Setting up fastmcp on kubernetes with a loadbalancer and https

[pepijnwoub]

We're currently trying to setup fastmcp on aws using eks. Everything works great with a regular application load balancer when only using http but trying to use https always results in garbled output. I'm not 100% sure if it's an issue with compression, encryption or buffering.

Has anyone gotten a similar setup to work?

[Colvin-Y]

Hi @pepijnwoub,

I'm doing the same things. Maybe you should run it as a http server by calling MCPServer.http_app()(see: https://gofastmcp.com/integrations/starlette#basic-usage), Here's my proxy set-up code

proxy = FastMCP.as_proxy(
    ProxyClient(backendUrl),
    name="InnerProxy",
    auth=auth,
)

app = proxy.http_app(transport=transport)



# Run the proxy (e.g., via stdio for Claude Desktop)
if __name__ == "__main__":
    uvicorn.run(app, host=host, port=port ,ssl_keyfile="./private.key",ssl_certfile="./certificate.crt")

[pepijnwoub]

Thanks that did indeed fix it!

My colleague had used .run() instead and I guess it doesn't support all the features required to serve fastmcp behind an ssl terminating loadbalancer

[Colvin-Y]

Thanks that did indeed fix it!

If it do works, could you plz mark this as answer? An answered question may help other developer to search