SSE MCP

HTTP+SSE 将逐步被替换为 Streamable HTTP

Replace HTTP+SSE with new "Streamable HTTP" transport

现状

• 本地通过stdio运行MCP不安全
  • 恶意MCP可以伪装成正常工具被LLM调用
  • 敏感数据泄漏
  • 安装不方便(npx/uvx/docker)
• MCP服务器托管开始流行
  • 经过筛选
  • 身份认证
  • 阿里云百练/腾讯云/Zapier
  • HTTP+SSE / Streamable HTTP

目标

• SSE是什么，原理 (Server Sent Event)
• ChatGPT使用SSE的例子
• 原生JS实现SSE的Server和Client
• MCP的SSE实现
• 实现一个SSE传输的MCP服务器
• CheeryStudio 调用
• MCP Inspector + Wireshark 抓包

Server Sent Events

• Server Sent Events
• SSE阮一峰老师博客

ChatGPT/KIMI/DeepSeek的SSE

// ChatGPT SSE
event: delta
data: {"p": "/message/content/parts/0", "o": "append", "v": "\u597d\uff0c\u54b1\u63a5\u7740\u8bf4\uff0c\u8bf4\u5b8c"} 

event: delta
data: {"v": "\u4e86\u5ba2\u6237\u7aef\u8fd9\u8fb9\uff0c\u63a5\u4e0b\u6765\u770b\u770b"}       

event: delta
data: {"v": " **\u670d\u52a1\u7aef\u600e\u4e48\u5b9e\u73b0 SSE**\u3002\n\n"}  

event: delta
data: {"v": "---\n\n### \ud83d\udd27 \u670d\u52a1\u7aef\u793a\u4f8b"} 

event: delta
data: {"v": "\uff08\u4ee5 Node.js \u4e3a\u4f8b\uff09\n\n```"} 

event: delta
data: {"v": "js\nconst http = require(\"http"}

// KIMI SSE
data: {"event":"cmpl","idx_s":0,"idx_z":0,"text":"好","view":"cmpl"}

data: {"event":"cmpl","idx_s":0,"idx_z":0,"text":"的","view":"cmpl"}

data: {"event":"cmpl","idx_s":0,"idx_z":0,"text":"，","view":"cmpl"}

data: {"event":"cmpl","idx_s":0,"idx_z":0,"text":"除","view":"cmpl"}

data: {"event":"cmpl","idx_s":0,"idx_z":0,"text":"了","view":"cmpl"}

data: {"event":"cmpl","idx_s":0,"idx_z":0,"text":"前","view":"cmpl"}

data: {"event":"cmpl","idx_s":0,"idx_z":0,"text":"面","view":"cmpl"}

// DeepSeek SSE
data: {"v": " **"}

data: {"v": "1"}

data: {"v": "."}

data: {"v": " "}

data: {"v": "高级"}

data: {"v": "用法"}

data: {"v": "与"}

data: {"v": "功能"}

• ChatGPT: 使用event来声明自定义事件
• KIMI: 全部用默认message事件，在JSON里面的event字段声明自定义事件
• 都没有定义ID
  • 无需短线重连
  • 有序发送数据，一次性消费

JS原生SSE实现

代码仓库

• Client
  • EventSource API
• Server

MCP SSE

• MCP SSE
• MCP SDK SSE实现
• HackerNews API
• MCP Inspector

Wireshark抓包

Connect

// 初次连接，SSE传输POST接口，用于后续请求
GET /sse HTTP/1.1
X-Powered-By: Express
Content-Type: text/event-stream
Cache-Control: no-cache, no-transform
Connection: keep-alive
Date: Tue, 15 Apr 2025 12:19:00 GMT
Transfer-Encoding: chunked

event: endpoint
data: /messages?sessionId=8838e9b4-d065-4b8e-9fa9-b96f31ef835c

---

// 客户端发送PSOT请求，初始化连接参数
POST /messages?sessionId=8838e9b4-d065-4b8e-9fa9-b96f31ef835c HTTP/1.1
host: localhost:3000
connection: keep-alive
Accept: text/event-stream
content-type: application/json
accept-language: *
sec-fetch-mode: cors
user-agent: node
accept-encoding: gzip, deflate
content-length: 204

{"jsonrpc":"2.0","id":0,"method":"initialize","params":{"protocolVersion":"2024-11-05","capabilities":{"sampling":{},"roots":{"listChanged":true}},"clientInfo":{"name":"mcp-inspector","version":"0.9.0"}}}

---

// SSE返回数据
event: message
data: {"result":{"protocolVersion":"2024-11-05","capabilities":{"tools":{}},"serverInfo":{"name":"hackernews-server","version":"1.0.0"}},"jsonrpc":"2.0","id":0}

