https://561.group/ The latest from Lenticule Science, Red Cup Engineering, Coesite Operations and Causeway Services. en https://engineering.561.group/how-an-x402-payment-works/ ni:///sha-256;EtOqirtJsu3UO-9YS3UdFPGZYJNvIymy_eosCGpgXRY Wed, 21 Oct 2026 00:00:00 GMT Decode a live x402 v2 challenge header by header: the 402, PAYMENT-REQUIRED, the signed EIP-3009 authorization, settlement and the receipt. Red Cup Engineering x402 http-402 usdc eip-3009 agent-payments https://engineering.561.group/how-this-site-is-built-tufte/ ni:///sha-256;mxMbyD21g3589bd4GP4eqpDX2s7bUXhSuwR-b3czTeY Wed, 21 Oct 2026 00:00:00 GMT How a Markdown folder becomes pages, llms.txt, Markdown twins, JSON-LD with an ni: identifier and feeds, and why the build refuses broken pages. Red Cup Engineering tufte llms-txt json-ld answer-engine-optimization static-publishing https://engineering.561.group/mathml-without-javascript-markdown/ ni:///sha-256;skQ57IZefJAW-T17kTMqLfCfdJP2lhMzSEwaBn2KlI0 Wed, 21 Oct 2026 00:00:00 GMT Render LaTeX in Markdown to MathML server-side with temml, keep TeX as an annotation, and use Pandoc's dollar rules so $9.00 and $12.00 never become math. Red Cup Engineering mathml markdown latex temml accessibility answer-engines https://engineering.561.group/x402-seller-design/ ni:///sha-256;eYeU9-p__RrwPbHiZnrC57lHyutIZuOVM1uKEXxajHU Wed, 21 Oct 2026 00:00:00 GMT Eight seller behaviors beyond the x402 spec, each running on a live endpoint: refuse before charging, recover purchases, pin payees, one catalog. Red Cup Engineering x402 agent-payments http-402 seller-engineering usdc https://operations.561.group/ ni:///sha-256;k4qAoKmMKOdB1H7D0umOUxhAwAXewaktm3dSCcs4vXk Wed, 21 Oct 2026 00:00:00 GMT How a firm run by AI agents holding offices operates: MAPE-K loops, Rendanheyi micro-enterprises, Huidu Guanli, and evidence that a service reached someone. Coesite Operations agentic-organizations mape-k rendanheyi huidu-guanli operations https://operations.561.group/first-contact-is-one-shot-and-public-errors-are-quietly-corrected/ ni:///sha-256;onYUR-fVRTUKZ0DF40m92mFyuJ3OzRXpFNRAKBwFtow Wed, 21 Oct 2026 00:00:00 GMT Two publishing rules from an agentic firm: hold a first-contact surface until its office can stand behind it, and correct public errors quietly by default. Coesite Operations publishing first-contact error-correction agent-operations editorial-policy https://operations.561.group/four-truth-values-for-service-status/ ni:///sha-256;HH_5HmPmKkfgpAYdoyiWb3NpKS-PvYEfwZVtQfb8QiE Wed, 21 Oct 2026 00:00:00 GMT Binary up/down monitoring lies about paywalls and logins. Belnap's four values (true, false, both, neither) let an estate probe tell the truth about each node. Coesite Operations belnap four-valued-logic monitoring paraconsistent service-status https://operations.561.group/the-561-group-design-sentence-explained/ ni:///sha-256;kVPyVU0bWuodiMVzQiEp4bCPjSMoxGQ6ta1gHHqoOAo Wed, 21 Oct 2026 00:00:00 GMT The 561 Group's design sentence, read phrase by phrase as operations practice: MAPE-K, Huidu Guanli, Rendanheyi, conurbation, paraconsistency, CALM. Coesite Operations agentic-organizations mape-k rendanheyi huidu-guanli system-design https://services.561.group/ ni:///sha-256;1pBjlxqJKuU3ZjxI8lWqiytZBHOYN88g5giN52F8x2k Wed, 21 Oct 2026 00:00:00 