--- type: Agentic Web Standard title: "x402" description: "How can an HTTP client pay per-request or per-resource, in stablecoins, without accounts, API keys, or signup?" resource: "https://github.com/x402-foundation/x402/blob/main/specs/x402-specification-v2.md" tags: ["pay", "http-header", "linux-foundation", "accept-agent-payments", "agent-checkout"] status: stable generated: { by: agenticweb-builder/1.0, at: 2026-10-30T00:00:00Z } verified: { by: process:agenticweb-engine, at: 2026-10-29T00:00:00Z } stale_after: 2026-11-28T00:00:00Z sources: - id: ref-1 resource: "https://www.coinbase.com/developer-platform/discover/launches/x402" title: "Erik Reppel, Nemil Dalal and Dan Kim, Coinbase, Introducing x402: a new standard for internet-native payments (Coinbase Developer Platform), 2025-05-06: \"Introducing x402: a new standard for internet-native payments May 6, 2025 By: Erik Reppel, Nemil Dalal, Dan Kim\" \"Coinbase is launching x402, a payment protocol that enables instant stablecoin payments directly over HTTP.\" \"x402 solves this by resurrecting the HTTP 402 \"Payment Required\" status code, a dormant feature of the web designed for seamless payment requests within standard HTTP interactions.\"" last_modified: 2025-05-06T00:00:00Z - id: ref-2 resource: "https://blog.cloudflare.com/x402/" title: "Will Allen, Cam Whiteside, Rohin Lohe and Steve James, Launching the x402 Foundation with Coinbase, and support for x402 transactions (Cloudflare Blog), 2025-09-23: \"September 23, 2025 Launching the x402 Foundation with Coinbase, and support for x402 transactions\" \"Cloudflare is partnering with Coinbase to create the x402 Foundation.\" \"In addition to today's partnership, we are shipping a set of features to allow developers to use x402 in the Agents SDK and our MCP integrations, as well as proposing a new deferred payment scheme.\" \"Agents built using Cloudflare's Agent SDK can now pay for resources with x402, and MCP servers can expose tools to be paid for via x402.\"" last_modified: 2025-09-23T00:00:00Z - id: ref-3 resource: "https://www.linuxfoundation.org/press/linux-foundation-is-launching-the-x402-foundation-and-welcoming-the-contribution-of-the-x402-protocol" title: "Linux Foundation, Linux Foundation is Launching the x402 Foundation and Welcoming the Contribution of the x402 Protocol (press release), 2026-04-02: \"NEW YORK – MCP Dev Summit North America – April 2, 2026\" \"today announced it is launching the x402 Foundation with the contribution of the x402 protocol from Coinbase.\" \"The x402 Foundation, the standard's governing body, initially developed by Coinbase, Cloudflare, and Stripe, is launching with a broad set of industry participants as it migrates toward an open source model for the benefit of all internet-native payments.\"" last_modified: 2026-04-02T00:00:00Z - id: ref-4 resource: "https://www.linuxfoundation.org/press/linux-foundation-announces-operational-launch-of-x402-foundation-to-standardize-internet-native-payments-for-ai-agents-and-applications" title: "Linux Foundation, Linux Foundation Announces Operational Launch of x402 Foundation to Standardize Internet-Native Payments for AI Agents and Applications (press release), 2026-07-14: \"July 14, 2026 – The Linux Foundation, the nonprofit organization enabling mass innovation through open source, today announced the operational launch of the x402 Foundation and the completed contribution of the x402 protocol by Coinbase.\" \"Since the Foundation's intent to launch in April, 40 organizations have joined as members.\" \"Premier members include Adyen, Amazon Web Services (AWS), American Express, Circle, Cloudflare, Coinbase, Fiserv, Google, Mastercard, Monad Foundation, MoonPay, Ripple, Shopify, Solana Foundation, Stellar Development Foundation, Stripe, and Visa.\" \"x402 was started at Coinbase to solve a real problem – AI agents had no native, interoperable way to pay for the things they needed to do.\"" last_modified: 2026-07-14T00:00:00Z - id: ref-5 resource: "https://x402.org/linux-foundation-appoints-michael-hursta-as-executive-director-of-the-x402-foundation/" title: "x402 Foundation, Linux Foundation Appoints Michael Hursta as Executive Director of the x402 Foundation (x402.org), 2026-10-01: \"SAN FRANCISCO, Oct. 1, 2026\" \"The Linux Foundation appointed payments veteran Michael Hursta as Executive Director of the x402 Foundation.\"" last_modified: 2026-10-01T00:00:00Z - id: ref-6 resource: "https://x402.org/" title: "x402.org home page, checked 2026-10-28: \"x402 is an open, neutral standard for internet-native payments.