---

// 初始化完成通知
POST /messages?sessionId=8838e9b4-d065-4b8e-9fa9-b96f31ef835c HTTP/1.1
host: localhost:3000
connection: keep-alive
Accept: text/event-stream
content-type: application/json
accept-language: *
sec-fetch-mode: cors
user-agent: node
accept-encoding: gzip, deflate
content-length: 54

{"jsonrpc":"2.0","method":"notifications/initialized"}

---

Accepted

---

List Tools

POST /messages?sessionId=32468b11-6f98-454d-b176-ffcf985602d6 HTTP/1.1
host: localhost:3000
connection: keep-alive
Accept: text/event-stream
content-type: application/json
accept-language: *
sec-fetch-mode: cors
user-agent: node
accept-encoding: gzip, deflate
content-length: 85

{"jsonrpc":"2.0","id":1,"method":"tools/list","params":{"_meta":{"progressToken":1}}}

---

event: message
data: {"result":{"tools":[{"name":"get-hackernews-top-stories","description":"Get the stories from Hacker News","inputSchema":{"type":"object","properties":{"type":{"type":"string","enum":["topstories","newstories","beststories"]},"amount":{"type":"number","minimum":1,"maximum":500,"default":10}},"required":["type"],"additionalProperties":false,"$schema":"http://json-schema.org/draft-07/schema#"}}]},"jsonrpc":"2.0","id":1}

Call Tool

POST /messages?sessionId=a03d6f2f-483a-4432-a685-f900aae6a15c HTTP/1.1
host: localhost:3000
connection: keep-alive
Accept: text/event-stream
content-type: application/json
accept-language: *
sec-fetch-mode: cors
user-agent: node
accept-encoding: gzip, deflate
content-length: 166

{"jsonrpc":"2.0","id":2,"method":"tools/call","params":{"_meta":{"progressToken":2},"name":"get-hackernews-top-stories","arguments":{"type":"topstories","amount":5}}}

---

event: message
data: {"result":{"content":[{"type":"text","text":"{\"by\":\"doener\",\"descendants\":26,\"id\":43690955,\"kids\":[43691597,43691629,43691555,43691554,43691616,43691669,43691546,43691621],\"score\":58,\"time\":1744712237,\"title\":\"Teuken-7B-Base and Teuken-7B-Instruct: Towards European LLMs\",\"type\":\"story\",\"url\":\"https://arxiv.org/abs/2410.03730\"}"},{"type":"text","text":"{\"by\":\"rbanffy\",\"descendants\":75,\"id\":43661954,\"kids\":[43690672,43691740,43690999,43690833,43691234,43690870,43691618,43691314,43690559,43691552,43662023,43690935,43690670,43690778,43691387,43690568],\"score\":154,\"time\":1744440499,\"title\":\"Wait. HOW MANY supernova explode every year?\",\"type\":\"story\",\"url\":\"https://badastronomy.beehiiv.com/p/ban-447-wait-how-many-supernova-explode\"}"},{"type":"text","text":"{\"by\":\"LookAtThatBacon\",\"descendants\":92,\"id\":43691334,\"kids\":[43691534,43691870,43691925,43691637,43691663,43691580,43691851,43691654,43691801,43691922,43691927,43691673,43691694,43691744,43691635,43691652,43691763,43691733,43691557],\"score\":135,\"time\":1744716656,\"title\":\"4chan hacked. Hacker reopens /QA/ and leaks all admins emails\",\"type\":\"story\",\"url\":\"https://old.reddit.com/r/4chan/comments/1jzkjlg/4chan_hacked_hacker_reopens_qa_and_leaks_all/\"}"},{"type":"text","text":"{\"by\":\"walterbell\",\"descendants\":46,\"id\":43688658,\"kids\":[43691249,43689886,43689209,43691657,43690253,43689327,43691628,43691289,43690261,43689700,43689175,43689172,43689747,43690464,43689992,43690388,43689144,43689473,43689002],\"score\":236,\"time\":1744686775,\"title\":\"Hacking a Smart Home Device (2024)\",\"type\":\"story\",\"url\":\"https://jmswrnr.com/blog/hacking-a-smart-home-device\"}"},{"type":"text","text":"{\"by\":\"TechTechTech\",\"descendants\":75,\"id\":43678590,\"kids\":[43689599,43689147,43691529,43690367,43689187,43690040,43689517,43690321,43689995,43680524,43689481,43690012,43691232,43689773,43690682,43691317,43684752,43689254,43689452,43689731],\"score\":229,\"time\":1744612068,\"title\":\"JSLinux\",\"type\":\"story\",\"url\":\"https://www.bellard.org/jslinux/\"}"}]},"jsonrpc":"2.0","id":2}