Alchemy Common Errors

Overview

Troubleshooting guide for Alchemy SDK errors covering rate limits, RPC failures, invalid parameters, and network-specific issues.

Error Reference

Authentication & Rate Limits

HTTP Code	Error	Root Cause	Fix
401	Unauthorized	Invalid or missing API key	Verify key in Alchemy Dashboard
403	Forbidden	API key disabled or app deleted	Create new app in Dashboard
429	Too Many Requests	Rate limit exceeded	Implement backoff; upgrade plan
429	Compute Units exceeded	CU quota depleted	Check CU usage in Dashboard

Alchemy Rate Limits by Plan

Plan	Compute Units/sec	Throughput
Free	330 CU/s	~25 requests/s
Growth	660 CU/s	~50 requests/s
Scale	Custom	Custom

RPC & Query Errors

// Common RPC error handler
import { Alchemy, Network } from 'alchemy-sdk';

async function safeAlchemyCall<T>(
  operation: () => Promise<T>,
  context: string
): Promise<T | null> {
  try {
    return await operation();
  } catch (error: any) {
    const code = error.code || error.response?.status;

    switch (code) {
      case -32602: // Invalid params
        console.error(`[${context}] Invalid parameters: ${error.message}`);
        console.error('Common causes: wrong address format, invalid block number, missing 0x prefix');
        break;

      case -32600: // Invalid request
        console.error(`[${context}] Malformed JSON-RPC request`);
        break;

      case -32601: // Method not found
        console.error(`[${context}] RPC method not available on this network`);
        console.error('Some Enhanced APIs are Ethereum-only');
        break;

      case -32000: // Server error
        console.error(`[${context}] Node server error — usually transient, retry`);
        break;

      case 429:
        const retryAfter = error.response?.headers?.['retry-after'] || 1;
        console.error(`[${context}] Rate limited — retry after ${retryAfter}s`);
        break;

      default:
        console.error(`[${context}] Unknown error: ${code} — ${error.message}`);
    }
    return null;
  }
}