Integrations

Built to sit
between things.

TapProof is a layer, not a destination. On one side, the acquiring partner who holds your contract. On the other, whatever system needs to know a payment happened.

Acquiring partners

Who can onboard you

Adapters are written and unit-tested against each provider's documented signature scheme — not aspirational integrations on a roadmap.

Easebuzz

Full-stack payment aggregator authorisation covering online, offline point-of-sale and cross-border, November 2025. SHA-512 signing across ten user-defined fields.

Adapter built

PayU

Integrated authorisation including PA-P, November 2025. SHA-512 signing, with the response hash reversing the user-defined field order — a well-known trap we test for.

Adapter built

PhonePe

Authorised aggregator with the deepest offline footprint in India. SHA-256 over a base64 body, amounts natively in paise. UPI rails here; card-present routes elsewhere.

Adapter built

Banks

For direct acquiring sponsorship, and separately for a Corporate Business Correspondent appointment that would let one visit also carry cash-in and remittance.

In conversation

Rails

Several ways to carry a payment, one surface to take it

The operator never chooses a rail. The platform decides what the amount, the configuration and the connectivity allow.

Rails

What can carry a payment

Card

Contactless tap

Debit and credit, up to the ₹5,000 no-PIN ceiling. The only rail that reaches Visa and Mastercard credit, which UPI cannot carry at all.

UPI

Intent and QR

Available at any amount within UPI limits, through an existing aggregator relationship. No card certification involved.

UPI Lite

Offline tap

Pre-funded and works without connectivity. NPCI is certifying point-of-sale devices for it; we are tracking that programme.

Phase 2

PIN on glass

For amounts above the no-PIN ceiling. Roughly doubles the certification burden, so it follows volume rather than leading it.

Two systems, one bridge

Why adapters, not integrations

Every acquirer signs differently

PayU reverses its user-defined field order on the response. Easebuzz carries ten of those fields where PayU carries five. PhonePe signs a base64 body with SHA-256 and counts in paise.

Each is implemented separately and unit-tested against its documented field order — because two of them produce byte-identical strings until someone uses the sixth field, and a copy-pasted integration would appear to work right up until it did not.

Downstream

Where the record goes

Anything that can verify an HMAC and accept an HTTP POST. There is no SDK to install on your server.

Webhook

Signed, sequenced, at-least-once with de-duplication and replay by sequence.

Recommended

Pull API

For systems that cannot accept inbound traffic.

Restricted egress

CSV

For reconciliation into finance systems that prefer a file.

Batch

FieldProof

Where your field operations already run on FieldProof, TapProof is the acceptance instrument inside it and needs no integration at all.

Native

POST https://your-endpoint/tapproof

X-TapProof-Event:     payment.collected
X-TapProof-Timestamp: 1804393800
X-TapProof-Signature: v1=<hex>
X-TapProof-Sequence:  42

{
  "eventId": "evt_…",
  "occurredAt": "2027-03-11T06:30:00.000Z",
  "data": {
    "amountPaise": 248000,
    "rail": "card_contactless",
    "scheme": "VISA",
    "cardMask": "XXXX XXXX XXXX 4242",
    "rrn": "742119003318",
    "operator": "OP-DEL-0417",
    "geo": { "lat": 28.6139, "lng": 77.2090 },
    "totalCollected": 248000,
    "outstandingAfter": 0
  }
}

Full event contract