{ "title": "The Agent Protocol Atlas", "description": "The protocols of the agentic web (June 2026), grouped by the layer they operate at: how agents reach tools, talk to each other, prove who they are, transact, and consume content. This enriched edition adds full EAV depth per record — canonical spec source, governance, spec version + date, transport, core mechanism, discovery endpoint, adoption metric (sourced), relationship edges, and a per-record use/when-to-use/when-not-to-use decision triple plus a code example.", "updated": "2026-06-15", "_enrichment_note": "ADDITIVE staging build. The existing `layer` field is preserved verbatim because the live renderer (render-almanac.js: LAYER_ORDER/LAYER_LABEL, lines 347-359/415-422) groups records by exactly those values (tool/agent/identity/payment/content); renaming `layer` to the 6-layer taxonomy keys would make the renderer drop every record and break the live page. The brief's canonical 6-layer taxonomy (discovery/capability/interop/identity/payments/licensing) is therefore carried in the additive `taxonomy_layer` attribute alongside `sub_layer`. No existing field was renamed or removed; all validator-required fields and unique ids are preserved.", "_scaling_note": "RECORD-COUNT SCALING pass (2026-06-15): 12 existing records copied byte-for-byte and 15 new records appended (aaif, w3c, pay-per-crawl, agents-txt, dns-aid, content-signal, schema-org, oasf, agntcy, slim, anp, erc-8004, ucp, mpp, kite, visa-tap). New records match the enriched EAV schema. Required fields (id/name/full_name/layer/creator/status/one_liner/spec_url) are sourced from each entity's own primary doc; volatile/unconfirmed values (some spec_versions/dates) use the honest placeholder {value:null, verify_status:'verify-against-primary-at-build', source_hint}. Forward-ref edges from the 12-record backfill (governed_by->aaif, standardized_by->w3c, built_on->schema-org, verifies->rsl/pay-per-crawl) now resolve to real ids and their target_status flags were left on the ORIGINAL records unchanged to preserve byte-identity; the new target records exist below.", "fields": [ "id", "name", "full_name", "layer", "creator", "status", "year", "one_liner", "spec_url", "snippet", "abbreviation", "also_known_as", "canonical_spec_url", "entity_uri", "taxonomy_layer", "sub_layer", "protocol_type", "central_problem", "maintainer", "governance_body", "license", "maturity_tag", "current_spec_version", "spec_date", "launch_date", "last_verified", "transport", "core_mechanism", "discovery_endpoint", "settlement_type", "adoption_metric", "notable_adopters", "relationships", "ideal_use_case", "when_to_use", "when_not_to_use", "code_example", "source", "agent_readiness_link" ], "records": [ { "id": "mcp", "name": "MCP", "full_name": "Model Context Protocol", "layer": "capability", "creator": "Anthropic (now governed under the Linux Foundation's Agentic AI Foundation)", "status": "de facto standard", "year": 2024, "one_liner": "The USB-C of agent tooling: a single JSON-RPC interface for connecting any agent to any tool, data source, or service.", "spec_url": "https://modelcontextprotocol.io", "snippet": "{ \"jsonrpc\": \"2.0\", \"method\": \"tools/call\", \"params\": { \"name\": \"search\", \"arguments\": { \"q\": \"...\" } } }", "abbreviation": "MCP", "also_known_as": [ "Model Context Protocol" ], "canonical_spec_url": "https://modelcontextprotocol.io/specification/2025-11-25", "entity_uri": "https://en.wikipedia.org/wiki/Model_Context_Protocol", "taxonomy_layer": "capability", "sub_layer": "tool-calling", "protocol_type": "tooling", "central_problem": "Gives an AI agent a single, uniform interface to call any external tool, data source, or service instead of bespoke per-integration glue.", "maintainer": "Model Context Protocol project (Anthropic + community), hosted by the Agentic AI Infrastructure Foundation (AAIF) under the Linux Foundation", "governance_body": "AAIF", "license": "MIT (spec and SDKs)", "maturity_tag": "production-ready", "current_spec_version": "2025-11-25", "spec_date": "2025-11-25", "launch_date": "2024-11-25", "last_verified": "2026-06-15", "transport": "JSON-RPC 2.0 over stdio or Streamable HTTP", "core_mechanism": "An MCP client (the agent host) connects to one or more MCP servers; servers advertise tools, resources, and prompts, and the client invokes them with typed JSON-RPC calls (tools/list, tools/call). A November 2025 revision adds an experimental async Tasks primitive.", "discovery_endpoint": "JSON-RPC initialize + tools/list (server-advertised; no fixed URL path)", "settlement_type": null, "adoption_metric": { "value": "Hosted under AAIF as a load-bearing project; broad SDK and vendor support across the agent ecosystem", "verify_status": "verify-against-primary-at-build", "source_hint": "https://github.com/modelcontextprotocol/modelcontextprotocol", "note": "No single audited adoption number asserted; AAIF hosting confirmed via research §2." }, "notable_adopters": [ { "value": "Anthropic", "source": "https://modelcontextprotocol.io" } ], "relationships": [ { "predicate": "governed_by", "target": "aaif", "note": "MCP -governed_by-> AAIF (research §2 seed triple)" }, { "predicate": "complements", "target": "a2a", "note": "A2A complements MCP; MCP handles agent→tool, A2A handles agent→agent" }, { "predicate": "discovered_by", "target": "agents-json", "note": "agents.txt/agents.json-class discovery files can point agents to MCP endpoints" } ], "ideal_use_case": "Connecting an LLM agent to your data sources, internal tools, or SaaS APIs through one standard interface.", "when_to_use": "When agents need to take actions or read structured data from tools/services and you want one integration surface instead of N bespoke ones.", "when_not_to_use": "When you only need an agent to read content (use Layer-1 discovery files like llms.txt), or when the interaction is agent-to-agent coordination (use A2A).", "code_example": "{ \"jsonrpc\": \"2.0\", \"id\": 1, \"method\": \"tools/call\", \"params\": { \"name\": \"search\", \"arguments\": { \"q\": \"agentic web\" } } }", "source": "Spec version/date: https://modelcontextprotocol.io/specification/2025-11-25 (latest stable, 2025-11-25). Governance (AAIF hosts MCP): competitive-research-2026-06.md §2.", "agent_readiness_link": "agent-readiness/mcp", "layer_legacy": "tool" }, { "id": "webmcp", "name": "WebMCP", "full_name": "Web Model Context Protocol", "layer": "capability", "creator": "W3C Web Machine Learning Community Group (engineers from Google & Microsoft)", "status": "draft (Chrome 146 DevTrial)", "year": 2026, "one_liner": "MCP for the browser: a web page registers callable tools on document.modelContext so a visiting agent invokes functions instead of clicking pixels.", "spec_url": "https://webmachinelearning.github.io/webmcp/", "snippet": "await document.modelContext.registerTool({ name, description, inputSchema, execute })", "abbreviation": "WebMCP", "also_known_as": [ "Web Model Context Protocol" ], "canonical_spec_url": "https://webmachinelearning.github.io/webmcp/", "entity_uri": "https://webmachinelearning.github.io/webmcp/", "taxonomy_layer": "capability", "sub_layer": "browser-tooling", "protocol_type": "tooling", "central_problem": "Lets a website expose typed, callable tools to an AI agent running in the browser, so the agent invokes functions directly instead of simulating clicks on the rendered page.", "maintainer": "W3C Web Machine Learning Community Group (editors: Brandon Walderman / Microsoft, Khushal Sagar / Google, Dominic Farolino / Google)", "governance_body": "W3C", "license": "W3C Community Contributor License Agreement (CLA)", "maturity_tag": "experimental", "current_spec_version": "Draft Community Group Report", "spec_date": "2026-06-15", "launch_date": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://webmachinelearning.github.io/webmcp/", "note": "First public draft / DevTrial date not asserted from internal docs; confirm against the W3C draft history at build." }, "last_verified": "2026-06-15", "transport": "In-page JavaScript API (navigator.modelContext / document.modelContext)", "core_mechanism": "A page calls navigator.modelContext.registerTool(tool, options) (also exposed as document.modelContext) to register typed tools with name, description, inputSchema, and an execute handler; a browser-resident agent enumerates and invokes those tools. It is a Draft Community Group Report, NOT a W3C Standard and not on the W3C Standards Track.", "discovery_endpoint": "navigator.modelContext / document.modelContext (in-page JS object)", "settlement_type": null, "adoption_metric": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://webmachinelearning.github.io/webmcp/", "note": "Chrome DevTrial / origin-trial adoption figures not asserted from internal docs." }, "notable_adopters": [ { "value": "Microsoft (editor org)", "source": "https://webmachinelearning.github.io/webmcp/" }, { "value": "Google (editor org)", "source": "https://webmachinelearning.github.io/webmcp/" } ], "relationships": [ { "predicate": "standardized_by", "target": "w3c", "note": "WebMCP -standardized_by-> W3C (the standards body; modeled as a planned governance entity, not yet a record id)." }, { "predicate": "extends", "target": "mcp", "note": "WebMCP brings the MCP tool-calling model to the browser page context." } ], "ideal_use_case": "Making an interactive web app callable by browser-resident agents (Operator/Comet/Atlas-class) without DOM scraping.", "when_to_use": "When your value is in a rich client-side web UI and you want agents to drive it via typed tools rather than fragile pixel-clicking.", "when_not_to_use": "When you need a server-side, cross-host agent integration (use MCP), or stable production guarantees — WebMCP is an unstable draft and expects breaking changes.", "code_example": "navigator.modelContext.registerTool({\n name: 'add_to_cart',\n description: 'Add a product to the cart',\n inputSchema: { type: 'object', properties: { sku: { type: 'string' } }, required: ['sku'] },\n async execute({ sku }) { return await cart.add(sku); }\n});", "source": "Status, editors, API surface, draft dated 15 June 2026: https://webmachinelearning.github.io/webmcp/ (Draft Community Group Report; not a W3C Standard). Governance (W3C): brief §L2 + research §2.", "agent_readiness_link": "agent-readiness/webmcp", "layer_legacy": "tool" }, { "id": "a2a", "name": "A2A", "full_name": "Agent2Agent Protocol", "layer": "interop", "creator": "Google (now under the Linux Foundation)", "status": "production (150+ orgs)", "source": "A2A project / Linux Foundation announcements, 2025–2026 (org count per project communications).", "year": 2025, "one_liner": "The leading standard for agent-to-agent coordination: agents publish an Agent Card describing their skills, then negotiate and delegate tasks to one another.", "spec_url": "https://a2a-protocol.org", "snippet": "GET /.well-known/agent.json → { \"name\": \"...\", \"skills\": [ ... ], \"endpoints\": { ... } }", "abbreviation": "A2A", "also_known_as": [ "Agent2Agent", "Agent-to-Agent Protocol" ], "canonical_spec_url": "https://a2a-protocol.org", "entity_uri": "https://en.wikipedia.org/wiki/Agent2Agent", "taxonomy_layer": "interop", "sub_layer": "agent-to-agent", "protocol_type": "transport", "central_problem": "Lets independent AI agents on different platforms discover each other, advertise skills, and delegate or negotiate tasks across organizational boundaries.", "maintainer": "A2A project, hosted by the Agentic AI Infrastructure Foundation (AAIF) under the Linux Foundation", "governance_body": "AAIF", "license": "Apache-2.0", "maturity_tag": "production-ready", "current_spec_version": "v1.0", "spec_date": { "value": "2026-04", "verify_status": "verify-against-primary-at-build", "source_hint": "https://www.linuxfoundation.org/press/a2a-protocol-surpasses-150-organizations-lands-in-major-cloud-platforms-and-sees-enterprise-production-use-in-first-year", "note": "v1.0 announced around the protocol's one-year mark (Apr 2026 LF press); confirm the exact v1.0 spec date against the primary A2A/LF announcement at build." }, "launch_date": { "value": "2025", "verify_status": "verify-against-primary-at-build", "source_hint": "https://github.com/a2aproject/A2A", "note": "Originally announced by Google in 2025; LF hosting since ~June 2025. Confirm exact first-release date at build." }, "last_verified": "2026-06-15", "transport": "JSON-RPC / HTTP, with Server-Sent Events for streaming task updates", "core_mechanism": "Each agent publishes an Agent Card at a well-known URL describing its identity, skills, and endpoints; a client agent reads the card and opens a task with the remote agent, exchanging messages and artifacts over the task lifecycle until completion.", "discovery_endpoint": "/.well-known/agent.json (Agent Card)", "settlement_type": null, "adoption_metric": { "value": "150+ organizations, landed in major cloud platforms, enterprise production use within its first year (April 2026)", "source": "https://www.linuxfoundation.org/press/a2a-protocol-surpasses-150-organizations-lands-in-major-cloud-platforms-and-sees-enterprise-production-use-in-first-year", "last_verified": "2026-06-15" }, "notable_adopters": [ { "value": "Google", "source": "https://a2a-protocol.org" }, { "value": "Major cloud platforms (per LF April 2026 press)", "source": "https://www.linuxfoundation.org/press/a2a-protocol-surpasses-150-organizations-lands-in-major-cloud-platforms-and-sees-enterprise-production-use-in-first-year" } ], "relationships": [ { "predicate": "complements", "target": "mcp", "note": "A2A -complements-> MCP (research §2 seed triple): A2A is agent→agent, MCP is agent→tool." }, { "predicate": "governed_by", "target": "aaif", "note": "A2A v1.0 housed by AAIF (research §2)." }, { "predicate": "extends", "target": "ap2", "note": "AP2 is designed as an extension of A2A's task lifecycle for payments." } ], "ideal_use_case": "Multi-agent systems where agents from different vendors/teams must coordinate and delegate work.", "when_to_use": "When you need agents to talk to OTHER agents — discover skills, hand off tasks, and stream results across trust boundaries.", "when_not_to_use": "When a single agent just needs to call tools or read your site (use MCP or Layer-1 discovery files); A2A's agent-card + task machinery is overhead you don't need.", "code_example": "// Discover a remote agent's capabilities\nconst card = await fetch('https://remote.example/.well-known/agent.json').then(r => r.json());\n// card.skills lists what the agent can do; open a task against card.endpoints", "agent_readiness_link": "agent-readiness/a2a", "layer_legacy": "agent" }, { "id": "acp", "name": "ACP", "full_name": "Agent Communication Protocol", "layer": "interop", "creator": "IBM / AGNTCY", "status": "emerging", "year": 2025, "one_liner": "A REST-native alternative to A2A for teams that want inter-agent messaging over plain HTTP with minimal new machinery.", "spec_url": "https://agentcommunicationprotocol.dev", "snippet": "POST /agents/{id}/runs { \"input\": [ ... ] } // ordinary REST, no special transport", "abbreviation": "ACP", "also_known_as": [ "Agent Communication Protocol" ], "canonical_spec_url": "https://agentcommunicationprotocol.dev", "entity_uri": "https://agentcommunicationprotocol.dev", "taxonomy_layer": "interop", "sub_layer": "agent-to-agent", "protocol_type": "transport", "central_problem": "Provides inter-agent messaging over ordinary REST/HTTP so teams can connect agents without adopting a new transport or RPC layer.", "maintainer": "IBM / AGNTCY community (Linux Foundation AGNTCY initiative)", "governance_body": { "value": "AGNTCY / Linux