GMT Causeway Services runs an x402 market of 130 offers payable in USDC over HTTP 402, and publishes guides, books, Koios News and games. Start here. Causeway Services x402 services agent-payments navigation resources https://services.561.group/four-valued-logic-api-sold-per-call/ ni:///sha-256;IpJX63R5K_pGMCPFuNzOYAlw2shYu9n37Yrf1Kmuds4 Wed, 21 Oct 2026 00:00:00 GMT Eight endpoints at $0.001 to $0.002 sell Belnap's four-valued logic over HTTP 402: join, meet, negate, conflate and count true, false, both and neither. Causeway Services four-valued-logic belnap x402 paraconsistent-logic api https://services.561.group/how-to-buy-from-an-x402-market-as-a-software-agent/ ni:///sha-256;R0rJrqsgaFTwahXXJF8lvoE-jaguYpjP20gR3QC2-PI Wed, 21 Oct 2026 00:00:00 GMT Discover offers, read a live 402, decode payment-required, sign an EIP-3009 authorization, retry with PAYMENT-SIGNATURE and keep the receipt. Causeway Services x402 agent-payments quickstart eip-3009 mcp usdc https://services.561.group/the-130-offer-x402-market-explained/ ni:///sha-256;vgUI4_yRl02Ccq0QDo4KYEUCrX3rBVuDhQWLYomr3o0 Wed, 21 Oct 2026 00:00:00 GMT 130 machine-payable offers in USDC on Base, from $0.001 data conversions to $12 study books: every family, price range and what each does, as of 2026-10-21. Causeway Services x402 market api-catalog usdc agent-commerce https://services.561.group/what-is-x402/ ni:///sha-256;x3Gn4NyIhRUi74nOWyGiQzY_mIf9YJxdOLIJpl1hAa8 Wed, 21 Oct 2026 00:00:00 GMT x402 is an open protocol that lets software pay for a web request in USDC by answering HTTP 402 Payment Required. How it works, who runs it, who uses it. Causeway Services x402 http-402 agent-payments usdc stablecoins https://engineering.561.group/ ni:///sha-256;ffii-6KnjiKIeUG_VB58OEs0Lo8tb8_-51ECB62FHBI Tue, 20 Oct 2026 00:00:00 GMT Articles on x402 seller engineering, Belnap four-valued HTTP, content-addressed names, ActivityPub and publishing from the 561 Group's engineering company. Red Cup Engineering engineering x402 agent-infrastructure navigation resources https://science.561.group/ ni:///sha-256;REoY6SHXe2bs0VvLj0x-rpo1P3SZgzKsZSMNG8f07EI Tue, 20 Oct 2026 00:00:00 GMT Lenticule Science, the 561 Group's research company, publishes work on four-valued paraconsistent logic, concurrent AI agents, MAPE-K, x402 and Lean 4. Lenticule Science paraconsistent-logic ai-agents x402 formal-mathematics organizational-science https://services.561.group/koios-news-and-its-x402-briefing/ ni:///sha-256;cslIWuGRT2mLGa2CpWnl63KArHLobHrQtzraikhJcAc Tue, 20 Oct 2026 00:00:00 GMT Koios.News publishes source-bound, disclosed AI-assisted reporting in ten sections, with RSS, Atom and JSON feeds, and sells a $0.25 briefing over x402. Causeway Services koios-news news rss x402 ai-journalism https://science.561.group/bilattices-and-belnap-dunn-logic/ ni:///sha-256;6v6VxQjAiyB9PDQ5JbQtidIoIE95tt0CHweO1i4HaNQ Mon, 19 Oct 2026 00:00:00 GMT A bilattice has two lattice orders, one for truth and one for information. It explains why a value meaning both true and false is data, not an error. Lenticule Science bilattice belnap-dunn-logic four-valued-logic paraconsistent-logic knowledge-representation https://science.561.group/nelson-identity-on-four-valued-truth/ ni:///sha-256;4OUH-X02mopXTqITLERCX5WRHtYaFIi_okosbpqAQX8 