chore(providers/langchain): extract to separate package (#5928)

Author: samdenty

.changeset/spotty-swans-know.md

@@ -0,0 +1,5 @@
+---
+'@ai-sdk/langchain': patch
+---
+
+chore(providers/langchain): extract to separate package

content/docs/07-reference/04-stream-helpers/16-langchain-adapter.mdx

@@ -1,11 +1,11 @@
 ---
-title: LangChainAdapter
-description: API Reference for LangChainAdapter.
+title: @ai-sdk/langchain Adapter
+description: API Reference for the LangChain Adapter.
 ---
 
-# `LangChainAdapter`
+# `@ai-sdk/langchain`
 
-The `LangChainAdapter` module provides helper functions to transform LangChain output streams into data streams and data stream responses.
+The `@ai-sdk/langchain` module provides helper functions to transform LangChain output streams into data streams and data stream responses.
 See the [LangChain Adapter documentation](/providers/adapters/langchain) for more information.
 
 It supports:
@@ -16,7 +16,10 @@ It supports:
 
 ## Import
 
-<Snippet text={`import { LangChainAdapter } from "ai"`} prompt={false} />
+<Snippet
+  text={`import { toDataStreamResponse } from "@ai-sdk/langchain"`}
+  prompt={false}
+/>
 
 ## API Signature
 
@@ -49,7 +52,7 @@ It supports:
 
 ```tsx filename="app/api/completion/route.ts" highlight={"14"}
 import { ChatOpenAI } from '@langchain/openai';
-import { LangChainAdapter } from 'ai';
+import { toDataStreamResponse } from '@ai-sdk/langchain';
 
 export async function POST(req: Request) {
   const { prompt } = await req.json();
@@ -61,15 +64,15 @@ export async function POST(req: Request) {
 
   const stream = await model.stream(prompt);
 
-  return LangChainAdapter.toDataStreamResponse(stream);
+  return toDataStreamResponse(stream);
 }
 ```
 
 ### Convert StringOutputParser Stream
 
 ```tsx filename="app/api/completion/route.ts" highlight={"16"}
 import { ChatOpenAI } from '@langchain/openai';
-import { LangChainAdapter } from 'ai';
+import { toDataStreamResponse } from '@ai-sdk/langchain';
 import { StringOutputParser } from '@langchain/core/output_parsers';
 
 export async function POST(req: Request) {
@@ -83,6 +86,6 @@ export async function POST(req: Request) {
   const parser = new StringOutputParser();
   const stream = await model.pipe(parser).stream(prompt);
 
-  return LangChainAdapter.toDataStreamResponse(stream);
+  return toDataStreamResponse(stream);
 }
 ```

content/docs/07-reference/04-stream-helpers/16-langchain-stream.mdx

@@ -81,12 +81,6 @@ collapsed: true
         "Transforms the response from LangChain's language models into a readable stream.",
       href: '/docs/reference/stream-helpers/langchain-stream',
     },
-    {
-      title: 'LangChainAdapter',
-      description:
-        "Transforms the response from LangChain's stream into data streams.",
-      href: '/docs/reference/stream-helpers/langchain-adapter',
-    },
     {
       title: 'LlamaIndexAdapter',
       description:

content/docs/07-reference/04-stream-helpers/index.mdx

@@ -13,12 +13,12 @@ However, LangChain does not provide a way to easily build UIs or a standard way
 
 Here is a basic example that uses both the AI SDK and LangChain together with the [Next.js](https://nextjs.org/docs) App Router.
 
-The AI SDK [`LangChainAdapter`](/docs/reference/stream-helpers/langchain-adapter) uses the result from [LangChain ExpressionLanguage streaming](https://js.langchain.com/docs/expression_language/streaming) to pipe text to the client.
-`LangChainAdapter.toDataStreamResponse()` is compatible with the LangChain Expression Language `.stream()` function response.
+The [`@ai-sdk/langchain` package](/docs/reference/stream-helpers/langchain-adapter) uses the result from [LangChain ExpressionLanguage streaming](https://js.langchain.com/docs/expression_language/streaming) to pipe text to the client.
+`toDataStreamResponse()` is compatible with the LangChain Expression Language `.stream()` function response.
 
 ```tsx filename="app/api/completion/route.ts" highlight={"16"}
 import { ChatOpenAI } from '@langchain/openai';
-import { LangChainAdapter } from 'ai';
+import { toDataStreamResponse } from '@ai-sdk/langchain';
 
 export const maxDuration = 60;
 
@@ -32,7 +32,7 @@ export async function POST(req: Request) {
 
   const stream = await model.stream(prompt);
 
-  return LangChainAdapter.toDataStreamResponse(stream);
+  return toDataStreamResponse(stream);
 }
 ```
 

