Create an account at /login?next=/dashboard, copy the sandbox API key from the dashboard, and call the IBAN validator as a smoke test.
The base URL is https://api.iso-compliant.com. Every mutating route requires two headers: Authorization: Bearer iso_live_… (or iso_test_… for the sandbox tier) and Idempotency-Key: <opaque string>.
Every response carries a X-Iso-Compliant-Sha256 header — a sha256 of the JSON response body, used as the audit-attestation handle for the evidence-export route. Save it alongside your business record if you need a tamper-evident audit trail later.
The SDK shape on the sandbox is identical to production; sandbox keys never charge, never call third-party services with money attached, and never write to the production Stripe meter.