Alchemy API

AI + Alchemy API Integration Guide

Prerequisites

1. Create a free API key at https://dashboard.alchemy.com/
2. Export the key: export ALCHEMY_API_KEY=<your-key>
3. If no API key is available, use the alchemy-agentic-gateway skill instead (wallet-based auth).

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 alchemy-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 alchemy-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.

Base URLs + Auth (Cheat Sheet)

Endpoint Selector (Top Tasks)

Full reference: https://www.alchemy.com/docs

One-File Quickstart (Copy/Paste)

No API key? Use the alchemy-agentic-gateway skill instead.

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"]}'

To verify webhook signatures, use HMAC-SHA256 with the webhook signing key from your dashboard. See https://www.alchemy.com/docs/webhooks for details.

Network Naming Rules

• Data APIs and JSON-RPC use lowercase network enums: eth-mainnet, base-mainnet
• Notify API uses uppercase enums: ETH_MAINNET, BASE_MAINNET

Pagination + Limits (Cheat Sheet)

Common Token Addresses

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.

Troubleshooting

API key not working

• Verify: echo $ALCHEMY_API_KEY
• Confirm the key is valid at https://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

Wrong network slug

• Data APIs and JSON-RPC use lowercase: eth-mainnet, base-mainnet
• Notify API uses uppercase: ETH_MAINNET, BASE_MAINNET

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

Related Skills

• alchemy-agentic-gateway — Access Alchemy APIs without an API key via x402 or MPP wallet auth

Official Links

• Developer docs
• Create a free API key