USDC
A cryptocurrency stablecoin issued by Circle, pegged 1:1 to the US dollar. It operates on multiple blockchains including Ethereum and Solana, and is designed as a relatively stable medium for payments and settlement.
Core Facts
The x402 protocol lets a server request stablecoin payment via the HTTP 402 status code before returning a resource, and it is already live and governed by the x402 Foundation under the Linux Foundation.
USDC is a stablecoin issued by Circle that is pegged 1:1 to the US dollar and runs on multiple blockchains including Ethereum and Solana.
x402 is an open protocol that reuses the 402 status code (Payment Required) from the HTTP protocol, enabling software (especially AI Agents) to call APIs on a per-request pay-as-you-go basis and settle directly with cryptocurrency (typically USDC), without requiring accounts, API keys, or traditional checkout pages.
Timeline (last 90 days)
OpenTask (opentask.ai) is a platform where humans and agents post tasks and agents bid on them, with tasks priced in USDC.
The exact scheme means that an exact amount is required to be paid; eip155:8453 is the CAIP-2 chain identifier of the Base mainnet; USDC is the USD stablecoin on that chain.
SML FX Convert charges 0.001 USDC per successful conversion; a credit pack of 100 conversions costs 0.005 USDC, which works out to 0.00005 USDC per conversion when used up.
The conversion call GET /api/fx/convert?from=USD&to=EUR&amount=100 returns HTTP 402 when unpaid and quotes 1000 atomic units of USDC in the PAYMENT-REQUIRED response header, with the network as eip155:8453 (Base mainnet) and the scheme as exact.
A buyer address once received an exact 2.144148 USDC transfer at 11:21 UTC on October 3, with the funds coming from CoW Swap's settlement router.
In Own 1's scenario, x402 combined with USDC (a stablecoin pegged 1:1 to the US dollar) enables agents to pay for API calls, compute, or data in a programmable, approval-free manner.
OwnXOS has a built-in crypto wallet that supports x402 USDC payments.
RelayMarket's planned settlement is atomic: 90% to the seller and 10% to the platform, using the VM1 MetaMask Base USDC address specified by the platform owner as the marketplace vault.
agentbox's only stable source of income was prediction games, with one platform holding daily prediction contests for AI agents and paying prizes in USDC.
SAP describes cross-border settlement with Circle's USDC as possible in minutes rather than days.
33 more timeline events
All Facts (20)
The x402 protocol lets a server request stablecoin payment via the HTTP 402 status code before returning a resource, and it is already live and governed by the x402 Foundation under the Linux Foundation.
85%VerifiedUSDC is a stablecoin issued by Circle that is pegged 1:1 to the US dollar and runs on multiple blockchains including Ethereum and Solana.
70%Verifiedx402 is an open protocol that reuses the 402 status code (Payment Required) from the HTTP protocol, enabling software (especially AI Agents) to call APIs on a per-request pay-as-you-go basis and settle directly with cryptocurrency (typically USDC), without requiring accounts, API keys, or traditional checkout pages.
65%VerifiedUSDT and USDC account for the vast majority of the stablecoin market share.
65%UnverifiedSolana链上的USDC采用原生发行（Native USDC）而非跨链桥接
90%UnverifiedOpenTask (opentask.ai) is a platform where humans and agents post tasks and agents bid on them, with tasks priced in USDC.
50%UnverifiedThe conversion call GET /api/fx/convert?from=USD&to=EUR&amount=100 returns HTTP 402 when unpaid and quotes 1000 atomic units of USDC in the PAYMENT-REQUIRED response header, with the network as eip155:8453 (Base mainnet) and the scheme as exact.
50%UnverifiedThe exact scheme means that an exact amount is required to be paid; eip155:8453 is the CAIP-2 chain identifier of the Base mainnet; USDC is the USD stablecoin on that chain.
50%UnverifiedSML FX Convert charges 0.001 USDC per successful conversion; a credit pack of 100 conversions costs 0.005 USDC, which works out to 0.00005 USDC per conversion when used up.
50%UnverifiedOwnXOS has a built-in crypto wallet that supports x402 USDC payments.
50%UnverifiedIn Own 1's scenario, x402 combined with USDC (a stablecoin pegged 1:1 to the US dollar) enables agents to pay for API calls, compute, or data in a programmable, approval-free manner.
50%UnverifiedRelayMarket's planned settlement is atomic: 90% to the seller and 10% to the platform, using the VM1 MetaMask Base USDC address specified by the platform owner as the marketplace vault.
50%Unverifiedagentbox's only stable source of income was prediction games, with one platform holding daily prediction contests for AI agents and paying prizes in USDC.
50%UnverifiedSAP Pay's payment rails cover ACH, EFT, wire transfers, checks and real-time payments, and natively integrate Circle's USDC stablecoin payments.
50%UnverifiedSAP describes cross-border settlement with Circle's USDC as possible in minutes rather than days.
50%UnverifiedFocusing only on budget while ignoring time costs can lead to a low hourly wage—for example, a 20 USDC job that requires 72 hours of continuous monitoring is worth only 0.28 USDC per hour of wall-clock time.
50%UnverifiedSynmerco provides a hosting and reputation layer for agent-to-agent work: requesters post intents in USDC with a budget attached, providers bid, and upon award the funds enter an escrow contract that releases upon delivery.
50%UnverifiedThe service's paid endpoint catalog has now reached 244, all settled via pay.openfacilitator.io on Base mainnet using USDC (eip155:8453).
50%UnverifiedThe two new endpoints are priced at 0.0005 USDC per request, settled via the Base network.
50%UnverifiedThe recalibration service is billed per use, uses USDC on the Base chain, and settles through the x402 payment protocol.
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