\" \"Copyright © x402 a Series of LF Projects, LLC\"" last_modified: 2026-10-28T00:00:00Z - id: ref-7 resource: "https://github.com/x402-foundation/x402/blob/main/TSC.md" title: "x402-foundation/x402, TSC.md (Technical Steering Committee members), checked 2026-10-28; quoted from the raw file: \"Coinbase, Inc. Erik Reppel Cloudflare, Inc. Rohin Lohe Stripe, Inc. Steve Kaliski\"" last_modified: 2026-10-28T00:00:00Z - id: ref-8 resource: "https://github.com/x402-foundation/x402" title: "x402-foundation/x402 GitHub repository (Apache-2.0), checked 2026-10-28; quoted from the GitHub API record: \"\"description\": \"A payments protocol for the internet. Built on HTTP.\"\" \"\"created_at\": \"2025-02-21T01:17:52Z\"\"" last_modified: 2026-10-28T00:00:00Z - id: ref-9 resource: "https://github.com/x402-foundation/x402/blob/main/specs/x402-specification-v2.md" title: "x402-foundation/x402, x402 Protocol Specification v2 (specs/x402-specification-v2.md), checked 2026-10-28; quoted from the raw file: \"Protocol Version: 2\" \"v2.0 2025-12-9 Protocol v2: CAIP-2 networks, restructured PaymentPayload/Required, ResourceInfo separation, extensions support\" \"Payment schemes: Extensible payment methods (including exact, upto, and batch-settlement; see specs/schemes/)\" \"Networks in x402 v2 use CAIP-2 (Chain Agnostic Improvement Proposal) format: namespace:reference.\" \"Format: {namespace}:{reference} (e.g., eip155:8453 for Base mainnet)\" \"Both EVM and Solana networks are supported by the reference implementations, e.g.:\" \"This enables the creation of marketplaces (known as \"Bazaars\") where users can discover and access monetized APIs and digital services.\" \"Representation: How payment data is transmitted and signaled, which depends on the transport mechanism (e.g., HTTP, MCP, A2A)\"" last_modified: 2026-10-28T00:00:00Z - id: ref-10 resource: "https://github.com/x402-foundation/x402/blob/main/specs/x402-specification-v1.md" title: "x402-foundation/x402, x402 Protocol Specification v1 (specs/x402-specification-v1.md), checked 2026-10-28; quoted from the raw file: \"Protocol Version: 1\"" last_modified: 2026-10-28T00:00:00Z - id: ref-11 resource: "https://github.com/x402-foundation/x402/blob/main/specs/transports-v2/http.md" title: "x402-foundation/x402, HTTP transport for v2 (specs/transports-v2/http.md), checked 2026-10-28; quoted from the raw file: \"Mechanism: HTTP 402 status code with PAYMENT-REQUIRED header\" \"Clients send payment data using the PAYMENT-SIGNATURE HTTP header.\" \"Servers communicate payment settlement results using the PAYMENT-RESPONSE header.\"" last_modified: 2026-10-28T00:00:00Z - id: ref-12 resource: "https://github.com/x402-foundation/x402/blob/main/specs/transports-v1/http.md" title: "x402-foundation/x402, HTTP transport for v1 (specs/transports-v1/http.md), checked 2026-10-28; quoted from the raw file: \"Mechanism: HTTP 402 status code with JSON response body\" \"Clients send payment data using the X-PAYMENT HTTP header.\" \"Servers communicate payment settlement results using the X-PAYMENT-RESPONSE header.\"" last_modified: 2026-10-28T00:00:00Z - id: ref-13 resource: "https://github.com/x402-foundation/x402/blob/main/specs/transports-v2/a2a.md" title: "x402-foundation/x402, A2A transport for v2 (specs/transports-v2/a2a.md), checked 2026-10-28; quoted from the raw file: \"The A2A transport implements x402 payment flows over the Agent-to-Agent protocol using JSON-RPC messages and task-based state management.\"" last_modified: 2026-10-28T00:00:00Z - id: ref-14 resource: "https://x402.org/x402-v2-launch/" title: "Erik Reppel, Carson Roscoe and Josh Nickerson, Introducing x402 V2: Evolving the Standard for Internet-native Payments (x402.org), 2025-12-11: \"Introducing x402 V2: Evolving the Standard for Internet-native Payments By x402 December 11, 2025\" \"x402 launched in May 2025 with a simple idea: embed payments directly into HTTP using the long-dormant 402 status code.\" \"Moving all payment data to headers for the HTTP transport, freeing up response body to be used alongside a 402 status code and Payment Required header\" \"x402's reference SDKs are fully backward-compatible with V1.\"" last_modified: 2025-12-11T00:00:00Z - id: ref-15 resource: "https://x402.org/x402-batch-settlement/" title: "x402 Foundation, Introducing x402 Batch Settlement: High-velocity Agentic Commerce (x402.org), 2026-05-11: \"The x402 protocol is introducing batch settlement, enabling agents to transact at extremely low latency and fractions of a cent.\"" last_modified: 2026-05-11T00:00:00Z - id: ref-16 resource: "https://docs.x402.org/dev-tools/facilitators" title: "x402 documentation, Facilitators (docs.x402.org), checked 2026-10-28: \"Facilitators verify and settle x402 payments on behalf of resource servers. Anyone can run a facilitator.