🐛 Bug: Browser Build Fails Due to Accidental Inclusion of AWS SDK

[zero8892084]

♻️ Reproduction Steps

Title: Browser Build Fails Due to Accidental Inclusion of AWS SDK via @langchain/core in @copilotkit/runtime@1.10.x

Description:

Hi team,

After upgrading to @copilotkit/runtime@1.10.6, our Vite-based React application fails at runtime in the browser with the following error:
Uncaught SyntaxError: Export 'import_getSSOTokenFromFile2' is not defined in module
This error originates from AWS SDK v3’s Node.js–specific module (@aws-sdk/shared-ini-file-loader), which is being bundled into the browser build.

Root Cause
We traced the dependency chain and found that:

@copilotkit/runtime@1.10.6
└─ @copilotkit/common@1.10.6
└─ @langchain/core@^0.3.0
└─ @aws-sdk/* (Node.js-only modules)
Although @langchain/core may be intended as an optional or backend-only dependency, Vite (and other bundlers) automatically include it during dependency pre-bundling, causing Node.js–specific code (e.g., file system operations for AWS SSO tokens) to be injected into the client-side bundle — which fails in the browser.

This breaks any frontend app using CopilotKit >=1.9.0, even when only using LangGraphAgent (which only needs HTTP/SSE and has no need for LangChain or AWS).

Impact
Frontend apps crash on load in the browser.
The issue persists even with a clean node_modules and cache because Vite re-prebundles the problematic dependencies.
Users cannot use the latest CopilotKit versions without workarounds.
Proposed Fixes
(Recommended) Mark @langchain/core as an optional peer dependency and exclude it from the main bundle.

If LangChain integration is needed, it should be opt-in via a separate package (e.g., @copilotkit/langchain-adapter).
Alternatively, ensure that any LangChain-related code is dynamically imported only in Node.js environments, or provide ESM builds with proper exports conditions that exclude Node.js modules from browser bundles.
At minimum, document this breaking change and provide guidance for frontend users to avoid the issue.
Temporary Workaround
Downgrading to @copilotkit/runtime@1.8.2 resolves the issue, as that version does not depend on @langchain/core.

npm install @copilotkit/runtime@1.8.2 @copilotkit/react-core@1.8.2 @copilotkit/react-ui@1.8.2

Thanks for your great work on CopilotKit! Let me know if you need more details or a minimal reproduction repo.

✅ Expected Behavior

111111

❌ Actual Behavior

After upgrading to @copilotkit/runtime@1.10.6, our Vite-based React application fails at runtime in the browser with the following error:
Uncaught SyntaxError: Export 'import_getSSOTokenFromFile2' is not defined in module
This error originates from AWS SDK v3’s Node.js–specific module (@aws-sdk/shared-ini-file-loader), which is being bundled into the browser build.

𝌚 CopilotKit Version

├── @copilotkit/react-core@1.10.6 -> ./node_modules/.pnpm/@copilotkit+react-core@1.10.6_@types+react@19.2.5_graphql@16.12.0_react-dom@19.2.0_react@19.2.0__react@19.2.0/node_modules/@copilotkit/react-core
├── @copilotkit/react-ui@1.10.6 -> ./node_modules/.pnpm/@copilotkit+react-ui@1.10.6_@types+react@19.2.5_graphql@16.12.0_react-dom@19.2.0_react@19.2.0__react@19.2.0/node_modules/@copilotkit/react-ui
├── @copilotkit/runtime@1.10.6 -> ./node_modules/.pnpm/@copilotkit+runtime@1.10.6_@ag-ui+client@0.0.41_@ag-ui+core@0.0.37_@ag-ui+encoder@0.0.4_b79ede7e685e274932e93c413cfb3a1d/node_modules/@copilotkit/runtime

📄 Logs (Optional)

