REST · HMAC · SSE · OPENAPI 3.1

An API built for engineers.

A REST API documented with OpenAPI 3.1 (Swagger), an unlimited sandbox and HMAC-SHA256-signed webhooks. Under the hood, Solana, Sui, Cronos and Tron run on our gRPC node backbone for ultra-fast on-chain dispatch.

Developers

One call. One payment.

A 100% REST API documented with OpenAPI 3.1 (Swagger) — no client library to install. Plus gRPC endpoints for Solana, Sui, Cronos and Tron.

OpenAPI 3.1 (Swagger)
HMAC-SHA256 signed webhooks
Hosted checkout pages
Embeddable Elements
Unlimited free sandbox
gRPC for low-latency

Read the docs GitHub

api · v1

// Node 18+ — native fetch, no library
const api = await fetch("https://api.abyxo.app/v1/checkout/sessions", {
  method: "POST",
  headers: {
    Authorization: "Bearer sk_live_…",
    "Content-Type": "application/json",
  },
  body: JSON.stringify({
    amount: 4990,            // 49,90 €
    currency: "EUR",
    accept: ["BTC", "ETH", "USDC", "SUI"],
    success_url: "https://shop.io/ok",
  }),
});

const session = await api.json();
res.redirect(session.url);

# plain HTTP — requests, no vendor lib
import requests

session = requests.post(
    "https://api.abyxo.app/v1/checkout/sessions",
    headers={"Authorization": "Bearer sk_live_…"},
    json={
        "amount": 4990,            # 49,90 €
        "currency": "EUR",
        "accept": ["BTC", "ETH", "USDC", "SUI"],
        "success_url": "https://shop.io/ok",
    },
).json()

return redirect(session["url"])

// stdlib only — net/http + encoding/json
body, _ := json.Marshal(map[string]any{
    "amount":      4990,
    "currency":    "EUR",
    "accept":      []string{"BTC", "ETH", "USDC", "SUI"},
    "success_url": "https://shop.io/ok",
})

req, _ := http.NewRequest("POST",
    "https://api.abyxo.app/v1/checkout/sessions",
    bytes.NewReader(body))
req.Header.Set("Authorization", "Bearer sk_live_…")

resp, _ := http.DefaultClient.Do(req)
var s map[string]any
json.NewDecoder(resp.Body).Decode(&s)

http.Redirect(w, r, s["url"].(string), 303)

# one POST — that's the whole integration
curl https://api.abyxo.app/v1/checkout/sessions \
  -H "Authorization: Bearer sk_live_…" \
  -d "amount=4990" \
  -d "currency=EUR" \
  -d "accept[]=BTC" \
  -d "accept[]=ETH" \
  -d "accept[]=USDC" \
  -d "accept[]=SUI" \
  -d "success_url=https://shop.io/ok"

Documentation

Everything you need.

OpenAPI 3.1 (Swagger) spec, Postman collection, copy-paste examples (cURL, JS, Python, Go), and the gRPC endpoint documented in Protobuf.

Quickstart

First integration in 10 minutes.

Open

API Reference

REST endpoints — every route.

Open

HMAC webhooks

Step-by-step validation.

Open

OpenAPI 3.1

Swagger UI · downloadable schema.

Open

Changelog

Versions and compatibility.

Open

Webhooks · HMAC-SHA256

Server-side validation.

Compute an HMAC-SHA256 over the raw body using your webhook secret, then constant-time compare with the Abyxo-Signature header.

· Exponential retries (5 attempts over 24 h)
· Inspectable dead-letter queue from the backoffice
· One-click secret rotation with a 24 h grace period
· Replay-protection via Abyxo-Timestamp

// Express.js — HMAC validation
import crypto from "node:crypto";

app.post("/webhook", express.raw({ type: "*/*" }), (req, res) => {
  const sig = req.headers["abyxo-signature"];
  if (typeof sig !== "string") return res.status(401).end();

  const expected = crypto
    .createHmac("sha256", process.env.ABYXO_WHSEC)
    .update(req.body)
    .digest("hex");

  const a = Buffer.from(sig, "hex");
  const b = Buffer.from(expected, "hex");
  if (a.length !== b.length || !crypto.timingSafeEqual(a, b)) {
    return res.status(401).end();
  }
  // + replay-check via Abyxo-Timestamp

  const event = JSON.parse(req.body.toString("utf8"));
  if (event.type === "checkout.completed") {
    // Fulfill the order
  }
  res.json({ ok: true });
});

Changelog

Recent releases.

2026-08-01

Tron added to the gRPC node backbone

v2.6
2026-07-29

Bitcoin Lightning support · Cronos added to the gRPC node backbone

v2.5
2026-04-22

Cronos GA · Sui added to the gRPC node backbone

v2.4
2026-03-08

On-chain anti-fraud v3 · sub-100 ms decision

v2.3
2026-02-04

PYUSD support · MiCA-ready disclosure

v2.2
2026-01-15

Webhooks: 24 h secret-rotation grace period

v2.1

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