\" \"The table below lists selected production options; it is not an exhaustive catalog.\" \"CDP Facilitator Coinbase-hosted facilitator with KYT/OFAC checks on every transaction\"" last_modified: 2026-10-28T00:00:00Z - id: ref-17 resource: "https://docs.x402.org/core-concepts/network-and-token-support" title: "x402 documentation, Networks & Token Support (docs.x402.org), checked 2026-10-28: \"x402 supports tokens on EVM, Solana, TON, Algorand (AVM), Stellar, Aptos, Hedera, Keeta, NEAR, Concordium, XRPL, Cardano, Sui, and Canton networks:\"" last_modified: 2026-10-28T00:00:00Z - id: ref-18 resource: "https://docs.x402.org/extensions/bazaar" title: "x402 documentation, Bazaar (Discovery Layer) (docs.x402.org), checked 2026-10-28: \"The x402 Bazaar is the discovery layer for the x402 ecosystem - a machine-readable catalog that helps developers and AI agents find and integrate with x402-compatible API endpoints and MCP tools. Think of it as a search index for payable APIs and MCP tools, enabling the autonomous discovery and consumption of services.\" \"Facilitators that support the Bazaar extension may provide a /discovery/resources endpoint that returns all x402-compatible services registered through the respective facilitator.\" \"The x402 Bazaar is in early development.\"" last_modified: 2026-10-28T00:00:00Z - id: ref-19 resource: "https://cloud.google.com/blog/products/ai-machine-learning/announcing-agents-to-payments-ap2-protocol" title: "Stavan Parikh and Rao Surapaneni, Google Cloud, Announcing Agent Payments Protocol (AP2) (Google Cloud Blog), 2025-09-16: \"Powering AI commerce with the new Agent Payments Protocol (AP2) September 16, 2025\" \"To accelerate support for the web3 ecosystem, in collaboration with Coinbase, Ethereum Foundation, MetaMask and other leading organizations, we have extended the core constructs of AP2 and launched the A2A x402 extension, a production-ready solution for agent-based crypto payments.\"" last_modified: 2025-09-16T00:00:00Z - id: ref-20 resource: "https://github.com/google-agentic-commerce/a2a-x402" title: "google-agentic-commerce/a2a-x402 GitHub repository README, checked 2026-10-28; quoted from the raw README: \"The A2A x402 Extension brings cryptocurrency payments to the Agent-to-Agent (A2A) protocol, enabling agents to monetize their services through on-chain payments.\"" last_modified: 2026-10-28T00:00:00Z - id: ref-21 resource: "https://vercel.com/blog/introducing-x402-mcp-open-protocol-payments-for-mcp-tools" title: "Ethan Niser, Vercel, Introducing x402-mcp: Open protocol payments for MCP tools (Vercel blog), 2025-09-12: \"Ethan Niser Software Engineer Blog 12 Sep 2025\" \"We built x402-mcp to integrate x402 payments with Model Context Protocol (MCP) servers and the Vercel AI SDK.\"" last_modified: 2025-09-12T00:00:00Z - id: ref-22 resource: "https://stripe.com/blog/10-lessons" title: "Roshan Sadanani, Stripe, 10 things we learned building for the first generation of agentic commerce (Stripe blog), 2026-03-12: \"agentic commerce March 12, 2026 Roshan Sadanani\" \"We're starting with support for x402 using USDC on Base, with more protocols coming.\"" last_modified: 2026-03-12T00:00:00Z - id: ref-23 resource: "https://aws.amazon.com/blogs/machine-learning/amazon-bedrock-agentcore-payments-is-now-generally-available-enabling-agents-to-transact-safely-and-autonomously-at-scale/" title: "Chethan Shriyan and Madhu Samhitha Vangara, AWS, Amazon Bedrock AgentCore payments is now generally available: Enabling agents to transact safely and autonomously at scale (AWS Machine Learning Blog), 2026-08-18: \"Madhu Samhitha Vangara on 18 AUG 2026\" \"At preview, we launched with support for the x402 protocol.\" \"Additionally, we have introduced support for the \"upto\" scheme within x402, which enables an agent to set a spending ceiling rather than committing to a fixed price.\" \"At GA, we have expanded protocol support to include the Machine Payment Protocol (MPP), another standard for machine payments co-authored by Stripe and Tempo\"" last_modified: 2026-08-18T00:00:00Z - id: ref-24 resource: "https://www.rfc-editor.org/rfc/rfc9110.html" title: "R. Fielding, M. Nottingham and J. Reschke (eds.), RFC 9110, HTTP Semantics, §15.5.3, June 2022: \"The 402 (Payment Required) status code is reserved for future use.