---
title: MCP Server Card Validator
description: Validate your MCP Server Card against SEP-1649. Confirm agents can discover your Model Context Protocol server at /.well-known/mcp.json.
last_updated: 2026-05-11
canonical_url: https://agent-ready.dev/mcp-card-validator
---

# MCP Server Card Validator

> Validate your MCP Server Card against SEP-1649 and SEP-2127. Confirm agents can discover your Model Context Protocol server at `/.well-known/mcp.json`.

## What is an MCP server card?

A JSON document published at `/.well-known/mcp.json` that advertises a Model Context Protocol server's transport, endpoint, capabilities, and authentication requirements. Clients like Claude Desktop, Cursor, and Cline fetch the card to auto-discover and connect without manual configuration.

## Why should I publish an MCP server card?

Without a server card, users have to type your server's URL and config by hand into their MCP client. With it, clients can fetch your domain, find the card, and offer a one-click install — same dynamic as robots.txt for crawlers. SEP-1649 ratified on 2025-11-25 and is the canonical discovery convention.

## What does the MCP card validator check?

- File at `/.well-known/mcp.json` returns HTTP 200
- Served over HTTPS with `Content-Type: application/json`
- Top-level `protocolVersion` is present (currently `2025-11-25`)
- `serverInfo` with `name` and `version`
- `transport` with `type` and `endpoint`
- `capabilities` object (can be empty)
- `authentication` object with `required` boolean
- If `authentication.required` is true: OAuth Protected Resource metadata at `/.well-known/oauth-protected-resource` (RFC 9728, SEP-985)

## Minimal valid example (SEP-1649)

```json
{
  "protocolVersion": "2025-11-25",
  "serverInfo": {
    "name": "acme-weather",
    "version": "1.0.0"
  },
  "transport": {
    "type": "http",
    "endpoint": "https://api.acme.dev/mcp"
  },
  "capabilities": {},
  "authentication": { "required": false }
}
```

## Specifications

- [Model Context Protocol](https://modelcontextprotocol.io)
- [SEP-1649 — MCP Server Cards](https://github.com/modelcontextprotocol/modelcontextprotocol/issues/1649)
- [RFC 9728 — OAuth Protected Resource Metadata](https://datatracker.ietf.org/doc/html/rfc9728)

---

Validate your MCP server card: <https://agent-ready.dev/mcp-card-validator>

Step-by-step guide: [How to publish an MCP server card](https://agent-ready.dev/how-to-publish-an-mcp-server-card)

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