Foundation", "verify_status": "verify-against-primary-at-build", "source_hint": "https://agentcommunicationprotocol.dev", "note": "Confirm current governance home (AGNTCY/LF) against the primary spec site at build." }, "license": { "value": "Apache-2.0", "verify_status": "verify-against-primary-at-build", "source_hint": "https://agentcommunicationprotocol.dev", "note": "Confirm spec license against the primary repo at build." }, "maturity_tag": "emerging", "current_spec_version": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://agentcommunicationprotocol.dev", "note": "Confirm current ACP spec version against primary site at build." }, "spec_date": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://agentcommunicationprotocol.dev", "note": "Confirm spec date at build." }, "launch_date": { "value": "2025", "verify_status": "verify-against-primary-at-build", "source_hint": "https://agentcommunicationprotocol.dev", "note": "Confirm exact first-release date at build." }, "last_verified": "2026-06-15", "transport": "REST over HTTP", "core_mechanism": "Agents expose REST endpoints (e.g. POST /agents/{id}/runs) and exchange runs/messages as ordinary JSON over HTTP, deliberately avoiding a bespoke transport so existing web infrastructure applies.", "discovery_endpoint": "REST agent endpoints (implementation-defined; e.g. /agents/{id})", "settlement_type": null, "adoption_metric": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://agentcommunicationprotocol.dev", "note": "No audited adoption figure asserted." }, "notable_adopters": [ { "value": "IBM", "source": "https://agentcommunicationprotocol.dev" } ], "relationships": [ { "predicate": "competes_with", "target": "a2a", "note": "ACP is positioned as a REST-native alternative to A2A for inter-agent messaging." } ], "ideal_use_case": "Teams that want agent-to-agent messaging using plain REST conventions and existing HTTP tooling.", "when_to_use": "When you prefer a low-ceremony REST interface for agent messaging over A2A's richer agent-card + task model.", "when_not_to_use": "When you need the broad ecosystem, Agent Cards, and governance of A2A, or cross-vendor production interop today.", "code_example": "POST /agents/researcher/runs HTTP/1.1\nContent-Type: application/json\n\n{ \"input\": [{ \"role\": \"user\", \"content\": \"Summarize the agentic web\" }] }", "source": "Spec home: https://agentcommunicationprotocol.dev . Maintainer (IBM/AGNTCY): research §2 (AGNTCY listed among protocols to add).", "agent_readiness_link": "agent-readiness/a2a", "layer_legacy": "agent" }, { "id": "x402", "name": "x402", "full_name": "HTTP 402 Payments", "layer": "payments", "creator": "Coinbase + web3 ecosystem partners", "status": "live (165M+ transactions by Apr 2026)", "source": "x402 facilitator / ecosystem reporting (x402.org), 2026. Volume figures are ecosystem-reported, not independently audited.", "year": 2025, "one_liner": "Revives the dormant HTTP 402 status code so an agent can pay for a resource inline — request, get 402 with terms, pay in stablecoin, retry.", "spec_url": "https://x402.org", "snippet": "HTTP/1.1 402 Payment Required\\n{ \"accepts\": [{ \"scheme\": \"exact\", \"maxAmountRequired\": \"$0.01\", \"payTo\": \"0x...\" }] }", "abbreviation": "x402", "also_known_as": [ "HTTP 402 Payments", "x402 protocol" ], "canonical_spec_url": "https://x402.org", "entity_uri": "https://github.com/coinbase/x402", "taxonomy_layer": "payments", "sub_layer": "inline-http-payment", "protocol_type": "settlement", "central_problem": "Lets an agent pay for a web resource inline over plain HTTP — no account, API key, or monthly invoice — by reviving the HTTP 402 status code.", "maintainer": "Coinbase (coinbase/x402 on GitHub) + open facilitator ecosystem", "governance_body": "vendor (Coinbase) + open facilitator ecosystem", "license": { "value": "Apache-2.0", "verify_status": "verify-against-primary-at-build", "source_hint": "https://github.com/coinbase/x402", "note": "Confirm spec/reference-impl license against the primary repo at build." }, "maturity_tag": "production-ready", "current_spec_version": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://x402.org", "note": "x402.org does not surface an explicit spec version number; confirm against the GitHub spec at build." }, "spec_date": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://github.com/coinbase/x402", "note": "Confirm current spec revision date at build." }, "launch_date": { "value": "2025", "verify_status": "verify-against-primary-at-build", "source_hint": "https://x402.org", "note": "Introduced by Coinbase in 2025; confirm exact announcement date at build." }, "last_verified": "2026-06-15", "transport": "HTTP (402 status + payment headers); on-chain stablecoin settlement (Base, Solana)", "core_mechanism": "A client requests a resource; the server returns HTTP 402 with accepted payment terms; the client signs a token-transfer authorization and retries with a payment header; a facilitator confirms on-chain settlement and the server delivers the resource — one extra round trip, fractions of a cent.", "discovery_endpoint": "HTTP 402 response with an `accepts` payment-terms array (per-resource; no fixed path)", "settlement_type": "stablecoin (on-chain, e.g. Base / Solana)", "adoption_metric": { "value": "165M+ transactions by ~69k agents (cumulative, by late April 2026)", "last_verified": null, "note": "Site-wide canonical x402 figure (x402 facilitator data; the live homepage uses it). NOT yet confirmed on a primary source — the cited Chainalysis page supports only ~100M+ tx through Q1 2026. Verify against the primary Coinbase/x402 source at build; do NOT ship a conflicting '50M+'.", "verify_status": "verify-against-primary-at-build", "source_hint": "https://www.coinbase.com/developer-platform/discover/launches/x402 (primary x402/Coinbase Agent.market report)" }, "notable_adopters": [ { "value": "Coinbase", "source": "https://x402.org" }, { "value": "Cloudflare (x402 Foundation participant)", "source": "https://blockeden.xyz/blog/2026/03/05/x402-foundation-ai-payment-internet/" } ], "relationships": [ { "predicate": "extends", "target": "ap2", "note": "AP2 -extends-> x402 (research §2 seed triple): AP2 builds mandate-based settlement on top of the x402 inline-payment pattern. Edge stored on both records." }, { "predicate": "verifies", "target": "web-bot-auth", "note": "Web Bot Auth can cryptographically verify the agent making a paid x402 request." } ], "ideal_use_case": "Metering API or content access by the call/byte for autonomous agents, with sub-cent payments and no account setup.", "when_to_use": "When agents must pay tiny amounts per request inline and you want stablecoin settlement without subscriptions or API keys.", "when_not_to_use": "When you need card/bank rails, human-in-the-loop mandates, or larger structured purchases (use AP2 or ACP/Agentic Commerce), or when you cannot accept on-chain settlement.", "code_example": "HTTP/1.1 402 Payment Required\nContent-Type: application/json\n\n{ \"accepts\": [{ \"scheme\": \"exact\", \"maxAmountRequired\": \"$0.01\", \"payTo\": \"0x...\", \"network\": \"base\" }] }", "agent_readiness_link": "agent-readiness/x402", "layer_legacy": "payment" }, { "id": "ap2", "name": "AP2", "full_name": "Agent Payments Protocol", "layer": "payments", "creator": "Google (with 60+ payments & finance orgs)", "status": "emerging", "year": 2025, "one_liner": "Payment-agnostic settlement inside the A2A task lifecycle — handles cards, bank transfers and crypto through one mandate-based framework.", "spec_url": "https://ap2-protocol.org", "snippet": "An agent presents a signed mandate; AP2 routes it to cards, ACH, or crypto rails.", "abbreviation": "AP2", "also_known_as": [ "Agent Payments Protocol", "Agents-to-Payments Protocol" ], "canonical_spec_url": "https://ap2-protocol.org", "entity_uri": "https://agentpaymentsprotocol.info/", "taxonomy_layer": "payments", "sub_layer": "mandate-based-settlement", "protocol_type": "settlement", "central_problem": "Gives an AI agent a verifiable, cryptographically signed permission slip (a mandate) from a human before it can spend money, and routes that mandate across cards, bank, and crypto rails.", "maintainer": "Google + 60+ payments/finance partners (AP2 project)", "governance_body": "vendor (Google-led, open partner consortium)", "license": { "value": "Apache-2.0", "verify_status": "verify-against-primary-at-build", "source_hint": "https://ap2-protocol.org", "note": "Confirm spec license against the primary site/repo at build." }, "maturity_tag": "emerging", "current_spec_version": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://ap2-protocol.org", "note": "Confirm current AP2 spec version at build." }, "spec_date": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://ap2-protocol.org", "note": "Confirm current spec date at build." }, "launch_date": "2025-09-16", "last_verified": "2026-06-15", "transport": "Extension of A2A / MCP task lifecycle; mandates carried as W3C Verifiable Credentials", "core_mechanism": "AP2 introduces three signed mandates — Intent, Cart, and Payment — carried as W3C Verifiable Credentials; the agent presents the signed mandate and AP2 routes settlement to cards, ACH, or crypto rails, with stablecoins treated as first-class alongside cards and bank transfers.", "discovery_endpoint": "Carried within the A2A task lifecycle (no standalone well-known endpoint)", "settlement_type": "card-rail / bank / stablecoin (payment-agnostic, routed by mandate)", "adoption_metric": { "value": "Announced with 60+ payments & technology partners (e.g. Mastercard, PayPal, American Express, Coinbase, Adyen, Worldpay)", "source": "https://cloud.google.com/blog/products/ai-machine-learning/announcing-agents-to-payments-ap2-protocol", "last_verified": "2026-06-15" }, "notable_adopters": [ { "value": "Google", "source": "https://cloud.google.com/blog/products/ai-machine-learning/announcing-agents-to-payments-ap2-protocol" }, { "value": "Mastercard, PayPal, American Express, Coinbase (launch partners)", "source": "https://cloud.google.com/blog/products/ai-machine-learning/announcing-agents-to-payments-ap2-protocol" } ], "relationships": [ { "predicate": "extends", "target": "x402", "note": "AP2 -extends-> x402 (research §2 seed triple)." }, { "predicate": "built_on", "target": "a2a", "note": "AP2 is designed as an extension of the A2A (and MCP) task lifecycle." } ], "ideal_use_case": "Agent-led purchases that need a human's signed, auditable authorization across mixed payment rails.", "when_to_use": "When an agent must spend a user's money with verifiable consent and you need card/bank/crypto routing under one mandate framework.", "when_not_to_use": "When you only need sub-cent inline API metering (use x402) or an in-conversation checkout for retail (use Agentic Commerce / ACP).", "code_example": "// AP2 mandates are W3C Verifiable Credentials (Intent → Cart → Payment).\n// The agent presents a signed Payment mandate; AP2 routes it to the chosen rail.\n// { \"type\": [\"VerifiableCredential\", \"PaymentMandate\"], \"credentialSubject\": { \"amount\": \"42.00\", \"currency\": \"USD\" } }", "source": "Launch 2025-09-16 + 60+ partners + three-mandate (Intent/Cart/Payment) VC design: https://cloud.google.com/blog/products/ai-machine-learning/announcing-agents-to-payments-ap2-protocol .", "agent_readiness_link": "agent-readiness/x402", "layer_legacy": "payment" }, { "id": "acp-commerce", "name": "ACP (Agentic Commerce)", "full_name": "Agentic Commerce Protocol", "layer": "payments", "creator": "OpenAI + Stripe", "status": "live (ChatGPT Instant Checkout)", "year": 2025, "one_liner": "Lets an agent complete a purchase inside the conversation — the checkout that powers ChatGPT's Instant Checkout.", "spec_url": "https://www.agenticcommerce.dev", "snippet": "Agent submits a delegated payment token; merchant confirms the order over the protocol.", "abbreviation": "ACP", "also_known_as": [ "Agentic Commerce Protocol" ], "canonical_spec_url": "https://github.com/agentic-commerce-protocol/agentic-commerce-protocol", "entity_uri": "https://www.agenticcommerce.dev", "taxonomy_layer": "payments", "sub_layer": "in-conversation-checkout", "protocol_type": "settlement", "central_problem": "Lets an AI agent complete a retail purchase inside the conversation while keeping the merchant as merchant of record and the payment provider swappable.", "maintainer": "OpenAI + Stripe (agentic-commerce-protocol on GitHub)", "governance_body": "vendor (OpenAI + Stripe)", "license": "Apache-2.0", "maturity_tag": "production-ready", "current_spec_version": { "value": "2026-04-17", "verify_status": "verify-against-primary-at-build", "source_hint": "https://github.com/agentic-commerce-protocol/agentic-commerce-protocol", "note": "Latest stable spec version reported as 2026-04-17 (initial 2025-09-29); confirm current version tag against the GitHub spec at build." }, "spec_date": { "value": "2026-04-17", "verify_status": "verify-against-primary-at-build", "source_hint": "https://github.com/agentic-commerce-protocol/agentic-commerce-protocol", "note": "Confirm latest spec date against the GitHub releases at build." }, "launch_date": "2025-09-29", "last_verified": "2026-06-15", "transport": "REST over HTTP (delegated payment token handed to the merchant)", "core_mechanism": "ACP defines a contract among buyer, the buyer's AI agent, the merchant, and a payment provider: the agent collects the buyer's payment selection, hands a narrowly scoped delegated token to the merchant, and the merchant charges that token through any compliant payment service provider while remaining merchant of record.", "discovery_endpoint": "Merchant-published ACP endpoints (implementation-defined)", "settlement_type": "card-rail (delegated token via any compliant payment service provider)", "adoption_metric": { "value": "Debuted with ChatGPT Instant Checkout (Etsy at launch; Shopify brands such as Glossier, Vuori, SKIMS added over following weeks)", "source": "https://github.com/agentic-commerce-protocol/agentic-commerce-protocol", "last_verified": "2026-06-15" }, "notable_adopters": [ { "value": "OpenAI (ChatGPT Instant Checkout)", "source": "https://github.com/agentic-commerce-protocol/agentic-commerce-protocol" }, { "value": "Stripe", "source": "https://commercetools.com/press-releases/commercetools-partners-with-stripe-to-launch-acp" }, { "value": "Etsy", "source": "https://github.com/agentic-commerce-protocol/agentic-commerce-protocol" } ], "relationships": [ { "predicate": "competes_with", "target": "ap2", "note": "ACP (OpenAI/Stripe in-conversation checkout) and AP2 (Google mandate framework) address overlapping agent-commerce ground." } ], "ideal_use_case": "Letting a conversational agent (e.g. ChatGPT) complete a retail checkout while the merchant keeps control and record.", "when_to_use": "When you sell goods and want agents to buy inside the chat surface, charging via your existing payment provider with the merchant of record intact.", "when_not_to_use": "When you need sub-cent API metering (x402) or a bank/crypto-agnostic mandate framework across rails (AP2).", "code_example": "// Agent hands the merchant a delegated, narrowly-scoped payment token;\n// the merchant charges it via any compliant PSP and confirms the order.\n// POST /checkout { \"delegated_token\": \"tok_...