Integritas Receipts and Provenance for x402 - RelAI x Integritas

Trust is the foundation of commerce. When you pay for an API call, you should be able to prove it happened. When you receive a payment, you should have an immutable record.

RelAI x402 now exposes two complementary verification layers:

1. Settlement provenance (provenance) for auditable settlement metadata.
2. Buyer opt-in Integritas receipt (integritas) for request-level stamp proofs, including Integritas stampData.

What Changed

Successful settlement responses can now include both provenance and Integritas receipt metadata:

{
  "success": true,
  "transaction": "p9hge2...",
  "transactionHash": "p9hge2...",
  "network": "solana",
  "payer": "GH93...",
  "integritasFeePaid": true,
  "splitTransfers": {
    "combinedTx": "p9hge2..."
  },
  "provenance": {
    "provenanceHash": "e3b0c44298fc1c149afb...",
    "timestamp": "2026-02-20T13:11:38.128Z"
  },
  "integritas": {
    "hash": "be55eb0dc80c5c4b...",
    "timestamp": "2026-02-20T13:11:38.128Z",
    "network": "solana",
    "txHash": "p9hge2...",
    "payer": "GH93...",
    "payTo": "D1rU...",
    "amount": "1200",
    "feeAmount": "1000",
    "stamped": true,
    "stampData": { "status": "success" }
  }
}

For paid relay calls, this metadata is also propagated in base64 via PAYMENT-RESPONSE / X-PAYMENT-RESPONSE, then decoded in the dashboard under paymentMeta.

Why This Matters

Compliance

Regulated industries need proof of data acquisition. With provenance and Integritas receipts, API payments have blockchain-backed evidence. Auditors can independently verify that a payment occurred at a specific time, for a specific amount, between specific parties.

Dispute Resolution

If there's ever a question about whether a payment was made, the provenance hash and optional Integritas receipt settle it. Both parties can reproduce the hash locally and verify it against the Minima blockchain - no trust in RelAI required.

AI Agent Accountability

As AI agents increasingly use x402 to pay for API access, provenance creates an audit trail. Every agent payment is recorded, verifiable, and attributable. This is critical for enterprise deployments where agent spending needs to be tracked and justified.

How It Works

1. Buyer opts in with X-Integritas: true (+ optional X-Integritas-Flow: single|dual)
2. User pays via x402 (EIP-3009 signature or Solana transaction)
3. RelAI Facilitator settles on-chain (SKALE, Base, Avalanche, Solana, etc.)
4. Settlement data is hashed: SHA3-256(network + txHash + payer + payTo + amount + timestamp)
5. Integritas stamp is requested for opt-in flow and returned as integritas receipt metadata
6. Middleware forwards settlement metadata in PAYMENT-RESPONSE headers and UI exposes it as paymentMeta

Single-signature fee math (buyer view)

In single-signature flow, the buyer sees one total amount:

Final amount = base API price + Integritas fee + facilitator fee

With the current setup, the Integritas add-on is 0.011 USDC in total.

Examples:

• Base price 0.100 USDC → Final amount 0.111 USDC
• Base price 1.000 USDC → Final amount 1.011 USDC

Wallets can still show a slightly different net balance change in some cases (for example when part of the transfer is routed internally), but the payment requirement itself is the final amount shown above.

Verify It Yourself

The hash is fully deterministic. You can reproduce it with any SHA3-256 implementation:

import crypto from 'crypto';
const hash = crypto.createHash('sha3-256').update(JSON.stringify({
  network: "skale-base",
  txHash: "0xabc123...",
  payer: "0x1234...",
  payTo: "0x5678...",
  amount: "100",
  timestamp: "2026-02-14T00:00:00.000Z"
})).digest('hex');

Then verify against the blockchain:

GET https://api.relai.fi/provenance/verify?hash=

Or verify directly through Integritas at integritas.technology. You can also inspect integritas.hash and integritas.stampData from paymentMeta.

About Integritas

What's Next

Next improvements we are targeting:

• Richer verification UX - one-click verification from paymentMeta
• Deeper response provenance - expand beyond settlement-level metadata
• Batch stamping - Merkle tree aggregation for high-frequency micropayments
• Extended receipt artifacts - optional NFT/PDF outputs from Integritas workflows

Documentation

Full technical documentation is available at relai.fi/documentation/integritas, including API reference, hash reproduction examples, and integration details.

If you are new to the payment model, start with the x402 overview and the RelAI documentation hub.