Developer growth engine

Accept crypto payments without making developers guess.

Create a test payment session, open checkout, verify webhook events, and move toward mainnet review with copy-paste examples instead of a sales call.

⚡ Try Live Demo Checkout ($10 Testnet) Create a test session AI & MCP Portal (mcp.xpayr.com) Download Postman
POST /api/v1/payments
curl -X POST https://xpayr.com/api/v1/payments \
  -H "Authorization: Bearer sk_test_xxx" \
  -H "Content-Type: application/json" \
  -d '{
    "amount": 49.90,
    "currency": "USDT",
    "network": "tron-mainnet",
    "metadata": {"order_id": "ORDER-1001"},
    "success_url": "https://example.com/paid",
    "cancel_url": "https://example.com/cancel",
    "ipn_callback_url": "https://example.com/webhooks/xpayr"
  }'
5 minfirst test session
0.5%gateway fee model
Testnetbefore mainnet review
Webhooksigned event records
Quick paths

Choose the integration question you need to answer first.

Create a payment session

Start with a real checkout object: amount, currency, network, metadata, success URL, and webhook callback.

Open quickstart

Verify webhooks

Handle payment.completed, payment.failed, and test.webhook events with HMAC signature checks.

Verify signatures

Run testnet end to end

Create a test session, open checkout, complete a wallet flow, and reconcile the status response.

Test safely

Debug API errors

Map authentication, validation, route, webhook, and fee delegation errors to the next fix.

Read error guide

Sell licensed software

License Kit: sell browser extensions and plugins for crypto where the license is the buyer wallet. No email, no license keys, no chargebacks.

Open License Kit

Official 21-Tool MCP Server

Connect Claude Desktop, Cursor, VS Code Copilot, Windsurf, Cline, or n8n via @xpayr/mcp-server or POST /api/mcp to create multi-chain checkouts and manage AI agent intents.

Open MCP Hub

HTTP 402 Agentic API Paywalls

Gate REST APIs and LLM inference endpoints with HTTP 402 Payment Required challenges and sub-millisecond ES256 JWKS token verification.

Explore HTTP 402 Kit

10 Provider Migration Playbooks

Field-by-field API and HMAC webhook adapters for NOWPayments, Coinbase Commerce, BitPay, BTCPay Server, Cryptomus, CoinGate, Stripe, CoinPayments, Helio, and Triple-A.

Open 10 Playbooks

Official SDKs & Packages

Install @xpayr/node-sdk, @xpayr/mcp-server, @xpayr/extension-kit, @xpayr/payment-evidence, browser Pay Button SDK, and 6-language copy-paste code.

Open SDKs Hub

Autonomous Agent Commerce & A2A

Unified agent stack combining 21-tool MCP, Google A2A v1.0 Agent Card (/.well-known/agent.json), HTTP 402 paywalls, and spend guardrails.

Open Agent Commerce

Gasless Checkout & Settlement Router

Eliminate native gas abandonment with ERC-2612 Permit sponsorship (/gasless) and route multi-chain checkouts into preferred stablecoins (/settlement-router).

Explore Gasless Flow

Interactive Live Checkout Sandbox

Test Web3 1-Click Pay, Direct Exchange QR with 1% tolerance, HTTP 402 paywalls, and ES256 License Kit payloads live in your browser with zero signup.

Launch Live Sandbox

Multi-Chain Gas & Finality Comparator

Rank 9 EVM, Solana, TRON, and Circle Arc payment rails by finality latency, payer gas, 0.5% split, and net merchant treasury outcome.

Compare 9 Chains

Interactive OpenAPI 3.1.0 Reference

Search all 20 REST API v1 endpoints, inspect request schemas, and download the official Postman v2.1 Collection (/postman.json).

Open API Reference

Unified Webhook Events Catalog

Inspect all 9 webhook event schemas (including payment.underpaid_accepted), 6-stage backoff schedule, and 6-language HMAC verifiers.

Explore Webhooks

16 Blockchain Network Blueprints

Per-chain Chain IDs, confirmation SLAs, ERC-2612 Gasless support, and API payloads for Solana, Base, Sui, Aptos, NEAR, Arbitrum, TRON, XRPL, TON, BTC, and Arc.

Explore 16 Chains

8-Language API Code Generator

Generate zero-placeholder Node.js, Next.js, Python FastAPI, PHP, Go, Rust, Ruby, and cURL code with shareable Permalinks.

Generate Code

16 Wallets, CEX QR & Multisig Vaults

EIP-6963, Solana Wallet Standard, Direct Exchange QR, and direct M-of-N settlement into Safe{Wallet}, Squads v4, Ledger, and Fireblocks MPC.

Explore 16 Wallets

Legacy Webhook & API Translator

Paste live NOWPayments, Coinbase Commerce, BitPay, Cryptomus, or CoinGate webhook payloads to generate drop-in XPayr HMAC-SHA256 middleware.

Launch Translator

ERC-2612 Permit & 16-Chain Finality SLA

Inspect EIP-712 Permit domain separators (/tools/erc2612-gasless-permit-inspector) and model confirmation SLAs across 16 chains (/tools/rpc-finality-sla-calculator).

Inspect EIP-712 Permit
Downloadable assets

Give your developer one folder, not ten scattered links.

The public developer kit includes Postman files, browser SDK demo, cURL examples, PHP examples, Node examples, and webhook verification snippets. It is built for testnet-first evaluation and maps to the live API router.

Postman collection Postman environment Browser SDK Node quickstart PHP quickstart Webhook verification OpenAPI 3.1.0 Spec GPT Actions Schema Google A2A Agent Card Official SDKs Hub NPM @xpayr/mcp-server AI & MCP Portal (mcp.xpayr.com) Docs Portal (docs.xpayr.com) GitHub.io Portal
Model Context Protocol (MCP) & AI Agents

One-click MCP setup for Cursor, VS Code & Claude.

Published on the Official Anthropic MCP Registry (io.github.xpayrcom/xpayr-mcp-server), NPM (@xpayr/mcp-server & xpayr-mcp), and GitHub Container Registry (ghcr.io/xpayrcom/xpayr-mcp-server:latest). Expose 21 strongly-typed crypto payment and agent-intent tools directly inside your IDE or autonomous agent runtime.

Install in Cursor Install in VS Code GitHub Repository
claude_desktop_config.json / mcp.json
{
  "mcpServers": {
    "xpayr": {
      "command": "npx",
      "args": ["-y", "@xpayr/mcp-server"],
      "env": {
        "XPAYR_API_KEY": "sk_test_your_key_here"
      }
    }
  }
}
01

Create

Call POST /api/v1/payments with amount, currency, network, and metadata.

02

Redirect

Open the returned payment_url so the buyer can complete the wallet payment.

03

Confirm

Poll GET /api/v1/payments/{id}/status or consume signed webhooks.

04

Reconcile

Store the session ID, transaction hash, status, gateway fee, and merchant order ID.

Ready to test a crypto checkout without production funds?

Open a merchant account, create a test session, and use the examples above to validate your integration before mainnet review.

Open testnet account Read API reference