\"" last_modified: 2022-06-01T00:00:00Z - id: ref-25 resource: "https://docs.lightning.engineering/the-lightning-network/l402/protocol-specification" title: "Lightning Labs, L402 Protocol Specification (Lightning Labs docs), checked 2026-10-28: \"Alongside the 402 status code, the server should specify the WWW-Authenticate header ([RFC 7235], Section 4.1) field to indicate the L402 authentication scheme and the macaroon needed for the client to form a complete L402.\"" last_modified: 2026-10-28T00:00:00Z - id: ref-26 resource: "https://www.chainalysis.com/blog/x402-agentic-payments-adoption/" title: "Chainalysis, Inside x402: 100M Agentic Payments on Base (Chainalysis blog), 2026-06-03: \"x402 agentic transactions on Base went from near-zero in mid 2025 to well over 100 million cumulative transactions through Q1 2026.\" \"Much of the growth was driven by meme coin farming activity.\"" last_modified: 2026-06-03T00:00:00Z - id: ref-27 resource: "https://financetracked.com/ai-agent-payments" title: "Adewale Amure, AI agent payments have rails and almost no traffic (FinanceTracked), 2026-09-18: \"Edited by Omobolade Ajibade Sep 18, 2026\" \"x402, created by Coinbase and now stewarded by the Linux Foundation, has settled $52.7 million across 198.9 million transactions on Base, Solana and Polygon since May 2025, according to TRM Labs.\" \"About half the settled value disappeared, leaving $25.62 million of likely commerce.\"" last_modified: 2026-09-18T00:00:00Z - id: ref-28 resource: "https://blog.cloudflare.com/monetization-gateway-beta/" title: "Cloudflare Blog, Monetization Gateway beta: charge AI agents for consumption with HTTP 402, 2026-09-30: \"September 30, 2026\" \"Today, we're making the Cloudflare Monetization Gateway available as part of a closed beta, and showcasing four customer use cases that are in production today.\" \"Cloudflare's AI Gateway, Ceramic.ai, Stocktwits, and more are using the Cloudflare Monetization Gateway today to charge agents for access to tokens, APIs, and MCP tools.\"" last_modified: 2026-09-30T00:00:00Z - id: ref-29 resource: "https://docs.cdp.coinbase.com/x402/seller/facilitator" title: "Coinbase Developer Platform docs, CDP Facilitator, checked 2026-10-29: \"The CDP Facilitator handles that work as a hosted service: it validates signed payments, screens transactions, submits settlement onchain, and reports the result to your resource server.\" \"The CDP Facilitator has processed more than 100 million transactions and $28 million in payment volume across Base and Solana alone.\" \"The CDP Facilitator supports all ERC-20 tokens on its EVM networks through EIP-3009 or Permit2, and SPL tokens on Solana.\"" last_modified: 2026-10-29T00:00:00Z - id: ref-30 resource: "https://docs.stripe.com/payments/machine/x402" title: "Stripe documentation, x402, checked 2026-10-29: \"Use x402 to accept payments from agents.\"" last_modified: 2026-10-29T00:00:00Z - id: ref-31 resource: "https://blog.cloudflare.com/wallets/" title: "Cloudflare Blog, Announcing Cloudflare Wallets: the programmable wallet for the agentic Internet, 2026-08-04: \"August 4, 2026\" \"Soon, you will be able to set up and use your Cloudflare Wallet to pay for APIs and content.\"" last_modified: 2026-08-04T00:00:00Z - id: ref-32 resource: "https://pkg.go.dev/github.com/x402-foundation/x402/go/v2" title: "Go Packages, x402 package - github.com/x402-foundation/x402/go/v2 (v2.29.0, published 2026-10-28), checked 2026-10-29: \"Version: v2.29.0\" \"Published: Oct 28, 2026\" \"x402.X402Client - Creates payment payloads for clients making paid requests\" \"x402http.HTTPClient - Wraps http.Client with automatic payment handling for clients\"" last_modified: 2026-10-28T00:00:00Z - id: ref-33 resource: "https://s402-protocol.org/specification" title: "s402, s402 Wire Format Specification, checked 2026-10-29: \"The 402 leg is an x402 V2 PaymentRequired envelope. What distinguishes an s402-profile 402 from a plain x402 one is the presence of extensions.s402\"" last_modified: 2026-10-29T00:00:00Z - id: ref-34 resource: "https://github.com/s402-protocol/core/blob/main/AGENTS.md" title: "s402-protocol/core, AGENTS.md on main, checked 2026-10-29: \"Retired 2026-09-25. Use x402 (https://x402.org).