alchemy-rate-limits

name	alchemy-rate-limits
description	Implement Alchemy Compute Unit (CU) rate limiting and request throttling. Use when handling 429 errors, optimizing CU usage, or managing concurrent blockchain queries within plan limits. Trigger: "alchemy rate limit", "alchemy 429", "alchemy compute units", "alchemy throttling", "alchemy CU budget".
allowed-tools	Read, Write, Edit, Bash(npm:*)
version	1.0.0
license	MIT
author	Jeremy Longshore <[e-mail]>
tags	["saas","blockchain","web3","alchemy","rate-limiting"]
compatible-with	claude-code

Alchemy Rate Limits

Overview

Alchemy uses Compute Units (CU) to measure API usage. Different methods cost different CU amounts. Rate limits are per-second, and exceeding them returns 429 errors.

Compute Unit Costs

Method	CU Cost	Category
eth_blockNumber	10	Core
eth_getBalance	19	Core
eth_call	26	Core
eth_getTransactionReceipt	15	Core
getTokenBalances	50	Enhanced
getTokenMetadata	50	Enhanced
getAssetTransfers	150	Enhanced
getNftsForOwner	50	NFT
getNftMetadataBatch	50	NFT
getContractMetadata	50	NFT

Plan Limits

Plan	CU/sec	Monthly CU	Price
Free	330	300M	$0
Growth	660	1.2B	$49/mo
Scale	Custom	Custom	Custom

Instructions

Step 1: CU-Aware Request Throttler

// src/alchemy/throttler.ts
import Bottleneck from 'bottleneck';

const CU_COSTS: Record<string, number> = {
  'eth_blockNumber': ,
  : ,
  : ,
  : ,
  : ,
  : ,
};


 limiter =  ({
  : ,                    
  : ,    
  : ,       
  : ,                 
  : ,                       
});

limiter.(,  {
  .();
});

  throttledAlchemyCall<T>(
  : ,
  :  <T>,
): <T> {
   cost = [method] || ; 
   limiter.({ : cost }, operation);
}

 { throttledAlchemyCall, limiter };