Testing & stubs

Every operation is served by a stub that returns the specification's own canonical example. The stub bodies and the documented examples are the same bytes. One host, two path prefixes:

That host is already selected in each API reference, so the copy-paste curl samples there point straight at it.

To exercise the whole flow in one command, use the end-to-end test.

What the stubs are not

• Stateless. No sequencing is enforced. You can report a deposit against a quote that was never created and the stub will answer happily.
• Unauthenticated. No mTLS, no API keys. The real auth model applies to the real implementations, not to the stub host.
• Fixed. Responses are always the canonical example, with the worked amounts: 250000.00 GTQ at 7.745100 GTQ/USDC = 32278.472841 USDC.

They exist so both teams can write and run client code against a real HTTP endpoint before either side has an implementation. They are not a simulator.

Magic error id

An id ending in dead makes a stub return that operation's primary error instead of the happy path. There is one canned error variant per operation, the one its error example in the API reference shows.

The canonical value is 9b2f6c1e-0000-4000-8000-00000000dead. Use it as the tesser_quote_id on the quote, deposit and payment operations, or as the nexa_payment_id on get payment [N].

Every other error below is documented and schema'd in the API references, but only the primary one per operation is reachable from a stub. Being stateless, it cannot distinguish the conditions that produce the others.

Error catalogue

The same envelope on both sides, on every operation:

Code
{
  "errors": [
    { "error_code": "QUOTE_EXPIRED", "error_message": "Quote expired at 2026-10-14T15:05:00Z." }
  ],
  "request_id": "req_01JA8F3K2M7Q"
}

The two vendored Tesser core-API operations (get account [T], create withdrawal [T]) keep the core API's own error codes (api-0001, api-0004, api-0006, counterparties-300x) rather than this catalogue. Their contract is already live and is not being redefined here.