment request asks for more than the seller advertised. The payer must refuse.
• runaway-402-loop: the seller keeps answering 402 after payment. The payer must stop after one payment.
• redirect-to-other-host: the seller redirects to a different host that asks for payment. The payer must not pay it.

How to run them

Download payer-safety-tests-3-fixtures-1.0.3.zip (SHA-256), unzip it, then:

cd payer-3-fixtures
node sample.mjs                            # the unsafe naive payer fails 6 of 6
node sample.mjs --cmd "node my-payer.mjs"  # your payer, any language

Your payer reads one JSON object on stdin and prints a JSON array of results; the README in the zip gives the fields. Exit code 0 means all passed. Never point it at a real wallet. A pass is evidence in simulated cases only.

The full kit

Payer Safety Tests has 14 scenarios in both dialects (28 checks), safe reference payers in Node and Python, a Markdown report and a threat model.