> Canonical URL: https://codingcat.dev/course/mcp-in-production/lesson/what-mcp-actually-is-stdio-vs-streamable-http

# What MCP Actually Is (Architecture Diagram & Stdio vs. Streamable HTTP) | MCP in Production: Building & Securing Model Context Protocol Servers | CodingCat.dev Course

[🧶 MCP in Production: Building & Securing Model Context Protocol Servers](/course/mcp-in-production)Section 1.1 · Lesson 1 of 5[Next Lesson →](/course/mcp-in-production/lesson/building-typescript-mcp-server-cloudflare-workers)

# What MCP Actually Is (Architecture Diagram & Stdio vs. Streamable HTTP)

![MCP in Production Architecture Diagram](https://cdn.sanity.io/media-libraries/mlttp0BZbCpV/images/dd8b89a42ee37457891b58d39c6273a31ac013e4-1376x768.jpg?rect=6,0,1365,768&w=1920&h=1080&q=82&fit=max&auto=format)[@CodingCatDev62.5K / 100K Subscribers Goal](https://www.youtube.com/@codingcatdev?sub_confirmation=1)[Subscribe on YouTube→](https://www.youtube.com/@codingcatdev?sub_confirmation=1)[Watch on YouTube App ↗](https://www.youtube.com/watch?v=gH9Q6-b1b4Y&list=UUnKZ8gEb78zXKMi1ns-IQ2g)

## The Mental Model: JSON-RPC 2.0 Across Process and Edge Boundaries

Every conference talk mentions MCP, yet most tutorials stop at a local Stdio script that only runs on your laptop. In production, remote agents connect over Streamable HTTP at the edge.

Copied! 🐾📄 src/mcp/transport.tstypescript

```
export interface JsonRpcRequest {
  jsonrpc: "2.0";
  id: string | number;
  method: "initialize" | "tools/list" | "tools/call";
  params?: Record;
}

export function createMcpResponse(id: string | number, result: unknown) {
  return Response.json({ jsonrpc: "2.0", id, result });
}
```

## Production Architecture Takeaway

Use Stdio strictly for local CLI tools that need filesystem access. Use Streamable HTTP on Cloudflare Workers for remote multi-tenant agent tools.

✏️ Visual Architecture Diagram

## how this course connects together.

Follow AJ from first principles to production-ready architecture.

Let’s build it!✏️ Visual Diagram: MCP in Production: Building & Securing Model Con…✓ Good PatternVISUAL DIAGRAM[Diagram Walkthrough]Step-by-step diagram breakdown for MCP in Production: Building & Securing Model Context Protocol Servers: What MCP Actually Is (Architecture Diagram & Stdio vs. Streamable HTTP): start with Core Architecture & Production Implementation, implement MCP in Production: Building & Securing Model Context Protocol Servers, and ship to production.AAA Contrast Verified[Course Outline](/course/mcp-in-production)

## MCP in Production: Building & Securing Model Context Protocol Servers

1/51

### Core Architecture & Production Implementation

- [1.1What MCP Actually Is (Architecture Diagram & Stdio vs. Streamable HTTP)▶](/course/mcp-in-production/lesson/what-mcp-actually-is-stdio-vs-streamable-http)
- [1.2Building Your First TypeScript MCP Server on Cloudflare Workers](/course/mcp-in-production/lesson/building-typescript-mcp-server-cloudflare-workers)
- [1.3Securing Remote MCP Servers with OAuth 2.1 & Better-Auth](/course/mcp-in-production/lesson/securing-remote-mcp-servers-oauth-better-auth)
- [1.4Client-Side WebMCP & RFC 9727 Agent Discovery](/course/mcp-in-production/lesson/client-side-webmcp-rfc-9727-agent-discovery)
- [1.5Connecting MCP to Verified Knowledge Bases (Sanity Context vs. Naive RAG)](/course/mcp-in-production/lesson/connecting-mcp-verified-knowledge-bases-sanity-context)

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