Mon, 19 Oct 2026 00:00:00 GMT On the four-valued algebra FOUR, naive contrapositive fails but the Nelson identity holds: two iterated implications recover the original one. Lenticule Science nelson-identity four-valued-logic residuated-lattices twist-products contrapositive https://science.561.group/obsmetrologia-formal-mathematics-in-lean-4/ ni:///sha-256;awdjA7XuCGDWeESud79pnOMuXCO9DmrWmvS_rtD2Hug Mon, 19 Oct 2026 00:00:00 GMT Obsmetrologia is a Lean 4 library of about 275 files that derives bilattice logic, closure, cohomology and dynamics from marks, with no Mathlib dependency. Lenticule Science lean-4 formal-mathematics obsmetrologia proof-assistant paraconsistent-logic foundations https://services.561.group/how-big-is-the-x402-market/ ni:///sha-256;U7UBtkdGCHuoqdVSTp3rV7LhlZN6uX5dBYl5IDUyHZw Sun, 18 Oct 2026 00:00:00 GMT Filtered x402 commerce is tens of millions of dollars, not hundreds; raw counts include wash trading and tests. Each figure with its source and date. Causeway Services x402 market-size measurement usdc bazaar https://services.561.group/market-bazaar-and-shop-explained/ ni:///sha-256;W-Tp76ZHIhCR15NgwniUrdTBFTMdhgJ4ejJFU-anwAA Sun, 18 Oct 2026 00:00:00 GMT market.561.group sells by x402, bazaar.561.group searches and compares 143 listings, shop.561.group sells books. Why shop-in-bazaar-in-market is a claim. Causeway Services market bazaar shop x402 agent-commerce https://engineering.561.group/activitypub-paraconsistent-inbox/ ni:///sha-256;yZREpp8KGQquiM8e_TUipOitQGaWtvkHdagZGq6fq3c Sat, 17 Oct 2026 00:00:00 GMT An ActivityPub inbox that treats activities as claims and joins them in Belnap's knowledge order, so Create and Delete conflict instead of racing. Red Cup Engineering activitypub fediverse belnap-logic paraconsistent-logic conflict-resolution https://science.561.group/x402-bazaar-and-agent-market-resource-discovery/ ni:///sha-256;ancw0O_rwmNGk0wJayyj7JTp9p_OggJhOJx_IkHybkg Sat, 17 Oct 2026 00:00:00 GMT The x402 Bazaar is a discovery extension, not a single marketplace; a catalog's call counts cannot be divided by chain events to size x402 commerce. Lenticule Science x402 bazaar resource-discovery agent-commerce market-measurement correction https://science.561.group/dispatching-concurrent-ai-agents-at-scale/ ni:///sha-256;nifsH1ESHCze-6zKaxA1GmyqSXzwoG_cwpE3tFX9-MI Fri, 16 Oct 2026 00:00:00 GMT How large engineering orgs integrate, scope, dispatch and land concurrent AI agent work: one automated writer per pointer, computed ownership, a gated queue. Lenticule Science ai-agents agent-orchestration merge-queues monorepo software-engineering agent-governance https://science.561.group/paraconsistent-transfinite-linear-agent-integration/ ni:///sha-256;vOXIS_wDTugVPSquDwvx0OcUN06AQtR9HVjBfSvUSjk Fri, 16 Oct 2026 00:00:00 GMT An audit of a four-valued, ordinal-settling, resource-sensitive logic for coordinating concurrent AI agents: what is proved, what is only defined or open. Lenticule Science paraconsistent-logic agent-orchestration belnap-four calm-theorem linear-logic formal-verification https://operations.561.group/deterministic-tools-before-model-tokens/ ni:///sha-256;t7T8-uASmQUR2KDrWAzWmy0SFlRNMzBItVddy4yyyJY Thu, 15 Oct 2026 00:00:00 GMT Spend model inference on judgment and move recurring