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Client.connect() accepts several transport inputs and resolves the right connection automatically: 
// HTTP (Streamable HTTP, falling back to SSE)
const a = await Client.connect('http://localhost:3000')

// stdio subprocess
import { StdioTransport } from '@prefecthq/fastmcp-ts/client'
const b = await Client.connect(new StdioTransport('npx', ['tsx', 'server.ts']))

// in-process FastMCP instance — no network, no subprocess
const c = await Client.connect(server)
This page is under construction. The outline below sketches what it will cover.
  • Resolution rules — string URLs become Streamable HTTP (with SSE fallback on 4xx); StdioTransport spawns a subprocess; a live server instance connects via an in-memory transport pair; raw SDK Transport objects pass through.
  • In-process connections — ideal for tests: full protocol fidelity without process or network overhead.
  • mcpServers configs — { mcpServers: { name: { url } | { command } } } entries; single-entry configs return a Client, multi-entry return a MultiServerClient.