Changelog

Changes to the A2A InstaPay Tenant API and the sandbox.

Changes within API version 1 are additive. Breaking changes come only in a new version and are announced here in advance.

October 2026#

The A2A InstaPay Sandbox opens, with the complete Tenant API v1.1.
Developer portal: workspaces, keys, webhooks, request logs, records explorer with live state machines, compliance and rail desk, time travel, seventeen scenarios, the API explorer and certification evidence.
Answer Requests for Payment as the payer's bank: pay, decline, let expire, reject or no answer.
Webhook drills: chaos options, tampered-signature test, secret rotation with two active secrets, bulk resend and the forwarding tool.
Hosted screens for consumers and merchants, and the bank-linking simulator.
Demo app with a Customer app and a Business app.

A2A Link SDK for web apps (WAP): window, full-page transition, return page and result handover.
Bank linking in web apps with a bank-linking return page.
POST /v1/sessions/exchange returns the outcome of a hosted screen for a result token.

POST /v1/sandbox/sessions/{id}/complete to finish hosted screens in automated tests.
GET /v1/sandbox/listen for the webhook forwarding tool.