MCP Server Cards (SEP-2127) vs Official MCP Registry
The map lists them as complementary: sites and agents commonly implement both.
| MCP Server Cards (SEP-2127) Server Card | Official MCP Registry MCP Registry | |
|---|---|---|
| Lifecycle step | 1 Discover: What is here, and where? | 1 Discover: What is here, and where? |
| Answers | How can a client learn what an MCP server offers before connecting to it? | Where can an agent or client find a catalogue of public MCP servers, and how do sub-registries mirror it? |
| Governed by | Model Context Protocol project (SEP process, MCP governance) | MCP Registry Working Group |
| 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 | Preview; API frozen at v0.1; "Registry API v1 GA: Ideating, no target date" |
| Version | SEP-2127 (Final) (2026-10-06) | API v0.1 (frozen, preview) |
| Form / transport | document format | endpoint |
| Found at | GET <streamable-http-url>/server-card | GET /v0.1/servers |
| Implementation | multi-implementation | shipping |
| Evidence | 7 verified, 1 reported | 3 verified |
| Primary use case | Let agents discover my API or service | Let agents discover my API or service |
| Last verified | 2026-10-23 (current) | 2026-10-23 (current) |
| Specification | https://github.com/modelcontextprotocol/modelcontextprotocol/blob/main/seps/2127-mcp-server-cards.md | https://modelcontextprotocol.io/community/working-groups/registry |
When to use which
- 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.
- Choose Official MCP Registry when your question is “Where can an agent or client find a catalogue of public MCP servers, and how do sub-registries mirror it?” and you accept its maturity: status "Preview; API frozen at v0.1; "Registry API v1 GA: Ideating, no target date"", implementation shipping.
Read the full articles
- MCP Server Cards (SEP-2127): How can a client learn what an MCP server offers before connecting to it?
- Official MCP Registry: Where can an agent or client find a catalogue of public MCP servers, and how do sub-registries mirror it?