{
 "url": "https://agenticweb.wiki/compare/webmcp-vs-agents-json/",
 "title": "WebMCP vs agents.json: differences, status, adoption",
 "description": "WebMCP vs agents.json: The map lists them as complementary: sites and agents commonly implement both. Side-by-side step, governance, status, version…",
 "markdown_url": "https://agenticweb.wiki/compare/webmcp-vs-agents-json/index.md",
 "markdown": "# WebMCP vs agents.json\n\nThe map lists them as complementary: sites and agents commonly implement both.\n\n[5 Act](/category/act/) [WebMCP](/protocols/webmcp/) · [5 Act](/category/act/) [agents.json](/protocols/agents-json/)\n\n|  | [WebMCP](/protocols/webmcp/) | [agents.json](/protocols/agents-json/) |\n| --- | --- | --- |\n| Lifecycle step | 5 Act: Do something for me | 5 Act: Do something for me |\n| Answers | What JavaScript tools can a web page register so an in-browser AI agent can call them directly instead of scraping the DOM? | How does an agent learn which multi-step API call sequences (\"flows\") a service supports, on top of its raw OpenAPI surface? |\n| Governed by | W3C Web Machine Learning Community Group; editors are Brandon Walderman (Microsoft), Khushal Sagar (Google), Dominic Farolino (Google) | Wildcard AI; single company controls the spec and the reference \"Wildcard Bridge\" runtime and maintains a discretionary registry of published files |\n| Status (issuer's words) | Draft Community Group Report, dated 4 September 2026; explicitly \"not a W3C Standard nor on the W3C Standards Track\" | Dormant: last push 2025-08-21, version 0.1.0 |\n| Version | Draft Community Group Report, 4 September 2026 (2026-09-04) | 0.1.0 (2025-03) |\n| Form / transport | browser API | well-known file |\n| Found at | 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\") | /.well-known/agents.json (proposed; not mandatory, per the spec's own FAQ) |\n| Implementation | prototype | prototype |\n| Evidence | 2 verified | 4 verified, 2 reported |\n| Primary use case | Let agents act on my website | Let agents discover my API or service |\n| Last verified | 2026-10-23 (current) | 2026-10-23 (current) |\n| Specification | [https://webmachinelearning.github.io/webmcp/](https://webmachinelearning.github.io/webmcp/) | [https://github.com/wild-card-ai/agents-json](https://github.com/wild-card-ai/agents-json) |\n\n## When to use which\n\n- 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: status \"Draft Community Group Report, dated 4 September 2026; explicitly \"not a W3C Standard nor on the W3C Standards Track\"\", implementation prototype.\n- Choose agents.json when your question is “How does an agent learn which multi-step API call sequences (\"flows\") a service supports, on top of its raw OpenAPI surface?” and you accept its maturity: status \"Dormant: last push 2025-08-21, version 0.1.0\", implementation prototype. It is no longer maintained; prefer its successor.\n\nGuidance is derived from the two records (question, status, implementation, prerequisites, pairings), not from opinion. Each record's page carries its numbered references.\n\n## Read the full articles\n\n- [WebMCP](/protocols/webmcp/): What JavaScript tools can a web page register so an in-browser AI agent can call them directly instead of scraping the DOM?\n- [agents.json](/protocols/agents-json/): How does an agent learn which multi-step API call sequences (\"flows\") a service supports, on top of its raw OpenAPI surface?\n\nAsk the MCP server to compare any two: the compare-protocols prompt, or get on both ids. [Connect](/connect/).\n\n[webmcp.json](/data/protocols/webmcp.json) · [agents-json.json](/data/protocols/agents-json.json) · [Markdown](/compare/webmcp-vs-agents-json/index.md)\n"
}