fix: prevent redundant initialization of server session state when already initialized

guglielmo-san · guglielmo-san · commit 6f1eba0ca2c8 · 2026-05-22T10:19:54.000Z
diff --git a/mcp/server.go b/mcp/server.go
@@ -1459,7 +1459,7 @@ func (ss *ServerSession) handle(ctx context.Context, req *jsonrpc.Request) (any,
 		return nil, perRequestErr
 	}
 
-	if validatedMeta.usesNewProtocol && validatedMeta.initializeParams != nil {
+	if !initialized && validatedMeta.usesNewProtocol && validatedMeta.initializeParams != nil {
 		ss.updateState(func(state *ServerSessionState) {
 			state.InitializeParams = validatedMeta.initializeParams
 		})

Original file line number	Diff line number	Diff line change
`@@ -1459,7 +1459,7 @@ func (ss ServerSession) handle(ctx context.Context, req jsonrpc.Request) (any,`
`1459`	`1459`	`return nil, perRequestErr`
`1460`	`1460`	`}`
`1461`	`1461`
`1462`		`- if validatedMeta.usesNewProtocol && validatedMeta.initializeParams != nil {`
	`1462`	`+ if !initialized && validatedMeta.usesNewProtocol && validatedMeta.initializeParams != nil {`
`1463`	`1463`	`ss.updateState(func(state *ServerSessionState) {`
`1464`	`1464`	`state.InitializeParams = validatedMeta.initializeParams`
`1465`	`1465`	`})`