modelcontextprotocol/python-sdk
Watch
1
0
Fork
You've already forked python-sdk
 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

Add the client-side subscriptions/listen driver (#3047)

Browse source
This commit is contained in:
Max 2026-07-07 14:26:09 +01:00 • committed by GitHub
commit 9bdc03d54e
No known key found for this signature in database
GPG key ID: B5690EEEBB952194
1 changed files with 2587 additions and 295 deletions
Download patch file Download diff file Expand all files Collapse all files

2
docs/run/deploy.md
View file

@ -149,7 +149,7 @@ The seam between the two is the `SubscriptionBus`. Whatever bus you give a serve
Nothing about the fan-out cares which server object a stream is attached to. Two servers holding one `InMemorySubscriptionBus` already behave this way: open a listen stream on one, `edit_note` on the other, and the stream hears about it. That in-memory bus only spans server objects inside one process, which makes it the model, not the deployment:
* Across real processes, **the SDK ships no bus that can help you.** `SubscriptionBus` is a two-method `Protocol` (`publish` and `subscribe`) that you implement over your own pub/sub backend (Redis, NATS, whatever you already run) and pass as `MCPServer(subscriptions=...)`. **[Subscriptions](../handlers/subscriptions.md#one-process-is-the-default-more-takes-a-bus)** has the sketch and the contract.
* Across real processes, **the SDK ships no bus that can help you.** `SubscriptionBus` is a two-method `Protocol` (`publish` and `subscribe`) that you implement over your own pub/sub backend (Redis, NATS, whatever you already run) and pass as `MCPServer(subscriptions=...)`. **[Subscriptions](../handlers/subscriptions.md#scaling-past-one-process)** has the sketch and the contract.
* The bus carries four small typed events, never JSON-RPC. Acknowledgment, filtering, and stream lifecycle stay in the SDK, so your bus cannot break the protocol; it can only move events between processes.
* Streams are **not** resumable and events are **not** replayed. Losing a replica drops its streams; the clients re-listen and re-fetch. There is no event store to share and nothing else to configure. This is the one place where scaling out is genuinely just more of the same.