feat(langchain): Add DeepSeek to initChatModel (#7609)

langchain/package.json

@@ -420,6 +420,7 @@
     "@langchain/cerebras": "*",
     "@langchain/cohere": "*",
     "@langchain/core": "workspace:*",
+    "@langchain/deepseek": "*",
     "@langchain/google-genai": "*",
     "@langchain/google-vertexai": "*",
     "@langchain/google-vertexai-web": "*",
@@ -469,6 +470,7 @@
     "@langchain/cerebras": "*",
     "@langchain/cohere": "*",
     "@langchain/core": ">=0.2.21 <0.4.0",
+    "@langchain/deepseek": "*",
     "@langchain/google-genai": "*",
     "@langchain/google-vertexai": "*",
     "@langchain/google-vertexai-web": "*",
@@ -494,6 +496,9 @@
     "@langchain/cohere": {
       "optional": true
     },
+    "@langchain/deepseek": {
+      "optional": true
+    },
     "@langchain/google-genai": {
       "optional": true
     },

langchain/src/chat_models/tests/universal.int.test.ts

@@ -436,6 +436,17 @@ describe("Works with all model providers", () => {
     expect(vertexAIWebResult).toBeDefined();
     expect(vertexAIWebResult.content.length).toBeGreaterThan(0);
   });
+
+  it("Can invoke deepseek", async () => {
+    const deepSeek = await initChatModel("deepseek-chat", {
+      modelProvider: "deepseek",
+      temperature: 0,
+    });
+
+    const deepSeekResult = await deepSeek.invoke("what's your name");
+    expect(deepSeekResult).toBeDefined();
+    expect(deepSeekResult.content.length).toBeGreaterThan(0);
+  });
 });
 
 test("Is compatible with agents", async () => {

langchain/src/chat_models/universal.ts

@@ -49,6 +49,8 @@ const _SUPPORTED_PROVIDERS = [
   "mistralai",
   "groq",
   "bedrock",
+  "cerebras",
+  "deepseek",
 ] as const;
 
 export type ChatModelProvider = (typeof _SUPPORTED_PROVIDERS)[number];
@@ -130,6 +132,10 @@ async function _initChatModelHelper(
         const { ChatBedrockConverse } = await import("@langchain/aws");
         return new ChatBedrockConverse({ model, ...passedParams });
       }
+      case "deepseek": {
+        const { ChatDeepSeek } = await import("@langchain/deepseek");
+        return new ChatDeepSeek({ model, ...passedParams });
+      }
       case "fireworks": {
         const { ChatFireworks } = await import(
           // We can not 'expect-error' because if you explicitly build `@langchain/community`
@@ -611,6 +617,7 @@ export async function initChatModel<
  *   - groq (@langchain/groq)
  *   - ollama (@langchain/ollama)
  *   - cerebras (@langchain/cerebras)
+ *   - deepseek (@langchain/deepseek)
  * @param {string[] | "any"} [fields.configurableFields] - Which model parameters are configurable:
  *   - undefined: No configurable fields.
  *   - "any": All fields are configurable. (See Security Note in description)

yarn.lock

@@ -12465,7 +12465,7 @@ __metadata:
   languageName: unknown
   linkType: soft
 
-"@langchain/deepseek@workspace:*, @langchain/deepseek@workspace:libs/langchain-deepseek":
+"@langchain/deepseek@*, @langchain/deepseek@workspace:*, @langchain/deepseek@workspace:libs/langchain-deepseek":
   version: 0.0.0-use.local
   resolution: "@langchain/deepseek@workspace:libs/langchain-deepseek"
   dependencies:
@@ -33477,6 +33477,7 @@ __metadata:
     "@langchain/cerebras": "*"
     "@langchain/cohere": "*"
     "@langchain/core": "workspace:*"
+    "@langchain/deepseek": "*"
     "@langchain/google-genai": "*"
     "@langchain/google-vertexai": "*"
     "@langchain/google-vertexai-web": "*"
@@ -33537,6 +33538,7 @@ __metadata:
     "@langchain/cerebras": "*"
     "@langchain/cohere": "*"
     "@langchain/core": ">=0.2.21 <0.4.0"
+    "@langchain/deepseek": "*"
     "@langchain/google-genai": "*"
     "@langchain/google-vertexai": "*"
     "@langchain/google-vertexai-web": "*"
@@ -33557,6 +33559,8 @@ __metadata:
       optional: true
     "@langchain/cohere":
       optional: true
+    "@langchain/deepseek":
+      optional: true
     "@langchain/google-genai":
       optional: true
     "@langchain/google-vertexai":