Alchemy Cost Tuning Skill

Alchemy Cost Tuning

Overview

Alchemy pricing is based on Compute Units (CU). Different API methods have different CU costs. Optimize by caching, batching, choosing cheaper methods, and right-sizing your plan.

Plan Comparison

| Plan | CU/sec | Monthly CU | Price | Best For | |------|--------|------------|-------|----------| | Free | 330 | 300M | $0 | Dev/prototyping | | Growth | 660 | 1.2B | $49/mo | Small dApps | | Scale | Custom | Custom | Custom | High-traffic apps |

CU Cost Reference (Top Methods)

| Method | CU | Optimization | |--------|-----|-------------| | eth_blockNumber | 10 | Cache 12s (1 block) | | eth_getBalance | 19 | Cache 30s | | eth_call | 26 | Cache based on use case | | getTokenBalances | 50 | Cache 60s; batch addresses | | getNftsForOwner | 50 | Cache 5 min | | getTokenMetadata | 50 | Cache 24h (rarely changes) | | getAssetTransfers | 150 | Cache aggressively; paginate | | getNftMetadataBatch | 50 | Use batch over individual calls |

Instructions

Step 1: CU Usage Monitor

// src/cost/cu-monitor.ts
const CU_COSTS: Record<string, number> = {
  'eth_blockNumber': 10, 'eth_getBalance': 19, 'eth_call': 26,
  'getTokenBalances': 50, 'getNftsForOwner': 50, 'getTokenMetadata': 50,
  'getAssetTransfers': 150, 'getNftMetadataBatch': 50,
};

class CuMonitor {
  private usage: Array<{ method: string; cu: number; timestamp: number }> = [];

  record(method: string): void {
    this.usage.push({ method, cu: CU_COSTS[method] || 26, timestamp: Date.now() });
  }

  getHourlyReport(): { totalCu: number; byMethod: Record<string, number> } {
    const cutoff = Date.now() - 3600000;
    const recent = this.usage.filter(u => u.timestamp > cutoff);
    const byMethod: Record<string, number> = {};
    let totalCu = 0;

    for (const u of recent) {
      byMethod[u.method] = (byMethod[u.method] || 0) + u.cu;
      totalCu += u.cu;
    }

    return { totalCu, byMethod };
  }

  getMonthlyProjection(): { projectedMonthly: number; planRecommendation: string } {
    const hourly = this.getHourlyReport();
    const projectedMonthly = hourly.totalCu * 24 * 30;

    let recommendation = 'Free';
    if (projectedMonthly > 300_000_000) recommendation = 'Growth';
    if (projectedMonthly > 1_200_000_000) recommendation = 'Scale';

    return { projectedMonthly, planRecommendation: recommendation };
  }
}

export { CuMonitor };

Step 2: Cost-Optimized Client Wrapper

// src/cost/optimized-client.ts
import { Alchemy, Network } from 'alchemy-sdk';

const cache = new Map<string, { data: any; expiry: number }>();

// Cache token metadata aggressively (rarely changes)
async function getTokenMetadataCached(alchemy: Alchemy, contract: string) {
  const key = `metadata:${contract}`;
  const cached = cache.get(key);
  if (cached && cached.expiry > Date.now()) return cached.data;

  const data = await alchemy.core.getTokenMetadata(contract);
  cache.set(key, { data, expiry: Date.now() + 86400000 }); // 24h cache
  return data;
}

// Use batch instead of individual NFT metadata calls
// 1 batch call (50 CU) vs 100 individual calls (5000 CU)
async function getNftMetadataOptimized(
  alchemy: Alchemy,
  tokens: Array<{ contractAddress: string; tokenId: string }>
) {
  const BATCH_SIZE = 100;
  const results = [];
  for (let i = 0; i < tokens.length; i += BATCH_SIZE) {
    const batch = tokens.slice(i, i + BATCH_SIZE);
    const batchResults = await alchemy.nft.getNftMetadataBatch(batch);
    results.push(...batchResults);
  }
  return results;
}

Step 3: Free Tier Optimization Checklist

// For staying within Free tier (330 CU/sec, 300M CU/month):
// 1. Cache eth_blockNumber (saves 10 CU per redundant call)
// 2. Cache token metadata (saves 50 CU per redundant call)
// 3. Use getNftMetadataBatch instead of getNftMetadata (100x savings)
// 4. Avoid getAssetTransfers loops (150 CU each — cache results)
// 5. Use WebSockets instead of polling (one connection vs repeated calls)
// 6. Rate-limit user-facing endpoints to prevent CU bursts

Output

CU usage monitor with hourly reports and plan projections
Cost-optimized client with aggressive caching
Batch operations reducing CU consumption by 100x
Free tier optimization checklist

Resources

Next Steps

For architecture design, see alchemy-reference-architecture.

Agent Skills: Alchemy Cost Tuning

Install this agent skill to your local

Skill Files