content/providers/04-adapters/01-langchain.mdx

@@ -1,6 +1,7 @@
 import { ChatOpenAI } from '@langchain/openai';
-import { LangChainAdapter, Message } from 'ai';
+import { Message } from 'ai';
 import { AIMessage, HumanMessage } from '@langchain/core/messages';
+import { toDataStreamResponse } from '@ai-sdk/langchain';
 
 // Allow streaming responses up to 30 seconds
 export const maxDuration = 30;
@@ -25,5 +26,5 @@ export async function POST(req: Request) {
     ),
   );
 
-  return LangChainAdapter.toDataStreamResponse(stream);
+  return toDataStreamResponse(stream);
 }

examples/next-langchain/app/api/chat/route.ts

@@ -1,5 +1,5 @@
+import { toDataStreamResponse } from '@ai-sdk/langchain';
 import { ChatOpenAI } from '@langchain/openai';
-import { LangChainAdapter } from 'ai';
 
 // Allow streaming responses up to 30 seconds
 export const maxDuration = 30;
@@ -14,5 +14,5 @@ export async function POST(req: Request) {
 
   const stream = await model.stream(prompt);
 
-  return LangChainAdapter.toDataStreamResponse(stream);
+  return toDataStreamResponse(stream);
 }

examples/next-langchain/app/api/completion-stream-data/route.ts

@@ -1,6 +1,6 @@
+import { toDataStreamResponse } from '@ai-sdk/langchain';
 import { StringOutputParser } from '@langchain/core/output_parsers';
 import { ChatOpenAI } from '@langchain/openai';
-import { LangChainAdapter } from 'ai';
 
 // Allow streaming responses up to 30 seconds
 export const maxDuration = 30;
@@ -17,5 +17,5 @@ export async function POST(req: Request) {
 
   const stream = await model.pipe(parser).stream(prompt);
 
-  return LangChainAdapter.toDataStreamResponse(stream);
+  return toDataStreamResponse(stream);
 }

examples/next-langchain/app/api/completion-string-output-parser/route.ts

@@ -1,5 +1,5 @@
+import { toDataStreamResponse } from '@ai-sdk/langchain';
 import { ChatOpenAI } from '@langchain/openai';
-import { LangChainAdapter } from 'ai';
 
 // Allow streaming responses up to 30 seconds
 export const maxDuration = 30;
@@ -14,5 +14,5 @@ export async function POST(req: Request) {
 
   const stream = await model.stream(prompt);
 
-  return LangChainAdapter.toDataStreamResponse(stream);
+  return toDataStreamResponse(stream);
 }

examples/next-langchain/app/api/completion/route.ts

@@ -10,6 +10,7 @@
   },
   "dependencies": {
     "@ai-sdk/react": "workspace:*",
+    "@ai-sdk/langchain": "workspace:*",
     "@langchain/openai": "0.0.28",
     "@langchain/core": "0.1.63",
     "ai": "workspace:*",

examples/next-langchain/package.json

@@ -45,6 +45,9 @@
     },
     {
       "path": "../../packages/react"
+    },
+    {
+      "path": "../../packages/langchain"
     }
   ]
 }

examples/next-langchain/tsconfig.json

@@ -4,5 +4,14 @@ export { prepareRetries } from '../core/prompt/prepare-retries';
 export { prepareCallSettings } from '../core/prompt/prepare-call-settings';
 export { convertToLanguageModelPrompt } from '../core/prompt/convert-to-language-model-prompt';
 export { calculateLanguageModelUsage } from '../core/types/usage';
+export { formatDataStreamPart } from '../core';
+export { type DataStreamWriter } from '../core/data-stream/data-stream-writer';
+export { mergeStreams } from '../core/util/merge-streams';
+export { prepareResponseHeaders } from '../core/util/prepare-response-headers';
+export {
+  createCallbacksTransformer,
+  type StreamCallbacks,
+} from '../streams/stream-callbacks';
+export { StreamData } from '../streams/stream-data';
 
 export * from '../util/constants';

packages/ai/internal/index.ts

@@ -1,6 +1,5 @@
 export * from '../core/index';
 export * from '../errors/index';
 
