Glossary
x402
x402 is defined here as follows. Open standard for per request HTTP payments. The server quotes a price, the client sends the request again with proof of payment, and a facilitator can verify and settle it. The directory source for this term is Coinbase documentation for how x402 works.
Last verified 2026-10-17
Sources
Listings
Directory listings whose sources describe this mechanism.
| Name | Status | Category | Open source | Mechanism |
|---|---|---|---|---|
| Coinbase Agentic Wallet | Live | Payment rails | No | Wallet for agents on Coinbase Developer Platform. The agent holds USDC, sends, trades, and pays x402 services through the awal CLI and skills, under per session and per transaction caps, while keys stay in Coinbase infrastructure. The MCP version is labeled beta. wallets, stablecoins, http-402, spend-limits |
| Hedera Agent Accounts | Designed | Payment rails | No | Owner funded spending account on Hedera. The owner sets a daily cap, a per transaction maximum, and a recipient allowlist in a smart contract, and can revoke the agent. Hedera says public testnet access is still forthcoming. wallets, spend-limits |
| MetaMask Agent Wallet | Live | Payment rails | No | Agent wallet CLI for sending tokens and paying x402 requests. Guard Mode can enforce address and recipient allowlists and a rolling 24 hour outflow limit, and it asks for 2FA outside that policy. wallets, spend-limits, http-402 |
| Nevermined | Live | Payment rails | No | Payments facilitator that verifies and settles x402 and MPP charges against a payment plan, with metering and delegated card spending. http-402, metering, cards |
| Polygon Agent CLI | Live | Payment rails | Yes | Agent CLI with an embedded smart wallet. Session mode spends only inside an allowance the owner approves, x402 payments can be capped per call, and session logout revokes that install. wallets, spend-limits, http-402 |
| Sui Agentic Payments | Beta | Payment rails | No | Testnet gateway where an agent pays per API call in USDC on Sui. The owner sets an onchain grant with allowed services, a total budget, a per payment cap, and an expiry, and can revoke it. http-402, spend-limits, stablecoins |
| x402 | Live | Payment rails | Yes | Open HTTP payment standard. A server answers with status 402, the client pays and retries, and a facilitator can verify and settle the payment. http-402, stablecoins, pay-per-call |
Questions
- What is x402?
- Open standard for per request HTTP payments. The server quotes a price, the client sends the request again with proof of payment, and a facilitator can verify and settle it.
- Which listings use x402?
- Coinbase Agentic Wallet, Hedera Agent Accounts, MetaMask Agent Wallet, Nevermined, Polygon Agent CLI, Sui Agentic Payments, x402.
- When was x402 last verified?
- Last verified 2026-10-17.