x402 Payments

x402 is the payment layer of RMI: standard HTTP 402 Payment Required, settled as on-chain USDC (or BTC/USDT/EUR) micropayments per tool call. No accounts, no subscriptions, no prepayment, no API-key billing plans.

Live gateway facts (from /.well-known/x402, verified 2026-08-24):

Protocol version	x402 v2.0
Total tools	346 (342 paid, all with free trials)
Price range	$0.01 – $0.50 per call
Payment chains	13 (see below)
Facilitators	7 (see below)

How a paid call works

1. You call a tool without payment.
2. The API answers 402 Payment Required with a quote: amount, asset, chain, receiving address, and a payment payload.
3. Your wallet signs a transfer authorization (EIP-3009 transferWithAuthorization or EIP-712 on EVM chains) for exactly that amount. No token approvals, no gas on most paths, no access to your funds beyond the quoted amount.
4. You retry the call with the signed proof in the X-PAYMENT header.
5. The facilitator verifies and settles on-chain; you get 200 + data + X-PAYMENT-RESPONSE receipt.

Discovery

curl https://rugmunch.io/.well-known/x402

{
  "x402_version": "2.0",
  "service": "Rug Munch Intelligence x402 Gateway",
  "operator": "Rug Munch Media LLC",
  "discovery_url": "https://mcp.rugmunch.io/.well-known/x402",
  "mcp_url": "https://mcp.rugmunch.io/mcp/x402",
  "docs_url": "https://docs.rugmunch.io/x402",
  "pricing": {
    "total_tools": 346,
    "paid_tools": 342,
    "price_range_usd": { "min": 0.01, "max": 0.5 },
    "free_trials": true
  },
  "facilitators": ["coinbase_cdp", "payai", "cloudflare_x402", "x402_rs", "primev", "asterpay", "eip7702"],
  "status": "active"
}

Per-tool pricing and schemas:

curl https://rugmunch.io/api/v1/x402/pricing      # price list
curl https://rugmunch.io/api/v1/x402-databus/catalog   # DataBus tool catalog
curl https://rugmunch.io/api/v1/x402-tools/discovery   # legacy tool catalog

Supported payment chains (13)

Base, Solana, BSC, Ethereum, TRON, Bitcoin, Arbitrum, Optimism, Polygon, Avalanche, Fantom, Gnosis, and SEPA (EUR) for European bank transfers.

Chain	Network id	Method	Facilitators
Base	eip155:8453	local EIP-712	coinbase_cdp, payai
BSC	eip155:56	local EIP-712	eip7702
Solana	solana:5eyk…	payai	payai
TRON	—	self-verify	USDT/USDC/USDD
Bitcoin	—	self-verify (1 conf)	BTC
SEPA	—	bank transfer	asterpay (EUR)

Full machine-readable list: GET /api/v1/x402/chains.

Facilitators

Facilitators are the settlement layer that verifies your payment and pays the API. Pick by cost and chain:

Facilitator	Notes
coinbase_cdp	Free, best for Base/Solana USDC — default choice
payai	Deferred settlement, Base + Solana
eip7702	Any EVM chain, low fee
cloudflare_x402	Cloudflare-operated settlement
x402_rs	Self-hostable Rust facilitator
primev	Alternative multi-chain
asterpay	SEPA/EUR bank transfers

Health: GET /api/v1/x402/facilitator-health/status/{name}.

Trials, usage, receipts

# Trial balance for a fingerprint or wallet
curl https://rugmunch.io/api/v1/x402-databus/trials/{identifier}

# Your usage + payment history (authenticated)
curl https://rugmunch.io/api/v1/x402/usage
curl https://rugmunch.io/api/v1/x402/history

# Receipt for a settled transaction
curl https://rugmunch.io/api/v1/x402/receipts/{tx_hash}

# Invoice flow (create → pay)
curl https://rugmunch.io/api/v1/x402/invoice/{invoice_id}
curl -X POST https://rugmunch.io/api/v1/x402/pay/{invoice_id}

Free trials: every tool grants 1–5 free calls, gated by device fingerprint or connected wallet (connecting a wallet raises the allotment). Trials are independent per tool.

Refunds

Calls that return no data are not charged. If you were billed for an empty result, request a refund within 48 hours — contact mcp@rugmunch.io with the transaction hash.

x402 for agents

MCP agents use the paid gateway https://mcp.rugmunch.io/mcp/x402 (see MCP Setup). Sandbox for integration testing: POST /x402/sandbox/create-invoice, POST /x402/sandbox/verify. Full interactive spec: /x402/docs on the API host.