Deutsch
Agent protocols

NLWeb

NLWeb (Natural Language Web) is an open project that gives websites a natural language interface for people and AI agents. Microsoft announced it on May 19, 2025, and the code now lives in the nlweb-ai organization on GitHub. R.V. Guha, who also created Schema.org and RSS, led its design.

At a glance

Publisher
Microsoft (announced 2025-05-19)
Connects
websites (Schema.org and RSS content) with users and AI agents; every instance is an MCP server
Status
open-source project without a published version number
License
MIT
Specification
NLWeb (GitHub)

Last checked:

How does NLWeb work?

NLWeb builds on formats many sites already publish, mainly Schema.org markup and RSS. A site owner connects a language model and a vector store, and NLWeb answers questions in natural language from the site’s own content. According to the GitHub project, supported models include OpenAI, Gemini and Anthropic models, and supported vector stores include Qdrant, Elasticsearch, Milvus and Postgres. The code is under the MIT license.

Every NLWeb instance also acts as a Model Context Protocol (MCP) server, as Microsoft puts it. Its core method is ask, which takes a natural language question. An AI agent can therefore query the site’s content through MCP.

AI agent protocols compared
ProtocolPublisherConnectsStatus and version
MCP (Model Context Protocol)by Anthropic, since 2025-12-09 at the Agentic AI Foundation (Linux Foundation)AI applications with servers that provide data, tools and promptscurrent version 2026-07-28
A2A (Agent2Agent)by Google, donated to the Linux Foundation; joining the Agentic AI Foundation announced on 2026-08-27AI agents from different vendors with each otherspecification 1.0 (release v1.0.1 of 2026-05-28)
ACP (Agentic Commerce Protocol)OpenAI and Stripebuyers and their AI agents with businesses and payment providersbeta, current version 2026-04-17
AP2 (Agent Payments Protocol)Google; standardisation continues in FIDO Alliance working groupsAI agents, merchants and payment providers for payments on behalf of usersv0.2 (release of 2026-04-28)
UCP (Universal Commerce Protocol)Google with commerce partners (incl. Shopify, Etsy, Wayfair, Target, Walmart)platforms and AI agents with businesses (profile at /.well-known/ucp)stable, version 2026-08-25
WebMCPW3C Web Machine Learning Community Group (editors from Microsoft and Google)websites with AI agents in the browserdraft (Draft Community Group Report of 2026-10-02), not a W3C standard; origin trial in Chrome from version 149
NLWeb (this term)Microsoft (announced 2025-05-19), open source under the MIT licencewebsites (Schema.org and RSS content) with users and AI agents; every instance is an MCP serveropen-source project without a published version number

Versions and status as stated in each specification or on the publisher's site, checked on 8 October 2026. These protocols change quickly. MCP, ACP and UCP use date-based versions (YYYY-MM-DD), A2A and AP2 use version numbers. Sources: Model Context Protocol: Specification 2026-07-28; Model Context Protocol: Versioning; Anthropic: Donating the Model Context Protocol and establishing the Agentic AI Foundation (2025-12-09); A2A Protocol: Specification; A2A: A new chapter for A2A, joining the Agentic AI Foundation (2026-08-27); A2A releases (GitHub); Agentic Commerce Protocol (GitHub); AP2: Agent Payments Protocol; AP2 releases (GitHub); Universal Commerce Protocol: Specification overview (2026-08-25); Universal Commerce Protocol; WebMCP: Draft Community Group Report (W3C Web Machine Learning CG); Chrome for Developers: WebMCP (updated 2026-10-07); Microsoft: Introducing NLWeb (2025-05-19); NLWeb (GitHub). Last checked: .

