A2A INSTAPAY · DEVELOPER SANDBOX
Build on instant,
bank-to-bank money.
The complete A2A InstaPay Tenant API in a safe sandbox: Digital Accounts, onboarding for consumers and merchants, bank linking, Requests for Payment over RTP, QR payments, refunds, withdrawals and disputes. Build it, test every failure, and collect your certification evidence as you go.
No credit card. No sales call. Credentials in minutes.
# Credentials in one call, no account needed
curl -X POST https://sandbox.a2ainstapay.com/sandbox/instant
# Then get an access token
curl -X POST https://sandbox.a2ainstapay.com/oauth/token \
-d grant_type=client_credentials \
-d client_id=$A2A_CLIENT_ID \
-d client_secret=$A2A_CLIENT_SECRETWhat you can build
One account layer for consumers and merchants.
Onboarding
Hosted onboarding for consumers and businesses: identity, owners and control person, documents and PIN, with every review outcome.
Bank linking
Link a customer's own bank account through Plaid Link, with test banks for every outcome, including banks that use their own sign-in.
Money movement
Add funds by Request for Payment, pay merchants from balance or by bank, QR codes, merchant-to-merchant payments, refunds and withdrawals over RTP.
Hosted screens and SDK
Customers confirm on A2A InstaPay's own screens with a PIN or passkey. One SDK call opens them from your web app.
Webhooks
Signed events for every change, the same retry schedule as production, and tools to receive them on your own computer.
Disputes and reporting
Regulation E disputes with provisional credit, monthly statements and a daily reconciliation report for your account structure.
Why this sandbox
Built for the way instant payments really fail.
Answer as the payer's bank
For every Request for Payment, choose what the payer and the bank do: pay, decline, let it expire, reject, or never answer. Each choice raises the same webhooks as production.
Certification evidence from your own traffic
Checks pass as your integration runs. When they are all green, the evidence report is ready for your go-live review with FINAP USA LLC.
A clock for every workspace
Move time forward to see retries, expiring sessions and payment requests, PIN unlocks, Regulation E deadlines, dormancy and month-end statements, in order.
See the network
Every load and pay by bank payment shows its RTP message timeline next to its webhooks, ledger postings and live state machine.
How it works
Three parts, one integration.
- Your serverCalls the Tenant API with OAuth client credentials, creates customers and records, and exchanges result tokens.
- Your appOpens A2A InstaPay's hosted screens with the A2A Link SDK, and Plaid Link for bank linking.
- WebhooksTell your server about every change, signed and retried. They are the source of truth for status.
From sandbox to production
A clear path to go-live.
- Get credentialsSign up, or call the instant endpoint.
- Run a scenarioSee every request and webhook of a full flow.
- Build and testAPI explorer, request logs, SDK, simulators and test data.
- Collect evidenceCertification checks pass from your own traffic.
- Go liveFINAP USA LLC reviews with you and the Sponsor Bank.
Resources
Everything in one place.
Documentation
Guides from the first call to go-live.
API reference
Every endpoint, field, error and event.
Documents
Contract files, data sheet, diagrams and partnership documents.
SDKs and tools
Web SDK, bank-linking simulator, Postman, webhook forwarding.
System status
Live status of the sandbox services.
Support
Questions, bug reports and document requests.