feat: Add @langchain/baseten provider package

libs/providers/baseten/package.json

@@ -0,0 +1,73 @@
+{
+  "name": "@langchain/baseten",
+  "version": "1.0.0-alpha.0",
+  "description": "Baseten LLM provider for LangChain and deepagents",
+  "main": "./dist/index.cjs",
+  "module": "./dist/index.js",
+  "types": "./dist/index.d.ts",
+  "type": "module",
+  "scripts": {
+    "build": "tsdown",
+    "clean": "rm -rf dist/ .tsdown/",
+    "dev": "tsc --watch",
+    "typecheck": "tsc --noEmit",
+    "prepublishOnly": "pnpm build",
+    "test": "vitest run",
+    "test:unit": "vitest run",
+    "test:int": "vitest run --mode int"
+  },
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/langchain-ai/deepagentsjs.git"
+  },
+  "keywords": [
+    "ai",
+    "agents",
+    "langgraph",
+    "langchain",
+    "typescript",
+    "llm",
+    "baseten",
+    "chat-model"
+  ],
+  "author": "LangChain",
+  "license": "MIT",
+  "bugs": {
+    "url": "https://github.com/langchain-ai/deepagentsjs/issues"
+  },
+  "homepage": "https://github.com/langchain-ai/deepagentsjs#readme",
+  "dependencies": {
+    "@langchain/openai": "^1.4.1"
+  },
+  "peerDependencies": {
+    "@langchain/core": "^1.1.38"
+  },
+  "devDependencies": {
+    "deepagents": "workspace:*",
+    "@langchain/core": "^1.1.38",
+    "@tsconfig/recommended": "^1.0.13",
+    "@types/node": "^25.1.0",
+    "@vitest/coverage-v8": "^4.0.18",
+    "dotenv": "^17.2.3",
+    "tsdown": "^0.21.4",
+    "tsx": "^4.21.0",
+    "typescript": "^6.0.2",
+    "vitest": "^4.0.18"
+  },
+  "exports": {
+    ".": {
+      "import": {
+        "types": "./dist/index.d.ts",
+        "default": "./dist/index.js"
+      },
+      "require": {
+        "types": "./dist/index.d.cts",
+        "default": "./dist/index.cjs"
+      }
+    },
+    "./package.json": "./package.json"
+  },
+  "files": [
+    "dist/**/*"
+  ]
+}

libs/providers/baseten/src/baseten.int.test.ts

@@ -0,0 +1,65 @@
+import { describe, it, expect } from "vitest";
+import { HumanMessage } from "@langchain/core/messages";
+import { ChatBaseten } from "./baseten.js";
+import { createDeepAgent } from "deepagents";
+
+const BASETEN_MODEL = "deepseek-ai/DeepSeek-V3.1";
+
+describe("ChatBaseten Integration Tests", () => {
+  it(
+    "should invoke ChatBaseten directly",
+    { timeout: 60_000 },
+    async () => {
+      const model = new ChatBaseten({ model: BASETEN_MODEL });
+
+      const result = await model.invoke([
+        new HumanMessage("What is 2 + 2? Answer with just the number."),
+      ]);
+
+      expect(result.content).toBeTruthy();
+      expect(typeof result.content).toBe("string");
+      expect(result.content).toContain("4");
+    },
+  );
+
+  it(
+    "should stream responses from ChatBaseten",
+    { timeout: 60_000 },
+    async () => {
+      const model = new ChatBaseten({ model: BASETEN_MODEL });
+
+      const chunks: string[] = [];
+      for await (const chunk of await model.stream(
+        "Say the word 'hello' and nothing else.",
+      )) {
+        if (typeof chunk.content === "string") {
+          chunks.push(chunk.content);
+        }
+      }
+
+      const fullResponse = chunks.join("");
+      expect(fullResponse.toLowerCase()).toContain("hello");
+    },
+  );
+
+  it(
+    "should work with createDeepAgent",
+    { timeout: 90_000 },
+    async () => {
+      const model = new ChatBaseten({ model: BASETEN_MODEL });
+
+      const agent = createDeepAgent({ model });
+
+      const result = await agent.invoke({
+        messages: [
+          new HumanMessage(
+            "What is the capital of France? Answer in one word.",
+          ),
+        ],
+      });
+
+      const lastMessage = result.messages[result.messages.length - 1];
+      expect(lastMessage.content).toBeTruthy();
+    },
+  );
+});