\", \"items\": [ ... ] }", "source": "Launch 2025-09-29 under Apache-2.0, four-actor contract, ChatGPT Instant Checkout: https://github.com/agentic-commerce-protocol/agentic-commerce-protocol (OpenAI + Stripe).", "agent_readiness_link": "agent-readiness/x402", "layer_legacy": "payment" }, { "id": "web-bot-auth", "name": "Web Bot Auth", "full_name": "Web Bot Authentication (HTTP Message Signatures)", "layer": "identity", "creator": "IETF drafts, championed by Cloudflare", "status": "emerging", "year": 2025, "one_liner": "Cryptographically proves which agent is making a request via HTTP Message Signatures — because a User-Agent string can be forged and a signature cannot.", "spec_url": "https://datatracker.ietf.org/doc/draft-meunier-web-bot-auth-architecture/", "snippet": "Signature-Agent: \"https://my-agent.example\"\\nSignature-Input: sig1=(\"@authority\" \"signature-agent\");keyid=\"...\"", "abbreviation": "Web Bot Auth", "also_known_as": [ "Web Bot Authentication", "HTTP Message Signatures for bots", "Signature Agent" ], "canonical_spec_url": "https://datatracker.ietf.org/doc/html/draft-meunier-web-bot-auth-architecture-02", "entity_uri": "https://datatracker.ietf.org/doc/draft-meunier-web-bot-auth-architecture/", "taxonomy_layer": "identity", "sub_layer": "request-signing", "protocol_type": "verification", "central_problem": "Lets a server cryptographically verify which agent is making an HTTP request, since a User-Agent string can be forged and an Ed25519 signature cannot.", "maintainer": "IETF (draft-meunier-web-bot-auth-architecture), championed by Cloudflare", "governance_body": "IETF", "license": "IETF Trust (RFC / Internet-Draft terms)", "maturity_tag": "emerging", "current_spec_version": { "value": "draft-meunier-web-bot-auth-architecture-02", "verify_status": "verify-against-primary-at-build", "source_hint": "https://datatracker.ietf.org/doc/draft-meunier-web-bot-auth-architecture/", "note": "Draft -02 observed; confirm the latest draft revision at build (datatracker increments these)." }, "spec_date": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://datatracker.ietf.org/doc/draft-meunier-web-bot-auth-architecture/", "note": "Confirm the current draft's date against datatracker at build." }, "launch_date": { "value": "2025", "verify_status": "verify-against-primary-at-build", "source_hint": "https://datatracker.ietf.org/doc/draft-meunier-web-bot-auth-architecture/", "note": "Confirm first-draft date at build." }, "last_verified": "2026-06-15", "transport": "HTTP message signatures (RFC 9421), Ed25519 keys; Signature-Agent header", "core_mechanism": "Built on RFC 9421 HTTP Message Signatures with Ed25519 keys: the agent signs covered components (e.g. @authority and signature-agent) and advertises its public keys as a JWKS at /.well-known/http-message-signatures-directory; the server fetches that directory and verifies the signature to confirm the agent's identity.", "discovery_endpoint": "/.well-known/http-message-signatures-directory (JWKS) + Signature-Agent header", "settlement_type": null, "adoption_metric": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://radar.cloudflare.com/", "note": "Adoption/verified-bot counts not asserted from internal docs; confirm against Cloudflare Radar / operator data at build." }, "notable_adopters": [ { "value": "Cloudflare (champion + reference implementation)", "source": "https://datatracker.ietf.org/doc/draft-meunier-web-bot-auth-architecture/" } ], "relationships": [ { "predicate": "verifies", "target": "x402", "note": "Web Bot Auth can verify the agent identity behind a paid request." }, { "predicate": "verifies", "target": "rsl", "note": "Web Bot Auth -verifies-> pay-per-crawl-class enforcement (research §2 seed triple: 'Web Bot Auth verifies pay-per-crawl'); RSL/pay-per-crawl licensing relies on knowing which agent is real." } ], "ideal_use_case": "Letting a site trust that a request claiming to be ClaudeBot/GPTBot really is that agent before granting access or charging it.", "when_to_use": "When you must verify agent identity for access control, licensing enforcement, or paid crawling — not just read a forgeable User-Agent string.", "when_not_to_use": "When you only need to declare content to agents (Layer-1 discovery) and don't gate or charge access by identity.", "code_example": "Signature-Agent: \"https://my-agent.example\"\nSignature-Input: sig1=(\"@authority\" \"signature-agent\");keyid=\"...\";alg=\"ed25519\"\nSignature: sig1=::", "source": "RFC 9421 + Ed25519 + Signature-Agent header + /.well-known/http-message-signatures-directory: https://datatracker.ietf.org/doc/html/draft-meunier-web-bot-auth-architecture-02 ; Cloudflare reference: https://http-message-signatures-example.research.cloudflare.com/ ; research §1.", "agent_readiness_link": "agent-readiness/web-bot-auth" }, { "id": "llms-txt", "name": "llms.txt", "full_name": "llms.txt", "layer": "discovery", "creator": "Jeremy Howard (Answer.AI)", "status": "widely adopted (~10% of studied sites)", "year": 2024, "one_liner": "A markdown file at the domain root that gives language models a curated map of a site's most important content.", "spec_url": "https://llmstxt.org", "snippet": "# Site Name\\n> One-line description.\\n## Core\\n- [Page](/page.md): what it is", "abbreviation": "llms.txt", "also_known_as": [ "/llms.txt", "llms.txt standard" ], "canonical_spec_url": "https://llmstxt.org", "entity_uri": "https://llmstxt.org", "taxonomy_layer": "discovery", "sub_layer": "site-summary-file", "protocol_type": "declaration", "central_problem": "Gives language models a curated, markdown map of a site's most important content so they don't have to parse complex HTML, ads, or JavaScript.", "maintainer": "Jeremy Howard / Answer.AI + community (llmstxt.org)", "governance_body": "none (community proposal)", "license": { "value": "Apache-2.0", "verify_status": "verify-against-primary-at-build", "source_hint": "https://github.com/AnswerDotAI/llms-txt", "note": "Confirm the spec repo's license at build." }, "maturity_tag": "emerging", "current_spec_version": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://llmstxt.org", "note": "llmstxt.org does not version the spec with a formal number; confirm at build." }, "spec_date": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://llmstxt.org", "note": "Confirm latest spec revision date at build." }, "launch_date": "2024-09-03", "last_verified": "2026-06-15", "transport": "Static markdown file at the domain root", "core_mechanism": "A markdown file at /llms.txt uses a fixed shape — H1 site name, a blockquote summary, then sectioned lists of links with short descriptions — so an LLM gets a concise, parseable map of the site's key pages (often with .md twins).", "discovery_endpoint": "/llms.txt (and the fuller /llms-full.txt)", "settlement_type": null, "adoption_metric": { "value": "Approximately 10% of studied sites by May 2026; adopters include Anthropic, Stripe, Cloudflare, Vercel, Mintlify, Supabase", "source": "https://www.answer.ai/posts/2024-09-03-llmstxt.html", "last_verified": "2026-06-15", "note": "~10% figure is from secondary surveys; treat as approximate. Origin proposal date is primary (answer.ai)." }, "notable_adopters": [ { "value": "Anthropic", "source": "https://codersera.com/blog/llms-txt-complete-guide-2026/" }, { "value": "Stripe", "source": "https://codersera.com/blog/llms-txt-complete-guide-2026/" } ], "relationships": [ { "predicate": "complements", "target": "agents-json", "note": "llms.txt declares content; agents.json declares APIs/workflows — paired Layer-1 discovery files." } ], "ideal_use_case": "Helping LLMs find and quote the right pages on a content/documentation site.", "when_to_use": "When you want models to read and cite your most important content — the cheapest, first agent-readiness step.", "when_not_to_use": "When agents need to take actions or call functions (use MCP/WebMCP/agents.json), not just read curated links.", "code_example": "# Acme Docs\n> Acme's developer documentation.\n\n## Core\n- [Quickstart](/quickstart.md): get started in 5 minutes\n- [API Reference](/api.md): every endpoint", "source": "Origin proposal (Jeremy Howard, Answer.AI), 2024-09-03: https://www.answer.ai/posts/2024-09-03-llmstxt.html . Spec home: https://llmstxt.org .", "agent_readiness_link": "agent-readiness/llms-txt", "layer_legacy": "content" }, { "id": "nlweb", "name": "NLWeb", "full_name": "Natural Language Web", "layer": "discovery", "creator": "Microsoft (R.V. Guha)", "status": "emerging", "year": 2025, "one_liner": "Turns a website into a conversational, queryable endpoint by combining Schema.org data, a vector store and an LLM — and every NLWeb endpoint is also an MCP server.", "spec_url": "https://github.com/nlweb-ai/NLWeb", "snippet": "POST /ask { \"query\": \"...\" } → grounded natural-language answer + structured sources", "abbreviation": "NLWeb", "also_known_as": [ "Natural Language Web" ], "canonical_spec_url": "https://github.com/nlweb-ai/NLWeb", "entity_uri": "https://github.com/nlweb-ai/NLWeb", "taxonomy_layer": "discovery", "sub_layer": "conversational-endpoint", "protocol_type": "declaration", "central_problem": "Turns a website into a conversational, queryable endpoint so agents can ask natural-language questions and get grounded, source-backed answers.", "maintainer": "Microsoft (project led by R.V. Guha) + community (nlweb-ai/NLWeb)", "governance_body": "vendor (Microsoft) + open-source community", "license": { "value": "MIT", "verify_status": "verify-against-primary-at-build", "source_hint": "https://github.com/nlweb-ai/NLWeb", "note": "Confirm the repo license at build." }, "maturity_tag": "emerging", "current_spec_version": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://github.com/nlweb-ai/NLWeb", "note": "Confirm current release/version at build." }, "spec_date": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://github.com/nlweb-ai/NLWeb", "note": "Confirm latest release date at build." }, "launch_date": { "value": "2025", "verify_status": "verify-against-primary-at-build", "source_hint": "https://github.com/nlweb-ai/NLWeb", "note": "Confirm first-release date at build (announced 2025)." }, "last_verified": "2026-06-15", "transport": "HTTP (POST /ask); each NLWeb endpoint is also exposed as an MCP server", "core_mechanism": "NLWeb combines a site's Schema.org structured data, a vector store, and an LLM behind a /ask endpoint; a query returns a grounded natural-language answer plus structured sources, and every NLWeb endpoint is simultaneously an MCP server.", "discovery_endpoint": "POST /ask (and MCP server interface)", "settlement_type": null, "adoption_metric": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://github.com/nlweb-ai/NLWeb", "note": "No audited adoption figure asserted." }, "notable_adopters": [ { "value": "Microsoft", "source": "https://github.com/nlweb-ai/NLWeb" } ], "relationships": [ { "predicate": "built_on", "target": "schema-org", "note": "NLWeb -built_on-> schema.org (research §2 seed triple). schema.org-for-agents is not a separate record in this 12-record pass; edge documented for the build-out." }, { "predicate": "complements", "target": "mcp", "note": "Every NLWeb endpoint is also an MCP server, so it pairs with the capability layer." } ], "ideal_use_case": "Giving a content-rich site a conversational, agent-queryable answer endpoint grounded in its own structured data.", "when_to_use": "When you have Schema.org data and want agents to ask questions and get cited, grounded answers from your site.", "when_not_to_use": "When a static curated link map (llms.txt) is enough, or when you need cross-agent coordination (A2A) rather than Q&A.", "code_example": "POST /ask HTTP/1.1\nContent-Type: application/json\n\n{ \"query\": \"What does Acme sell under $50?\" }\n// → { \"answer\": \"...\", \"sources\": [ { \"url\": \"...\", \"schema\": \"Product\" } ] }", "source": "Project (Microsoft / R.V. Guha), built on schema.org, MCP-server duality: https://github.com/nlweb-ai/NLWeb ; seed triple research §2.", "agent_readiness_link": "agent-readiness/discoverability", "layer_legacy": "content" }, { "id": "rsl", "name": "RSL", "full_name": "Really Simple Licensing", "layer": "licensing", "creator": "RSL Collective (Reddit, Yahoo, Medium, O'Reilly and others)", "status": "emerging standard", "year": 2025, "one_liner": "Machine-readable content-licensing terms, referenced from robots.txt — say which AI uses are free and which require a license or royalty.", "spec_url": "https://rslstandard.org", "snippet": "robots.txt: License: https://example.com/license.xml → ... search ... ", "abbreviation": "RSL", "also_known_as": [ "Really Simple Licensing", "RSL Standard" ], "canonical_spec_url": "https://rslstandard.org", "entity_uri": "https://en.wikipedia.org/wiki/Really_Simple_Licensing", "taxonomy_layer": "licensing", "sub_layer": "content-licensing-terms", "protocol_type": "license", "central_problem": "Lets publishers attach machine-readable licensing terms to content — declaring which AI uses are free and which require a license or royalty — referenced from robots.txt.", "maintainer": "RSL Collective (nonprofit; co-founded by Eckart Walther and Doug Leeds)", "governance_body": "RSL Collective", "license": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://rslstandard.org", "note": "Confirm the spec's own license/terms at build." }, "maturity_tag": "emerging", "current_spec_version": "RSL 1.0", "spec_date": "2025-12-10", "launch_date": "2025-09-10", "last_verified": "2026-06-15", "transport": "robots.txt License: directive → RSL XML license document", "core_mechanism": "A site references an RSL license document (XML) from robots.txt via a License: directive; the RSL document declares per-use permissions (e.g. search vs. training) and any royalty/licensing requirement, with RSL 1.0 adding dynamic pricing and collective-rights-organization integration.", "discovery_endpoint": "robots.txt License: directive → RSL XML (e.g. /license.xml)", "settlement_type": null, "adoption_metric": { "value": "Launch backed by publishers including Reddit, Yahoo, People Inc., Internet Brands, Ziff Davis, Quora, O'Reilly Media, and Medium", "source": "https://rslstandard.org/press/rsl-standard", "last_verified": "2026-06-15" }, "notable_adopters": [ { "value": "Reddit", "source": "https://rslstandard.org/press/rsl-standard" }, { "value": "Yahoo", "source": "https://rslstandard.org/press/rsl-standard" }, { "value": "O'Reilly Media", "source": "https://rslstandard.org/press/rsl-standard" } ], "relationships": [ { "predicate": "enforced_by", "target": "web-bot-auth", "note": "RSL -enforced_by-> Cloudflare (research §2 seed triple); enforcement in practice depends on verifying which agent is real (Web Bot Auth). Cloudflare is the enforcing operator, not a protocol record id." }, { "predicate": "competes_with", "target": "pay-per-crawl", "note": "RSL and pay-per-crawl both price/gate AI access in the licensing layer (pay-per-crawl is not a separate record in this 12-record pass)." } ], "ideal_use_case": "A publisher who wants to license content to AI — free for some uses, paid for others — in a machine-readable way.", "when_to_use": "When you must price or gate AI use of your content and want terms that crawlers and licensing intermediaries can read automatically.", "when_not_to_use": "When you simply want to welcome agents to read your content (Layer-1 discovery) and have no licensing or royalty requirement.", "code_example": "# robots.txt\nLicense: https://example.com/license.xml\n\n\nsearchtrain", "source": "First published 2025-09-10; RSL 1.0 official spec 2025-12-10: https://rslstandard.org/press/rsl-1-specification-2025 and https://rslstandard.org/press/rsl-standard . Enforced_by Cloudflare: research §2.", "agent_readiness_link": "access-economics", "layer_legacy": "content" }, { "id": "agents-json", "name": "agents.json", "full_name": "agents.json / Arazzo API manifests", "layer": "discovery", "creator": "open community (built on the OpenAPI