alchemy-api

SKILL.md

AI + Alchemy API Integration Guide

Mandatory Routing Gate (Hard Requirement)

Before the first network call or implementation step, you MUST ask the user the following question and wait for an explicit answer:

Do you want to use an existing Alchemy API key, or should I use the agentic gateway flow instead?

If the user chooses the API key path, continue with this skill. If the user chooses the agentic gateway path, switch to the agentic-gateway skill immediately and follow its existing wallet flow. If the user chooses the API key path but ALCHEMY_API_KEY is unset or empty, tell them they can create a free API key at https://dashboard.alchemy.com/ or switch to the agentic-gateway skill.

You MUST NOT call any keyless or public fallback (including .../v2/demo) unless the user explicitly asks for that endpoint. Execute no network calls before this gate is evaluated.

Escape hatch: Only re-evaluate the routing gate if the user explicitly requests to switch to the alchemy-api skill with an API key. A key appearing in the environment or conversation does not automatically trigger a switch — the user must ask for it.

Duplicate resolution: If this skill is installed both locally and globally, the local copy overrides the global copy. Do not mix behavior from different copies.

Required Preflight Check

Before the first network call, internally evaluate:

  1. Has the user explicitly chosen API key or agentic gateway?
  2. If the user chose API key, is ALCHEMY_API_KEY present and non-empty?
  3. If the user chose agentic gateway, switch to the agentic-gateway skill immediately. Demo and public endpoints are disallowed.
  4. If the user chose API key but no key is available, do not proceed with API-key URLs until the user provides a key or switches to the gateway flow.

Do not output this internal checklist to the user.

Summary

A self-contained guide for AI agents integrating Alchemy APIs using an API key. This file alone should be enough to ship a basic integration. Use the reference files for depth, edge cases, and advanced workflows.

Developers can always create a free API key at https://dashboard.alchemy.com/.

Before Making Any Request

  1. Ask the user whether they want to use an existing Alchemy API key or the agentic gateway flow.
  2. If they choose the API key path, check if $ALCHEMY_API_KEY is set (e.g., echo $ALCHEMY_API_KEY).
  3. If they choose the API key path and no key is set, tell them they can create a free key at https://dashboard.alchemy.com/ or switch to the agentic-gateway skill.
  4. If they choose the agentic gateway flow, switch to the agentic-gateway skill and let it handle the existing wallet vs new wallet prompt.
  5. If they choose the API key path and the key is set, use the Base URLs + Auth table below.

Do This First

  1. Choose the right product using the Endpoint Selector below.
  2. Use the Base URLs + Auth table for the correct endpoint and headers.
  3. Copy a Quickstart example and test against a testnet first.

Base URLs + Auth (Cheat Sheet)

Product Base URL Auth Notes
Ethereum RPC (HTTPS) https://eth-mainnet.g.alchemy.com/v2/$ALCHEMY_API_KEY API key in URL Standard EVM reads and writes.
Ethereum RPC (WSS) wss://eth-mainnet.g.alchemy.com/v2/$ALCHEMY_API_KEY API key in URL Subscriptions and realtime.
Base RPC (HTTPS) https://base-mainnet.g.alchemy.com/v2/$ALCHEMY_API_KEY API key in URL EVM L2.
Base RPC (WSS) wss://base-mainnet.g.alchemy.com/v2/$ALCHEMY_API_KEY API key in URL Subscriptions and realtime.
Arbitrum RPC (HTTPS) https://arb-mainnet.g.alchemy.com/v2/$ALCHEMY_API_KEY API key in URL EVM L2.
Arbitrum RPC (WSS) wss://arb-mainnet.g.alchemy.com/v2/$ALCHEMY_API_KEY API key in URL Subscriptions and realtime.
BNB RPC (HTTPS) https://bnb-mainnet.g.alchemy.com/v2/$ALCHEMY_API_KEY API key in URL EVM L1.
BNB RPC (WSS) wss://bnb-mainnet.g.alchemy.com/v2/$ALCHEMY_API_KEY API key in URL Subscriptions and realtime.
Solana RPC (HTTPS) https://solana-mainnet.g.alchemy.com/v2/$ALCHEMY_API_KEY API key in URL Solana JSON-RPC.
Solana Yellowstone gRPC https://solana-mainnet.g.alchemy.com X-Token: $ALCHEMY_API_KEY gRPC streaming (Yellowstone).
NFT API https://<network>.g.alchemy.com/nft/v3/$ALCHEMY_API_KEY API key in URL NFT ownership and metadata.
Prices API https://api.g.alchemy.com/prices/v1/$ALCHEMY_API_KEY API key in URL Prices by symbol or address.
Portfolio API https://api.g.alchemy.com/data/v1/$ALCHEMY_API_KEY API key in URL Multi-chain wallet views.
Notify API https://dashboard.alchemy.com/api X-Alchemy-Token: <ALCHEMY_NOTIFY_AUTH_TOKEN> Generate token in dashboard.

