{
 "url": "https://agenticweb.wiki/compare/mcp-server-cards-vs-ai-catalog-well-known-file/",
 "title": "MCP Server Cards (SEP-2127) vs AI Catalog well-known file",
 "description": "MCP Server Cards (SEP-2127) vs AI Catalog well-known file: The map lists them as complementary: sites and agents commonly implement both. Side-by-side…",
 "markdown_url": "https://agenticweb.wiki/compare/mcp-server-cards-vs-ai-catalog-well-known-file/index.md",
 "markdown": "# MCP Server Cards (SEP-2127) vs AI Catalog well-known file\n\nThe map lists them as complementary: sites and agents commonly implement both.\n\n[1 Discover](/category/discover/) [MCP Server Cards (SEP-2127)](/protocols/mcp-server-cards/) · [1 Discover](/category/discover/) [AI Catalog well-known file](/protocols/ai-catalog-well-known-file/)\n\n|  | [MCP Server Cards (SEP-2127)](/protocols/mcp-server-cards/) Server Card | [AI Catalog well-known file](/protocols/ai-catalog-well-known-file/) |\n| --- | --- | --- |\n| Lifecycle step | 1 Discover: What is here, and where? | 1 Discover: What is here, and where? |\n| Answers | How can a client learn what an MCP server offers before connecting to it? | Which AI-capable artifacts and registries does this domain publish? (superseded question -- see ard) |\n| Governed by | Model Context Protocol project (SEP process, MCP governance) | ARD / ards-project (see ard) |\n| Status (issuer's words) | SEP-2127 Final (2026-10-06), Extensions Track charter; the MCP Registry working group page still describes Server Cards as experimental | Deprecated predecessor path of the ARD manifest |\n| Version | SEP-2127 (Final) (2026-10-06) | n/a -- not a separately versioned artifact |\n| Form / transport | document format | well-known file |\n| Found at | GET <streamable-http-url>/server-card | /.well-known/ai-catalog.json |\n| Implementation | multi-implementation | shipping — agenticweb.wiki /check/ probe (43/268 origins still serving the legacy /.well-known/ai-catalog.json path) |\n| Evidence | 7 verified, 1 reported | 2 verified |\n| Primary use case | Let agents discover my API or service | Let agents discover my API or service |\n| Last verified | 2026-10-23 (current) | 2026-10-23 (current) |\n| Specification | [https://github.com/modelcontextprotocol/modelcontextprotocol/blob/main/seps/2127-mcp-server-cards.md](https://github.com/modelcontextprotocol/modelcontextprotocol/blob/main/seps/2127-mcp-server-cards.md) | [https://raw.githubusercontent.com/ards-project/ard-spec/main/spec/ard.md](https://raw.githubusercontent.com/ards-project/ard-spec/main/spec/ard.md) |\n\n## When to use which\n\n- Choose MCP Server Cards (SEP-2127) when your question is “How can a client learn what an MCP server offers before connecting to it?” and you accept its maturity: status \"SEP-2127 Final (2026-10-06), Extensions Track charter; the MCP Registry working group page still describes Server Cards as experimental\", implementation multi-implementation.\n- Choose AI Catalog well-known file when your question is “Which AI-capable artifacts and registries does this domain publish? (superseded question -- see ard)” and you accept its maturity: status \"Deprecated predecessor path of the ARD manifest\", implementation shipping (agenticweb.wiki /check/ probe (43/268 origins still serving the legacy /.well-known/ai-catalog.json path)). 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- [MCP Server Cards (SEP-2127)](/protocols/mcp-server-cards/): How can a client learn what an MCP server offers before connecting to it?\n- [AI Catalog well-known file](/protocols/ai-catalog-well-known-file/): Which AI-capable artifacts and registries does this domain publish? (superseded question -- see ard)\n\nAsk the MCP server to compare any two: the compare-protocols prompt, or get on both ids. [Connect](/connect/).\n\n[mcp-server-cards.json](/data/protocols/mcp-server-cards.json) · [ai-catalog-well-known-file.json](/data/protocols/ai-catalog-well-known-file.json) · [Markdown](/compare/mcp-server-cards-vs-ai-catalog-well-known-file/index.md)\n"
}