How to accept stablecoin payments on your own infrastructure: a practical guide.

Most guides to stablecoin payments start with a wallet address and end with a screenshot of a transaction. That is the easy ten percent. The other ninety is what happens after a customer clicks pay: tracking, confirming, telling your application, and explaining the result to finance.

This guide walks through the full path for a team that wants to accept stablecoin payments on infrastructure it controls. It is written for engineers and technical founders. It is not legal, tax, or compliance advice — those questions belong to your own advisers.

What you are actually building

Strip away the branding and a payment gateway does five jobs. Every option — building it, buying it, or renting it — has to cover all five.

Before you write code: five decisions

1. 01

   Who holds the keys?

   If your organisation holds them, you operate software. If a vendor does, you use a service. This choice drives your legal, security, and operational posture.

2. 02

   Which network and which token?

   Start with one of each. Choose what your customers already hold, and only enable what your software actually implements and tests.

3. 03

   What does "confirmed" mean?

   Confirmation is a policy: the point at which your business treats a payment as paid. Write it down per network, per amount tier.

4. 04

   How will the application find out?

   Signed webhooks with a replay path, not polling. Decide who verifies, who deduplicates, and who is on call.

5. 05

   Who reconciles, and how often?

   Name the person and the routine before the first live payment, not after the first incident.

The reference architecture

A self-hosted deployment is smaller than most people expect. The pieces are ordinary: an API, a database, an indexer that watches the network, and an operator dashboard.

What this is not

This architecture describes StablePay, which is payment gateway software you deploy. It is not a hosted processor, a custodian, or a bank, and the studio does not hold your funds.

The integration, end to end

1. Create the intent

Your application creates a payment intent with its own reference — usually the order id — and an amount. Use an idempotency key derived from the order so retries never create duplicates.

2. Show the payer what to do

The checkout surface presents the amount, network, and address or link. Keep the instructions unambiguous: wrong-network payments are the most common support ticket in this category.

3. Listen for signed events

The gateway emits events as the payment moves through its lifecycle. Your handler verifies the signature on the raw body, deduplicates on the event id, stores the event, and returns 2xx quickly.

export async function POST(req: Request) {
  const raw = await req.text();
  if (!verifySignature(raw, req.headers.get("x-signature") ?? "", SECRET)) {
    return new Response("invalid", { status: 401 });
  }
  const event = JSON.parse(raw);
  if (await alreadyProcessed(event.id)) return new Response(null, { status: 204 });

  await db.transaction(async (tx) => {
    await tx.recordEvent(event.id);
    if (event.type === "payment.confirmed") await tx.markOrderPaid(event.reference);
  });
  return new Response(null, { status: 204 });
}

4. Fulfil only on your confirmation policy

Do not fulfil on "seen". Fulfil when the gateway reports the payment as confirmed under your policy.

5. Reconcile daily

Run a query for payments confirmed at the gateway but not fulfilled by the application. It should return nothing. When it does not, that is your first warning of a broken handler.

Common mistakes

A realistic launch plan

1. Deploy to staging with the same secrets architecture you will use in production.
2. Run test payments through every state, including failures and expiries.
3. Fire-drill the runbook: break a webhook and recover with a replay.
4. Go live with low limits and a named person on call.
5. Review reconciliation daily for the first two weeks, then weekly.

Choosing networks and tokens with care

Start with what your customers already hold and what your software actually implements. Every additional network multiplies your operational surface: another RPC provider, another confirmation policy, another set of failure modes, another runbook entry. One network and one token is a legitimate launch scope.

Read decimals per token and per network

Do not hard-code six or eighteen. The ERC-20 standard treats decimals as an optional convenience ^[1], and stablecoins are deployed with different values across networks. Read it from the token contract for the network in question and store amounts as integer minor units.

Address strategy: how a payment finds its order

The core design question of any crypto checkout is how to know which payment belongs to which order. There are three common approaches, each with trade-offs.

Per-payment addresses are the most robust for most business use, at the cost of a sweeping and monitoring process. Whichever you choose, write down the matching rule and how it fails, because the failures are what your support team will see.

Underpayments, overpayments, and the messy middle

Real payers send the wrong amount, send twice, pay after expiry, or pay on the wrong network. Decide the policy for each case before launch, and make the software's states match.

Testing before real money

1. 01

   Run against a test network

   Use a public test network and test tokens to exercise every state, including failures.

2. 02

   Simulate the ugly cases

   Send an underpayment, an overpayment, a late payment, and a payment to an expired link.

3. 03

   Break the webhook

   Return errors from your endpoint and confirm retries, dead-lettering, and replay all work.

4. 04

   Kill the provider

   Block your RPC provider and verify failover and alerting.

5. 05

   Restore from backup

   Prove you can rebuild the gateway and reconcile afterwards.

Security hardening in five moves

The OWASP cheat sheets on secrets management ^[2] and on securing Docker deployments ^[3] are a practical baseline; the twelve-factor app ^[4] is a useful reference for the configuration and logging conventions around the deployment.

What to monitor from day one

Frequently asked questions

Do I need to run my own blockchain node?

Not necessarily. Many teams start with reputable RPC providers, ideally two for redundancy. Running your own node gives you more control and independence and becomes attractive as value at risk grows.

How long does a first integration take?

In our engagements the median first release of a focused system is around six weeks, and Vellum reached a first live payment on StablePay in seventeen days. The variance comes from the confirmation policy, the approval flow, and the runbook — not from the API calls.

Can we accept several tokens at once?

Yes, but add them one at a time, each with its own tested confirmation policy and runbook entries.

Where to go next

If you would rather not assemble this yourself, StablePay is the software version of everything above — deployed on your infrastructure, with the event contract, dashboard, and runbooks included. If you would rather build it, the same five jobs and five decisions apply.