Overview

Quicknode supports two wallet-based payment protocols that let any application or AI agent pay for Quicknode requests with stablecoins. Both protocols build on HTTP 402 Payment Required but take different approaches to payment negotiation and settlement. They support two access modes: one-shot RPC calls without an account, or paying for an Agent Subscription to receive a Quicknode full platform API key and unlock the full product suite.

• x402 is an open standard by Coinbase. Quicknode maintains client libraries (@quicknode/x402, @quicknode/x402-solana) that handle authentication and payment automatically. The x402 proxy is available at x402.quicknode.com.
• MPP (Machine Payments Protocol) is an IETF Internet-Draft by Tempo Labs and Stripe. It uses standard HTTP authentication headers and supports multiple payment methods. The MPP proxy is available at mpp.quicknode.com.

Both protocols provide access to all supported blockchain networks.

TL;DR

• Two wallet-based payment protocols settle Quicknode requests via HTTP 402: x402 (Coinbase open standard) and MPP (IETF Internet-Draft by Tempo Labs + Stripe)
• Two ways to use them:
  • One-shot RPC calls (no account): pay per request or via credit drawdown, agent makes calls directly against x402.quicknode.com or mpp.quicknode.com
  • Create a Quicknode account: use the same protocols against Agent Subscriptions to receive a QN_* full platform API key and unlock the full Quicknode product suite (RPC endpoints, Streams, Webhooks, SQL Explorer, Key-Value Store, Admin API)
• x402 supports pay-per-request and credit drawdown; MPP supports charge and session billing. Both handle payment negotiation automatically via their SDKs
• The payment chain is independent of the RPC chain: pay on one network, query any Quicknode-supported blockchain

Comparison

	x402	MPP
Origin	Coinbase (open-source spec)	Tempo Labs + Stripe (IETF Internet-Draft)
Wire format	Custom payment headers	Standard HTTP auth scheme (WWW-Authenticate / Authorization / Payment-Receipt)
Payment methods	Stablecoins (see x402 Payments for supported networks)	Stablecoins (see MPP Payments for details)
Billing patterns	Pay-per-request or credit drawdown (see x402 Payments for pricing)	Charge or session (see MPP Payments for pricing)
Session support	Credit drawdown with SIWX auth and JWT sessions	Native payment channels with off-chain vouchers and batched settlement
SDKs	@quicknode/x402, @quicknode/x402-solana	mppx (TypeScript), solana-mpp
Protocols	JSON-RPC, REST, gRPC-Web, WebSocket	JSON-RPC, REST, gRPC-Web, WebSocket
Status	Alpha	Alpha

x402

x402 on Quicknode supports two access patterns:

• Pay-per-request: $0.001 per request. No authentication, no session state. Each request is self-contained using the standard x402 protocol.
• Credit drawdown: Authenticate once with SIWX (Sign-In with X), purchase a credit bundle ($10 for 1,000,000 requests), and consume credits per call. Better cost economics for sustained usage, and required for gRPC-Web and WebSocket.

For supported payment networks and tokens, see x402 Payments. The payment network is decoupled from the RPC network, so you can pay on one chain and query another.

tip

For a step-by-step walkthrough, see the x402 Getting Started guide.

MPP

MPP (Machine Payments Protocol) on Quicknode supports two intent types:

• Charge: $0.001 per request. One on-chain settlement per call. The simplest integration path.
• Session: $0.00001 per request ($10 per million). The client deposits into an escrow contract and signs off-chain vouchers for each request. Settlement is batched.

For supported payment networks and methods, see MPP Payments. The mppx SDK polyfills fetch to handle 402 challenges automatically.

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