Crypto Payment API: The Easy Integration Guide for Developers (2026)

TL;DR — A crypto payment API lets your app accept Bitcoin, Ethereum, Solana, and stablecoins programmatically. The best APIs settle in seconds, charge under 1.5%, and don't custody your funds. NETTEN's API is built on the XRP Ledger with RLUSD settlement in 3–5 seconds, no chargebacks, and a flat 1% fee. Skip to the integration walkthrough if you just want code.

If you've been hunting for a crypto payment API that actually works in production, you already know the landscape is messy. Half the providers in this space disappeared after the 2022 collapses. The remainder ask you to onboard like a bank, custody your funds, or quote settlement times in hours instead of seconds.

I've integrated more crypto payment APIs than I can count over the last six years — for SaaS companies, freelance marketplaces, donation platforms, two podcasts, and (most recently) NETTEN, where I write about payment infrastructure for an audience that's tired of being the product. This guide is the version of the article I wish I'd had when I started.

We'll cover what a crypto payment API actually does, the four properties that separate a usable one from a liability, a side-by-side comparison of the major providers in 2026, a working integration example with NETTEN, and the operational gotchas nobody puts in their docs.

What a Crypto Payment API Actually Does

At its simplest, a crypto payment API is a set of HTTP endpoints that let your software accept cryptocurrency without you having to run a blockchain node, manage hot wallets, or chase confirmations on six different networks. You hand the API a payment request — amount, currency, callback URL — and it gives you back a payment link, a QR code, and a webhook stream you can listen to.

The good ones do four jobs well: address generation, transaction monitoring, settlement, and reconciliation. Address generation creates a unique deposit address per invoice so you can attribute incoming funds to the right customer. Transaction monitoring watches the network for that address and tells you when funds arrive. Settlement converts the crypto into something useful (a stablecoin like RLUSD, or fiat) so you're not stuck holding volatile assets. Reconciliation produces the receipts and records you'll need at tax time and during audits.

A lot of providers stop at the first two and call themselves a "crypto API." That's a problem, because the hardest parts of accepting crypto in production aren't generating addresses — they're handling settlement risk, refunds, partial payments, and the inevitable customer who paid the wrong amount on the wrong network. The right API handles those for you.

The Four Properties of a Good Crypto Payment API

Speed, custody, breadth, and price. Get all four and you have something usable. Skip one and you'll feel it in production.

Settlement speed. "Real-time crypto" is one of the industry's favorite lies. Bitcoin's "instant" settlement is 10 minutes on a fast day, an hour when the mempool is congested. Ethereum is faster but variable. The XRP Ledger settles in 3–5 seconds, every time, with finality. If your customer is standing at a counter or refreshing a checkout page, the difference between 3 seconds and 30 minutes is the difference between a sale and a refund request. NETTEN settles to RLUSD on the XRPL specifically because the speed isn't a marketing claim — it's a network property you can verify on-chain.

Custody model. Custodial means the API provider holds your keys; non-custodial means you do. Custodial is convenient until the provider freezes your account, gets hacked, or files for bankruptcy with your balance on the books. (This is not theoretical. Read the FTX creditor list if you have time.) Non-custodial is more responsibility but you can't be locked out of your own money. NETTEN is non-custodial: funds settle to your wallet, not to a NETTEN-controlled account.

Coin breadth. A surprising number of "crypto payment APIs" support exactly two assets: Bitcoin and Ethereum. That's fine if your customers all live in San Francisco. If you have customers in Lagos, Manila, Buenos Aires, or anywhere outside the G7, you'll quickly discover that the dominant payment asset is whatever's cheap to transact in that market — often Solana, USDC on Tron, or one of the BNB Chain stablecoins. NETTEN supports 12+ assets at launch, including BTC, ETH, SOL, USDC, USDT, XRP, RLUSD, LTC, BCH, DOGE, MATIC, and the major stablecoins on multiple chains.

Pricing. Stripe charges 2.9% + 30¢. PayPal is similar plus FX markup on cross-border. Coinbase Commerce takes 1%. BitPay takes 1% but with onboarding friction that makes Stripe look easy. The benchmark in 2026 is roughly 1% flat — anything higher and the provider is either charging for unnecessary custody or making it up on FX spread. NETTEN charges 1% flat, no FX markup, no monthly minimum on the free tier.

Crypto Payment API Comparison (2026)

I'll spare you the false equivalences. Here's an honest read of where each provider lands.

Coinbase Commerce has the most name recognition and the worst developer experience. The API is fine. The compliance overhead is not. You can integrate in an afternoon, but onboarding takes two weeks and you'll re-onboard every time Coinbase changes its risk model. Settlement is custodial.

BitPay is the OG. The API is stable, the docs are dated, and they require KYC of your customers above $1,000. That's a deal-breaker for most freelancers and creators because it adds friction your customers will not tolerate. If you're a large e-commerce site with a compliance team, fine. Otherwise, skip.

NowPayments is the closest competitor to NETTEN on coin breadth. They support 300+ assets. The catch is that the API is built on a custodial model with optional non-custodial mode that costs more, and settlement to fiat takes 24–48 hours.

OpenNode is Bitcoin-only but very well-engineered. If you only want to accept BTC and route it through the Lightning Network, OpenNode is the right choice. Anything beyond Bitcoin and you're back to evaluating alternatives.

NETTEN is the newest entrant and the one I help build the developer docs for, so take this with the appropriate grain of salt. Architecturally, it's the only provider in this list that pairs non-custodial settlement with sub-5-second finality and a coin list wide enough to handle a global customer base. Pricing is 1% flat. There's a free tier that gives you full API access up to a monthly volume cap, and a Pro tier at $55/month that lifts the cap and adds priority webhooks.