Which protocol covers what? Agent protocols as of 2026-10-08Map of protocols for AI agents in four layers, as of 8 October 2026. Agent to tools and data: MCP, by Anthropic, at the Agentic AI Foundation since December 2025, version 2026-07-28. Agent to agent: A2A, donated by Google to the Linux Foundation, specification 1.0; it includes the Agent Card, a JSON description at /.well-known/agent-card.json. Agent to website: WebMCP, a draft of the W3C Web Machine Learning Community Group and not a W3C standard, in which a web page provides tools in the browser; NLWeb by Microsoft, open source, where every instance is also an MCP server. Agent to merchant, checkout and payment: ACP by OpenAI and Stripe (beta) with a checkout API and Delegate Payment; UCP by Google with commerce partners (stable) with checkout and payment handlers, plus AP2 mandates as an optional extension; AP2 by Google (v0.2) with a checkout mandate and a payment mandate. Cross-links: ACP and UCP can also be used via MCP, UCP also via A2A; AP2 is an extension for A2A and MCP.PROTOCOL · PUBLISHER · STATUSAs of 2026-10-08Agent ↔ tools, dataMCPModel Context ProtocolAnthropic; at theAgentic AI Foundation(Linux Foundation) since2025-12-09Version 2026-07-28Based on specifications andpublisher sites, checkedon 2026-10-08.↳ = link to otherprotocols.Grey: draft or beta.Agent ↔ agentA2A · Agent2AgentGoogle, donated to the LinuxFoundation; joining the AgenticAI Foundation announced on2026-08-27Specification 1.0(v1.0.1 of 2026-05-28)Agent CardJSON description of an agent:skills, endpoint, auth/.well-known/agent-card.jsonPart of the A2A specificationAgent ↔ websiteWebMCPW3C Web Machine Learning CommunityGroup (editors: Microsoft, Google)Draft of 2026-10-02, not a W3Cstandard; Chrome origin trial from 149↳ the web page provides tools in thebrowser, much like an MCP serverNLWebMicrosoft (announced 2025-05-19),open source under the MIT licence,no published version number;uses the site’s Schema.org and RSS↳ every NLWeb instance is alsoan MCP serverAgent ↔ merchant: checkout, payment, linksACPbeta, 2026-04-17Agentic Commerce ProtocolOpenAI and StripeAgentic Checkout: create,update and complete sessionsDelegate Payment: paymenttokens passed via the agent↳ REST; MCP binding sinceversion 2026-04-17UCPstable, 2026-08-25Universal Commerce ProtocolGoogle with commercepartnersCheckout capability: create,update, completePayment handlers; AP2 mandatesas an optional extension↳ REST, MCP, A2A,Embedded ProtocolAP2v0.2 (2026-04-28)Agent Payments ProtocolGoogle; standardisation inFIDO working groupsCheckout mandate: recordsitems and purchase detailsPayment mandate: authorises apayment with an instrument↳ extension for A2A and MCP;usable in UCP
Map of agent protocols as of 2026-10-08: which connection each protocol covers, who publishes it and what its status is. In commerce, ACP, UCP and AP2 overlap, and several protocols build on MCP or A2A. Versions change quickly. Sources: Model Context Protocol: Specification 2026-07-28; A2A Protocol: Specification (Agent Card, relationship to MCP); W3C Web Machine Learning CG: WebMCP (Draft Community Group Report); NLWeb (GitHub, Microsoft); Agentic Commerce Protocol (GitHub, OpenAI and Stripe); Universal Commerce Protocol: Specification overview; AP2: Agent Payments Protocol.

Example

A recipe site publishes recipes with Schema.org markup and runs an NLWeb instance. A visitor asks for vegetarian dinners that take under 20 minutes and gets matching recipes from the site. An AI agent can send the same question to the instance through MCP.

What it means for SEO

NLWeb depends on well-maintained structured data. Sites that already keep their Schema.org markup accurate have the input it uses (assessment, not a documented ranking effect).

FAQ

Is NLWeb a standard like robots.txt? It is an open source project with reference code from Microsoft. No standards body has adopted it.

Which sites adopted it early? Microsoft’s announcement names publishers such as Eventbrite, O’Reilly Media and Tripadvisor as early adopters.

Sources

  1. Introducing NLWeb – Microsoft Source (May 19, 2025)news.microsoft.com
  2. nlweb-ai/NLWeb – GitHubgithub.com

Last updated: