> ## Documentation Index
> Fetch the complete documentation index at: https://docs.b3.fun/llms.txt
> Use this file to discover all available pages before exploring further.

# Error Handling

Comprehensive error handling patterns and recovery strategies for CreateKit

## Overview

Robust error handling is crucial for production applications using CreateKit. This guide covers common error scenarios, best practices, and recovery strategies.

## Common Error Types

### Signature Errors

```typescript title="Signature Error Handling"
import { CollectionManager } from '@b3dotfun/basemint'

async function handleSignatureErrors(walletClient: any, metadata: any) {
  try {
    const signature = await collectionManager.generateCreatorSignature(
      walletClient,
      metadata
    )
    return signature
  } catch (error: any) {
    if (error.message.includes('User rejected')) {
      throw new Error('SIGNATURE_REJECTED: User rejected the signature request')
    } else if (error.message.includes('Insufficient funds')) {
      throw new Error('INSUFFICIENT_FUNDS: Not enough funds for gas')
    } else if (error.message.includes('Network error')) {
      throw new Error('NETWORK_ERROR: Unable to connect to network')
    } else {
      throw new Error(`SIGNATURE_FAILED: ${error.message}`)
    }
  }
}
```

### Storage Errors

```typescript title="Storage Error Handling"
import { BaseMintStorage } from '@b3dotfun/basemint'

async function handleStorageErrors(storage: BaseMintStorage, metadata: any, signature: string) {
  try {
    return await storage.submitCollection(metadata, signature)
  } catch (error: any) {
    if (error.message.includes('Invalid signature')) {
      throw new Error('INVALID_SIGNATURE: Signature verification failed')
    } else if (error.message.includes('Collection exists')) {
      throw new Error('DUPLICATE_COLLECTION: Collection already exists')
    } else if (error.message.includes('Rate limit')) {
      throw new Error('RATE_LIMITED: Too many requests, please try again later')
    } else if (error.status === 503) {
      throw new Error('SERVICE_UNAVAILABLE: Storage service temporarily unavailable')
    } else {
      throw new Error(`STORAGE_ERROR: ${error.message}`)
    }
  }
}
```

### Contract Interaction Errors

```typescript title="Contract Error Handling"
async function handleMintingErrors(collection: any, walletClient: any, params: any) {
  try {
    return await collection.mint(walletClient, ...params)
  } catch (error: any) {
    if (error.message.includes('Invalid merkle proof')) {
      throw new Error('NOT_WHITELISTED: Address not in whitelist')
    } else if (error.message.includes('Insufficient payment')) {
      throw new Error('INSUFFICIENT_PAYMENT: Incorrect mint price')
    } else if (error.message.includes('Max per wallet exceeded')) {
      throw new Error('WALLET_LIMIT_EXCEEDED: Wallet minting limit reached')
    } else if (error.message.includes('Max supply exceeded')) {
      throw new Error('SUPPLY_EXHAUSTED: Collection fully minted')
    } else if (error.message.includes('Minting not active')) {
      throw new Error('MINTING_INACTIVE: Minting period not active')
    } else {
      throw new Error(`MINT_FAILED: ${error.message}`)
    }
  }
}
```

## Error Recovery Patterns

### Retry Logic

```typescript title="Retry with Exponential Backoff"
async function retryWithBackoff<T>(
  operation: () => Promise<T>,
  maxRetries: number = 3,
  baseDelayMs: number = 1000
): Promise<T> {
  let lastError: Error

  for (let attempt = 1; attempt <= maxRetries; attempt++) {
    try {
      return await operation()
    } catch (error: any) {
      lastError = error

      // Don't retry certain errors
      if (error.message.includes('SIGNATURE_REJECTED') ||
          error.message.includes('INVALID_SIGNATURE') ||
          error.message.includes('DUPLICATE_COLLECTION')) {
        throw error
      }

      if (attempt < maxRetries) {
        const delay = baseDelayMs * Math.pow(2, attempt - 1)
        console.warn(`Attempt ${attempt} failed, retrying in ${delay}ms...`)
        await new Promise(resolve => setTimeout(resolve, delay))
      }
    }
  }

  throw lastError
}

// Usage
const result = await retryWithBackoff(async () => {
  return await storage.submitCollection(metadata, signature)
})
```

### Circuit Breaker

```typescript title="Circuit Breaker Pattern"
class CircuitBreaker {
  private failures = 0
  private lastFailTime = 0
  private state: 'CLOSED' | 'OPEN' | 'HALF_OPEN' = 'CLOSED'

  constructor(
    private maxFailures: number = 5,
    private timeoutMs: number = 60000
  ) {}

  async call<T>(operation: () => Promise<T>): Promise<T> {
    if (this.state === 'OPEN') {
      if (Date.now() - this.lastFailTime > this.timeoutMs) {
        this.state = 'HALF_OPEN'
      } else {
        throw new Error('CIRCUIT_OPEN: Service temporarily unavailable')
      }
    }

    try {
      const result = await operation()
      this.reset()
      return result
    } catch (error) {
      this.recordFailure()
      throw error
    }
  }

  private recordFailure() {
    this.failures++
    this.lastFailTime = Date.now()

    if (this.failures >= this.maxFailures) {
      this.state = 'OPEN'
    }
  }

  private reset() {
    this.failures = 0
    this.state = 'CLOSED'
  }
}

// Usage
const circuitBreaker = new CircuitBreaker()
const result = await circuitBreaker.call(() => storage.submitCollection(metadata, signature))
```

## User-Friendly Error Messages

```typescript title="Error Message Translation"
const ERROR_MESSAGES = {
  SIGNATURE_REJECTED: "Please approve the signature in your wallet to continue.",
  INSUFFICIENT_FUNDS: "You don't have enough funds to cover gas fees.",
  NOT_WHITELISTED: "Your address is not eligible for whitelist minting.",
  WALLET_LIMIT_EXCEEDED: "You've reached the maximum number of tokens per wallet.",
  SUPPLY_EXHAUSTED: "This collection is fully minted out.",
  MINTING_INACTIVE: "Minting is not currently active for this collection.",
  NETWORK_ERROR: "Network connection issue. Please check your internet and try again.",
  SERVICE_UNAVAILABLE: "Service is temporarily unavailable. Please try again in a few minutes.",
  RATE_LIMITED: "Too many requests. Please wait a moment before trying again."
}

function getUserFriendlyError(error: Error): string {
  const errorCode = error.message.split(':')[0]
  return ERROR_MESSAGES[errorCode] || "An unexpected error occurred. Please try again."
}

// Usage in React
export function ErrorDisplay({ error }: { error: Error | null }) {
  if (!error) return null

  return (
    <div className="bg-red-100 border border-red-400 text-red-700 px-4 py-3 rounded">
      <p>{getUserFriendlyError(error)}</p>
    </div>
  )
}
```

## Error Monitoring

```typescript title="Error Tracking"
class ErrorTracker {
  private errors: Array<{ timestamp: Date; error: Error; context: any }> = []

  track(error: Error, context: any = {}) {
    this.errors.push({
      timestamp: new Date(),
      error,
      context
    })

    // Send to monitoring service
    this.sendToMonitoring(error, context)
  }

  private sendToMonitoring(error: Error, context: any) {
    // Integration with error monitoring services
    console.error('Error tracked:', {
      message: error.message,
      stack: error.stack,
      context,
      timestamp: new Date().toISOString()
    })
  }

  getErrorStats() {
    const last24h = this.errors.filter(
      e => Date.now() - e.timestamp.getTime() < 24 * 60 * 60 * 1000
    )

    return {
      total: this.errors.length,
      last24h: last24h.length,
      mostCommon: this.getMostCommonErrors()
    }
  }

  private getMostCommonErrors() {
    const errorCounts = new Map<string, number>()

    this.errors.forEach(({ error }) => {
      const errorType = error.message.split(':')[0]
      errorCounts.set(errorType, (errorCounts.get(errorType) || 0) + 1)
    })

    return Array.from(errorCounts.entries())
      .sort(([,a], [,b]) => b - a)
      .slice(0, 5)
  }
}

// Global error tracker
export const errorTracker = new ErrorTracker()
```

## Validation Helpers

```typescript title="Input Validation"
export class ValidationError extends Error {
  constructor(field: string, message: string) {
    super(`${field}: ${message}`)
    this.name = 'ValidationError'
  }
}

export function validateCollectionMetadata(metadata: any): void {
  if (!metadata.name || metadata.name.length < 1) {
    throw new ValidationError('name', 'Collection name is required')
  }

  if (!metadata.symbol || metadata.symbol.length < 1) {
    throw new ValidationError('symbol', 'Collection symbol is required')
  }

  if (!metadata.creator || !isValidAddress(metadata.creator)) {
    throw new ValidationError('creator', 'Valid creator address is required')
  }

  if (metadata.maxSupply && metadata.maxSupply <= 0n) {
    throw new ValidationError('maxSupply', 'Max supply must be greater than 0')
  }

  if (metadata.mintPrice && metadata.mintPrice < 0n) {
    throw new ValidationError('mintPrice', 'Mint price cannot be negative')
  }
}

function isValidAddress(address: string): boolean {
  return /^0x[a-fA-F0-9]{40}$/.test(address)
}
```

## React Error Boundaries

```tsx title="Error Boundary Component"
import React, { Component, ErrorInfo, ReactNode } from 'react'

interface Props {
  children: ReactNode
  fallback?: ReactNode
}

interface State {
  hasError: boolean
  error?: Error
}

export class CreateKitErrorBoundary extends Component<Props, State> {
  constructor(props: Props) {
    super(props)
    this.state = { hasError: false }
  }

  static getDerivedStateFromError(error: Error): State {
    return { hasError: true, error }
  }

  componentDidCatch(error: Error, errorInfo: ErrorInfo) {
    console.error('CreateKit Error Boundary caught an error:', error, errorInfo)

    // Track error
    errorTracker.track(error, { errorInfo })
  }

  render() {
    if (this.state.hasError) {
      return this.props.fallback || (
        <div className="bg-red-50 border border-red-200 rounded-lg p-6">
          <h2 className="text-red-800 text-lg font-semibold mb-2">
            Something went wrong
          </h2>
          <p className="text-red-600">
            {getUserFriendlyError(this.state.error!)}
          </p>
          <button
            onClick={() => this.setState({ hasError: false })}
            className="mt-4 px-4 py-2 bg-red-600 text-white rounded hover:bg-red-700"
          >
            Try Again
          </button>
        </div>
      )
    }

    return this.props.children
  }
}
```

## Best Practices

**Error Classification**

- Categorize errors by type and severity
    - Use consistent error codes
    - Provide actionable error messages
    - Log errors with sufficient context
  **Recovery Strategies**

- Implement appropriate retry logic
    - Use circuit breakers for external services
    - Provide fallback mechanisms
    - Allow manual error recovery

## Next Steps

Now that you have comprehensive CreateKit documentation, you can:

**Start Building**

Use the quickstart guide to create your first collection
  **Join Community**

Connect with other developers in the B3 Discord