MCP Server on Val Town

A Model Context Protocol server deployed as a serverless HTTP endpoint on Val Town.

Transport

Uses Streamable HTTP (the modern MCP transport as of spec 2025-03-26), replacing the older SSE transport.

Endpoint

POST https://NK5--beb4815432c311f19d3342dde27851f2.web.val.run/mcp

Health check:

GET https://NK5--beb4815432c311f19d3342dde27851f2.web.val.run/

Capabilities

Tools

Tool	Description
`echo`	Returns the exact message you send
`calculate`	Evaluates a safe math expression (e.g. `2 + 2 * 3`)
`fetch_url`	Fetches a URL and returns its text content

Resources

URI	Description
`info://server`	Server info and capability listing

Prompts

Prompt	Description
`summarize`	Template to ask a model to summarize text (brief or detailed)

Connecting

Claude Desktop / Cursor

Add to your MCP config:

{
  "mcpServers": {
    "val-town-mcp": {
      "transport": "http",
      "url": "https://NK5--beb4815432c311f19d3342dde27851f2.web.val.run/mcp"
    }
  }
}

MCP Inspector

npx @modelcontextprotocol/inspector
# Enter the URL above and select "Streamable HTTP"

Architecture

Rendering mermaid diagram...

Stateless mode: Each request creates a fresh server instance — ideal for serverless. No session state is maintained between calls.

Extending

Add your own tools inside buildServer() in main.ts:


server.registerTool("my-tool", {
  title: "My Tool",
  description: "Does something useful",
  inputSchema: { input: z.string() },
}, async ({ input }) => ({
  content: [{ type: "text", text: `Result: ${input}` }],
}));