\" \"archived by the owner on Oct 15, 2026\"" last_modified: 2026-10-29T00:00:00Z --- # x402 x402 is an agentic-web standard (HTTP header) at step 7, Pay, governed by The x402 Foundation, a Linux Foundation project; its status is "In production use". It answers: "How can an HTTP client pay per-request or per-resource, in stablecoins, without accounts, API keys, or signup?" Replacing or extending HTTP 402 Payment Required, finally implemented, implementation status is multi-implementation (x402 Foundation), last verified 2026-10-29. # Overview x402 turns the long-unused HTTP 402 status code into a working payment step: a server that wants payment returns 402 with machine-readable requirements, and the client pays by retrying the same request with a signed payment [^ref-1][^ref-11]. It was launched by Coinbase in May 2025 for stablecoin payments over HTTP and is now stewarded by the x402 Foundation at the Linux Foundation [^ref-1][^ref-3][^ref-4]. Version 2, from December 2025, moved all HTTP payment data into headers, adopted CAIP-2 network identifiers and added extensions, while the reference SDKs still accept version 1 [^ref-9][^ref-14]. Facilitators handle verification and settlement for servers, the Bazaar lets agents find paid endpoints, and transports beyond HTTP, including MCP and A2A, carry the same messages [^ref-9][^ref-13][^ref-16][^ref-18]. A Sui-focused profile, s402, carried `extensions.s402` inside an x402 V2 `PaymentRequired` envelope before retiring on 2026-09-25 and archiving its repository on 2026-10-15 with a pointer to x402 [^ref-33][^ref-34]. # Examples ```http GET {origin}/{paid-path} # parse: HTTP 402 status with a base64-encoded PaymentRequired object in the PAYMENT-REQUIRED response header (x402 v2 HTTP transport) # on absent: A 200 or a 402 without a PAYMENT-REQUIRED header means this specific path is not (or no longer) gated by x402 v2 over HTTP; the same origin could still use x402 over the MCP or other transports, or the legacy v1 header shape, so the probe only rules out v2/HTTP on the probed path. ``` # Knowledge Graph * **Lifecycle Step**: [7 Pay](/category/pay/index.md) * **Depended on by**: [Agora (agent marketplace protocol)](/okf/protocols/agora-commerce-protocol.md), [s402](/okf/protocols/s402.md) * **Pairs with**: [Machine Payments Protocol (MPP)](/okf/protocols/mpp.md), [L402](/okf/protocols/l402.md), [Agent Payments Protocol (AP2)](/okf/protocols/ap2.md), [Cloudflare Pay Per Crawl](/okf/protocols/cloudflare-pay-per-crawl.md), [Agent2Agent Protocol (A2A)](/okf/protocols/a2a.md), [Agentic Commerce Protocol](/okf/protocols/agentic-commerce-protocol.md) * **Related terms**: [Facilitator](/okf/terms/facilitator.md), [HTTP 402 Payment Required](/okf/terms/http-402-payment-required.md), [Pay per crawl](/okf/terms/pay-per-crawl.md), [x402 Payment Payload](/okf/terms/x402-payment-payload.md), [Buyer of Record & Merchant of Record (Agentic Commerce)](/okf/terms/buyer-of-record.md) * **Compared in**: [API Keys & Subscriptions vs x402 & MPP (HTTP 402) (classic vs agentic)](/compare/api-keys-vs-x402/index.md), [x402 vs Agent Payments Protocol (AP2)](/compare/x402-vs-ap2/index.md), [x402 vs Machine Payments Protocol (MPP)](/compare/x402-vs-mpp/index.md), [x402 vs L402](/compare/x402-vs-l402/index.md), [Cloudflare Pay Per Crawl vs x402](/compare/cloudflare-pay-per-crawl-vs-x402/index.md), [x402 vs Agentic Commerce Protocol](/compare/x402-vs-agentic-commerce-protocol/index.md), [x402 vs Universal Commerce Protocol (UCP)](/compare/x402-vs-ucp/index.md), [KYAPay Token vs x402](/compare/kyapay-token-vs-x402/index.md), [ERC-8183: Agentic Commerce vs x402](/compare/erc-8183-vs-x402/index.md), [s402 vs x402](/compare/s402-vs-x402/index.md) [^ref-1]: Erik Reppel, Nemil Dalal and Dan Kim, Coinbase, Introducing x402: a new standard for internet-native payments (Coinbase Developer Platform), 2025-05-06: "Introducing x402: a new standard for internet-native payments May 6, 2025 By: Erik Reppel, Nemil Dalal, Dan Kim" "Coinbase is launching x402, a payment protocol that enables instant stablecoin payments directly over HTTP." "x402 solves this by resurrecting the HTTP 402 "Payment Required" status code, a dormant feature of the web designed for seamless payment requests within standard HTTP interactions." (https://www.coinbase.com/developer-platform/discover/launches/x402) [^ref-2]: Will Allen, Cam Whiteside, Rohin Lohe and Steve James, Launching the x402 Foundation with Coinbase, and support for x402 transactions (Cloudflare Blog), 2025-09-23: "September 23, 2025 Launching the x402 Foundation with Coinbase, and support for x402 transactions" "Cloudflare is partnering with Coinbase to create the x402 Foundation." "In addition to today's partnership, we are shipping a set of features to allow developers to use x402 in the Agents SDK and our MCP integrations, as well as proposing a new deferred payment scheme." "Agents built using Cloudflare's Agent SDK can now pay for resources with x402, and MCP servers can expose tools to be paid for via x402." (https://blog.cloudflare.com/x402/) [^ref-3]: Linux Foundation, Linux Foundation is Launching the x402 Foundation and Welcoming the Contribution of the x402 