# MCP Server Cards (SEP-2127) vs Official MCP Registry

The map lists them as complementary: sites and agents commonly implement both.

[1 Discover](/category/discover/) [MCP Server Cards (SEP-2127)](/protocols/mcp-server-cards/) · [1 Discover](/category/discover/) [Official MCP Registry](/protocols/mcp-registry/)

|  | [MCP Server Cards (SEP-2127)](/protocols/mcp-server-cards/) Server Card | [Official MCP Registry](/protocols/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://github.com/modelcontextprotocol/modelcontextprotocol/blob/main/seps/2127-mcp-server-cards.md) | [https://modelcontextprotocol.io/community/working-groups/registry](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.

Guidance is derived from the two records (question, status, implementation, prerequisites, pairings), not from opinion. Each record's page carries its numbered references.

## Read the full articles

- [MCP Server Cards (SEP-2127)](/protocols/mcp-server-cards/): How can a client learn what an MCP server offers before connecting to it?
- [Official MCP Registry](/protocols/mcp-registry/): Where can an agent or client find a catalogue of public MCP servers, and how do sub-registries mirror it?

Ask the MCP server to compare any two: the compare-protocols prompt, or get on both ids. [Connect](/connect/).

[mcp-server-cards.json](/data/protocols/mcp-server-cards.json) · [mcp-registry.json](/data/protocols/mcp-registry.json) · [Markdown](/compare/mcp-server-cards-vs-mcp-registry/index.md)