DocsCapabilitiesMCP server card
MCP server card
Advertises a Model Context Protocol endpoint agents can call.
Why an agent cares
A card is how an agent finds the site's MCP endpoint without being told about it. The card format is still a draft extension and it explicitly rejects hosting under /.well-known/, so a card found at the paths we probe is real adoption at a non-standard path.
Adoption
Early pilots. Named early adopters exist, behind flags or trials. Nothing has been independently measured yet. For this one in particular, the protocol itself is everywhere; the discovery card we read for it is not.
Direction of travel: ▲ rising, as at .
The protocol is in production at GitHub, Stripe, Atlassian, Linear, Sentry and PayPal, but the card itself is a draft SEP with no published measurement of deployment.
| Adopter | Depth | Evidence |
|---|---|---|
| Cloudflare (remote MCP hosting) | production | blog.cloudflare.com |
| GitHub, Stripe, Linear, Sentry, Asana | production | hidekazu-konishi.com |
| Atlassian (remote server GA) | production | github.com |
What we check
mcpServerPresent is true, so a site that has not adopted this is not assessed on it and appears in no report. 9 of these 13 can fail it. In a Lumar crawl these land on one row per site, in the crawl-level table where itemType is mcp_server.| Check | Severity | Raises | On whose authority |
|---|---|---|---|
mcpServerInvalidJson | high | usability | Lumar readiness profile |
mcpServerMissingUrl | high | usability | Lumar readiness profile |
mcpServerEndpointNotMcp | high | usability | specification (MCP transports 2025-06-18 (Streamable HTTP)) |
mcpServerEndpointUnavailable | high | usability | Lumar readiness profile |
mcpServerToolMissingName | high | conformance, usability | specification (MCP schema 2025-06-18 / 2025-11-25 / 2026-07-28 (Tool)) |
mcpServerToolMissingInputSchema | high | conformance, usability | specification (MCP schema 2025-06-18 / 2025-11-25 / 2026-07-28 (Tool)) |
mcpServerDuplicateToolName | high | usability | specification (MCP 2026-07-28 server/tools (Tool Names)) |
mcpServerToolMissingDescription | medium | usability | Lumar readiness profile |
mcpServerUnknownMethodAccepted | medium | usability | specification (JSON-RPC 2.0 §5.1 (Error object), as MCP's wire format) |
mcpServerNonstandardToolName | informational | nothing | specification (MCP 2026-07-28 server/tools (Tool Names)) |
mcpServerStaleEndpoint | informational | nothing | Lumar readiness profile |
mcpServerMissingTransport | informational | nothing | Lumar readiness profile |
mcpServerPartiallyAssessed | coverage note | nothing | our own coverage |
Examples
Both of these are fixtures the test suite runs through the real collector, not snippets written for a document: the first is a shape we score as valid, the second is one we flag.
{
"$schema": "https://static.modelcontextprotocol.io/schemas/v1/server.schema.json",
"name": "io.github.example/catalog-mcp",
"description": "Catalog search and account operations for agents.",
"version": "1.0.0",
"remotes": [{ "type": "streamable-http", "url": "https://example.com/mcp" }]
}{
"$schema": "https://static.modelcontextprotocol.io/schemas/v1/server.schema.json",
"name": "io.github.example/broken-mcp",
"description": "Present but not connectable: the remote endpoint isn't an absolute http(s) URL.",
"version": "1.0.0",
"remotes": [{ "type": "streamable-http", "url": "example.com/mcp" }]
}Specifications
| Document | Revision | Kind |
|---|---|---|
| MCP Server Card working group (SEP-2127, draft) | Draft | specification |
| MCP Server Card experimental extension | living | specification |
| MCP Streamable HTTP transport | 2026-07-28 | specification |
| MCP versioning — modern, legacy and dual-era servers | 2026-07-28 | specification |
| MCP transports (legacy era: the initialize handshake and session generation) | 2025-06-18 | specification |
| MCP server/discover — the one method a modern server must implement | 2026-07-28 | specification |
Last re-read against the published documents: .
<mcp-url>/server-card and explicitly rejects hosting it under /.well-known/, so a card at either path we probe is adoption at a non-standard path rather than conformance. Secondary claims that the SEP was ratified in Nov 2025 do not survive the document, which reads Status: Draft, Created: 2026-01-21.