Model Context Protocol vs WebMCP
The map lists them as complementary: sites and agents commonly implement both. Model Context Protocol is a prerequisite of WebMCP.
| Model Context Protocol MCP | WebMCP | |
|---|---|---|
| Lifecycle step | 5 Act: Do something for me | 5 Act: Do something for me |
| Answers | How does an AI application call tools and pull structured context, prompts, and data from an external server? | What JavaScript tools can a web page register so an in-browser AI agent can call them directly instead of scraping the DOM? |
| Governed by | Agentic AI Foundation (Linux Foundation umbrella); day-to-day spec work in the modelcontextprotocol GitHub org via public SEPs (Specification Enhancement Proposals) and working groups | W3C Web Machine Learning Community Group; editors are Brandon Walderman (Microsoft), Khushal Sagar (Google), Dominic Farolino (Google) |
| Status (issuer's words) | Active open specification, current dated release 2026-07-28 | Draft Community Group Report, dated 4 September 2026; explicitly "not a W3C Standard nor on the W3C Standards Track" |
| Phase | living | draft |
| Version | 2026-07-28 (2026-07-28) | Draft Community Group Report, 4 September 2026 (2026-09-04) |
| Form / transport | endpoint | browser API |
| Found at | GET {endpoint}/server-card (SEP-2127 Server Card, Final 2026-10-06; found via an AI Catalog entry) | none — a client or agent must load the page itself to see whether it registers WebMCP tools; this is a stated limitation of the API ("Clients and browsers must visit a site directly to know if it has callable tools") |
| Adoption | claimed — Wikipedia (OpenAI, Google DeepMind adopted MCP by March 2025) and WorkOS ('adopted by OpenAI, Google DeepMind, Microsoft, and thousands of development teams') | unmeasured |
| Evidence | 7 verified, 2 reported | 2 verified |
| Primary use case | Expose tools to agents | Let agents act on my website |
| Last verified | 2026-10-19 (current) | 2026-10-18 (current) |
| Specification | https://modelcontextprotocol.io/specification/2026-07-28/index | https://webmachinelearning.github.io/webmcp/ |
When to use which
- Choose Model Context Protocol when your question is “How does an AI application call tools and pull structured context, prompts, and data from an external server?” and you accept its maturity: phase living, adoption claimed (Wikipedia (OpenAI, Google DeepMind adopted MCP by March 2025) and WorkOS ('adopted by OpenAI, Google DeepMind, Microsoft, and thousands of development teams')).
- Choose WebMCP when your question is “What JavaScript tools can a web page register so an in-browser AI agent can call them directly instead of scraping the DOM?” and you accept its maturity: phase draft, adoption unmeasured.
Read the full articles
- Model Context Protocol: How does an AI application call tools and pull structured context, prompts, and data from an external server?
- WebMCP: What JavaScript tools can a web page register so an in-browser AI agent can call them directly instead of scraping the DOM?