Arazzo spec)", "status": "emerging", "year": 2025, "one_liner": "A manifest that describes a site's APIs and workflows in a form agents can discover and execute, typically served from /.well-known/.", "spec_url": "https://github.com/wild-card-ai/agents-json", "snippet": "GET /.well-known/agents.json → { \"endpoints\": [ ... ], \"workflows\": [ ... ] }", "abbreviation": "agents.json", "also_known_as": [ "agents.json", "Arazzo API manifest" ], "canonical_spec_url": "https://github.com/wild-card-ai/agents-json", "entity_uri": "https://github.com/wild-card-ai/agents-json", "taxonomy_layer": "discovery", "sub_layer": "api-workflow-manifest", "protocol_type": "manifest", "central_problem": "Describes a site's APIs and multi-step workflows in a machine-readable manifest agents can discover and execute, rather than reverse-engineering the UI.", "maintainer": "Wild Card AI + open community (built on the OpenAPI Arazzo spec)", "governance_body": "none (community; layered on OpenAPI Arazzo)", "license": { "value": "MIT", "verify_status": "verify-against-primary-at-build", "source_hint": "https://github.com/wild-card-ai/agents-json", "note": "Confirm the repo license at build." }, "maturity_tag": "emerging", "current_spec_version": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://github.com/wild-card-ai/agents-json", "note": "Confirm current version at build." }, "spec_date": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://github.com/wild-card-ai/agents-json", "note": "Confirm latest spec date at build." }, "launch_date": { "value": "2025", "verify_status": "verify-against-primary-at-build", "source_hint": "https://github.com/wild-card-ai/agents-json", "note": "Confirm first-release date at build." }, "last_verified": "2026-06-15", "transport": "Static JSON manifest at /.well-known/agents.json (OpenAPI Arazzo workflows)", "core_mechanism": "A JSON manifest served from /.well-known/agents.json enumerates a site's API endpoints and chained workflows using the OpenAPI Arazzo format, so an agent can discover which calls exist and execute multi-step flows without scraping the UI.", "discovery_endpoint": "/.well-known/agents.json", "settlement_type": null, "adoption_metric": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://github.com/wild-card-ai/agents-json", "note": "No audited adoption figure asserted." }, "notable_adopters": [ { "value": "Wild Card AI", "source": "https://github.com/wild-card-ai/agents-json" } ], "relationships": [ { "predicate": "complements", "target": "llms-txt", "note": "agents.json declares APIs/workflows; llms.txt declares content — paired Layer-1 discovery files." }, { "predicate": "built_on", "target": "mcp", "note": "Both expose machine-callable actions; agents.json built on OpenAPI Arazzo and can front MCP-style execution." } ], "ideal_use_case": "Publishing a discoverable, executable description of your site's APIs and workflows for agents.", "when_to_use": "When agents need to call your APIs or run multi-step workflows and you already have an OpenAPI surface to expose.", "when_not_to_use": "When you only have content to expose (use llms.txt) or want a live tool-calling session rather than a static manifest (use MCP).", "code_example": "GET /.well-known/agents.json HTTP/1.1\n\n{ \"endpoints\": [ { \"path\": \"/api/search\", \"method\": \"GET\" } ], \"workflows\": [ { \"id\": \"checkout\", \"steps\": [ ... ] } ] }", "source": "Spec/repo (built on OpenAPI Arazzo): https://github.com/wild-card-ai/agents-json ; agents.json/agents.txt listed among Layer-1 discovery additions in research §2.", "agent_readiness_link": "agent-readiness/discoverability", "layer_legacy": "content" }, { "id": "aaif", "name": "AAIF", "full_name": "Agentic AI Foundation", "layer": "governance", "creator": "Linux Foundation (anchored by contributions from Anthropic, Block, OpenAI and others)", "status": "active (formed Dec 2025)", "year": 2025, "one_liner": "The Linux Foundation body, formed December 2025, that gives the agentic web's load-bearing protocols — MCP, goose and AGENTS.md — a neutral, vendor-independent governance home.", "spec_url": "https://aaif.io", "snippet": "AAIF (Linux Foundation) hosts MCP, goose and AGENTS.md under neutral, open governance.", "abbreviation": "AAIF", "also_known_as": [ "Agentic AI Foundation", "Agentic AI Infrastructure Foundation" ], "canonical_spec_url": "https://aaif.io", "entity_uri": "https://aaif.io", "taxonomy_layer": "governance", "sub_layer": "foundation", "protocol_type": "governance", "central_problem": "Gives the agentic web's load-bearing protocols a single neutral, vendor-independent home so no one company controls the core standards.", "maintainer": "The Linux Foundation (Agentic AI Foundation)", "governance_body": "Linux Foundation", "license": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://aaif.io", "note": "AAIF is a governance foundation, not a single licensed spec; member projects carry their own licenses (e.g. MCP is MIT). Confirm the foundation charter/IP policy at build." }, "maturity_tag": "production-ready", "current_spec_version": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://aaif.io", "note": "Governance body — no spec version. N/A." }, "spec_date": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://aaif.io", "note": "Governance body — no spec date. N/A." }, "launch_date": "2025-12-09", "last_verified": "2026-06-15", "transport": "n/a (governance foundation, not a wire protocol)", "core_mechanism": "AAIF is a Linux Foundation umbrella that hosts agentic-AI projects under neutral, community-driven governance; its founding project contributions are Anthropic's Model Context Protocol (MCP), Block's goose agent framework, and OpenAI's AGENTS.md, with research §2 also listing A2A v1.0 and UCP among hosted/affiliated projects (confirm the full hosted-project list against aaif.io at build).", "discovery_endpoint": "https://aaif.io (foundation site) / https://github.com/aaif", "settlement_type": null, "adoption_metric": { "value": "8 platinum members at formation: Amazon Web Services, Anthropic, Block, Bloomberg, Cloudflare, Google, Microsoft, OpenAI", "source": "https://www.linuxfoundation.org/press/linux-foundation-announces-the-formation-of-the-agentic-ai-foundation", "last_verified": "2026-06-15" }, "notable_adopters": [ { "value": "Anthropic (contributed MCP)", "source": "https://www.linuxfoundation.org/press/linux-foundation-announces-the-formation-of-the-agentic-ai-foundation" }, { "value": "Block (contributed goose)", "source": "https://www.linuxfoundation.org/press/linux-foundation-announces-the-formation-of-the-agentic-ai-foundation" }, { "value": "OpenAI (contributed AGENTS.md)", "source": "https://www.linuxfoundation.org/press/linux-foundation-announces-the-formation-of-the-agentic-ai-foundation" } ], "relationships": [ { "predicate": "governs", "target": "mcp", "note": "AAIF -governs-> MCP (founding project contribution; inverse of MCP governed_by AAIF)." }, { "predicate": "governs", "target": "a2a", "note": "A2A v1.0 listed among AAIF-hosted projects (research §2); confirm against aaif.io at build." } ], "ideal_use_case": "Providing a neutral standards home so MCP, A2A and other core agentic protocols are not controlled by any single vendor.", "when_to_use": "When you need to point to the vendor-neutral governance authority behind the agentic web's core protocols.", "when_not_to_use": "n/a — AAIF is a governance meta-entity, not a protocol you implement on a site.", "code_example": "// AAIF is a governance foundation, not a wire protocol — there is no client snippet.\n// Hosted projects expose their own interfaces (e.g. MCP: tools/call over JSON-RPC).", "source": "Formation date (Dec 9 2025), Linux Foundation parent, 8 platinum members (AWS, Anthropic, Block, Bloomberg, Cloudflare, Google, Microsoft, OpenAI), founding contributions MCP/goose/AGENTS.md: https://www.linuxfoundation.org/press/linux-foundation-announces-the-formation-of-the-agentic-ai-foundation . A2A v1.0/UCP hosting per research §2 (verify at build).", "agent_readiness_link": "agent-readiness/mcp", "layer_legacy": "agent" }, { "id": "w3c", "name": "W3C", "full_name": "World Wide Web Consortium", "layer": "governance", "creator": "Tim Berners-Lee (founded 1994)", "status": "active", "year": 1994, "one_liner": "The international web standards body that incubates agentic-web specs such as WebMCP (via its Web Machine Learning Community Group) and stewards the schema.org and Verifiable Credentials foundations agents build on.", "spec_url": "https://www.w3.org", "snippet": "W3C standardizes web specs; the Web Machine Learning CG develops the WebMCP draft.", "abbreviation": "W3C", "also_known_as": [ "World Wide Web Consortium", "W3C standards body" ], "canonical_spec_url": "https://www.w3.org", "entity_uri": "https://en.wikipedia.org/wiki/World_Wide_Web_Consortium", "taxonomy_layer": "governance", "sub_layer": "standards-body", "protocol_type": "governance", "central_problem": "Provides the neutral, international standards process under which load-bearing web (and now agentic-web) specifications are developed and ratified.", "maintainer": "World Wide Web Consortium (W3C)", "governance_body": "W3C", "license": "W3C Document License / Community Contributor License Agreement (CLA)", "maturity_tag": "standard", "current_spec_version": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://www.w3.org", "note": "Standards body — not a single versioned spec. N/A." }, "spec_date": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://www.w3.org", "note": "Standards body — no single spec date. N/A." }, "launch_date": "1994-10-01", "last_verified": "2026-06-15", "transport": "n/a (standards body, not a wire protocol)", "core_mechanism": "W3C runs Working Groups and Community Groups that draft and ratify web standards through the W3C Process; for the agentic web, its Web Machine Learning Community Group develops the WebMCP Draft Community Group Report (not yet on the W3C Standards Track), and W3C also stewards the Verifiable Credentials and DID specs that agent identity/payment protocols rely on.", "discovery_endpoint": "https://www.w3.org (specs and group pages)", "settlement_type": null, "adoption_metric": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://www.w3.org/Consortium/Member/List", "note": "W3C member count not asserted from internal docs; confirm against the W3C member list at build." }, "notable_adopters": [ { "value": "Web Machine Learning Community Group (hosts the WebMCP draft)", "source": "https://webmachinelearning.github.io/webmcp/" } ], "relationships": [ { "predicate": "standardizes", "target": "webmcp", "note": "W3C -standardizes-> WebMCP (inverse of WebMCP standardized_by W3C); developed in the Web Machine Learning Community Group as a Draft Community Group Report." }, { "predicate": "stewards", "target": "schema-org", "note": "W3C hosts the community/process around the structured-data vocabularies (schema.org / Verifiable Credentials / DID) that agentic protocols build on." } ], "ideal_use_case": "Citing the neutral international body that standardizes the browser-facing agentic-web specs (WebMCP) and the credential/identity foundations.", "when_to_use": "When you need to attribute the governance/standards process behind a browser or structured-data agentic spec.", "when_not_to_use": "n/a — W3C is a governance meta-entity, not a protocol you implement on a site.", "code_example": "// W3C is a standards body, not a wire protocol — there is no client snippet.\n// Its agentic-web output (WebMCP) exposes navigator.modelContext.registerTool(...).", "source": "W3C as the standards body developing WebMCP via the Web Machine Learning Community Group: https://webmachinelearning.github.io/webmcp/ . W3C founding/role: https://en.wikipedia.org/wiki/World_Wide_Web_Consortium . Seed triple (WebMCP standardized_by W3C): research §2.", "agent_readiness_link": "agent-readiness/webmcp", "layer_legacy": "agent" }, { "id": "pay-per-crawl", "name": "Pay Per Crawl", "full_name": "Cloudflare Pay Per Crawl", "layer": "licensing", "creator": "Cloudflare", "status": "live (beta, 2025)", "year": 2025, "one_liner": "Cloudflare's HTTP 402-based mechanism that lets publishers charge AI crawlers per request — allow free, set a price, or block — with Cloudflare as merchant of record.", "spec_url": "https://blog.cloudflare.com/introducing-pay-per-crawl/", "snippet": "HTTP/1.1 402 Payment Required\\ncrawler-price: USD 0.01 → crawler retries with: crawler-exact-price: USD 0.01", "abbreviation": "Pay Per Crawl", "also_known_as": [ "Cloudflare Pay Per Crawl", "pay-per-crawl" ], "canonical_spec_url": "https://developers.cloudflare.com/ai-crawl-control/features/pay-per-crawl/", "entity_uri": "https://blog.cloudflare.com/introducing-pay-per-crawl/", "taxonomy_layer": "licensing", "sub_layer": "per-crawl-paywall", "protocol_type": "settlement", "central_problem": "Lets a publisher charge AI crawlers for each request to their content — flipping unpaid scraping into a metered, monetizable transaction over HTTP 402.", "maintainer": "Cloudflare (Pay Per Crawl / AI Crawl Control)", "governance_body": "vendor (Cloudflare)", "license": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://developers.cloudflare.com/ai-crawl-control/features/pay-per-crawl/", "note": "Cloudflare product/feature, not an open-licensed spec; confirm terms against Cloudflare docs at build." }, "maturity_tag": "emerging", "current_spec_version": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://developers.cloudflare.com/ai-crawl-control/features/pay-per-crawl/", "note": "Product feature, not a numbered spec; confirm current beta/GA status at build." }, "spec_date": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://blog.cloudflare.com/introducing-pay-per-crawl/", "note": "Confirm any spec/feature revision date at build." }, "launch_date": "2025-07-01", "last_verified": "2026-06-15", "transport": "HTTP 402 Payment Required + crawler-price / crawler-exact-price headers (Cloudflare network)", "core_mechanism": "When a configured AI crawler requests content, Cloudflare can return HTTP 402 Payment Required with a crawler-price header; a crawler that agrees retries with a crawler-exact-price header, and Cloudflare — acting as merchant of record — aggregates billing, charges the crawler, and pays the publisher. Publishers can allow free, charge a flat per-request rate, or block.", "discovery_endpoint": "HTTP 402 response with crawler-price header (per-request; Cloudflare-managed)", "settlement_type": "credits (Cloudflare as merchant of record; per-request billing)", "adoption_metric": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://blog.cloudflare.com/introducing-pay-per-crawl/", "note": "Launched as a private beta in July 2025; no audited adoption figure asserted. Confirm GA/scale at build." }, "notable_adopters": [ { "value": "Cloudflare (operator / merchant of record)", "source": "https://blog.cloudflare.com/introducing-pay-per-crawl/" } ], "relationships": [ { "predicate": "verified_by", "target": "web-bot-auth", "note": "Pay Per Crawl -verified_by-> Web Bot Auth (research §2 seed triple, inverse of 'Web Bot Auth verifies pay-per-crawl'): charging the right crawler depends on cryptographically verifying which agent is real." }, { "predicate": "competes_with", "target": "rsl", "note": "Pay Per Crawl and RSL both price/gate AI access in the licensing layer; RSL is an open licensing spec, Pay Per Crawl is a Cloudflare-operated paywall." }, { "predicate": "built_on", "target": "x402", "note": "Pay Per Crawl uses the HTTP 402 Payment Required pattern that x402 also revives." } ], "ideal_use_case": "A publisher behind Cloudflare who wants to monetize AI crawling per request without building payment infrastructure.", "when_to_use": "When you are on Cloudflare and want to charge AI crawlers per request (or block them) with Cloudflare handling billing and settlement.", "when_not_to_use": "When you want an open, vendor-neutral licensing declaration (use RSL) or you are not behind Cloudflare's network.", "code_example": "# Cloudflare returns to an AI crawler:\nHTTP/1.1 402 Payment Required\ncrawler-price: USD 0.01\n\n# Crawler agrees and retries:\nGET /article HTTP/1.1\ncrawler-exact-price: USD 0.01", "source": "Launch (private beta, July 1 2025), HTTP 402 + crawler-price/crawler-exact-price headers, Cloudflare as merchant of record: https://blog.cloudflare.com/introducing-pay-per-crawl/ . Seed triple (Web Bot Auth verifies pay-per-crawl): research §2.", "agent_readiness_link": "access-economics", "layer_legacy": "content" }, { "id": "agents-txt", "name": "agents.txt", "full_name": "agents.txt", "layer": "discovery", "creator": "open community (multiple competing proposals; asturwebs reference among them)", "status": "draft (community proposal)", "year": 2025, "one_liner": "A root-level file that declares a site's identity, terms of use for AI agents, service catalog and agentic endpoints in a machine-readable form.", "spec_url": "https://github.com/asturwebs/agents-txt", "snippet": "GET /agents.txt → identity, permissions, services, agentic endpoints (with /api/agents JSON twin)", "abbreviation": "agents.txt", "also_known_as": [ "/agents.txt", "agent-manifest.txt (proposed 2026 rename of one variant)" ], "canonical_spec_url": "https://github.com/asturwebs/agents-txt", "entity_uri": "https://github.com/asturwebs/agents-txt", "taxonomy_layer": "discovery", "sub_layer": "agent-capability-declaration", "protocol_type": "declaration", "central_problem": "Gives a site a sanctioned, machine-readable channel to tell AI agents who it is, what they are permitted to do, and which agentic endpoints exist — instead of agents guessing.", "maintainer": "Community proposal (asturwebs reference implementation; other variants by kaylacar, dennj, and the agent-manifest.txt rename)", "governance_body": "none (community proposal; IANA well-known registration pending review)", "license": { "value": "MIT", "verify_status": "verify-against-primary-at-build", "source_hint": "https://github.com/asturwebs/agents-txt", "note": "MIT for the asturwebs variant; other competing agents.txt proposals carry their own terms. Confirm at build." }, "maturity_tag": "experimental", "current_spec_version": { "value": "2.0 (asturwebs variant, draft)", "verify_status": "verify-against-primary-at-build", "source_hint": "https://github.com/asturwebs/agents-txt", "note": "Version 2.0 observed on the asturwebs variant; there is no single canonical agents.txt spec — confirm the relevant variant at build." }, "spec_date": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://github.com/asturwebs/agents-txt", "note": "Confirm latest spec date at build." }, "launch_date": { "value": "2025", "verify_status": "verify-against-primary-at-build", "source_hint": "https://github.com/asturwebs/agents-txt", "note": "Confirm first-release date at build." }, "last_verified": "2026-06-15", "transport": "Static file at the domain root (/agents.txt) with a JSON twin (/api/agents)", "core_mechanism": "A site serves a human-readable, machine-parseable file at /agents.txt declaring its identity, AI-agent terms of use, service catalog, and agentic endpoints (with a JSON twin); agents fetch it to learn what they are permitted to do. Note: multiple competing agents.txt proposals exist and one variant was renamed agent-manifest.txt in early 2026, so the format is not yet converged.", "discovery_endpoint": "/agents.txt (and /.well-known/agents.txt per pending IANA registration)", "settlement_type": null, "adoption_metric": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://github.com/asturwebs/agents-txt", "note": "No audited adoption figure asserted; several competing proposals dilute any single count." }, "notable_adopters": [ { "value": "AsturWebs (reference implementation)", "source": "https://github.com/asturwebs/agents-txt" } ], "relationships": [ { "predicate": "discovers", "target": "mcp", "note": "agents.txt -discovers-> MCP (research §2 seed triple): an agents.txt-class discovery file can point agents to a site's MCP / agentic endpoints." }, { "predicate": "complements", "target": "llms-txt", "note": "agents.txt declares agent permissions/endpoints; llms.txt declares readable content — paired Layer-1 discovery files." } ], "ideal_use_case": "Declaring, in one root file, what AI agents are allowed to do on your site and where your agentic endpoints live.", "when_to_use": "When you want to publish agent permissions and a service/endpoint catalog beyond what llms.txt (content) or robots.txt (crawl rules) cover.", "when_not_to_use": "When you only need to expose readable content (use llms.txt) or you require a converged, stable standard — agents.txt has multiple competing drafts.", "code_example": "# /agents.txt\nName: Acme\nPolicy: agents may read and call the catalog API; no scraping of /account\nServices:\n - search: /api/search\n - checkout: /.well-known/agents.json#checkout", "source": "Reference variant (MIT, v2.0 draft, identity/permissions/services/endpoints, /agents.txt + /api/agents, IANA well-known pending, agent-manifest.txt rename of one variant): https://github.com/asturwebs/agents-txt . Seed triple (agents.txt discovers MCP): research §2. Honesty note: multiple competing agents.txt proposals exist.", "agent_readiness_link": "agent-readiness/discoverability", "layer_legacy": "content" }, { "id": "dns-aid", "name": "DNS-AID", "full_name": "DNS-based Agent Identification and Discovery", "layer": "discovery", "creator": "IETF draft (draft-mozleywilliams-dnsop-dnsaid), community reference implementation", "status": "draft (IETF Internet-Draft)", "year": 2025, "one_liner": "Lets organizations publish and discover AI agents through standard DNS records — a naming convention over SVCB/TXT/TLSA records, signed with DNSSEC, with no new record types or servers.", "spec_url": "https://datatracker.ietf.org/doc/draft-mozleywilliams-dnsop-dnsaid/", "snippet": "_agent._tcp.example.com IN SVCB ... → DNS-SD discovery of an org's agent index (DNSSEC-signed)", "abbreviation": "DNS-AID", "also_known_as": [ "DNS for AI Discovery", "DNS-based Agent Identification and Discovery", "BANDAID (IETF work)" ], "canonical_spec_url": "https://datatracker.ietf.org/doc/html/draft-mozleywilliams-dnsop-dnsaid-02", "entity_uri": "https://dns-aid.org/", "taxonomy_layer": "discovery", "sub_layer": "dns-agent-discovery", "protocol_type": "declaration", "central_problem": "Lets organizations publish and discover AI agents through the existing DNS system instead of centralized registries — using a well-known namespace over standard records, secured by DNSSEC/DANE.", "maintainer": "IETF (draft-mozleywilliams-dnsop-dnsaid) + dns-aid community reference implementation", "governance_body": "IETF (dnsop work; Internet-Draft)", "license": "IETF Trust (Internet-Draft terms)", "maturity_tag": "experimental", "current_spec_version": { "value": "draft-mozleywilliams-dnsop-dnsaid-02", "verify_status": "verify-against-primary-at-build", "source_hint": "https://datatracker.ietf.org/doc/draft-mozleywilliams-dnsop-dnsaid/", "note": "Draft -02 observed (a -01 also exists); datatracker increments these — confirm the latest revision at build. A separate AID draft (draft-nemethi-aid-agent-identity-discovery) also exists; do not conflate." }, "spec_date": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://datatracker.ietf.org/doc/draft-mozleywilliams-dnsop-dnsaid/", "note": "Confirm the current draft's date against datatracker at build." }, "launch_date": { "value": "2025", "verify_status": "verify-against-primary-at-build", "source_hint": "https://datatracker.ietf.org/doc/draft-mozleywilliams-dnsop-dnsaid/", "note": "Confirm first-draft date at build." }, "last_verified": "2026-06-15", "transport": "DNS (SVCB, TXT, TLSA records; DNS-SD labels; DNSSEC/DANE for trust)", "core_mechanism": "DNS-AID is a naming convention layered on existing DNS records (SVCB for connectivity/metadata per RFC 9460, TXT, optional TLSA) using DNS-SD labels and a well-known entry point into an organization's agent index; all discovery records MUST be DNSSEC-signed, with DANE/TLSA for end-to-end trust. No new record types, servers, or protocols are introduced.", "discovery_endpoint": "Well-known DNS-SD label into an organization's agent index (DNSSEC-signed)", "settlement_type": null, "adoption_metric": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://datatracker.ietf.org/doc/draft-mozleywilliams-dnsop-dnsaid/", "note": "No audited adoption figure asserted; early IETF draft." }, "notable_adopters": [ { "value": "DNS-AID community reference implementation (dns-aid/dns-aid-core)", "source": "https://github.com/dns-aid/dns-aid-core" } ], "relationships": [ { "predicate": "complements", "target": "agents-txt", "note": "DNS-AID discovers agents at the DNS layer; agents.txt/llms.txt declare them at the HTTP/file layer — complementary discovery surfaces." } ], "ideal_use_case": "An organization that wants its AI agents discoverable and verifiable through DNS, reusing existing DNSSEC trust.", "when_to_use": "When you want agent discovery and trust anchored in DNS infrastructure you already operate, without new servers.", "when_not_to_use": "When a simple HTTP file (llms.txt/agents.txt) or an in-band Agent Card (A2A) is sufficient and you don't need DNS-level trust.", "code_example": "; DNS zone (DNSSEC-signed)\n_agents._tcp.example.com. IN PTR acme-agent._agents._tcp.example.com.\nacme-agent._agents._tcp.example.com. IN SVCB 1 agent.example.com. ( alpn=\"h2\" )", "source": "IETF Internet-Draft (naming convention over SVCB/TXT/TLSA per RFC 9460/4033, DNS-SD, DNSSEC/DANE-signed): https://datatracker.ietf.org/doc/html/draft-mozleywilliams-dnsop-dnsaid-02 ; project site https://dns-aid.org/ ; reference impl https://github.com/dns-aid/dns-aid-core . Listed for addition in research §2.", "agent_readiness_link": "agent-readiness/discoverability", "layer_legacy": "content" }, { "id": "content-signal", "name": "Content Signals", "full_name": "Cloudflare Content Signals Policy", "layer": "licensing", "creator": "Cloudflare", "status": "live (2025)", "year": 2025, "one_liner": "A robots.txt extension that lets a site declare how its content may be used after access — search, ai-input, and ai-train — as machine-readable preferences.", "spec_url": "https://blog.cloudflare.com/content-signals-policy/", "snippet": "# robots.txt\\nContent-Signal: search=yes, ai-input=yes, ai-train=no", "abbreviation": "Content Signals", "also_known_as": [ "Content Signals Policy", "Content-Signal" ], "canonical_spec_url": "https://contentsignals.org", "entity_uri": "https://blog.cloudflare.com/content-signals-policy/", "taxonomy_layer": "licensing", "sub_layer": "content-use-preferences", "protocol_type": "declaration", "central_problem": "Lets a site express, in robots.txt, how crawlers may use its content after access — for search, AI input (RAG/grounding), or AI training — as clear machine-readable preferences.", "maintainer": "Cloudflare (Content Signals Policy; published openly under CC0)", "governance_body": "vendor (Cloudflare); spec released under CC0", "license": "CC0 (the policy text is released under a CC0 license for open adoption)", "maturity_tag": "emerging", "current_spec_version": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://contentsignals.org", "note": "Confirm any version number against contentsignals.org at build." }, "spec_date": "2025-09-24", "launch_date": "2025-09-24", "last_verified": "2026-06-15", "transport": "robots.txt extension (Content-Signal directive: search / ai-input / ai-train)", "core_mechanism": "The policy adds a short human-readable block plus a machine-readable Content-Signal line to robots.txt declaring per-use preferences with yes/no values: search (use in a search index), ai-input (use to ground/answer queries, e.g. RAG), and ai-train (use to train models). Cloudflare's managed robots.txt defaults to search=yes, ai-train=no. Signals express preferences, not technical enforcement.", "discovery_endpoint": "robots.txt Content-Signal directive", "settlement_type": null, "adoption_metric": { "value": "Auto-applied to Cloudflare's managed robots.txt (Cloudflare states 3.8M+ domains) with default Content-Signal: search=yes, ai-train=no", "source": "https://blog.cloudflare.com/content-signals-policy/", "last_verified": "2026-06-15" }, "notable_adopters": [ { "value": "Cloudflare (creator; applied across its managed robots.txt fleet)", "source": "https://blog.cloudflare.com/content-signals-policy/" } ], "relationships": [ { "predicate": "complements", "target": "rsl", "note": "Content Signals expresses non-binding use preferences in robots.txt; RSL declares enforceable machine-readable licensing terms — paired Layer-6 declarations." }, { "predicate": "extends", "target": "agents-json", "note": "Content Signals is a robots.txt extension in the same Layer-1/6 declaration family as the other root-file declarations; it adds an after-access use dimension robots.txt's allow/disallow lacks." } ], "ideal_use_case": "A site that wants to state, in robots.txt, that search use is welcome but AI training is not — without standing up enforcement.", "when_to_use": "When you want to communicate after-access content-use preferences (search vs AI-input vs AI-train) to crawlers in a standard, machine-readable line.", "when_not_to_use": "When you need binding, enforceable licensing or payment (use RSL or Pay Per Crawl) — Content Signals are preferences, not controls.", "code_example": "# robots.txt\n# Content usage preferences (Cloudflare Content Signals Policy)\nUser-agent: *\nContent-Signal: search=yes, ai-input=yes, ai-train=no\nAllow: /", "source": "Launch 2025-09-24, three signals (search / ai-input / ai-train), robots.txt extension, CC0, Cloudflare managed-robots default search=yes/ai-train=no, contentsignals.org: https://blog.cloudflare.com/content-signals-policy/ . Listed for addition in research §2.", "agent_readiness_link": "access-economics", "layer_legacy": "content" }, { "id": "schema-org", "name": "schema.org", "full_name": "Schema.org structured data vocabulary (for agents)", "layer": "discovery", "creator": "Schema.org founding sponsors (Google, Microsoft, Yahoo, Yandex)", "status": "active (the agentic-web data foundation)", "year": 2011, "one_liner": "The shared structured-data vocabulary (JSON-LD) that gives agents machine-readable entities and relationships to read off a page — the noun layer the agentic web is built on.", "spec_url": "https://schema.org", "snippet": "", "abbreviation": "schema.org", "also_known_as": [ "Schema.org", "schema.org for agents", "structured data vocabulary" ], "canonical_spec_url": "https://schema.org/docs/schemas.html", "entity_uri": "https://en.wikipedia.org/wiki/Schema.org", "taxonomy_layer": "discovery", "sub_layer": "structured-data-vocabulary", "protocol_type": "declaration", "central_problem": "Gives the web a shared vocabulary for describing entities and relationships in machine-readable JSON-LD, so an agent can read off a page's meaning instead of inferring it from layout.", "maintainer": "Schema.org community (W3C Schema.org Community Group; founding sponsors Google, Microsoft, Yahoo, Yandex)", "governance_body": "Schema.org Community Group (under W3C)", "license": "Schema.org terms (vocabulary is openly usable; see