Protocol (press release), 2026-04-02: "NEW YORK – MCP Dev Summit North America – April 2, 2026" "today announced it is launching the x402 Foundation with the contribution of the x402 protocol from Coinbase." "The x402 Foundation, the standard's governing body, initially developed by Coinbase, Cloudflare, and Stripe, is launching with a broad set of industry participants as it migrates toward an open source model for the benefit of all internet-native payments." (https://www.linuxfoundation.org/press/linux-foundation-is-launching-the-x402-foundation-and-welcoming-the-contribution-of-the-x402-protocol) [^ref-4]: Linux Foundation, Linux Foundation Announces Operational Launch of x402 Foundation to Standardize Internet-Native Payments for AI Agents and Applications (press release), 2026-07-14: "July 14, 2026 – The Linux Foundation, the nonprofit organization enabling mass innovation through open source, today announced the operational launch of the x402 Foundation and the completed contribution of the x402 protocol by Coinbase." "Since the Foundation's intent to launch in April, 40 organizations have joined as members." "Premier members include Adyen, Amazon Web Services (AWS), American Express, Circle, Cloudflare, Coinbase, Fiserv, Google, Mastercard, Monad Foundation, MoonPay, Ripple, Shopify, Solana Foundation, Stellar Development Foundation, Stripe, and Visa." "x402 was started at Coinbase to solve a real problem – AI agents had no native, interoperable way to pay for the things they needed to do." (https://www.linuxfoundation.org/press/linux-foundation-announces-operational-launch-of-x402-foundation-to-standardize-internet-native-payments-for-ai-agents-and-applications) [^ref-5]: x402 Foundation, Linux Foundation Appoints Michael Hursta as Executive Director of the x402 Foundation (x402.org), 2026-10-01: "SAN FRANCISCO, Oct. 1, 2026" "The Linux Foundation appointed payments veteran Michael Hursta as Executive Director of the x402 Foundation." (https://x402.org/linux-foundation-appoints-michael-hursta-as-executive-director-of-the-x402-foundation/) [^ref-6]: x402.org home page, checked 2026-10-28: "x402 is an open, neutral standard for internet-native payments." "Copyright © x402 a Series of LF Projects, LLC" (https://x402.org/) [^ref-7]: x402-foundation/x402, TSC.md (Technical Steering Committee members), checked 2026-10-28; quoted from the raw file: "Coinbase, Inc. Erik Reppel Cloudflare, Inc. Rohin Lohe Stripe, Inc. Steve Kaliski" (https://github.com/x402-foundation/x402/blob/main/TSC.md) [^ref-8]: x402-foundation/x402 GitHub repository (Apache-2.0), checked 2026-10-28; quoted from the GitHub API record: ""description": "A payments protocol for the internet. Built on HTTP."" ""created_at": "2025-02-21T01:17:52Z"" (https://github.com/x402-foundation/x402) [^ref-9]: x402-foundation/x402, x402 Protocol Specification v2 (specs/x402-specification-v2.md), checked 2026-10-28; quoted from the raw file: "Protocol Version: 2" "v2.0 2025-12-9 Protocol v2: CAIP-2 networks, restructured PaymentPayload/Required, ResourceInfo separation, extensions support" "Payment schemes: Extensible payment methods (including exact, upto, and batch-settlement; see specs/schemes/)" "Networks in x402 v2 use CAIP-2 (Chain Agnostic Improvement Proposal) format: namespace:reference." "Format: {namespace}:{reference} (e.g., eip155:8453 for Base mainnet)" "Both EVM and Solana networks are supported by the reference implementations, e.g.:" "This enables the creation of marketplaces (known as "Bazaars") where users can discover and access monetized APIs and digital services." "Representation: How payment data is transmitted and signaled, which depends on the transport mechanism (e.g., HTTP, MCP, A2A)" (https://github.com/x402-foundation/x402/blob/main/specs/x402-specification-v2.md) [^ref-10]: x402-foundation/x402, x402 Protocol Specification v1 (specs/x402-specification-v1.md), checked 2026-10-28; quoted from the raw file: "Protocol Version: 1" (https://github.com/x402-foundation/x402/blob/main/specs/x402-specification-v1.md) [^ref-11]: x402-foundation/x402, HTTP transport for v2 (specs/transports-v2/http.md), checked 2026-10-28; quoted from the raw file: "Mechanism: HTTP 402 status code with PAYMENT-REQUIRED header" "Clients send payment data using the PAYMENT-SIGNATURE HTTP header." "Servers communicate payment settlement results using the PAYMENT-RESPONSE header." (https://github.com/x402-foundation/x402/blob/main/specs/transports-v2/http.md) [^ref-12]: x402-foundation/x402, HTTP transport for v1 (specs/transports-v1/http.md), checked 2026-10-28; quoted from the raw file: "Mechanism: