name: ai-sdk-core description: Vercel AI SDK v5 for backend AI (text generation, structured output, tools, agents). Multi-provider. Use for server-side AI or encountering AI_APICallError, AI_NoObjectGeneratedError, streaming failures.

Keywords: ai sdk core, vercel ai sdk, generateText, streamText, generateObject, streamObject, ai sdk node, ai sdk server, zod ai schema, ai tools calling, ai agent class, openai sdk, anthropic sdk, google gemini sdk, workers-ai-provider, ai streaming backend, multi-provider ai, ai sdk errors, AI_APICallError, AI_NoObjectGeneratedError, streamText fails, worker startup limit ai license: MIT

AI SDK Core

Production-ready backend AI with Vercel AI SDK v5.

Last Updated: 2025-11-21

Quick Start
Core Functions
Provider Setup & Configuration
Tool Calling & Agents
Critical v4→v5 Migration
Top 12 Errors & Solutions
Production Best Practices
When to Load References
When to Use This Skill
Dependencies & Versions
Links to Official Documentation
Templates & References

Quick Start (5 Minutes)

Installation

bun add ai @ai-sdk/openai @ai-sdk/anthropic @ai-sdk/google workers-ai-provider zod  # preferred
# or: npm install ai @ai-sdk/openai @ai-sdk/anthropic @ai-sdk/google workers-ai-provider zod

Environment Variables

# .env
OPENAI_API_KEY=sk-...
ANTHROPIC_API_KEY=sk-ant-...
GOOGLE_GENERATIVE_AI_API_KEY=...

First Example: Generate Text

import { generateText } from 'ai';
import { openai } from '@ai-sdk/openai';

const result = await generateText({
  model: openai('gpt-4-turbo'),
  prompt: 'What is TypeScript?',
});

console.log(result.text);

First Example: Streaming Chat

import { streamText } from 'ai';
import { anthropic } from '@ai-sdk/anthropic';

const stream = streamText({
  model: anthropic('claude-sonnet-4-5-20250929'),
  messages: [
    { role: 'user', content: 'Tell me a story' },
  ],
});

for await (const chunk of stream.textStream) {
  process.stdout.write(chunk);
}

First Example: Structured Output

import { generateObject } from 'ai';
import { openai } from '@ai-sdk/openai';
import { z } from 'zod';

const result = await generateObject({
  model: openai('gpt-4'),
  schema: z.object({
    name: z.string(),
    age: z.number(),
    skills: z.array(z.string()),
  }),
  prompt: 'Generate a person profile for a software engineer',
});

console.log(result.object);
// { name: "Alice", age: 28, skills: ["TypeScript", "React"] }

Core Functions

Load references/core-functions.md for complete API reference of all 4 core functions.

Quick Overview

AI SDK v5 provides 4 core functions:

Function	Output	Streaming	Use Case
`generateText()`	Text	No	Batch processing, simple completions
`streamText()`	Text	Yes	Chat UIs, long responses
`generateObject()`	Structured	No	Data extraction, JSON generation
`streamObject()`	Structured	Yes	Real-time forms, progressive UIs

Basic Example

import { generateText } from 'ai';
import { openai } from '@ai-sdk/openai';

const result = await generateText({
  model: openai('gpt-4-turbo'),
  prompt: 'Explain quantum computing',
});

console.log(result.text);

→ Load references/core-functions.md for: Complete signatures, tool usage patterns, error handling, streaming examples, comparison table

Provider Setup & Configuration

Load references/provider-setup.md for complete setup instructions for all providers.

Quick Overview

AI SDK v5 supports 4 major providers:

Provider	Environment Variable	Latest Models
OpenAI	`OPENAI_API_KEY`	GPT-5, GPT-4 Turbo
Anthropic	`ANTHROPIC_API_KEY`	Claude Sonnet 4.5, Opus 4
Google	`GOOGLE_GENERATIVE_AI_API_KEY`	Gemini 2.5 Pro/Flash
Cloudflare	Workers AI binding	Llama 3.1, Qwen 2.5

Basic Setup

import { openai } from '@ai-sdk/openai';
import { generateText } from 'ai';

// API key from environment
const result = await generateText({
  model: openai('gpt-4-turbo'),
  prompt: 'Hello',
});

→ Load references/provider-setup.md for: Complete API configuration, rate limiting, error handling, Cloudflare Workers optimization, model selection guides

Tool Calling & Agents

Load references/tools-and-agents.md for complete tool and agent documentation.

Quick Overview

Tools allow models to call external functions. Agents manage multi-step workflows.

v5 Tool Changes:

parameters → inputSchema (Zod schema)
Tool properties: args → input, result → output
maxSteps → stopWhen(stepCountIs(n))

Basic Tool Example

import { generateText, tool } from 'ai';
import { z } from 'zod';

const result = await generateText({
  model: openai('gpt-4'),
  tools: {
    weather: tool({
      description: 'Get weather for a location',
      inputSchema: z.object({ location: z.string() }),
      execute: async ({ location }) => {
        return { temperature: 72, condition: 'sunny' };
      },
    }),
  },
  prompt: 'What is the weather in Tokyo?',
});

→ Load references/tools-and-agents.md for: Agent class usage, multi-step execution, dynamic tools, stop conditions

Critical v4→v5 Migration

Load references/v4-to-v5-migration.md for complete migration guide.