schema.org/docs/terms.html)", "maturity_tag": "standard", "current_spec_version": { "value": "30.0", "verify_status": "verify-against-primary-at-build", "source_hint": "https://schema.org/docs/releases.html", "note": "Schema.org v30.0 reported released 2026-03-25; confirm the current release against schema.org/docs/releases.html at build." }, "spec_date": { "value": "2026-03-25", "verify_status": "verify-against-primary-at-build", "source_hint": "https://schema.org/docs/releases.html", "note": "v30.0 release date reported as 2026-03-25; confirm against the primary releases page at build." }, "launch_date": "2011-06-02", "last_verified": "2026-06-15", "transport": "JSON-LD (also Microdata / RDFa) embedded in HTML", "core_mechanism": "Schema.org defines a hierarchy of types (Product, Organization, FAQPage, Person, etc.) and properties; a page embeds JSON-LD using @context https://schema.org so crawlers and agents extract structured entities and relationships. It is the noun/vocabulary layer that NLWeb is built on and that WebMCP's verbs act over; there is no separate 'schema.org-for-agents' spec — agentic use reuses the existing vocabulary.", "discovery_endpoint": "In-page ", "source": "Schema.org vocabulary as the agentic-web data foundation (v30.0 reported 2026-03-25), JSON-LD: https://schema.org and https://schema.org/docs/releases.html . Seed triple (NLWeb built_on schema.org): research §2. Honesty note: there is no distinct 'schema.org-for-agents' spec; this records the existing vocabulary applied to agentic use.", "agent_readiness_link": "agent-readiness/discoverability", "layer_legacy": "content" }, { "id": "oasf", "name": "OASF", "full_name": "Open Agentic Schema Framework", "layer": "capability", "creator": "AGNTCY project (originated at Cisco / Outshift)", "status": "active (Linux Foundation AGNTCY)", "year": 2025, "one_liner": "A standardized schema for describing AI agents — their capabilities, metadata and relationships — so agents can be discovered and understood across platforms; the 'DNS for agents' within AGNTCY.", "spec_url": "https://docs.agntcy.org/oasf/open-agentic-schema-framework/", "snippet": "An OASF record describes an agent's capabilities via attribute-based taxonomies for cross-platform discovery.", "abbreviation": "OASF", "also_known_as": [ "Open Agentic Schema Framework", "Open Agent Schema Framework" ], "canonical_spec_url": "https://docs.agntcy.org/oasf/open-agentic-schema-framework/", "entity_uri": "https://github.com/agntcy/oasf", "taxonomy_layer": "capability", "sub_layer": "agent-capability-schema", "protocol_type": "manifest", "central_problem": "Gives AI agents a standardized schema to describe their capabilities, attributes, and relationships so they can be discovered and understood across different platforms.", "maintainer": "AGNTCY project (Linux Foundation); originated at Cisco / Outshift", "governance_body": "Linux Foundation (AGNTCY)", "license": { "value": "Apache-2.0", "verify_status": "verify-against-primary-at-build", "source_hint": "https://github.com/agntcy/oasf", "note": "Confirm the agntcy/oasf repo license at build." }, "maturity_tag": "emerging", "current_spec_version": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://github.com/agntcy/oasf", "note": "Confirm current OASF schema version at build." }, "spec_date": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://docs.agntcy.org/oasf/open-agentic-schema-framework/", "note": "Confirm latest spec date at build." }, "launch_date": { "value": "2025", "verify_status": "verify-against-primary-at-build", "source_hint": "https://docs.agntcy.org/oasf/open-agentic-schema-framework/", "note": "AGNTCY open-sourced by Cisco March 2025; confirm OASF first-release date at build." }, "last_verified": "2026-06-15", "transport": "Schema/manifest (attribute-based taxonomies; agent capability records)", "core_mechanism": "OASF defines a standardized, attribute-based schema for agent capabilities, interactions, and metadata; agents publish OASF records so other agents and directories can discover and understand them across platforms. It functions as a 'DNS for agents' and underpins AGNTCY's Agent Discovery.", "discovery_endpoint": "OASF agent capability records (AGNTCY Agent Directory)", "settlement_type": null, "adoption_metric": { "value": "Part of AGNTCY, which reports 75+ supporting companies (formative members Cisco, Dell, Google Cloud, Oracle, Red Hat)", "source": "https://www.linuxfoundation.org/press/linux-foundation-welcomes-the-agntcy-project-to-standardize-open-multi-agent-system-infrastructure-and-break-down-ai-agent-silos", "last_verified": "2026-06-15" }, "notable_adopters": [ { "value": "Cisco / Outshift (originator)", "source": "https://www.linuxfoundation.org/press/linux-foundation-welcomes-the-agntcy-project-to-standardize-open-multi-agent-system-infrastructure-and-break-down-ai-agent-silos" } ], "relationships": [ { "predicate": "part_of", "target": "agntcy", "note": "OASF -part_of-> AGNTCY: OASF is AGNTCY's agent-discovery schema component." }, { "predicate": "competes_with", "target": "a2a", "note": "OASF agent capability descriptions overlap with A2A Agent Cards as ways to advertise what an agent can do." } ], "ideal_use_case": "Publishing a standardized, discoverable description of an agent's capabilities for cross-platform multi-agent systems.", "when_to_use": "When you are building on the AGNTCY 'Internet of Agents' stack and need a common capability schema for agent discovery.", "when_not_to_use": "When you have committed to A2A Agent Cards or only need a single agent to call tools (use MCP).", "code_example": "// OASF agent capability record (schematic)\n{ \"name\": \"researcher\", \"schema_version\": \"oasf\", \"capabilities\": [ { \"class\": \"nlp/summarization\" } ], \"locators\": [ { \"type\": \"docker-image\" } ] }", "source": "OASF as AGNTCY's standardized agent-capability schema ('DNS for agents'), Apache-2.0, Linux Foundation: https://docs.agntcy.org/oasf/open-agentic-schema-framework/ and https://github.com/agntcy/oasf . AGNTCY/LF context: https://www.linuxfoundation.org/press/linux-foundation-welcomes-the-agntcy-project-to-standardize-open-multi-agent-system-infrastructure-and-break-down-ai-agent-silos . Listed for addition in research §2.", "agent_readiness_link": "agent-readiness/discoverability", "layer_legacy": "tool" }, { "id": "agntcy", "name": "AGNTCY", "full_name": "AGNTCY (Internet of Agents project)", "layer": "interop", "creator": "Cisco (Outshift), with LangChain and Galileo; now Linux Foundation", "status": "active (Linux Foundation, since 29 July 2025)", "year": 2025, "one_liner": "A Linux Foundation project building open infrastructure for an 'Internet of Agents' — discovery (OASF), identity, messaging (SLIM) and observability — so agents from different vendors interoperate.", "spec_url": "https://agntcy.org/", "snippet": "AGNTCY: Agent Discovery (OASF) + Agent Identity + Agent Messaging (SLIM) + Observability.", "abbreviation": "AGNTCY", "also_known_as": [ "AGNTCY", "Internet of Agents" ], "canonical_spec_url": "https://docs.agntcy.org/", "entity_uri": "https://agntcy.org/", "taxonomy_layer": "interop", "sub_layer": "multi-agent-infrastructure", "protocol_type": "transport", "central_problem": "Provides open, vendor-neutral infrastructure (discovery, identity, messaging, observability) so AI agents from different frameworks and vendors can find each other and collaborate.", "maintainer": "AGNTCY project under the Linux Foundation (originated at Cisco / Outshift)", "governance_body": "Linux Foundation", "license": { "value": "Apache-2.0", "verify_status": "verify-against-primary-at-build", "source_hint": "https://github.com/agntcy", "note": "Confirm component repo licenses (OASF, SLIM, etc.) at build." }, "maturity_tag": "emerging", "current_spec_version": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://docs.agntcy.org/", "note": "AGNTCY is a multi-component project, not a single versioned spec; confirm component versions at build." }, "spec_date": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://docs.agntcy.org/", "note": "Confirm latest release date at build." }, "launch_date": "2025-03", "last_verified": "2026-06-15", "transport": "Multi-component (OASF schema discovery; SLIM messaging; identity; observability)", "core_mechanism": "AGNTCY bundles the building blocks of an 'Internet of Agents': Agent Discovery via OASF, cryptographically verifiable Agent Identity and access control, Agent Messaging via SLIM (Secure Low-latency Interactive Messaging), and end-to-end Agent Observability. Cisco open-sourced it in March 2025 with LangChain and Galileo; it joined the Linux Foundation on 29 July 2025.", "discovery_endpoint": "AGNTCY Agent Directory (OASF records); component endpoints per module", "settlement_type": null, "adoption_metric": { "value": "75+ supporting companies; formative members Cisco, Dell Technologies, Google Cloud, Oracle, Red Hat", "source": "https://www.linuxfoundation.org/press/linux-foundation-welcomes-the-agntcy-project-to-standardize-open-multi-agent-system-infrastructure-and-break-down-ai-agent-silos", "last_verified": "2026-06-15" }, "notable_adopters": [ { "value": "Cisco (originator)", "source": "https://www.linuxfoundation.org/press/linux-foundation-welcomes-the-agntcy-project-to-standardize-open-multi-agent-system-infrastructure-and-break-down-ai-agent-silos" }, { "value": "Dell Technologies, Google Cloud, Oracle, Red Hat (formative members)", "source": "https://www.linuxfoundation.org/press/linux-foundation-welcomes-the-agntcy-project-to-standardize-open-multi-agent-system-infrastructure-and-break-down-ai-agent-silos" } ], "relationships": [ { "predicate": "competes_with", "target": "a2a", "note": "AGNTCY's interop stack overlaps with A2A as a multi-agent collaboration layer (though AGNTCY also supports A2A)." }, { "predicate": "complements", "target": "acp", "note": "ACP (Agent Communication Protocol) is associated with the AGNTCY community as a REST messaging option." } ], "ideal_use_case": "Standing up a vendor-neutral multi-agent system with discovery, identity, secure messaging and observability out of the box.", "when_to_use": "When you need the full 'Internet of Agents' infrastructure stack rather than a single protocol like MCP or A2A.", "when_not_to_use": "When a single interop protocol (A2A) or tool protocol (MCP) covers your need without adopting a whole framework.", "code_example": "// AGNTCY is an infrastructure project, not one wire format.\n// Discover an agent via OASF, message it via SLIM:\n// directory.lookup('researcher') -> slim.connect(agent.endpoint)", "source": "Cisco-originated (March 2025, with LangChain + Galileo), joined Linux Foundation 29 July 2025, 75+ companies, components OASF + SLIM + identity + observability: https://www.linuxfoundation.org/press/linux-foundation-welcomes-the-agntcy-project-to-standardize-open-multi-agent-system-infrastructure-and-break-down-ai-agent-silos and https://agntcy.org/ . Listed for addition in research §2.", "agent_readiness_link": "agent-readiness/a2a", "layer_legacy": "agent" }, { "id": "slim", "name": "SLIM", "full_name": "Secure Low-latency Interactive Messaging", "layer": "interop", "creator": "AGNTCY project (Cisco / Outshift); Linux Foundation", "status": "active (AGNTCY component)", "year": 2025, "one_liner": "AGNTCY's secure, low-latency messaging substrate for agent-to-agent, human-in-the-loop and tool communication, designed for multi-modal exchange and quantum-safe security.", "spec_url": "https://docs.agntcy.org/", "snippet": "SLIM carries agent ↔ agent / human / tool messages with low latency and quantum-safe security.", "abbreviation": "SLIM", "also_known_as": [ "Secure Low-latency Interactive Messaging" ], "canonical_spec_url": "https://docs.agntcy.org/messaging/slim-core/", "entity_uri": "https://github.com/agntcy", "taxonomy_layer": "interop", "sub_layer": "agent-messaging-substrate", "protocol_type": "transport", "central_problem": "Gives multi-agent systems a secure, low-latency messaging substrate for agent-to-agent, human-in-the-loop, and tool communication with multi-modal data and quantum-safe security.", "maintainer": "AGNTCY project under the Linux Foundation (originated at Cisco / Outshift)", "governance_body": "Linux Foundation (AGNTCY)", "license": { "value": "Apache-2.0", "verify_status": "verify-against-primary-at-build", "source_hint": "https://github.com/agntcy", "note": "Confirm the SLIM component repo license at build." }, "maturity_tag": "emerging", "current_spec_version": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://docs.agntcy.org/", "note": "Confirm current SLIM version at build." }, "spec_date": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://docs.agntcy.org/", "note": "Confirm latest spec date at build." }, "launch_date": { "value": "2025", "verify_status": "verify-against-primary-at-build", "source_hint": "https://docs.agntcy.org/", "note": "Confirm SLIM first-release date at build." }, "last_verified": "2026-06-15", "transport": "Low-latency messaging substrate (multi-modal; quantum-safe security by design)", "core_mechanism": "SLIM (Secure Low-latency Interactive Messaging) handles the communication patterns of AGNTCY: agent-to-agent, human-in-the-loop, and tool exchanges, optimized for low-latency multi-modal data with quantum-safe security designed in. It is the messaging leg of AGNTCY's Internet-of-Agents stack, paired with OASF discovery.", "discovery_endpoint": "SLIM messaging endpoints (AGNTCY component; implementation-defined)", "settlement_type": null, "adoption_metric": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://docs.agntcy.org/", "note": "No standalone audited adoption figure asserted; part of AGNTCY (75+ companies)." }, "notable_adopters": [ { "value": "Cisco / Outshift (originator)", "source": "https://www.linuxfoundation.org/press/linux-foundation-welcomes-the-agntcy-project-to-standardize-open-multi-agent-system-infrastructure-and-break-down-ai-agent-silos" } ], "relationships": [ { "predicate": "part_of", "target": "agntcy", "note": "SLIM -part_of-> AGNTCY: SLIM is AGNTCY's secure messaging component (paired with OASF discovery)." }, { "predicate": "competes_with", "target": "a2a", "note": "SLIM is an agent messaging transport, overlapping with A2A's task/message transport." } ], "ideal_use_case": "The secure, low-latency message bus for a multi-agent system built on AGNTCY, including human-in-the-loop steps.", "when_to_use": "When you need a purpose-built, low-latency, quantum-safe messaging substrate across agents, humans, and tools within AGNTCY.", "when_not_to_use": "When A2A's HTTP/JSON-RPC transport or plain REST (ACP) already meets your messaging needs.", "code_example": "// SLIM messaging (schematic)\n// slim.connect(agent.endpoint); slim.send({ to: 'planner', modality: 'text', body: '...' })", "source": "SLIM as AGNTCY's secure low-latency messaging component (agent/human/tool, multi-modal, quantum-safe): https://docs.agntcy.org/ ; AGNTCY/LF context https://www.linuxfoundation.org/press/linux-foundation-welcomes-the-agntcy-project-to-standardize-open-multi-agent-system-infrastructure-and-break-down-ai-agent-silos . Listed for addition in research §2.", "agent_readiness_link": "agent-readiness/a2a", "layer_legacy": "agent" }, { "id": "anp", "name": "ANP", "full_name": "Agent Network Protocol", "layer": "interop", "creator": "Agent Network Protocol open-source community", "status": "emerging (open source)", "year": 2025, "one_liner": "An open protocol aiming to be the 'HTTP of the agent internet': decentralized DID-based identity, a meta-protocol negotiation layer, and JSON-LD agent descriptions