通知客户端更新
在资源内容发生变化时发出信号。
通知客户端更新 是 CoddyKit 上的免费 MCP Academy 课时。 这是第 4 节课,共 4 节。 你可以在下方免费阅读本课时的完整内容 — 然后在浏览器中使用内置代码编辑器和全天候 AI 导师进行实践。 这是 MCP Academy 学习路径的一部分,你的进度在网页和 CoddyKit 应用中同步。 MCP Academy 课程共包含 4 节课。
本课时的部分内容尚未翻译,以英文显示。
Data Doesn't Sit Still
Resources change: a file is edited, a record updates. MCP lets a server notify clients so they don't keep reading stale content. 🔔
Notifications Are One-Way
An update signal is a notification: a JSON-RPC message with no id and no reply. The server tells the client something happened and moves on.
Subscribe First
A client opts in by calling resources/subscribe for a specific URI. Only then does the server bother sending updates about that resource.
{"method": "resources/subscribe",
"params": {"uri": "file://notes.txt"}}The Updated Signal
When a watched resource changes, the server sends resources/updated carrying the URI. It says what changed, but not the new content itself.
{"method": "notifications/resources/updated",
"params": {"uri": "file://notes.txt"}}Notify, Then Re-Read
The pattern is two steps: the server notifies, then the client decides to re-read. This keeps payloads tiny and lets the client control timing.
The List Can Change Too
Sometimes the whole catalog shifts as resources appear or vanish. The server sends a list_changed notification so the client refreshes its listing.
{"method":
"notifications/resources/list_changed"}Capabilities Gate It
These features are negotiated up front. A server advertises subscribe and listChanged support during initialize, so both sides know what's possible.
Unsubscribe to Stop
When a client no longer cares, it calls resources/unsubscribe for that URI. The server then stops sending updates, saving needless traffic.
{"method": "resources/unsubscribe",
"params": {"uri": "file://notes.txt"}}Fire on Real Change
Send an update only when content actually changes. Noisy, needless notifications waste the client's effort and can trigger pointless re-reads.
Watch the Source
To know when to notify, your server watches the source, such as a file watcher or a database trigger, then emits an updated signal in response.
Why This Matters
Update notifications turn a resource into something live. The model stays in sync with reality without polling, keeping its context honest. 🎯
Quick Check
What does a resources/updated notification include?
Recap
You learned how clients subscribe, receive updated and list_changed notifications, and re-read on demand, keeping dynamic resources fresh and live. Course complete! 🚀
常见问题解答
「通知客户端更新」课时是免费的吗?
是的 — 「通知客户端更新」的完整文本可在网页上免费阅读。要进行交互式练习(内置代码编辑器和全天候 AI 导师)并解锁 MCP Academy 课程的其余内容,请升级到 CoddyKit PRO。 MCP Academy 课程共包含 4 节课。
「通知客户端更新」这节课中我会学到什么?
在资源内容发生变化时发出信号。 你通过在浏览器中直接运行的动手代码来练习 MCP Academy,全天候 AI 导师会在你学习这节课的过程中回答你的问题。
学习 MCP Academy 需要有经验吗?
无需任何先前经验。CoddyKit 上的 MCP Academy 课程适合初学者到高级学习者,你可以从这里开始或从头开始,按照自己的节奏学习。 这是第 4 节课,共 4 节。
「通知客户端更新」课时需要多长时间?
大多数 CoddyKit 课程大约需要 5–10 分钟。每节课都很精短且互动,所以你能稳步进步,并在网页和应用中从离开的地方继续。
我能在这节 MCP Academy 课中编写并运行代码吗?
能。每节 MCP Academy 课都包含内置代码编辑器,你可以在浏览器中直接编写并运行真实代码,并获得即时 AI 反馈 — 无需本地设置。
此课程中的所有课时
- 带参数的资源 URI
- 在读取时构建内容
- 列表资源与模板资源
- 通知客户端更新