-export * as LangChainAdapter from './langchain-adapter';
 export * as LlamaIndexAdapter from './llamaindex-adapter';
 export * from './stream-data';

packages/ai/streams/index.ts

@@ -0,0 +1,3 @@
+# AI SDK - LangChain Adapter
+
+This package contains a LangChain adapter for the AI SDK.

packages/langchain/CHANGELOG.md

@@ -0,0 +1,61 @@
+{
+  "name": "@ai-sdk/langchain",
+  "version": "1.0.0-canary.0",
+  "license": "Apache-2.0",
+  "sideEffects": false,
+  "main": "./dist/index.js",
+  "module": "./dist/index.mjs",
+  "types": "./dist/index.d.ts",
+  "files": [
+    "dist/**/*",
+    "CHANGELOG.md"
+  ],
+  "scripts": {
+    "build": "pnpm clean && tsup --tsconfig tsconfig.build.json",
+    "build:watch": "pnpm clean && tsup --watch",
+    "clean": "rm -rf dist *.tsbuildinfo",
+    "lint": "eslint \"./**/*.ts*\"",
+    "type-check": "tsc --build",
+    "prettier-check": "prettier --check \"./**/*.ts*\"",
+    "test": "pnpm test:node && pnpm test:edge",
+    "test:update": "pnpm test:node -u",
+    "test:watch": "vitest --config vitest.node.config.js",
+    "test:edge": "vitest --config vitest.edge.config.js --run",
+    "test:node": "vitest --config vitest.node.config.js --run"
+  },
+  "exports": {
+    "./package.json": "./package.json",
+    ".": {
+      "types": "./dist/index.d.ts",
+      "import": "./dist/index.mjs",
+      "require": "./dist/index.js"
+    }
+  },
+  "dependencies": {
+    "ai": "workspace:*",
+    "@ai-sdk/provider-utils": "workspace:*"
+  },
+  "devDependencies": {
+    "@types/node": "20.17.24",
+    "@vercel/ai-tsconfig": "workspace:*",
+    "tsup": "^8",
+    "typescript": "5.8.3"
+  },
+  "engines": {
+    "node": ">=18"
+  },
+  "publishConfig": {
+    "access": "public"
+  },
+  "homepage": "https://sdk.vercel.ai/docs",
+  "repository": {
+    "type": "git",
+    "url": "git+https://github.com/vercel/ai.git"
+  },
+  "bugs": {
+    "url": "https://github.com/vercel/ai/issues"
+  },
+  "keywords": [
+    "ai"
+  ]
+}

packages/langchain/README.md

@@ -0,0 +1 @@
+export * from './langchain-adapter';

packages/langchain/package.json

@@ -3,7 +3,7 @@ import {
   convertReadableStreamToArray,
   convertResponseStreamToArray,
 } from '@ai-sdk/provider-utils/test';
-import { createDataStream } from '../core/data-stream/create-data-stream';
+import { createDataStream } from 'ai';
 import {
   mergeIntoDataStream,
   toDataStream,

packages/langchain/src/index.ts

@@ -1,12 +1,10 @@
-import { formatDataStreamPart } from '../core';
-import { DataStreamWriter } from '../core/data-stream/data-stream-writer';
-import { mergeStreams } from '../core/util/merge-streams';
-import { prepareResponseHeaders } from '../core/util/prepare-response-headers';
+import { formatDataStreamPart, DataStreamWriter, StreamData } from 'ai';
 import {
+  mergeStreams,
+  prepareResponseHeaders,
   createCallbacksTransformer,
   StreamCallbacks,
-} from './stream-callbacks';
-import { StreamData } from './stream-data';
+} from 'ai/internal';
 
 type LangChainImageDetail = 'auto' | 'low' | 'high';
 

packages/ai/streams/langchain-adapter.test.ts renamed to packages/langchain/src/langchain-adapter.test.ts

@@ -0,0 +1,7 @@
+{
+  "extends": "./tsconfig.json",
+  "compilerOptions": {
+    // Disable project configuration for tsup builds
+    "composite": false
+  }
+}