Uncaught SyntaxError: Export 'import_getSSOTokenFromFile2' is not defined in module (at chunk-YUHLK2RX.js?v=fce810a6:378:3)


export {
  require_os,
  require_path,
  require_crypto,
  ENV_PROFILE,
  getProfileName,
  getSSOTokenFilepath,
  loadSharedConfigFiles,
  loadSsoSessionData,
  parseKnownFiles,
  externalDataInterceptor,
  import_getSSOTokenFromFile2 as import_getSSOTokenFromFile,
  init_dist_es2 as init_dist_es
};
//# sourceMappingURL=chunk-YUHLK2RX.js.map

[copilotkit-support-bot]

The browser build fails due to the inclusion of @langchain/core (and thus AWS SDK Node.js modules) via @copilotkit/runtime, which is not required for browser builds unless LangChain integrations are used. This happens because @langchain/core is always bundled due to the current export structure, and bundlers cannot tree-shake these runtime dependencies.

Details

Is @langchain/core required for browser builds?

No, @langchain/core is NOT required for browser builds unless you're specifically using LangChain integrations. However, it gets bundled anyway due to the current architecture.

Root Cause Analysis

• Always bundled dependency: @langchain/core is included whenever you import from @copilotkit/runtime because the langchain-adapter is exported by default in the main exports
• Runtime imports: The LangChain adapter uses regular imports (not type-only) from @langchain/core, requiring the full package
• No tree-shaking: These are runtime dependencies that can't be eliminated by bundlers

Current Workarounds

1. Import specific adapters directly (if possible)

// Instead of importing from main runtime
import { OpenAIAdapter } from '@copilotkit/runtime/lib/service-adapters/openai';
import { AnthropicAdapter } from '@copilotkit/runtime/lib/service-adapters/anthropic';

// Avoid importing from main exports that include langchain
// import { OpenAIAdapter } from '@copilotkit/runtime'; // This includes langchain

2. Bundler configuration workarounds

// webpack.config.js
module.exports = {
  resolve: {
    alias: {
      // Alias problematic modules to empty implementations
      '@langchain/core': false,
    }
  },
  externals: {
    '@langchain/core': 'commonjs @langchain/core'
  }
};

// vite.config.js
export default {
  define: {
    global: 'globalThis',
  },
  resolve: {
    alias: {
      '@langchain/core': '/dev/null'
    }
  }
}

3. Use alternative service adapters

• OpenAI Adapter: Direct integration without LangChain dependency
• Anthropic Adapter: Native implementation
• Google Genai Adapter: Direct Google integration
• Groq Adapter: Native Groq implementation

No Current Plans for Separation

Based on the codebase analysis:
• No optional dependencies: @langchain/core is a hard dependency in package.json
• No separate packages: All adapters are bundled together in the runtime package
• Deep integration: Service adapters are embedded throughout the runtime system

Recommended Solutions

Short-term (Immediate fixes)

• Use specific imports: Import only the adapters you need directly from their paths
• Configure bundler exclusions: Add bundler rules to exclude @langchain/core
• Switch to non-LangChain adapters: Use OpenAI, Anthropic, or Google adapters directly

Long-term (Architecture changes needed)

• Separate adapter packages: Move each adapter to its own optional package
• Peer dependencies: Make @langchain/core a peer dependency
• Conditional exports: Use package.json exports to provide browser-specific entry points

Alternative Approach

Consider using the runtime on the backend only and connecting to it from your frontend via the GraphQL client:

// Frontend (browser-safe)
import { CopilotRuntimeClient } from '@copilotkit/runtime-client-gql';

// Backend (Node.js with full runtime)
import { CopilotRuntime, OpenAIAdapter } from '@copilotkit/runtime';

Sources:

• Runtime Package Structure
• Service Adapters Documentation

This issue highlights a common challenge in full-stack frameworks where server-side dependencies leak into client bundles. The most reliable current solution is using bundler configuration to exclude the problematic dependencies while importing only the specific adapters you need.

---

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✅ Issue Solved | ❌ Need more help

[NathanTarbert]

Hey @zero8892084, thanks for opening the issue. We will look into this and get back to you.

[jpr5]

@langchain/core pulling AWS SDK is addressed by making it an optional peer dependency in newer releases.