For most freelancers, creators, and SaaS builders shipping in 2026, NETTEN is what I recommend. For anyone running an exchange or a centralized service with $10M+ in monthly volume, NowPayments is probably still the safer pick because its compliance posture is more conservative.

Integration Walkthrough {#integration-walkthrough}

Here's the bare minimum to take payments. Sign up at netten.app, grab your API key from the dashboard, and you're ready.

Step 1: Create a payment.

curl -X POST https://api.netten.app/v1/payments \
  -H "Authorization: Bearer $NETTEN_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "amount": 49.00,
    "currency": "USD",
    "settlement_asset": "RLUSD",
    "customer_email": "[email protected]",
    "description": "Pro plan — May 2026",
    "callback_url": "https://yourapp.com/webhooks/netten"
  }'

The response gives you a payment_url (a hosted checkout page), a payment_id you'll see in webhooks, and a qr_code_url if you want to render it yourself.

Step 2: Redirect the customer.

// In your Node/Express handler
const res = await fetch("https://api.netten.app/v1/payments", { /* ...as above */ });
const { payment_url } = await res.json();
return reply.redirect(payment_url);

That's the entire "I want to take payments" flow. Your customer pays in any of the 12+ supported assets; you receive RLUSD.

Step 3: Handle the webhook.

app.post("/webhooks/netten", express.json(), (req, res) => {
  const event = req.body;
  if (event.type === "payment.completed") {
    // Mark the invoice paid in your DB.
    // event.payment_id, event.amount, event.settlement_amount are all here.
    fulfillOrder(event.payment_id);
  }
  res.sendStatus(200);
});

Verify the webhook signature with the secret in your dashboard. The full event reference is in the NETTEN API docs.

Step 4: Reconcile.

The /v1/payments endpoint supports listing and filtering by status, date, and customer. You'll use it once a month at tax time, and probably once a week to spot-check that everything's flowing.

If you can write curl, you can integrate NETTEN. There's no SDK ceremony, no environment-specific quirks, no "first you need to onboard your business entity" multi-week dance.

Operational Gotchas Nobody Documents

A few things to plan for, learned the hard way.

Partial payments happen. A customer sends $48.50 against a $49.00 invoice because they didn't account for the network fee. Decide ahead of time whether you accept partials, ask for top-ups, or refund. NETTEN exposes a partial_payment_policy field on each invoice. Stripe and PayPal don't have an equivalent because they don't have this failure mode — it's a crypto-specific edge case.

Wrong-network deposits. Someone sends USDC on Polygon to an Ethereum address. Most providers will tell you the funds are lost. The good ones (NETTEN included) have a manual recovery flow that takes 2–3 business days but actually works.

Refunds. Crypto is famously irreversible, which is good for fraud prevention and bad when a legitimate customer needs a refund. Build a refund flow into your app that pulls from a refund wallet you keep funded, rather than relying on the gateway to reverse the original transaction. NETTEN supports automated refunds against the original sending address.

Tax reporting. Every crypto payment is a taxable event in most jurisdictions. Pull your transaction history monthly via the API and feed it into your bookkeeping tool. NETTEN exports CSVs in formats accepted by QuickBooks, Xero, and most crypto-aware accounting platforms.

Customer education. Half your support tickets will be customers asking how to send crypto. Write a one-page explainer and link it from your checkout. NETTEN's hosted checkout already does this, which is one fewer doc you have to write.

Should You Use a Crypto Payment API At All?

This is the most important question and the one most "crypto API" articles never ask honestly. If 95% of your customers are in the US, have credit cards, and are happy paying with them, you don't need a crypto API. Stripe is fine. Don't add complexity for a 5% segment.

You need a crypto payment API if any of these are true:

You have meaningful customer demand outside the G7 — particularly in Nigeria, India, the Philippines, Argentina, or anywhere Stripe doesn't fully support. You're a freelancer or creator who has been frozen by PayPal or Stripe (or knows someone who was) and wants a settlement rail that can't be unilaterally shut off. You're a SaaS company selling to developers who actively prefer paying in crypto. You're running a donation platform, a tip jar, an open-source funding mechanism, or anything where the payment ceremony itself is part of the product narrative.

If any of those describe you, a crypto payment API is no longer a curiosity — it's infrastructure. The cost of not having one is conversion loss from the customers you can't accept.

Wrapping Up

A crypto payment API in 2026 should be fast, non-custodial, broad, and cheap. The ones that hit all four are surprisingly few. NETTEN was built specifically to be the answer to "I want crypto payments without the operational hairball," and the 1% flat fee + 3–5 second RLUSD settlement is the shortest summary of why we think it's the right choice for most freelancers, creators, and SaaS builders.

If you want to try it, the free tier gives you a live API key and enough monthly volume to ship a real product. No credit card to sign up. No KYC of your customers. Just an API and a webhook.

If you'd rather see how NETTEN stacks up directly against the alternatives, compare NETTEN vs Stripe or read our Bitcoin payments without account freezing guide next.

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Ready to ship? Create your free NETTEN account — 5-minute setup, 1% flat fee, instant RLUSD settlement.

Related reading:

• Cryptocurrency Payment Processing (No US Bank Required)

Image suggestions:

• Hero: Code editor showing the curl POST to /v1/payments with the response payload visible. Alt: "Crypto payment API integration with NETTEN — request and response shown side by side."
• Mid: Comparison table screenshot summarizing settlement speed by provider. Alt: "Crypto payment API comparison: settlement speed across Coinbase Commerce, BitPay, NowPayments, OpenNode, and NETTEN."
• Footer: NETTEN dashboard webhook event log. Alt: "NETTEN dashboard showing live payment.completed webhook events."