fix(deepagents): pass on subagent name (#218)

* fix(deepagents): pass on subagent name

* Add changeset for deepagents patch

* update deps

* format

Author: christian-bromann

.changeset/quiet-doors-yawn.md

@@ -0,0 +1,5 @@
+---
+"deepagents": patch
+---
+
+fix(deepagents): pass on subagent name

libs/deepagents/package.json

@@ -38,26 +38,26 @@
   },
   "homepage": "https://github.com/langchain-ai/deepagentsjs#readme",
   "dependencies": {
-    "@langchain/core": "^1.1.21",
+    "@langchain/core": "^1.1.22",
     "@langchain/langgraph": "^1.1.4",
     "fast-glob": "^3.3.3",
-    "langchain": "^1.2.20",
+    "langchain": "^1.2.21",
     "micromatch": "^4.0.8",
     "yaml": "^2.8.2",
     "zod": "^4.3.6"
   },
   "devDependencies": {
     "@langchain/langgraph-checkpoint": "^1.0.0",
-    "@langchain/openai": "^1.2.3",
+    "@langchain/openai": "^1.2.7",
     "@langchain/tavily": "^1.2.0",
     "@tsconfig/recommended": "^1.0.13",
     "@types/micromatch": "^4.0.10",
-    "@types/node": "^25.1.0",
+    "@types/node": "^25.2.3",
     "@types/uuid": "^11.0.0",
     "@vitest/coverage-v8": "^4.0.18",
     "@vitest/ui": "^4.0.18",
-    "dotenv": "^17.2.3",
-    "tsdown": "^0.20.1",
+    "dotenv": "^17.2.4",
+    "tsdown": "^0.20.3",
     "tsx": "^4.21.0",
     "typescript": "^5.9.3",
     "uuid": "^13.0.0",

libs/deepagents/src/middleware/subagents.int.test.ts

@@ -1,7 +1,8 @@
 import { describe, it, expect } from "vitest";
-import { createAgent, createMiddleware, ReactAgent } from "langchain";
+import { createAgent, createMiddleware, ReactAgent, tool } from "langchain";
 import { AIMessage, BaseMessage, HumanMessage } from "@langchain/core/messages";
 import { MemorySaver } from "@langchain/langgraph";
+import { z } from "zod/v4";
 import {
   createSubAgentMiddleware,
   createFilesystemMiddleware,
@@ -842,4 +843,64 @@ Use the write_file tool to save your code.`,
       expect(usedConsoleLog).toBe(false);
     },
   );
+
+  it.concurrent(
+    "should propagate lc_agent_name metadata to tools inside subagents",
+    { timeout: 90 * 1000 }, // 90s
+    async () => {
+      /**
+       * This test verifies that when a subagent is created with a name,
+       * its tools can access the agent name via config.metadata.lc_agent_name.
+       * This is critical for identifying which agent invoked a shared tool.
+       */
+      let capturedAgentName: string | undefined;
+
+      const identifyingTool = tool(
+        (input, config) => {
+          capturedAgentName = config.metadata?.lc_agent_name;
+          return `Weather in ${input.location} is sunny. Agent: ${capturedAgentName}`;
+        },
+        {
+          name: "get_weather_with_identity",
+          description: "Get the weather and identify the calling agent",
+          schema: z.object({ location: z.string() }),
+        },
+      );
+
+      const agent = createAgent({
+        model: SAMPLE_MODEL,
+        systemPrompt:
+          "Use the weather-agent subagent to get the weather. Always delegate to the subagent.",
+        middleware: [
+          createSubAgentMiddleware({
+            defaultModel: SAMPLE_MODEL,
+            defaultTools: [],
+            subagents: [
+              {
+                name: "weather-agent",
+                description:
+                  "A weather specialist agent. Use this for any weather queries.",
+                systemPrompt:
+                  "You are a weather specialist. Use the get_weather_with_identity tool to answer weather questions.",
+                tools: [identifyingTool],
+              },
+            ],
+          }),
+        ],
+      });
+
+      const response = await agent.invoke({
+        messages: [new HumanMessage("What is the weather in Tokyo?")],
+      });
+
+      // Verify the task tool was called with the weather-agent subagent
+      const toolCalls = extractAllToolCalls(response);
+      const taskCall = toolCalls.find((tc) => tc.name === "task");
+      expect(taskCall).toBeDefined();
+      expect(taskCall!.args.subagent_type).toBe("weather-agent");
+
+      // Verify the tool captured the correct agent name
+      expect(capturedAgentName).toBe("weather-agent");
+    },
+  );
 });

libs/deepagents/src/middleware/subagents.ts

@@ -435,6 +435,7 @@ function getSubagents(options: {
       systemPrompt: DEFAULT_SUBAGENT_PROMPT,
       tools: defaultTools as any,
       middleware: generalPurposeMiddleware,
+      name: "general-purpose",
     });
 
     agents["general-purpose"] = generalPurposeSubagent;
@@ -465,6 +466,7 @@ function getSubagents(options: {
         systemPrompt: agentParams.systemPrompt,
         tools: agentParams.tools ?? defaultTools,
         middleware,
+        name: agentParams.name,
       });
     }
   }

package.json

@@ -48,13 +48,13 @@
     "eslint-config-prettier": "^10.1.8",
     "eslint-plugin-import": "^2.32.0",
     "eslint-plugin-no-instanceof": "^1.0.1",
-    "eslint-plugin-prettier": "^5.5.4",
-    "globals": "^17.0.0",
-    "jiti": "^2.4.2",
-    "prettier": "^3.7.4",
+    "eslint-plugin-prettier": "^5.5.5",
+    "globals": "^17.3.0",
+    "jiti": "^2.6.1",
+    "prettier": "^3.8.1",
     "tsx": "^4.21.0",
     "typescript": "^5.9.3",
-    "typescript-eslint": "^8.52.0"
+    "typescript-eslint": "^8.55.0"
   },
-  "packageManager": "pnpm@10.27.0"
+  "packageManager": "pnpm@10.29.2"
 }