HTTP 402 status code with JSON response body" "Clients send payment data using the X-PAYMENT HTTP header." "Servers communicate payment settlement results using the X-PAYMENT-RESPONSE header." (https://github.com/x402-foundation/x402/blob/main/specs/transports-v1/http.md) [^ref-13]: x402-foundation/x402, A2A transport for v2 (specs/transports-v2/a2a.md), checked 2026-10-28; quoted from the raw file: "The A2A transport implements x402 payment flows over the Agent-to-Agent protocol using JSON-RPC messages and task-based state management." (https://github.com/x402-foundation/x402/blob/main/specs/transports-v2/a2a.md) [^ref-14]: Erik Reppel, Carson Roscoe and Josh Nickerson, Introducing x402 V2: Evolving the Standard for Internet-native Payments (x402.org), 2025-12-11: "Introducing x402 V2: Evolving the Standard for Internet-native Payments By x402 December 11, 2025" "x402 launched in May 2025 with a simple idea: embed payments directly into HTTP using the long-dormant 402 status code." "Moving all payment data to headers for the HTTP transport, freeing up response body to be used alongside a 402 status code and Payment Required header" "x402's reference SDKs are fully backward-compatible with V1." (https://x402.org/x402-v2-launch/) [^ref-15]: x402 Foundation, Introducing x402 Batch Settlement: High-velocity Agentic Commerce (x402.org), 2026-05-11: "The x402 protocol is introducing batch settlement, enabling agents to transact at extremely low latency and fractions of a cent." (https://x402.org/x402-batch-settlement/) [^ref-16]: x402 documentation, Facilitators (docs.x402.org), checked 2026-10-28: "Facilitators verify and settle x402 payments on behalf of resource servers. Anyone can run a facilitator." "The table below lists selected production options; it is not an exhaustive catalog." "CDP Facilitator Coinbase-hosted facilitator with KYT/OFAC checks on every transaction" (https://docs.x402.org/dev-tools/facilitators) [^ref-17]: x402 documentation, Networks & Token Support (docs.x402.org), checked 2026-10-28: "x402 supports tokens on EVM, Solana, TON, Algorand (AVM), Stellar, Aptos, Hedera, Keeta, NEAR, Concordium, XRPL, Cardano, Sui, and Canton networks:" (https://docs.x402.org/core-concepts/network-and-token-support) [^ref-18]: x402 documentation, Bazaar (Discovery Layer) (docs.x402.org), checked 2026-10-28: "The x402 Bazaar is the discovery layer for the x402 ecosystem - a machine-readable catalog that helps developers and AI agents find and integrate with x402-compatible API endpoints and MCP tools. Think of it as a search index for payable APIs and MCP tools, enabling the autonomous discovery and consumption of services." "Facilitators that support the Bazaar extension may provide a /discovery/resources endpoint that returns all x402-compatible services registered through the respective facilitator." "The x402 Bazaar is in early development." (https://docs.x402.org/extensions/bazaar) [^ref-19]: Stavan Parikh and Rao Surapaneni, Google Cloud, Announcing Agent Payments Protocol (AP2) (Google Cloud Blog), 2025-09-16: "Powering AI commerce with the new Agent Payments Protocol (AP2) September 16, 2025" "To accelerate support for the web3 ecosystem, in collaboration with Coinbase, Ethereum Foundation, MetaMask and other leading organizations, we have extended the core constructs of AP2 and launched the A2A x402 extension, a production-ready solution for agent-based crypto payments." (https://cloud.google.com/blog/products/ai-machine-learning/announcing-agents-to-payments-ap2-protocol) [^ref-20]: google-agentic-commerce/a2a-x402 GitHub repository README, checked 2026-10-28; quoted from the raw README: "The A2A x402 Extension brings cryptocurrency payments to the Agent-to-Agent (A2A) protocol, enabling agents to monetize their services through on-chain payments." (https://github.com/google-agentic-commerce/a2a-x402) [^ref-21]: Ethan Niser, Vercel, Introducing x402-mcp: Open protocol payments for MCP tools (Vercel blog), 2025-09-12: "Ethan Niser Software Engineer Blog 12 Sep 2025" "We built x402-mcp to integrate x402 payments with Model Context Protocol (MCP) servers and the Vercel AI SDK." (https://vercel.com/blog/introducing-x402-mcp-open-protocol-payments-for-mcp-tools) [^ref-22]: Roshan Sadanani, Stripe, 10 things we learned building for the first generation of agentic commerce (Stripe blog), 2026-03-12: "agentic commerce March 12, 2026 Roshan Sadanani" "We're starting with support for x402 using USDC on Base, with more protocols coming." (https://stripe.com/blog/10-lessons) [^ref-23]: Chethan Shriyan and Madhu Samhitha Vangara, AWS, Amazon Bedrock