fix: remove duplicate tools in langgraph integrations

Author: ranst91

typescript-sdk/integrations/langgraph/python/ag_ui_langgraph/agent.py

@@ -446,12 +446,26 @@ def langgraph_default_merge_state(self, state: State, messages: List[BaseMessage
                 else:
                     tools_as_dicts.append(tool)
 
+        all_tools = [*state.get("tools", []), *tools_as_dicts]
+
+        # Remove duplicates based on tool name
+        seen_names = set()
+        unique_tools = []
+        for tool in all_tools:
+            tool_name = tool.get("name") if isinstance(tool, dict) else getattr(tool, "name", None)
+            if tool_name and tool_name not in seen_names:
+                seen_names.add(tool_name)
+                unique_tools.append(tool)
+            elif not tool_name:
+                # Keep tools without names (shouldn't happen, but just in case)
+                unique_tools.append(tool)
+
         return {
             **state,
             "messages": new_messages,
-            "tools": [*state.get("tools", []), *tools_as_dicts],
+            "tools": unique_tools,
             "ag-ui": {
-                "tools": [*state.get("tools", []), *tools_as_dicts],
+                "tools": unique_tools,
                 "context": input.context or []
             }
         }

typescript-sdk/integrations/langgraph/src/agent.ts

@@ -25,7 +25,7 @@ import {
   PredictStateTool,
   LangGraphReasoning,
   StateEnrichment,
-  LangGraphTool,
+  LangGraphToolWithName,
 } from "./types";
 import {
   AbstractAgent,
@@ -1003,21 +1003,25 @@ export class LangGraphAgent extends AbstractAgent {
 
     const newMessages = messages.filter((message) => !existingMessageIds.has(message.id));
 
-    const langGraphTools: LangGraphTool[] = [...(state.tools ?? []), ...(input.tools ?? [])].map((tool) => {
-      if (tool.type) {
-        return tool;
+    const langGraphTools: LangGraphToolWithName[] = [...(state.tools ?? []), ...(input.tools ?? [])].reduce((acc, tool) => {
+      let mappedTool = tool;
+      if (!tool.type) {
+        mappedTool = {
+            type: "function",
+            name: tool.name,
+            function: {
+                name: tool.name,
+                description: tool.description,
+                parameters: tool.parameters,
+            },
+        }
       }
 
-      return {
-        type: "function",
-        name: tool.name,
-        function: {
-          name: tool.name,
-          description: tool.description,
-          parameters: tool.parameters,
-        },
-      };
-    });
+      // Verify no duplicated
+      if (acc.find((t: LangGraphToolWithName) => (t.name === mappedTool.name) || t.function.name === mappedTool.function.name)) return acc;
+
+      return [...acc, mappedTool];
+    }, []);
 
     return {
       ...state,

typescript-sdk/integrations/langgraph/src/types.ts

@@ -15,8 +15,9 @@ export enum LangGraphEventTypes {
   OnInterrupt = "on_interrupt",
 }
 
-export type LangGraphTool = {
+export type LangGraphToolWithName = {
   type: "function";
+  name?: string;
   function: {
     name: string;
     description: string;
@@ -29,9 +30,9 @@ export type State<TDefinedState = Record<string, any>> = {
 } & Record<string, any>;
 export interface StateEnrichment {
   messages: LangGraphMessage[];
-  tools: LangGraphTool[];
+  tools: LangGraphToolWithName[];
   'ag-ui': {
-    tools: LangGraphTool[];
+    tools: LangGraphToolWithName[];
     context: RunAgentInput['context']
   }
 }