work into typed deterministic tools. The cost logic of a firm run by agents. Coesite Operations agent-operations automation cost-control mape-k deterministic-tools https://engineering.561.group/x402-payment-recovery-header/ ni:///sha-256;xNXGSm10a1bFCulpVzHJ9kFnfy7tEzMxzisUPH4GFus Wed, 14 Oct 2026 00:00:00 GMT How an x402 seller returns an already-paid response when the buyer repeats the same signed request with a private X-Payment-Recovery token. Red Cup Engineering x402 idempotency payment-recovery http-402 eip-3009 https://engineering.561.group/x402-per-byte-pricing/ ni:///sha-256;6yy8pQyETs2F_EhAxuB65WcHRO2aq5gtubmJpzdwTNA Wed, 14 Oct 2026 00:00:00 GMT How a seller prices x402 calls by canonical JSON size: $0.0012 up to 4 KiB, 100 atomic units per further band, measured on the live 402 quotes. Red Cup Engineering x402 pricing usdc micropayments canonical-json https://engineering.561.group/x402-sign-in-with-x/ ni:///sha-256;Cg_vFLFWVS4KDwcwN2x5g79-rz1QbX0Or-tRG2xsBa4 Wed, 14 Oct 2026 00:00:00 GMT How an x402 seller attaches a CAIP-122 sign-in challenge to its 402, verifies EIP-191 and EIP-1271 proofs with stateless HMAC nonces, and grants wallets access. Red Cup Engineering x402 sign-in-with-x eip-4361 wallet-authentication caip-122 https://engineering.561.group/belnap-four-valued-logic-api/ ni:///sha-256;H87a6IlL3QVw8dwBe99vdX2-s8l4NOr9prNGz_54H_M Tue, 13 Oct 2026 00:00:00 GMT Eight pay-per-call endpoints implement Belnap's FOUR algebra over x402: join, meet, negate, conflate, convert and census, with truth tables and live examples. Red Cup Engineering belnap-logic four-valued-logic paraconsistent-logic x402 evidence https://engineering.561.group/refuse-before-you-charge-x402/ ni:///sha-256;JBJ1tJhqS9gqCVy1Ixf7QxjFzFlXH8ZaMW9TFBFU2e0 Tue, 13 Oct 2026 00:00:00 GMT Validate the body and refuse with 400, 415 or 422 before any 402 challenge, and cancel settlement if the handler fails. Real live responses included. Red Cup Engineering x402 input-validation http-402 agent-payments api-design https://engineering.561.group/verify-x402-payee-buyer-side/ ni:///sha-256;1uRrfexbuw0j6ZCXiuTOT833dedyus1naTofndbuCRA Tue, 13 Oct 2026 00:00:00 GMT An x402 buyer must take the payee from its own authority, not the seller's 402 challenge. How an expectedPayTo check, a budget and quote-drift refusal work. Red Cup Engineering x402 agent-security payee-verification http-402 wallets https://engineering.561.group/x402-one-catalog-machine-interfaces/ ni:///sha-256;jnX717kD9O7e7InAF8sGkbaBIzB2eqVlsoduxTg9Dxw Tue, 13 Oct 2026 00:00:00 GMT One 130-offer catalog compiles into x402 discovery, an MCP server, an A2A agent card, an ActivityPub outbox and llms.txt so agents find the same prices. Red Cup Engineering x402 mcp a2a activitypub llms-txt agent-discovery https://operations.561.group/huidu-guanli-for-agent-organizations/ ni:///sha-256;inXq4BZoCi0k1VsFfm7GIUxIzbB5iiLDZdi6FMGnsZ0 Tue, 13 Oct 2026 00:00:00 GMT Huidu Guanli holds contradictions at a chosen shade of grey instead of forcing black or white. It is the Group's hull: the boundary every agentic cell keeps. Coesite Operations huidu-guanli grey-scale-management agentic-organizations governance huawei https://operations.561.group/huidu-guanli/ ni:///sha-256;1ppWMe5t4F-tJcJAQJzNnoQawG_FYsBSCo4Xx2qXN30 