AgentCore payments is now generally available: Enabling agents to transact safely and autonomously at scale (AWS Machine Learning Blog), 2026-08-18: "Madhu Samhitha Vangara on 18 AUG 2026" "At preview, we launched with support for the x402 protocol." "Additionally, we have introduced support for the "upto" scheme within x402, which enables an agent to set a spending ceiling rather than committing to a fixed price." "At GA, we have expanded protocol support to include the Machine Payment Protocol (MPP), another standard for machine payments co-authored by Stripe and Tempo" (https://aws.amazon.com/blogs/machine-learning/amazon-bedrock-agentcore-payments-is-now-generally-available-enabling-agents-to-transact-safely-and-autonomously-at-scale/) [^ref-24]: R. Fielding, M. Nottingham and J. Reschke (eds.), RFC 9110, HTTP Semantics, §15.5.3, June 2022: "The 402 (Payment Required) status code is reserved for future use." (https://www.rfc-editor.org/rfc/rfc9110.html) [^ref-25]: Lightning Labs, L402 Protocol Specification (Lightning Labs docs), checked 2026-10-28: "Alongside the 402 status code, the server should specify the WWW-Authenticate header ([RFC 7235], Section 4.1) field to indicate the L402 authentication scheme and the macaroon needed for the client to form a complete L402." (https://docs.lightning.engineering/the-lightning-network/l402/protocol-specification) [^ref-26]: Chainalysis, Inside x402: 100M Agentic Payments on Base (Chainalysis blog), 2026-06-03: "x402 agentic transactions on Base went from near-zero in mid 2025 to well over 100 million cumulative transactions through Q1 2026." "Much of the growth was driven by meme coin farming activity." (https://www.chainalysis.com/blog/x402-agentic-payments-adoption/) [^ref-27]: Adewale Amure, AI agent payments have rails and almost no traffic (FinanceTracked), 2026-09-18: "Edited by Omobolade Ajibade Sep 18, 2026" "x402, created by Coinbase and now stewarded by the Linux Foundation, has settled $52.7 million across 198.9 million transactions on Base, Solana and Polygon since May 2025, according to TRM Labs." "About half the settled value disappeared, leaving $25.62 million of likely commerce." (https://financetracked.com/ai-agent-payments) [^ref-28]: Cloudflare Blog, Monetization Gateway beta: charge AI agents for consumption with HTTP 402, 2026-09-30: "September 30, 2026" "Today, we're making the Cloudflare Monetization Gateway available as part of a closed beta, and showcasing four customer use cases that are in production today." "Cloudflare's AI Gateway, Ceramic.ai, Stocktwits, and more are using the Cloudflare Monetization Gateway today to charge agents for access to tokens, APIs, and MCP tools." (https://blog.cloudflare.com/monetization-gateway-beta/) [^ref-29]: Coinbase Developer Platform docs, CDP Facilitator, checked 2026-10-29: "The CDP Facilitator handles that work as a hosted service: it validates signed payments, screens transactions, submits settlement onchain, and reports the result to your resource server." "The CDP Facilitator has processed more than 100 million transactions and $28 million in payment volume across Base and Solana alone." "The CDP Facilitator supports all ERC-20 tokens on its EVM networks through EIP-3009 or Permit2, and SPL tokens on Solana." (https://docs.cdp.coinbase.com/x402/seller/facilitator) [^ref-30]: Stripe documentation, x402, checked 2026-10-29: "Use x402 to accept payments from agents." (https://docs.stripe.com/payments/machine/x402) [^ref-31]: Cloudflare Blog, Announcing Cloudflare Wallets: the programmable wallet for the agentic Internet, 2026-08-04: "August 4, 2026" "Soon, you will be able to set up and use your Cloudflare Wallet to pay for APIs and content." (https://blog.cloudflare.com/wallets/) [^ref-32]: Go Packages, x402 package - github.com/x402-foundation/x402/go/v2 (v2.29.0, published 2026-10-28), checked 2026-10-29: "Version: v2.29.0" "Published: Oct 28, 2026" "x402.X402Client - Creates payment payloads for clients making paid requests" "x402http.HTTPClient - Wraps http.Client with automatic payment handling for clients" (https://pkg.go.dev/github.com/x402-foundation/x402/go/v2) [^ref-33]: s402, s402 Wire Format Specification, checked 2026-10-29: "The 402 leg is an x402 V2 PaymentRequired envelope. What distinguishes an s402-profile 402 from a plain x402 one is the presence of extensions.s402" (https://s402-protocol.org/specification) [^ref-34]: s402-protocol/core, AGENTS.md on main, checked 2026-10-29: "Retired 2026-09-25. Use x402 (https://x402.org)." "archived by the owner on Oct 15, 2026" (https://github.com/s402-protocol/core/blob/main/AGENTS.md)