Publish /.well-known/mcp/server-card.json — A Builder’s Guide

Robauto Team · Published Sep 19, 2026 · Last updated Sep 19, 2026

Claude, ChatGPT, and Grok Bot connectors need a discoverable MCP server card. Here’s how to publish /.well-known/mcp/server-card.json and verify it with Robauto agent_scan’s mcp_card check.

If Claude, ChatGPT, or Grok Bot connectors cannot discover your tools, start with one file: /.well-known/mcp/server-card.json. Anthropic open-sourced the Model Context Protocol so assistants can attach to data and tools through a shared contract — and Robauto’s agent_scan checks whether that card is published.

Robauto agent_scan Agent Integration tier with MCP server card passing on robauto.ai

Why builders need an MCP server card

On November 25, 2024, Anthropic introduced the Model Context Protocol (MCP) as an open standard for connecting AI assistants to systems where data lives. Docs at modelcontextprotocol.io describe the client/server model: expose tools through an MCP server; assistants connect as clients.

A public server card at a well-known URL turns private desktop config into something connectors can find without a human pasting an endpoint. Robauto’s Agent Integration check mcp_card looks for /.well-known/mcp/server-card.json.

What Robauto’s agent_scan checks

A live agent_scan of robauto.ai on 2026-09-19 scored 98/100 (pixel-verified). The MCP finding:

id: mcp_card
title: Share your tool context engine
status: pass
detail: MCP server card published — assistants can attach without a human pasting a URL.
evidence: https://robauto.ai/.well-known/mcp/server-card.json
spec: modelcontextprotocol.io

Tiers on that scan: Signal Basics 6/6, Technical Groundwork 4/4, Agent Integration 9/10 (95%), Agentic Commerce 5/5. Re-run any domain at robauto.ai/scan.

{
  "example_scan": {
    "domain": "robauto.ai",
    "scanned_at": "2026-09-19T21:59:48.107Z",
    "score": 98,
    "tiers": {
      "Signal Basics": "6/6",
      "Technical Groundwork": "4/4",
      "Agent Integration": "9/10",
      "Agentic Commerce": "5/5"
    },
    "mcp_card": {
      "status": "pass",
      "evidence": "https://robauto.ai/.well-known/mcp/server-card.json",
      "serverInfo.name": "robauto",
      "transports": ["streamable-http → https://mcp.robauto.ai"]
    }
  },
  "sources": [
    "https://robauto.ai/scan?url=robauto.ai",
    "https://robauto.ai/.well-known/mcp/server-card.json",
    "https://www.anthropic.com/news/model-context-protocol",
    "https://modelcontextprotocol.io"
  ]
}

Minimal server-card shape

Publish JSON at https://YOUR_DOMAIN/.well-known/mcp/server-card.json. Include serverInfo, transports, a honest tool catalog, and auth expectations matching your protected-resource metadata.

Builder checklist

Step	What to ship	Why it matters	Source
1. Spec literacy	Read MCP architecture	Avoid one-off connector glue	modelcontextprotocol.io
2. Announce path	`/.well-known/mcp/server-card.json` over HTTPS	Connectors can discover you	Anthropic MCP announcement
3. Declare transport	Stable endpoint + auth mode	Clients attach without a pasted URL	robauto.ai server card
4. List tools honestly	Only tools you expose	Hallucinated tools waste agent turns	MCP docs
5. Pair with OAuth discovery	`/.well-known/oauth-protected-resource`	Scored in Agent Integration	agent_scan example
6. Verify with agent_scan	Confirm `mcp_card` = pass	Catch missing cards early	robauto.ai/scan

Claude, ChatGPT, and Grok Bot connectors

MCP began with local servers and open SDKs. Remote well-known discovery lets product connectors fetch a card, negotiate transport, and call tools. Publish the open card first; map product-specific connector UIs onto the same endpoint.

Network context: Agent Readiness Index median is still 18 across 79 scored of 99 attempted (readiness index). An MCP card is high-leverage Agent Integration work.

Sources

Where can an agent get this data live?

Robauto MCP — Agent Intelligence & Brand Discovery Infrastructure. A public, stateless Streamable HTTP endpoint at https://mcp.robauto.ai/mcp, callable with no key. Setup and the full tool list are in the Robauto MCP directory.

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