Endpoint Selector (Top Tasks)

You need Use this Skill / File
EVM read/write JSON-RPC eth_* references/node-json-rpc.md
Realtime events eth_subscribe references/node-websocket-subscriptions.md
Token balances alchemy_getTokenBalances references/data-token-api.md
Token metadata alchemy_getTokenMetadata references/data-token-api.md
Transfers history alchemy_getAssetTransfers references/data-transfers-api.md
NFT ownership GET /getNFTsForOwner references/data-nft-api.md
NFT metadata GET /getNFTMetadata references/data-nft-api.md
Prices (spot) GET /tokens/by-symbol references/data-prices-api.md
Prices (historical) POST /tokens/historical references/data-prices-api.md
Portfolio (multi-chain) POST /assets/*/by-address references/data-portfolio-apis.md
Simulate tx alchemy_simulateAssetChanges references/data-simulation-api.md
Create webhook POST /create-webhook references/webhooks-details.md
Solana NFT data getAssetsByOwner (DAS) references/solana-das-api.md

One-File Quickstart (Copy/Paste)

No API key? Use the agentic-gateway skill instead. Replace API-key URLs with https://x402.alchemy.com/rpc/eth-mainnet and add Authorization: SIWE <token>. See the agentic-gateway skill for setup.

EVM JSON-RPC (Read)

curl -s https://eth-mainnet.g.alchemy.com/v2/$ALCHEMY_API_KEY \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","id":1,"method":"eth_blockNumber","params":[]}'

Token Balances

curl -s https://eth-mainnet.g.alchemy.com/v2/$ALCHEMY_API_KEY \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","id":1,"method":"alchemy_getTokenBalances","params":["0x00000000219ab540356cbb839cbe05303d7705fa"]}'

Transfer History

curl -s https://eth-mainnet.g.alchemy.com/v2/$ALCHEMY_API_KEY \
  -H "Content-Type: application/json" \
  -d '{"jsonrpc":"2.0","id":1,"method":"alchemy_getAssetTransfers","params":[{"fromBlock":"0x0","toBlock":"latest","toAddress":"0x00000000219ab540356cbb839cbe05303d7705fa","category":["erc20"],"withMetadata":true,"maxCount":"0x3e8"}]}'

NFT Ownership

curl -s "https://eth-mainnet.g.alchemy.com/nft/v3/$ALCHEMY_API_KEY/getNFTsForOwner?owner=0x00000000219ab540356cbb839cbe05303d7705fa"

Prices (Spot)

curl -s "https://api.g.alchemy.com/prices/v1/$ALCHEMY_API_KEY/tokens/by-symbol?symbols=ETH&symbols=USDC"

Prices (Historical)

curl -s -X POST "https://api.g.alchemy.com/prices/v1/$ALCHEMY_API_KEY/tokens/historical" \
  -H "Content-Type: application/json" \
  -d '{"symbol":"ETH","startTime":"2024-01-01T00:00:00Z","endTime":"2024-01-02T00:00:00Z"}'