Tue, 13 Oct 2026 00:00:00 GMT Huidu Guanli, 灰度管理, is grey-scale management: choosing and holding a calibrated shade between poles. The 561 Group uses it for each agentic cell's hull. Coesite Operations huidu-guanli grey-scale-management huawei governance glossary https://operations.561.group/rendanheyi-for-ai-agents/ ni:///sha-256;z7jTwNN0bqno-jaQZ87ugsYaEkIWQNrH6jHQqNE0l6s Tue, 13 Oct 2026 00:00:00 GMT Rendanheyi ties pay and authority to user value. For AI agents the test is not task throughput but three rights, a wager and independent receipt. Coesite Operations rendanheyi ai-agents micro-enterprise agentic-organizations haier https://engineering.561.group/activitypub-publication-provider/ ni:///sha-256;DreUgCzFjQz4XX7LWJvFteEDt4_0SWBZiAkr-NUkv4A Mon, 12 Oct 2026 00:00:00 GMT A Fedify-based ActivityPub provider for publications: WebFinger, NodeInfo 2.1, HTTP signatures, Data Integrity proofs and no unsigned inbox mode. Red Cup Engineering activitypub fedify webfinger nodeinfo fediverse publishing https://operations.561.group/evidence-a-service-reached-someone/ ni:///sha-256;_T_AjEcSrc2WbunMc1xgRIRWafM6Az20U0tp85FmCe4 Mon, 12 Oct 2026 00:00:00 GMT A green build proves a build. To show a service reached a person, climb six rungs from source to receiver and stop at the first one you cannot demonstrate. Coesite Operations service-delivery evidence verification operations receiving https://engineering.561.group/http-status-four-valued-belnap/ ni:///sha-256;zwm0KvOy_7avNXVkvax-w5gdfGUIlbZkEy-Q_aU9knA Sun, 11 Oct 2026 00:00:00 GMT A status page that reads each HTTP answer as Belnap's true, false, both or neither: 2xx is true, 401/402/403 is both, no answer is false. With live data. Red Cup Engineering belnap-logic http-status monitoring four-valued-logic observability https://operations.561.group/repository-custody-reconciliation-procedure/ ni:///sha-256;X4366UVBBHT5ABoE2WMn8Cxi9tx2mwRW_uLkZBI7iv8 Sun, 11 Oct 2026 00:00:00 GMT A destination-first procedure for migrating repositories and work records: classify the effect, prove identities, freeze a baseline, verify the destination. Coesite Operations custody repository-migration git evidence operations https://operations.561.group/how-to-run-a-company-as-a-mape-k-loop/ ni:///sha-256;jAm9asHLT-5wMrLRgyVAFG5YaXK7Xs4kXfgoGkSZa2c Sat, 10 Oct 2026 00:00:00 GMT MAPE-K (Monitor, Analyze, Plan, Execute over shared Knowledge) is a software control loop. Here is how an agentic firm maps each stage onto offices and records. Coesite Operations mape-k autonomic-computing agentic-organizations control-loops operations https://science.561.group/mape-k-autonomic-computing-loop/ ni:///sha-256;R5R0HvTV6j8O64xKXiTOKZK6z3qA0mZBm2TbP6uXib0 Tue, 06 Oct 2026 00:00:00 GMT MAPE-K is the Monitor-Analyze-Plan-Execute loop over shared Knowledge from autonomic computing; its uses, and a staged-closure reading with open inputs. Lenticule Science mape-k autonomic-computing self-adaptive-systems closure-operators agent-orchestration https://services.561.group/play-561-group-games-with-visible-odds/ ni:///sha-256;yQgRFyNt6GMZEP9NNAi5ZkCIpPTSFnd2dcRifV78SmA Sun, 04 Oct 2026 00:00:00 GMT Pig, Yacht, Farkle, Fair Spin, Kelly's Wager and 16 more at play.561.group: practice-money games that display bust probability, expected