Key Breaking Changes

AI SDK v5 has 9 major breaking changes:

maxTokens → maxOutputTokens
parameters → inputSchema (Zod)
maxSteps → stopWhen(stepCountIs(n))
CoreMessage → ModelMessage
Package reorganization (ai/rsc → @ai-sdk/rsc)

Automated Migration

bunx ai migrate  # Auto-migrates most changes

→ Load references/v4-to-v5-migration.md for: Complete breaking changes list, migration examples, checklist, official migration guide link

Top 12 Errors & Solutions

1. AI_APICallError

Cause: API request failed (network, auth, rate limit).

Solution:

import { AI_APICallError } from 'ai';

try {
  const result = await generateText({
    model: openai('gpt-4'),
    prompt: 'Hello',
  });
} catch (error) {
  if (error instanceof AI_APICallError) {
    console.error('API call failed:', error.message);
    console.error('Status code:', error.statusCode);
    console.error('Response:', error.responseBody);

    // Check common causes
    if (error.statusCode === 401) {
      // Invalid API key
    } else if (error.statusCode === 429) {
      // Rate limit - implement backoff
    } else if (error.statusCode >= 500) {
      // Provider issue - retry
    }
  }
}

Prevention:

Validate API keys at startup
Implement retry logic with exponential backoff
Monitor rate limits
Handle network errors gracefully

2. AI_NoObjectGeneratedError

Cause: Model didn't generate valid object matching schema.

Solution:

import { AI_NoObjectGeneratedError } from 'ai';

try {
  const result = await generateObject({
    model: openai('gpt-4'),
    schema: z.object({ /* complex schema */ }),
    prompt: 'Generate data',
  });
} catch (error) {
  if (error instanceof AI_NoObjectGeneratedError) {
    console.error('No valid object generated');

    // Solutions:
    // 1. Simplify schema
    // 2. Add more context to prompt
    // 3. Provide examples in prompt
    // 4. Try different model (gpt-4 better than gpt-3.5 for complex objects)
  }
}

Prevention:

Start with simple schemas, add complexity incrementally
Include examples in prompt: "Generate a person like: { name: 'Alice', age: 30 }"
Use GPT-4 for complex structured output
Test schemas with sample data first

3. Worker Startup Limit (270ms+)

Cause: AI SDK v5 + Zod initialization overhead in Cloudflare Workers exceeds startup limits.

Solution:

// BAD: Top-level imports cause startup overhead
import { createWorkersAI } from 'workers-ai-provider';
import { complexSchema } from './schemas';

const workersai = createWorkersAI({ binding: env.AI });

// GOOD: Lazy initialization inside handler
export default {
  async fetch(request, env) {
    const { createWorkersAI } = await import('workers-ai-provider');
    const workersai = createWorkersAI({ binding: env.AI });

    // Use workersai here
  }
}

Prevention:

Move AI SDK imports inside route handlers
Minimize top-level Zod schemas
Monitor Worker startup time (must be <400ms)
Use Wrangler's startup time reporting

GitHub Issue: Search for "Workers startup limit" in Vercel AI SDK issues

→ Load references/error-catalog.md for errors #4-#12 with complete solutions.

Remaining 9 errors: 4. streamText Fails Silently (RESOLVED in v4.1.22) 5. AI_LoadAPIKeyError 6. AI_InvalidArgumentError 7. AI_NoContentGeneratedError 8. AI_TypeValidationError 9. AI_RetryError 10. Rate Limiting Errors 11. TypeScript Performance with Zod 12. Invalid JSON Response (Provider-Specific)

For complete error catalog: See complete error reference at https://ai-sdk.dev/docs/reference/ai-sdk-errors

Production Best Practices

Load references/production-guide.md for complete production deployment guide.

Key Categories

Performance: Streaming patterns, token limits, provider caching, Zod optimization
Error Handling: try-catch patterns, retry logic, proper logging
Cost Optimization: Model selection, token limits, response caching
Cloudflare Workers: Lazy imports, startup monitoring, streaming responses
Next.js/Vercel: Server Actions, Server Components, loading states

Quick Example

// Use streaming for user-facing responses
const stream = streamText({
  model: openai('gpt-4'),
  prompt: 'Long essay',
  maxOutputTokens: 500,
  maxRetries: 3,
});

return stream.toDataStreamResponse();

→ Load references/production-guide.md for: Platform-specific patterns, deployment checklists, optimization strategies

When to Load References

Load references/core-functions.md when:

User needs complete API documentation for generateText, streamText, generateObject, or streamObject
Questions about function signatures, parameters, or return types
Need detailed tool usage patterns or streaming examples
Troubleshooting function-specific errors