so billions of agents can connect.", "spec_url": "https://agent-network-protocol.com/", "snippet": "did:wba identity + meta-protocol negotiation + JSON-LD agent description for open agent discovery.", "abbreviation": "ANP", "also_known_as": [ "Agent Network Protocol" ], "canonical_spec_url": "https://agent-network-protocol.com/specs/agent-description.html", "entity_uri": "https://github.com/agent-network-protocol/AgentNetworkProtocol", "taxonomy_layer": "interop", "sub_layer": "decentralized-agent-network", "protocol_type": "transport", "central_problem": "Defines how agents connect across an open, decentralized network — establishing identity and trust, exchanging interpretable messages, and understanding each other's intent — to build an 'internet of agents'.", "maintainer": "Agent Network Protocol open-source community (agent-network-protocol on GitHub)", "governance_body": "open-source community (ANP)", "license": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://github.com/agent-network-protocol/AgentNetworkProtocol", "note": "Confirm the ANP repo license at build." }, "maturity_tag": "emerging", "current_spec_version": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://agent-network-protocol.com/specs/agent-description.html", "note": "Confirm current ANP spec version at build (multi-document spec set: communication / meta-protocol / agent-description)." }, "spec_date": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://agent-network-protocol.com/specs/agent-description.html", "note": "Confirm latest spec date at build." }, "launch_date": { "value": "2025", "verify_status": "verify-against-primary-at-build", "source_hint": "https://github.com/agent-network-protocol/AgentNetworkProtocol", "note": "Confirm first-release date at build." }, "last_verified": "2026-06-15", "transport": "HTTPS + W3C DID (did:wba) for identity/encryption; JSON-LD agent descriptions; meta-protocol negotiation", "core_mechanism": "ANP layers three tiers: (1) an Identity & Encrypted Communication layer using W3C DIDs (the did:wba method, each DID resolving to an HTTPS-hosted DID document) for decentralized authentication and end-to-end encryption; (2) a Meta-Protocol layer where agents negotiate which protocol to speak; and (3) an Application Protocol layer using semantic-web/JSON-LD agent descriptions to advertise capabilities, endpoints, and auth schemes.", "discovery_endpoint": "JSON-LD agent description document (HTTPS) + did:wba DID document", "settlement_type": null, "adoption_metric": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://github.com/agent-network-protocol/AgentNetworkProtocol", "note": "No audited adoption figure asserted." }, "notable_adopters": [ { "value": "Agent Network Protocol community", "source": "https://github.com/agent-network-protocol/AgentNetworkProtocol" } ], "relationships": [ { "predicate": "competes_with", "target": "a2a", "note": "ANP is an alternative agent-interop protocol to A2A, distinguished by decentralized DID-based identity and a meta-protocol negotiation layer." }, { "predicate": "complements", "target": "erc-8004", "note": "Both bring decentralized identity to agents; ANP uses W3C DIDs off-chain, ERC-8004 uses on-chain registries." } ], "ideal_use_case": "Building an open, decentralized agent network where identity and trust are self-sovereign (DID-based) rather than platform-issued.", "when_to_use": "When you want decentralized DID identity and protocol negotiation for agents instead of a single vendor's interop stack.", "when_not_to_use": "When you need the broad ecosystem and production interop of A2A, or you don't want to adopt DID infrastructure.", "code_example": "// ANP agent description (JSON-LD, schematic)\n{ \"@context\": \"https://agent-network-protocol.com/context\", \"did\": \"did:wba:example.com:agent\", \"name\": \"researcher\", \"interfaces\": [ ... ] }", "source": "ANP three-layer architecture (did:wba identity, meta-protocol negotiation, JSON-LD agent description): https://agent-network-protocol.com/ and https://agent-network-protocol.com/specs/agent-description.html ; repo https://github.com/agent-network-protocol/AgentNetworkProtocol . Compared with MCP/ACP/A2A in arXiv:2505.02279. Listed for addition in research §2.", "agent_readiness_link": "agent-readiness/a2a", "layer_legacy": "agent" }, { "id": "erc-8004", "name": "ERC-8004", "full_name": "ERC-8004: Trustless Agents", "layer": "identity", "creator": "Marco De Rossi, Davide Crapis, Jordan Ellis, Erik Reppel (Ethereum Improvement Proposal)", "status": "Draft (Standards Track: ERC)", "year": 2025, "one_liner": "An Ethereum standard adding on-chain Identity, Reputation and Validation registries so agents can be discovered and trusted across organizational boundaries — a trust layer that extends A2A.", "spec_url": "https://eips.ethereum.org/EIPS/eip-8004", "snippet": "Three on-chain registries — Identity, Reputation, Validation — give A2A agents portable, verifiable trust.", "abbreviation": "ERC-8004", "also_known_as": [ "ERC-8004", "Trustless Agents", "EIP-8004" ], "canonical_spec_url": "https://eips.ethereum.org/EIPS/eip-8004", "entity_uri": "https://eips.ethereum.org/EIPS/eip-8004", "taxonomy_layer": "identity", "sub_layer": "on-chain-agent-trust-registry", "protocol_type": "verification", "central_problem": "Lets AI agents be discovered, authenticated, and trusted across organizational boundaries without preexisting relationships, by anchoring identity, reputation, and validation in on-chain registries.", "maintainer": "Ethereum community via the EIP/ERC process (authors: Marco De Rossi, Davide Crapis, Jordan Ellis, Erik Reppel)", "governance_body": "Ethereum (EIP/ERC Standards Track)", "license": "CC0 (Ethereum EIPs are published under CC0)", "maturity_tag": "emerging", "current_spec_version": { "value": "Draft", "verify_status": "verify-against-primary-at-build", "source_hint": "https://eips.ethereum.org/EIPS/eip-8004", "note": "Status observed as Draft (Standards Track: ERC) on the canonical EIP page; confirm whether it has advanced (Review/Last Call/Final) at build." }, "spec_date": { "value": "2025-08-13", "verify_status": "verify-against-primary-at-build", "source_hint": "https://eips.ethereum.org/EIPS/eip-8004", "note": "Created date 2025-08-13 per the canonical EIP header; confirm at build." }, "launch_date": "2025-08-13", "last_verified": "2026-06-15", "transport": "On-chain smart-contract registries (Ethereum and EVM networks)", "core_mechanism": "ERC-8004 specifies three lightweight on-chain registries: an Identity Registry (discoverable, cross-chain agent IDs), a Reputation Registry (structured, verifiable feedback), and a Validation Registry (cryptographic / crypto-economic task verification via reputation, stake-secured validation, or TEEs). It complements A2A and MCP — A2A handles message/capability exchange, ERC-8004 adds the verifiable identity, portable reputation, and validation A2A lacks.", "discovery_endpoint": "On-chain Identity Registry lookups (agent IDs); cross-chain", "settlement_type": null, "adoption_metric": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://eips.ethereum.org/EIPS/eip-8004", "note": "Reputation/Identity contract deployments reported on Ethereum mainnet + 20+ networks (Jan 2026) per secondary sources; not asserted from a primary doc — confirm at build." }, "notable_adopters": [ { "value": "Authored with contributors from MetaMask, the Ethereum Foundation, Google, and Coinbase", "source": "https://eips.ethereum.org/EIPS/eip-8004" } ], "relationships": [ { "predicate": "provides_identity_for", "target": "a2a", "note": "ERC-8004 -provides_identity_for-> A2A (research §2 seed triple): it adds the verifiable identity/reputation/validation trust layer to A2A's communication." }, { "predicate": "complements", "target": "web-bot-auth", "note": "Both establish agent identity/trust; ERC-8004 is on-chain (decentralized registries), Web Bot Auth is off-chain (HTTP message signatures)." } ], "ideal_use_case": "Giving cross-organization agents a portable, on-chain identity and reputation so they can be trusted without prior relationships.", "when_to_use": "When agents must transact/collaborate across trust boundaries and you want decentralized, verifiable identity, reputation, and validation on-chain.", "when_not_to_use": "When an off-chain signature (Web Bot Auth) or a vendor directory is sufficient, or you cannot use on-chain infrastructure.", "code_example": "// ERC-8004 Identity Registry (schematic Solidity interface)\ninterface IIdentityRegistry {\n function registerAgent(string calldata agentDomain, address agentAddress) external returns (uint256 agentId);\n function resolveByAddress(address agentAddress) external view returns (uint256 agentId);\n}", "source": "Canonical EIP (Status: Draft; Created 2025-08-13; three registries Identity/Reputation/Validation; complements A2A and MCP): https://eips.ethereum.org/EIPS/eip-8004 . Authors: Marco De Rossi, Davide Crapis, Jordan Ellis, Erik Reppel. Seed triple (ERC-8004 provides identity for A2A): research §2.", "agent_readiness_link": "agent-readiness/web-bot-auth" }, { "id": "ucp", "name": "UCP", "full_name": "Universal Commerce Protocol", "layer": "payments", "creator": "Universal-Commerce-Protocol project (open standard; ucp.dev)", "status": "active (open standard)", "year": 2026, "one_liner": "An open standard for interoperability between commerce entities so AI agents can discover products, fill carts, and complete purchases — orchestrating A2A, AP2 and MCP across the commerce journey.", "spec_url": "https://ucp.dev", "snippet": "UCP: an open standard enabling interoperability between commerce entities for agent-driven shopping.", "abbreviation": "UCP", "also_known_as": [ "Universal Commerce Protocol" ], "canonical_spec_url": "https://ucp.dev/specification/overview", "entity_uri": "https://github.com/universal-commerce-protocol/ucp", "taxonomy_layer": "payments", "sub_layer": "commerce-interoperability", "protocol_type": "settlement", "central_problem": "Gives AI agents a single open standard to interoperate across commerce entities — discovering products, building carts, and completing purchases — instead of integrating each retailer/payment stack bespoke.", "maintainer": "Universal-Commerce-Protocol project (ucp.dev / github.com/universal-commerce-protocol)", "governance_body": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://ucp.dev", "note": "Research §2 lists UCP among AAIF-hosted projects; the primary repo did not confirm AAIF/Linux Foundation governance. Confirm the governance home at build." }, "license": "Apache-2.0", "maturity_tag": "emerging", "current_spec_version": { "value": "v2026-04-08", "verify_status": "verify-against-primary-at-build", "source_hint": "https://github.com/universal-commerce-protocol/ucp", "note": "Latest release v2026-04-08 (dated Apr 9 2026) observed on github.com/universal-commerce-protocol/ucp; confirm current tag at build." }, "spec_date": { "value": "2026-04-08", "verify_status": "verify-against-primary-at-build", "source_hint": "https://github.com/universal-commerce-protocol/ucp", "note": "Release v2026-04-08; confirm against the GitHub releases at build." }, "launch_date": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://ucp.dev", "note": "Secondary sources cite a Google/Shopify/Walmart UCP launch at NRF 2026; confirm the authoritative launch date/sponsors against ucp.dev at build." }, "last_verified": "2026-06-15", "transport": "Open commerce-interoperability standard (orchestrates A2A / AP2 / MCP across the commerce journey)", "core_mechanism": "UCP is an open standard for interoperability between commerce entities (retailers, agents, payment providers) covering the journey from product discovery through cart-building, checkout, and post-purchase. Secondary analyses describe it as orchestrating existing protocols — A2A for agent communication, AP2 for payments, and MCP for tool/data access — into one commerce layer.", "discovery_endpoint": "UCP commerce endpoints (per the ucp.dev specification; implementation-defined)", "settlement_type": { "value": "card-rail / payment-agnostic (delegates settlement to AP2-class rails)", "verify_status": "verify-against-primary-at-build", "source_hint": "https://ucp.dev/specification/overview", "note": "Confirm UCP's settlement model against the primary spec at build." }, "adoption_metric": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://ucp.dev", "note": "Secondary sources cite Shopify and Walmart involvement; not confirmed from the primary repo. Confirm at build." }, "notable_adopters": [ { "value": "Universal-Commerce-Protocol project", "source": "https://github.com/universal-commerce-protocol/ucp" } ], "relationships": [ { "predicate": "built_on", "target": "a2a", "note": "Secondary analyses describe UCP as orchestrating A2A for the agent-communication layer of commerce." }, { "predicate": "built_on", "target": "ap2", "note": "UCP delegates the payment leg to AP2-class settlement." }, { "predicate": "competes_with", "target": "acp-commerce", "note": "UCP and ACP (Agentic Commerce Protocol) both address agent-driven commerce/checkout interoperability." } ], "ideal_use_case": "Giving retailers, agents, and payment providers one open interoperability standard for agent-driven shopping end to end.", "when_to_use": "When you want a full commerce-journey interoperability layer (discovery → cart → checkout → post-purchase) rather than a single checkout or payment protocol.", "when_not_to_use": "When an in-conversation checkout (ACP) or a single payment mandate framework (AP2) already covers your need.", "code_example": "// UCP orchestrates commerce protocols (schematic):\n// agent --A2A--> retailer.discover(query)\n// agent --AP2--> pay(cartMandate)\n// retailer --MCP--> inventory.lookup(sku)", "source": "Open commerce-interoperability standard, Apache-2.0, release v2026-04-08: https://ucp.dev and https://github.com/universal-commerce-protocol/ucp . Secondary attribution (Google/Shopify/Walmart, NRF 2026) and AAIF hosting per research §2 + trade press — flagged for primary verification at build (possible distinct 'UCP' efforts).", "agent_readiness_link": "agent-readiness/x402", "creator_meta": { "value": "Universal-Commerce-Protocol project (open standard; ucp.dev)", "verify_status": "verify-against-primary-at-build", "source_hint": "https://ucp.dev", "note": "Secondary sources attribute a UCP launch to Google with Shopify and Walmart at NRF 2026, and research §2 lists UCP among AAIF-hosted projects; the primary ucp.dev / github.com/universal-commerce-protocol repo did not confirm those sponsors or AAIF hosting. Confirm the authoritative creator/host against ucp.dev at build — possible multiple 'UCP' efforts." }, "layer_legacy": "payment" }, { "id": "mpp", "name": "MPP", "full_name": "Machine Payments Protocol", "layer": "payments", "creator": "Stripe + Tempo", "status": "live (shipped 2026; IETF Internet-Draft)", "year": 2026, "one_liner": "Stripe and Tempo's open standard for billing AI agents over HTTP — agents discover prices, pay, subscribe and reconcile across stablecoins, cards and BNPL, with cryptographic receipts.", "spec_url": "https://stripe.com/blog/machine-payments-protocol", "snippet": "HTTP 402 + machine-readable price discovery → pay (stablecoin/card) → cryptographic receipt, in one cycle.", "abbreviation": "MPP", "also_known_as": [ "Machine Payments Protocol", "Stripe/Tempo MPP" ], "canonical_spec_url": "https://stripe.com/blog/machine-payments-protocol", "entity_uri": "https://stripe.com/blog/machine-payments-protocol", "taxonomy_layer": "payments", "sub_layer": "machine-billing-over-http", "protocol_type": "settlement", "central_problem": "Gives