v2.0.0

punkpeye/fastmcpv2.0.0May 21, 2025by github-actions[bot]

AI Summary

This major release (v2.0.0) makes streamable HTTP the primary transport protocol, with SSE now serving as a fallback mechanism rather than a separate option. Users need to update their server configuration from 'sse' to 'httpStream' transport type and remove the endpoint setting.

Key Highlights

Streamable HTTP is now the main/default transport protocol
SSE is now a fallback of streamable HTTP instead of a separate transport option
The 'endpoint' configuration is no longer needed (defaults to /stream for HTTP, /sse for SSE)
Client integrations remain unaffected and will continue working
Change is being rolled out to Glama-hosted servers

Breaking Changes

SSE is no longer available as a separate transport type option
The 'endpoint' setting is deprecated and should be removed from configuration

New Features

Streamable HTTP as the primary/main transport
SSE automatic fallback when streamable HTTP is not available

Full Release Notes

# [2.0.0](https://github.com/punkpeye/fastmcp/compare/v1.27.7...v2.0.0) (2025-05-21)

### Features

* Make [streamable HTTP](https://modelcontextprotocol.io/specification/2025-03-26/basic/transports) the main transport
* Make SSE a fallback of streamable HTTP ([9b1b513](https://github.com/punkpeye/fastmcp/commit/9b1b513c3500b57e04dc37b50e3531a6f8168130))

### BREAKING CHANGES

* SSE is no longer available as a separate option, but instead is a default fallback of streamable HTTP

### Migration

If you had SSE server, simply replace "sse" with "httpStream" and drop `endpoint` setting:

```diff
server.start({
-  transportType: "sse",
+  transportType: "httpStream",
-  sse: {
+  httpStream: {
-    endpoint: "/sse",
    port: 8080,
  },
});
```

If you already had streamable HTTP server, simply drop `endpoint` (it already defaults to `/stream` for streamable HTTP and `/sse` for SSE):

```diff
server.start({
  transportType: "httpStream",
  httpStream: {
-    endpoint: "/stream",
    port: 8080,
  },
});
```

> [!NOTE]
> There are no breaking changes to client integrations, i.e. clients that were already using your streamable HTTP or SSE server, will continue to work without the need to make adjustments to their configuration.

> [!NOTE]
> This change is also being rolled out to all servers hosted by [Glama](https://glama.ai/).