Guide · Events

How to monitor crypto addresses with webhooks

Get a callback the instant an address receives a payment, a token transfer lands, or a new block is mined — across Bitcoin, Ethereum and 20+ chains. Subscribe once and your app reacts in real time, with no polling and no node to run.

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Stop polling the chain

Polling for on-chain activity is slow, wasteful and easy to get wrong around confirmations and reorgs. Webhooks flip it around: you tell CryptoAPIs what to watch, and it calls you the moment it happens.

Monitoring is entirely read-only — it observes public on-chain activity for the addresses you name. No keys, no custody; just a real-time signal your backend can act on.

Read-only by design: a subscription watches public data and posts a callback. It never touches a private key.

Set it up in three steps

Expose an HTTPS callback URL

Stand up an endpoint on your server that accepts POST callbacks, and verify your callback domain once in the dashboard so CryptoAPIs will deliver to it.

# Your endpoint just needs to accept a POST and 200 it
POST https://your-app.com/webhooks/crypto # ← you host this

Subscribe an address to an event

Create a subscription for the address and the event you care about — confirmed coin transactions, token transfers, or new blocks. You get a referenceId back to manage it later.

POST /blockchain-events/{blockchain}/{network}/address-coins-transactions-confirmed ↗ docs
# Callback on confirmed incoming/outgoing coin transactions for an address
curl -X POST \
  https://rest.cryptoapis.io/blockchain-events/ethereum/mainnet/address-coins-transactions-confirmed \
  -H "x-api-key: YOUR_API_KEY" \
  -d '{ "data": { "item": {
      "address": "{address}",
      "callbackUrl": "https://your-app.com/webhooks/crypto" } } }'

Handle the callback

When the event confirms, CryptoAPIs POSTs the details to your URL — react in your app, update an order, credit a balance. Subscribe to token transfers or new blocks the same way for other signals.

token transfers → /address-tokens-transactions-confirmed  ·  new blocks → /new-block ↗ docs

What you can watch

Confirmed and unconfirmed coin transactions, token (ERC-20/TRC-20) transfers, internal transactions, per-confirmation updates, mined transactions and new blocks — across Bitcoin, Ethereum and 20+ chains, all through Blockchain Events. This is the same real-time layer behind the accept-crypto-payments and automated-forwarding flows.

Frequently asked questions

How do I monitor a crypto address in real time?

Create a webhook subscription on the address for the event you want — confirmed coin or token transactions, or new blocks — and CryptoAPIs POSTs a callback to your URL the moment it confirms, with no polling and no node to run.

What events can I subscribe to?

Confirmed and unconfirmed coin transactions, token (ERC-20/TRC-20) transfers, internal transactions, per-confirmation updates, mined transactions and new blocks — across Bitcoin, Ethereum and 20+ chains.

Do I need to run a node to get webhooks?

No. CryptoAPIs watches the chain for you and calls your endpoint when the event happens. You only need an HTTPS callback URL.

Is address monitoring custodial?

No. Monitoring is read-only — it observes public on-chain activity for addresses you specify. No keys are involved at any point.

Start monitoring in real time

Subscribe any address to payments, token transfers or blocks across 20+ chains — webhooks, no polling, no node.

Start building free See Blockchain Events