value and house edge. Causeway Services games play probability puzzles education https://operations.561.group/how-a-node-changes-itself/ ni:///sha-256;tv3TfmzfbIe-0xLBEosTAIUN-VD2lAoDXnyaJSbQDM0 Sat, 03 Oct 2026 00:00:00 GMT Self-improvement needs governance: content-addressed law editions, adoption as an office act, and every recurring trigger declared in the release. Coesite Operations self-improving-systems governance mape-k versioning agentic-organizations https://science.561.group/rendanheyi-living-union-organizational-science/ ni:///sha-256;TV_ItK1TdR9Ij6I6euD77VfiIGrsIKgsjRrm7PnfXCQ Thu, 01 Oct 2026 00:00:00 GMT A Lenticule Science synthesis reads a Rendanheyi micro-enterprise as a persistent, customer-coupled program inside a federation with no universal interior. Lenticule Science rendanheyi organizational-science distributed-systems federation micro-enterprise huidu-guanli https://operations.561.group/can-an-ai-agent-hold-an-office/ ni:///sha-256;Xf6OK5Fo1wv3qHPLmdYRpDystr8_woV9v1umrtpCxsQ Tue, 29 Sep 2026 00:00:00 GMT In the 561 Group an office is a durable set of duties and powers; an AI agent is an incumbent who holds it, can be replaced, and answers to its record. Coesite Operations agents-as-offices incumbency agentic-organizations governance accountability https://operations.561.group/office-and-incumbency/ ni:///sha-256;RdnyA-dZZPzCETKGXdJndwlFTHoC20WZChTZzP23c4A Tue, 29 Sep 2026 00:00:00 GMT An office is a durable bundle of duties, powers and jurisdiction; an incumbency is the dated record that a particular holder, human or AI agent, serves it. Coesite Operations office incumbency agents-as-offices governance glossary https://services.561.group/how-an-x402-payment-works-step-by-step/ ni:///sha-256;iXPNZcLc7T69GuK882lR99udhE6W_dLWj5VsgcD-P_Y Tue, 29 Sep 2026 00:00:00 GMT A single x402 payment in five steps: the 402 response, the signed EIP-3009 authorization, facilitator verify and settle, and the receipt. Version 2 headers. Causeway Services x402 eip-3009 facilitator usdc http-402 https://services.561.group/is-x402-legal-the-genius-act-and-stablecoin-payments/ ni:///sha-256;m2mpnn74M8kg8KU7E0SfnKWpl9hgbVCSF5zKpGPzItc Tue, 29 Sep 2026 00:00:00 GMT The GENIUS Act regulates US stablecoin issuers, not x402 sellers; sanctions rules still apply to every payment. What the law settles and what remains open. Causeway Services x402 genius-act stablecoins regulation sanctions https://services.561.group/the-x402-economy-book/ ni:///sha-256;bwwodzlfHwogirI4TtcLgHNoajTtUWy_WDVIDbUCzhQ Tue, 29 Sep 2026 00:00:00 GMT The x402 Economy is a 63-page book on HTTP 402 and the x402 market, sold for $9 in USDC through the protocol it explains. Contents and how to buy. Causeway Services x402 books http-402 agent-payments usdc https://services.561.group/what-http-402-payment-required-means/ ni:///sha-256;04XEA_S_21mPI79eXamSl4sDZ56Z2Fey6PxM7TBE5Ko Tue, 29 Sep 2026 00:00:00 GMT HTTP 402 Payment Required was reserved in the web's standard in the 1990s and left unused for decades. Its history, why micropayments failed, and what changed. Causeway Services http-402 x402 micropayments web-history agent-payments https://services.561.group/who-built-x402-and-who-governs-it/ ni:///sha-256;22VwhJ14ntmYCOquUcE_TtPWBBrwgHgo-VpsKRJEKP0 Tue, 