# TypeScript performance issues with Zod and AI SDK 5

## Issue

When using the AI SDK 5 with Zod, you may experience:

- TypeScript server crashes or hangs
- Extremely slow type checking in files that import AI SDK functions
- Error messages like "Type instantiation is excessively deep and possibly infinite"
- IDE becoming unresponsive when working with AI SDK code

## Background

The AI SDK 5 has specific compatibility requirements with Zod versions. When importing Zod using the standard import path (`import { z } from 'zod'`), TypeScript's type inference can become excessively complex, leading to performance degradation or crashes.

## Solution

### Upgrade Zod to 4.1.8 or Later

The primary solution is to upgrade to Zod version 4.1.8 or later, which includes a fix for this module resolution issue:

```bash
pnpm add zod@^4.1.8
```

This version resolves the underlying problem where different module resolution settings were causing TypeScript to load the same Zod declarations twice, leading to expensive structural comparisons.

### Alternative: Update TypeScript Configuration

If upgrading Zod isn't possible, you can update your `tsconfig.json` to use `moduleResolution: "nodenext"`:

```json
{
  "compilerOptions": {
    "moduleResolution": "nodenext"
    // ... other options
  }
}
```

This resolves the TypeScript performance issues while allowing you to continue using the standard Zod import.


## Navigation

- [Azure OpenAI Slow to Stream](/docs/troubleshooting/azure-stream-slow)
- [Server Actions in Client Components](/docs/troubleshooting/server-actions-in-client-components)
- [useChat/useCompletion stream output contains 0:... instead of text](/docs/troubleshooting/strange-stream-output)
- [Streamable UI Errors](/docs/troubleshooting/streamable-ui-errors)
- [Tool Invocation Missing Result Error](/docs/troubleshooting/tool-invocation-missing-result)
- [Streaming Not Working When Deployed](/docs/troubleshooting/streaming-not-working-when-deployed)
- [Streaming Not Working When Proxied](/docs/troubleshooting/streaming-not-working-when-proxied)
- [Getting Timeouts When Deploying on Vercel](/docs/troubleshooting/timeout-on-vercel)
- [Unclosed Streams](/docs/troubleshooting/unclosed-streams)
- [useChat Failed to Parse Stream](/docs/troubleshooting/use-chat-failed-to-parse-stream)
- [Server Action Plain Objects Error](/docs/troubleshooting/client-stream-error)
- [useChat No Response](/docs/troubleshooting/use-chat-tools-no-response)
- [Custom headers, body, and credentials not working with useChat](/docs/troubleshooting/use-chat-custom-request-options)
- [TypeScript performance issues with Zod and AI SDK 5](/docs/troubleshooting/typescript-performance-zod)
- [useChat "An error occurred"](/docs/troubleshooting/use-chat-an-error-occurred)
- [Repeated assistant messages in useChat](/docs/troubleshooting/repeated-assistant-messages)
- [onFinish not called when stream is aborted](/docs/troubleshooting/stream-abort-handling)
- [Tool calling with structured outputs](/docs/troubleshooting/tool-calling-with-structured-outputs)
- [Abort and resumable streams](/docs/troubleshooting/abort-breaks-resumable-streams)
- [streamText fails silently](/docs/troubleshooting/stream-text-not-working)
- [Streaming Status Shows But No Text Appears](/docs/troubleshooting/streaming-status-delay)
- [Stale body values with useChat](/docs/troubleshooting/use-chat-stale-body-data)
- [Type Error with onToolCall](/docs/troubleshooting/ontoolcall-type-narrowing)
- [Unsupported model version error](/docs/troubleshooting/unsupported-model-version)
- [Object generation failed with OpenAI](/docs/troubleshooting/no-object-generated-content-filter)
- [Missing Tool Results Error](/docs/troubleshooting/missing-tool-results-error)
- [Model is not assignable to type "LanguageModelV1"](/docs/troubleshooting/model-is-not-assignable-to-type)
- [TypeScript error "Cannot find namespace 'JSX'"](/docs/troubleshooting/typescript-cannot-find-namespace-jsx)
- [React error "Maximum update depth exceeded"](/docs/troubleshooting/react-maximum-update-depth-exceeded)
- [Jest: cannot find module '@ai-sdk/rsc'](/docs/troubleshooting/jest-cannot-find-module-ai-rsc)
- [High memory usage when processing many images](/docs/troubleshooting/high-memory-usage-with-images)


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