AI agents a standard way to discover prices, pay for resources, manage subscriptions, and reconcile balances over HTTP across stablecoins, cards, and BNPL — with cryptographic receipts.", "maintainer": "Stripe + Tempo (co-authored); proposed to the IETF as a Standards Track Internet-Draft", "governance_body": { "value": "vendor (Stripe + Tempo); IETF Internet-Draft submitted", "verify_status": "verify-against-primary-at-build", "source_hint": "https://stripe.com/blog/machine-payments-protocol", "note": "Confirm IETF draft name/status against datatracker at build." }, "license": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://stripe.com/blog/machine-payments-protocol", "note": "Confirm the MPP spec license at build." }, "maturity_tag": "emerging", "current_spec_version": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://stripe.com/blog/machine-payments-protocol", "note": "Confirm current MPP spec/draft version at build." }, "spec_date": { "value": "2026-03-18", "verify_status": "verify-against-primary-at-build", "source_hint": "https://stripe.com/blog/machine-payments-protocol", "note": "Announcement reported 2026-03-18; confirm against the primary Stripe blog at build." }, "launch_date": { "value": "2026-03-18", "verify_status": "verify-against-primary-at-build", "source_hint": "https://stripe.com/blog/machine-payments-protocol", "note": "Reported ship date 2026-03-18; confirm at build." }, "last_verified": "2026-06-15", "transport": "HTTP (formalizes the 402 status code); settlement via Stripe PaymentIntents with Tempo as default stablecoin chain", "core_mechanism": "MPP gives HTTP's 402 status code a formal specification so agents can, in one request-response cycle, discover pricing, pay for a resource (stablecoins via Tempo, cards via Stripe/Visa, Bitcoin via Lightning, or custom methods), and receive a cryptographic receipt. It is lifecycle-aware — subscriptions, streaming charges, cancellations, and balance reconciliation are first-class — with funds settling through Stripe PaymentIntents.", "discovery_endpoint": "HTTP 402 price-discovery response (per-resource); MPP Services Directory", "settlement_type": "stablecoin (Tempo) / card-rail (Stripe, Visa) / Bitcoin (Lightning) / custom", "adoption_metric": { "value": "100+ services listed in the MPP Services Directory (per the Stripe/Tempo announcement)", "source": "https://stripe.com/blog/machine-payments-protocol", "last_verified": "2026-06-15", "note": "Directory count is vendor-reported; confirm against the primary Stripe/Tempo source at build." }, "notable_adopters": [ { "value": "Stripe (co-author; PaymentIntents settlement)", "source": "https://stripe.com/blog/machine-payments-protocol" }, { "value": "Tempo (co-author; default stablecoin chain)", "source": "https://stripe.com/blog/machine-payments-protocol" } ], "relationships": [ { "predicate": "competes_with", "target": "x402", "note": "MPP and x402 both formalize HTTP 402 for agent payments; MPP adds lifecycle primitives (subscriptions, reconciliation) and multi-rail settlement." }, { "predicate": "complements", "target": "ap2", "note": "Both target agent payments; MPP is an HTTP 402 billing protocol with Tempo settlement, AP2 is a mandate framework across rails." } ], "ideal_use_case": "Billing AI agents for API/resource access over HTTP with subscriptions, streaming charges, and multi-rail settlement.", "when_to_use": "When you need lifecycle-aware agent billing (not just one-shot payments) across stablecoins, cards, and BNPL with cryptographic receipts.", "when_not_to_use": "When a simple inline stablecoin micropayment (x402) or a mandate-routed checkout (AP2) is all you need.", "code_example": "HTTP/1.1 402 Payment Required\nMPP-Accepts: stablecoin; chain=tempo; price=0.02 USD\n\n# Agent pays and retries; server returns a cryptographic receipt:\nMPP-Receipt: ", "source": "Stripe + Tempo Machine Payments Protocol (shipped 2026-03-18; formalizes HTTP 402; price discovery + subscriptions + reconciliation; stablecoin via Tempo, cards via Stripe/Visa, Bitcoin via Lightning; Stripe PaymentIntents settlement; IETF Internet-Draft; 100+ services directory): https://stripe.com/blog/machine-payments-protocol . Listed for addition in research §2.", "agent_readiness_link": "agent-readiness/x402", "layer_legacy": "payment" }, { "id": "kite", "name": "Kite", "full_name": "Kite (Agent payments / identity infrastructure)", "layer": "payments", "creator": "Kite AI", "status": "live (Kite Chain + Agent Passport, 2026)", "year": 2025, "one_liner": "A payments-and-identity layer for the agent economy: verifiable agent identities (Agent Passport), cryptographically enforced spending constraints, and stablecoin rails, integrating x402, AP2 and MCP.", "spec_url": "https://gokite.ai", "snippet": "Kite AIR: verifiable agent identity + programmable spend constraints + stablecoin rails (x402 / AP2 / MCP).", "abbreviation": "Kite", "also_known_as": [ "Kite AI", "Kite AIR", "Kite Agent Passport" ], "canonical_spec_url": "https://gokite.ai/kite-whitepaper", "entity_uri": "https://gokite.ai", "taxonomy_layer": "payments", "sub_layer": "agent-payment-identity-rails", "protocol_type": "settlement", "central_problem": "Treats AI agents as first-class economic actors by giving them verifiable identities, cryptographically enforced spending guardrails, and stablecoin payment rails for micropayments at scale.", "maintainer": "Kite AI", "governance_body": "vendor (Kite AI)", "license": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://gokite.ai/kite-whitepaper", "note": "Confirm any open-spec license; Kite is largely a platform/network rather than an open spec. Confirm at build." }, "maturity_tag": "emerging", "current_spec_version": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://gokite.ai/kite-whitepaper", "note": "Confirm whitepaper/spec version at build." }, "spec_date": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://gokite.ai/kite-whitepaper", "note": "Confirm whitepaper date at build (a 2025-10-30 research paper is referenced)." }, "launch_date": { "value": "2026-04-30", "verify_status": "verify-against-primary-at-build", "source_hint": "https://dailyhodl.com/2026/04/30/kite-launches-kite-chain-and-kite-agent-passport-enabling-autonomous-ai-agent-payments/", "note": "Kite Chain + Agent Passport launch reported 2026-04-30 (secondary source); Kite raised $18M in Sep 2025. Confirm the launch date against a Kite primary at build." }, "last_verified": "2026-06-15", "transport": "Kite Chain (Layer-1) + stablecoin rails; integrates x402 / AP2 / MCP envelopes", "core_mechanism": "Kite provides agent payment-and-identity infrastructure: Kite AIR gives agents verifiable identities (Agent Passport) and a hierarchical identity model with mathematical delegation; the SPACE framework adds stablecoin-native sub-cent payments with instant finality, cryptographically enforced programmable constraints (smart contracts), immutable audit trails, and economically viable micropayments. It uses x402 as the interoperability envelope between agents and services, with AP2 specializing the flow for stablecoin settlement and MCP for tool access.", "discovery_endpoint": "Kite Agent Passport identity (Kite AIR); on-chain (Kite Chain)", "settlement_type": "stablecoin (on-chain, Kite Chain; instant finality, sub-cent fees)", "adoption_metric": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://gokite.ai/kite-whitepaper", "note": "Kite reports investment from Coinbase Ventures (Oct 2025) and an $18M raise (Sep 2025); no audited usage figure asserted. Confirm at build." }, "notable_adopters": [ { "value": "Kite AI (operator)", "source": "https://gokite.ai/kite-whitepaper" }, { "value": "Coinbase Ventures (investor; x402 collaboration)", "source": "https://www.globenewswire.com/news-release/2025/10/27/3174837/0/en/kite-announces-investment-from-coinbase-ventures-to-advance-agentic-payments-with-the-x402-protocol.html" } ], "relationships": [ { "predicate": "built_on", "target": "x402", "note": "Kite uses x402 as the interoperability envelope between agents and services for payment intent/authorization." }, { "predicate": "complements", "target": "ap2", "note": "Kite specializes the AP2 flow for stablecoin settlement on Kite Chain." }, { "predicate": "complements", "target": "erc-8004", "note": "Kite Agent Passport provides verifiable agent identity, an off/on-chain analogue to ERC-8004's identity registries." } ], "ideal_use_case": "Running autonomous agents that hold verifiable identities and spend within cryptographically enforced limits using stablecoin micropayments.", "when_to_use": "When you need agent identity, delegation, spend guardrails, and stablecoin rails together on a purpose-built network.", "when_not_to_use": "When a single open payment protocol (x402) or mandate framework (AP2) on existing rails meets your need without a dedicated chain.", "code_example": "// Kite Agent Passport + x402 (schematic)\n// passport = kite.air.issue({ owner, limits: { perTx: '$0.50', daily: '$20' } })\n// agent pays via x402 envelope; constraints enforced on-chain by Kite Chain", "source": "Kite agent payments-and-identity infrastructure (Kite AIR identity / Agent Passport, SPACE framework, stablecoin rails; x402 envelope + AP2 settlement + MCP), Kite Chain + Agent Passport launch reported 2026-04-30: https://gokite.ai/kite-whitepaper ; Coinbase Ventures/x402 collaboration https://www.globenewswire.com/news-release/2025/10/27/3174837/0/en/kite-announces-investment-from-coinbase-ventures-to-advance-agentic-payments-with-the-x402-protocol.html . Listed for addition in research §2.", "agent_readiness_link": "agent-readiness/x402", "layer_legacy": "payment" }, { "id": "visa-tap", "name": "Visa TAP", "full_name": "Visa Trusted Agent Protocol", "layer": "payments", "creator": "Visa (with Cloudflare)", "status": "live (launched Oct 2025)", "year": 2025, "one_liner": "An open specification that signs an AI agent's identity into HTTP request headers so any merchant can cryptographically verify the agent is legitimate before agent-driven checkout.", "spec_url": "https://developer.visa.com/capabilities/trusted-agent-protocol", "snippet": "RFC 9421 HTTP message signatures over Web Bot Auth → merchant verifies agent against Visa's key directory.", "abbreviation": "Visa TAP", "also_known_as": [ "Trusted Agent Protocol", "Visa TAP", "TAP" ], "canonical_spec_url": "https://developer.visa.com/capabilities/trusted-agent-protocol/trusted-agent-protocol-specifications", "entity_uri": "https://github.com/visa/trusted-agent-protocol", "taxonomy_layer": "identity", "sub_layer": "agent-identity-for-commerce", "protocol_type": "verification", "central_problem": "Lets a merchant cryptographically answer one question at agent-driven checkout — is this AI agent legitimate — by verifying a signed agent identity carried in HTTP headers, distinguishing real agents from malicious bots.", "maintainer": "Visa (visa/trusted-agent-protocol), announced with Cloudflare", "governance_body": "vendor (Visa); open specification", "license": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://github.com/visa/trusted-agent-protocol", "note": "Repo shows a license link but the exact license was not captured; confirm against the visa/trusted-agent-protocol repo at build." }, "maturity_tag": "emerging", "current_spec_version": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://developer.visa.com/capabilities/trusted-agent-protocol/trusted-agent-protocol-specifications", "note": "No tagged release on the repo at observation; confirm the current spec version against Visa Developer at build." }, "spec_date": { "value": null, "verify_status": "verify-against-primary-at-build", "source_hint": "https://developer.visa.com/capabilities/trusted-agent-protocol/trusted-agent-protocol-specifications", "note": "Confirm current spec revision date at build." }, "launch_date": { "value": "2025-10-14", "verify_status": "verify-against-primary-at-build", "source_hint": "https://investor.visa.com/news/news-details/2025/Visa-Introduces-Trusted-Agent-Protocol-An-Ecosystem-Led-Framework-for-AI-Commerce/default.aspx", "note": "Announced with Cloudflare on 2025-10-14 (secondary sources); confirm against the Visa primary press release at build." }, "last_verified": "2026-06-15", "transport": "HTTP Message Signatures (RFC 9421) over the Web Bot Auth pattern; Ed25519; Visa-operated key directory", "core_mechanism": "Visa TAP signs an approved agent's identity into HTTP request headers using RFC 9421 HTTP Message Signatures built on the emerging Web Bot Auth standard; merchants verify the Ed25519 signature against a Visa-operated directory of agent public keys. Agents are vetted through Visa's Intelligent Commerce program and issued a unique key. TAP sits as an identity wrapper in front of whatever payment rail the merchant runs, layering on top of agent-commerce protocols like ACP and UCP.", "discovery_endpoint": "Signed HTTP request headers verified against Visa's agent public-key directory", "settlement_type": null, "adoption_metric": { "value": "Announced with launch partners including Adyen, Ant International, Checkout.com, Coinbase, Cybersource, Elavon, Fiserv, Microsoft, Nuvei, Shopify, Stripe, and Worldpay", "source": "https://investor.visa.com/news/news-details/2025/Visa-Introduces-Trusted-Agent-Protocol-An-Ecosystem-Led-Framework-for-AI-Commerce/default.aspx", "last_verified": "2026-06-15", "note": "Partner list per secondary reporting of the Visa announcement; confirm against the Visa primary at build." }, "notable_adopters": [ { "value": "Visa (creator)", "source": "https://github.com/visa/trusted-agent-protocol" }, { "value": "Cloudflare (co-announcer)", "source": "https://investor.visa.com/news/news-details/2025/Visa-Introduces-Trusted-Agent-Protocol-An-Ecosystem-Led-Framework-for-AI-Commerce/default.aspx" } ], "relationships": [ { "predicate": "built_on", "target": "web-bot-auth", "note": "Visa TAP -built_on-> Web Bot Auth: it uses RFC 9421 HTTP Message Signatures over the Web Bot Auth pattern to sign agent identity." }, { "predicate": "complements", "target": "acp-commerce", "note": "TAP is an identity wrapper that layers on top of agent-commerce protocols like ACP and UCP, verifying the agent before checkout." } ], "ideal_use_case": "Letting merchants verify that an AI agent attempting checkout is a vetted, legitimate agent before processing payment.", "when_to_use": "When you run agent-driven commerce and need to cryptographically distinguish legitimate, Visa-vetted agents from malicious bots at the request layer.", "when_not_to_use": "When you need the payment/settlement itself (use AP2/ACP/x402) — TAP only verifies identity — or you don't want a Visa-operated directory in the loop.", "code_example": "Signature-Agent: \"https://agent.visa-vetted.example\"\nSignature-Input: sig1=(\"@authority\" \"signature-agent\");keyid=\"visa-key-id\";alg=\"ed25519\"\nSignature: sig1=::\n# Merchant verifies against Visa's agent public-key directory (RFC 9421).", "source": "Visa Trusted Agent Protocol: open spec signing agent identity into HTTP headers via RFC 9421 / Web Bot Auth, Ed25519, Visa key directory, launched with Cloudflare ~2025-10-14, 12 launch partners, layers over ACP/UCP: https://github.com/visa/trusted-agent-protocol , https://developer.visa.com/capabilities/trusted-agent-protocol , https://investor.visa.com/news/news-details/2025/Visa-Introduces-Trusted-Agent-Protocol-An-Ecosystem-Led-Framework-for-AI-Commerce/default.aspx . Listed for addition in research §2.", "agent_readiness_link": "agent-readiness/web-bot-auth", "layer_legacy": "identity" } ] }