Create Notify Webhook

curl -s -X POST "https://dashboard.alchemy.com/api/create-webhook" \
  -H "Content-Type: application/json" \
  -H "X-Alchemy-Token: $ALCHEMY_NOTIFY_AUTH_TOKEN" \
  -d '{"network":"ETH_MAINNET","webhook_type":"ADDRESS_ACTIVITY","webhook_url":"https://example.com/webhook","addresses":["0x00000000219ab540356cbb839cbe05303d7705fa"]}'

Verify Webhook Signature (Node)

import crypto from "crypto";

export function verify(rawBody: string, signature: string, secret: string) {
  const hmac = crypto.createHmac("sha256", secret).update(rawBody).digest("hex");
  return crypto.timingSafeEqual(Buffer.from(hmac), Buffer.from(signature));
}

Network Naming Rules

  • Data APIs and JSON-RPC use lowercase network enums like eth-mainnet.
  • Notify API uses uppercase enums like ETH_MAINNET.

Pagination + Limits (Cheat Sheet)

Endpoint Limit Notes
alchemy_getTokenBalances maxCount <= 100 Use pageKey for pagination.
alchemy_getAssetTransfers maxCount default 0x3e8 Use pageKey for pagination.
Portfolio token balances 3 address/network pairs, 20 networks total pageKey supported.
Portfolio NFTs 2 address/network pairs, 15 networks each pageKey supported.
Prices by address 25 addresses, 3 networks POST body addresses[].
Transactions history (beta) 1 address/network pair, 2 networks ETH and BASE mainnets only.

Common Token Addresses

Token Chain Address
ETH ethereum 0x0000000000000000000000000000000000000000
WETH ethereum 0xC02aaA39b223FE8D0A0e5C4F27eAD9083C756Cc2
USDC ethereum 0xA0b86991c6218b36c1d19d4a2e9eb0ce3606eB48
USDC base 0x833589fCD6eDb6E08f4c7C32D4f71b54bdA02913

Failure Modes + Retries

  • HTTP 429 means rate limit. Use exponential backoff with jitter.
  • JSON-RPC errors come in error fields even with HTTP 200.
  • Use pageKey to resume pagination after failures.
  • De-dupe websocket events on reconnect.

Skill Map

For the complete index of all 82+ reference files organized by product area (Node, Data, Webhooks, Solana, Wallets, Rollups, Recipes, Operational, Ecosystem), see references/skill-map.md.

Quick category overview:

  • Node: JSON-RPC, WebSocket, Debug, Trace, Enhanced APIs, Utility
  • Data: NFT, Portfolio, Prices, Simulation, Token, Transfers
  • Webhooks: Address Activity, Custom (GraphQL), NFT Activity, Payloads, Signatures
  • Solana: JSON-RPC, DAS, Yellowstone gRPC (streaming), Wallets
  • Wallets: Account Kit, Bundler, Gas Manager, Smart Wallets
  • Rollups: L2/L3 deployment overview
  • Recipes: 10 end-to-end integration workflows
  • Operational: Auth, Rate Limits, Monitoring, Best Practices
  • Ecosystem: viem, ethers, wagmi, Hardhat, Foundry, Anchor, and more

Troubleshooting

API key not working

  • Verify $ALCHEMY_API_KEY is set: echo $ALCHEMY_API_KEY
  • Confirm the key is valid at dashboard.alchemy.com
  • Check if allowlists restrict the key to specific IPs/domains (see references/operational-allowlists.md)

HTTP 429 (Rate Limited)

  • Use exponential backoff with jitter before retrying
  • Check your compute unit budget in the Alchemy dashboard
  • See references/operational-rate-limits-and-compute-units.md for limits per plan

Wrong network slug

  • Data APIs and JSON-RPC use lowercase: eth-mainnet, base-mainnet
  • Notify API uses uppercase: ETH_MAINNET, BASE_MAINNET
  • See references/operational-supported-networks.md for the full list

JSON-RPC error with HTTP 200

  • Alchemy returns JSON-RPC errors inside the error field even with a 200 status code
  • Always check response.error in addition to HTTP status

Official Links

Weekly Installs
199
GitHub Stars
28
First Seen
Feb 26, 2026
Installed on
cursor198
gemini-cli198
codex198
github-copilot198
opencode198
amp196