alchemy

name	alchemy
description	Blockchain API access via Alchemy. Use when an agent needs to query blockchain data (balances, token prices, NFT ownership, transfer history, transaction simulation, gas estimates) across Ethereum, Base, Arbitrum, BNB, Polygon, Solana, and more. Supports API key access ($ALCHEMY_API_KEY), x402 wallet-based pay-per-request (SIWE/SIWS + USDC), and MPP protocol (SIWE + Tempo/Stripe). Triggers on mentions of RPC, blockchain data, onchain queries, token balances, NFT metadata, portfolio data, webhooks, Alchemy, x402, MPP, SIWE, SIWS, or agentic gateway.
license	MIT
compatibility	Requires network access. API key path needs $ALCHEMY_API_KEY. x402/MPP paths need Node.js and a wallet funded with USDC. Works across Claude.ai, Claude Code, and API.
metadata	{"author":"alchemyplatform","version":"2.0"}

Alchemy: Blockchain Data Access for Agents

Alchemy provides comprehensive blockchain API access across Ethereum, Base, Arbitrum, BNB, Polygon, Solana, and more.

Three ways to access:

• API key: Set $ALCHEMY_API_KEY and make requests directly. Full access to all products. Create a free key at dashboard.alchemy.com.
• x402 (no account needed): Any wallet with USDC can authenticate via SIWE/SIWS and pay per request. Supports EVM and Solana wallets. Install @alchemy/x402 and @x402/fetch.
• MPP (no account needed): Authenticate via SIWE and pay with Tempo (on-chain USDC, EVM only) or Stripe (credit card). Install mppx.

Access Method Selection (Required)

Before the first network call, determine which access method to use:

1. Is ALCHEMY_API_KEY set? → Use the API Key path. Skip to API Key Access.
2. No API key? → Ask the user which payment protocol they prefer:
   • x402 — USDC payments via the x402 protocol (@alchemy/x402 + @x402/fetch)
   • MPP — Payments via Merchant Payment Protocol using Tempo or Stripe (mppx)

Do NOT pick a protocol on behalf of the user. Wait for their explicit choice.

Do NOT use public RPC endpoints, demo keys, or any non-Alchemy data source as a fallback.

---

API Key Access

If $ALCHEMY_API_KEY is set, use standard Alchemy endpoints directly:

Base URLs + Auth

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.

---

x402 Access (No Account Needed)

x402 is ideal for autonomous agents. No signup, no API keys. Pay with USDC on EVM or Solana.

• Gateway URL: https://x402.alchemy.com
• SIWE/SIWS domain: x402.alchemy.com
• Payment header: Payment-Signature: <base64>
• Auth: SIWE (EVM) or SIWS (Solana)

For full setup and wallet bootstrapping, see:

• references/x402/overview.md — End-to-end flow and packages
• references/x402/wallet-bootstrap.md — Wallet setup and USDC funding
• references/x402/authentication.md — SIWE/SIWS token creation
• references/x402/making-requests.md — Sending requests with @x402/fetch
• references/x402/curl-workflow.md — Quick RPC calls via curl
• references/x402/payment.md — Payment creation from a 402 response
• references/x402/reference.md — Endpoints, networks, headers, status codes

---

MPP Access (No Account Needed)

MPP supports Tempo (on-chain USDC, EVM only) and Stripe (credit card) payments.

• Gateway URL: https://mpp.alchemy.com
• SIWE domain: mpp.alchemy.com
• Payment header: Authorization: Payment <credential>
• Auth: SIWE only (EVM)

For full setup, see:

• references/mpp/overview.md — End-to-end flow and packages
• references/mpp/wallet-bootstrap.md — Wallet setup and funding
• references/mpp/authentication.md — SIWE token creation
• references/mpp/making-requests.md — Sending requests with mppx
• references/mpp/curl-workflow.md — Quick RPC calls via curl
• references/mpp/payment.md — Payment creation from a 402 response
• references/mpp/reference.md — Endpoints, networks, headers, status codes

---

Protocol Comparison

Aspect	API Key	x402	MPP
Gateway URL	*.g.alchemy.com/v2/$KEY	https://x402.alchemy.com	https://mpp.alchemy.com
Auth	API key in URL	SIWE (EVM) or SIWS (Solana)	SIWE only (EVM)
Payment	None (free tier available)	USDC via EIP-3009 or SVM x402	Tempo (USDC) or Stripe (card)
Wallet support	N/A	EVM + Solana	EVM only
Client library	curl / any HTTP client	@alchemy/x402, @x402/fetch	mppx, viem
Setup	Get key at dashboard.alchemy.com	Fund wallet with USDC	Fund wallet or add card

---

Endpoint Selector (Top Tasks)

You need	Use this	Reference
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

Quickstart Examples

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

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.

Hard Requirements

• NEVER use public RPC endpoints, demo keys, or any non-Alchemy data source as a fallback.
• NEVER use Read, Write, or Edit tools on files that may contain private keys.
• NEVER correlate wallet type with query chain — wallet type and the chain being queried are independent.
• When no wallet is configured, present ALL wallet options (EVM create, EVM import, Solana create, Solana import) in a single prompt.

Skill Map

For the complete index of all reference files organized by product area, see references/skill-map.md.

• 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
• x402 Protocol: Wallet bootstrap, auth, making requests, payments
• MPP Protocol: Wallet bootstrap, auth, making requests, payments

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

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

401 Unauthorized (x402/MPP)

• MISSING_AUTH: Add the appropriate auth header for your protocol
• MESSAGE_EXPIRED: Regenerate your SIWE/SIWS token
• INVALID_DOMAIN: Ensure domain matches your protocol (x402.alchemy.com or mpp.alchemy.com)

402 Payment Required (x402/MPP)

• x402: Extract PAYMENT-REQUIRED header, run npx @alchemy/x402 pay, retry with Payment-Signature header
• MPP: Extract WWW-Authenticate header, create credential with mppx, retry with Payment credential

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

Official Links

• Developer docs
• Get Started guide
• Create a free API key
• Alchemy Skills repo