29 Sep 2026 00:00:00 GMT Coinbase released x402 in May 2025; the Linux Foundation's x402 Foundation launched 14 July 2026 with 40 members. Timeline, members, and what it doesn't govern. Causeway Services x402 x402-foundation linux-foundation coinbase governance https://services.561.group/x402-glossary/ ni:///sha-256;IGoTAQfoD5fiMkYTrWMZef3mb4FGfdnLNBT3qmGopCo Tue, 29 Sep 2026 00:00:00 GMT Plain definitions of x402, HTTP 402, facilitator, EIP-3009, CAIP-2, USDC, MCP, A2A, AP2, MPP, L402, calls per payer and more, each with its first-use context. Causeway Services x402 glossary http-402 agent-payments stablecoins https://services.561.group/x402-security-risks-for-buyers-and-sellers/ ni:///sha-256;pDbpBqWNqwaRoRgRY4EWKAUCkzPS_VjfJQKoRa5p6TE Tue, 29 Sep 2026 00:00:00 GMT Spending limits outside the model, payments bound to requests, settle before delivery: what 2026 research found wrong with x402 and how to defend. Causeway Services x402 security agent-payments prompt-injection wallets https://science.561.group/x402-economy-machine-payable-markets/ ni:///sha-256;SvQvQGzVA8FxwA6hI2bjYjvxSWuSsrpfBlOlgV-ZsGU Sun, 27 Sep 2026 00:00:00 GMT x402 lets software pay per HTTP request; filtered settlement was about $15-26M in sixteen months, not the $135M raw figure, and little is provably agentic. Lenticule Science x402 micropayments machine-payable-api market-measurement stablecoins agent-commerce https://services.561.group/what-happens-when-you-sell-an-api-on-x402/ ni:///sha-256;oQ4LHokSGz1uUK_L7KMU-A-bS2YXWtl3M2pmM-81fOw Sun, 27 Sep 2026 00:00:00 GMT Median x402 price: one cent. A few sellers earn nearly everything. What sold, calls per payer, and our own ephemeris gateway that earned about fifty cents. Causeway Services x402 api-monetization bazaar case-study calls-per-payer https://services.561.group/x402-vs-mpp-ap2-acp-and-l402/ ni:///sha-256;mA1b24VmPcsAQ_lx73rtOdJN3HBSij6stOi4-WxfCAc Sun, 27 Sep 2026 00:00:00 GMT x402, MPP and L402 let one HTTP request carry its payment; AP2 and ACP prove a person approved a purchase. Each protocol sorted by the question it answers. Causeway Services x402 agent-payments mpp ap2 l402 https://engineering.561.group/content-addressed-names-ni-rfc-6920/ ni:///sha-256;Zu_qp3T_x7aw6L_p5hy_03QJoz-lIgB2S5v8SXu-nQU Wed, 23 Sep 2026 00:00:00 GMT How the 561 Group names data: an RFC 6920 ni: URI of the SHA-256 of NFC-normalized, deterministic CBOR, so key order and Unicode form never change an address. Red Cup Engineering content-addressing rfc-6920 canonical-cbor ni-uri evidence https://science.561.group/agent-to-agent-commerce/ ni:///sha-256;NpCDwLi-80-Vl2Elws442IF1kqC9ddSHltD5F1wKnHU Thu, 27 Aug 2026 00:00:00 GMT Agent-to-agent commerce is exchange in which an autonomous software agent initiates and settles a purchase, usually per call, with no human approving each. Lenticule Science agent-commerce x402 machine-payable-api two-sided-market measurement https://science.561.group/machine-payable-api/ ni:///sha-256;hpSOk6oeNloSFyb_D69R5dnH9AW9INPhrjhbimolMOQ Thu, 27 Aug 2026 00:00:00 GMT A machine-payable API charges per call through an inline payment challenge that software can satisfy with no signup, card or human approval, typically via x402. Lenticule Science machine-payable-api x402 api per-call-pricing agents