Load references/provider-setup.md when:

Setting up OpenAI, Anthropic, Google, or Cloudflare Workers AI
Configuring API keys or environment variables
Troubleshooting provider-specific errors (rate limits, authentication)
Questions about model selection or best practices for each provider
Cloudflare Workers startup optimization needed

Load references/tools-and-agents.md when:

Implementing tool calling or agent workflows
Questions about Agent class vs raw generateText
Setting up multi-step execution with stopWhen
Dynamic tools or complex agentic patterns

Load references/v4-to-v5-migration.md when:

Migrating existing v4 codebase to v5
Questions about breaking changes
Need migration examples or automated migration tool
Troubleshooting migration-related errors

Load references/error-catalog.md when:

User encounters any of the 12 common errors (beyond top 3 shown inline)
Need complete error solutions with code examples
Troubleshooting production errors
Questions about error prevention strategies

Load references/production-guide.md when:

Deploying to production (any platform)
Performance optimization needed
Cost optimization questions
Platform-specific patterns (Cloudflare Workers, Next.js/Vercel)
Error handling or logging strategies

When to Use This Skill

Use ai-sdk-core when:

Building backend AI features (server-side text generation)
Implementing server-side text generation (Node.js, Workers, Next.js)
Creating structured AI outputs (JSON, forms, data extraction)
Building AI agents with tools (multi-step workflows)
Integrating multiple AI providers (OpenAI, Anthropic, Google, Cloudflare)
Migrating from AI SDK v4 to v5
Encountering AI SDK errors (AI_APICallError, AI_NoObjectGeneratedError, etc.)
Using AI in Cloudflare Workers (with workers-ai-provider)
Using AI in Next.js Server Components/Actions
Need consistent API across different LLM providers

Don't use this skill when:

Building React chat UIs (use ai-sdk-ui skill instead)
Need frontend hooks like useChat (use ai-sdk-ui skill instead)
Need advanced topics like embeddings or image generation (check official docs)
Building native Cloudflare Workers AI apps without multi-provider (use cloudflare-workers-ai skill instead)
Need Generative UI / RSC (see https://ai-sdk.dev/docs/ai-sdk-rsc)

Dependencies & Versions

{
  "dependencies": {
    "ai": "^5.0.116",
    "@ai-sdk/openai": "^2.0.88",
    "@ai-sdk/anthropic": "^2.0.56",
    "@ai-sdk/google": "^2.0.51",
    "workers-ai-provider": "^2.0.0",
    "zod": "^3.23.8"
  },
  "devDependencies": {
    "@types/node": "^24.10.1",
    "typescript": "^5.9.3"
  }
}

Version Notes:

AI SDK v5.0.116+ (stable, latest as of December 2025)
v6 is in beta - not covered in this skill
Zod compatibility: This skill uses Zod 3.x, but AI SDK 5 officially supports both Zod 3.x and Zod 4.x (4.1.12 latest)
- Zod 4 recommended for new projects (released August 2025)
- Zod 4 has breaking changes: error APIs, .default() behavior, ZodError.errors removed
- Some peer dependency warnings may occur with zod-to-json-schema when using Zod 4
- See https://zod.dev/v4/changelog for migration guide
Provider packages at 2.0+ for v5 compatibility

Check Latest Versions:

npm view ai version
npm view @ai-sdk/openai version
npm view @ai-sdk/anthropic version
npm view @ai-sdk/google version
npm view workers-ai-provider version
npm view zod version  # Check for Zod 4.x updates

Links to Official Documentation

Templates & References

This skill includes:

13 Templates: Ready-to-use code examples in templates/
5 Reference Docs: Detailed guides in references/
1 Script: Version checker in scripts/

All files are optimized for copy-paste into your project.

Last Updated: 2025-12-22 Skill Version: 1.1.0 AI SDK Version: 5.0.116+

Unnamed Skill

$ Installer

AI SDK Core

Table of Contents

Quick Start (5 Minutes)

Installation

Environment Variables

First Example: Generate Text

First Example: Streaming Chat

First Example: Structured Output

Core Functions

Quick Overview

Basic Example

Provider Setup & Configuration

Quick Overview

Basic Setup

Tool Calling & Agents

Quick Overview

Basic Tool Example

Critical v4→v5 Migration

Key Breaking Changes

Automated Migration

Top 12 Errors & Solutions

1. AI_APICallError

2. AI_NoObjectGeneratedError

3. Worker Startup Limit (270ms+)

Production Best Practices

Key Categories

Quick Example

When to Load References

When to Use This Skill

Use ai-sdk-core when:

Don't use this skill when:

Dependencies & Versions

Links to Official Documentation

Core Documentation

Advanced Topics (Not Replicated in This Skill)

Migration & Troubleshooting

Provider Documentation

Cloudflare Integration

Vercel / Next.js Integration

GitHub & Community

Templates & References

Repository

Actions

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