# Blockchain Events Get a webhook instead of polling. Subscribe to an address or to new blocks, and Crypto APIs calls your URL when a transaction confirms, at each new confirmation if you want, or when a block is mined. - Coins, tokens and internal transactions - Callbacks carry your secret - All 19 blockchains ## Key facts | | | | --- | --- | | Endpoints | 12 | | Blockchains | 19 | | Chain families | EVM, UTXO, XRP, Solana, Tezos, Kaspa | | Custody | Non-custodial, you sign | | Free trial | 14 days, no card | ## Webhooks for deposits, payouts and monitoring **Credit deposits.** Subscribe to your deposit addresses and credit a customer when the coin or token transaction confirms. **Count confirmations.** Get a callback at every new confirmation, and release funds at the depth your risk policy needs. **React to new blocks.** Receive a callback for every mined block to drive your own indexing or scheduled jobs. ## Make your first Blockchain Events call Real paths and example responses from the API reference. Add your API key and run it. ### Confirmed payment ``` curl -X POST https://rest.cryptoapis.io/blockchain-events/ethereum/mainnet/address-coins-transactions-confirmed \ -H "Content-Type: application/json" \ -H "X-API-Key: YOUR_API_KEY" \ -d '{"data":{"item":{"address":"mho4jHBcrNCncKt38trJahXakuaBnS7LK5","allowDuplicates":false,"callbackSecretKey":"yourSecretKey","callbackUrl":"https://example.com","receiveCallbackOn":3}}}' ``` ### New block ``` curl -X POST https://rest.cryptoapis.io/blockchain-events/ethereum/mainnet/block-mined \ -H "Content-Type: application/json" \ -H "X-API-Key: YOUR_API_KEY" \ -d '{"data":{"item":{"allowDuplicates":false,"callbackSecretKey":"yourSecretKey","callbackUrl":"https://example.com"}}}' ``` ### List subscriptions ``` curl https://rest.cryptoapis.io/blockchain-events/ethereum/mainnet \ -H "X-API-Key: YOUR_API_KEY" ``` ## Every Blockchain Events endpoint Each operation links to its page in the API reference, with its parameters and responses. Paths take the blockchain and the network, so moving to another chain is a change of path. | What it does | Method and path | Blockchains | Reference | | --- | --- | --- | --- | | List Blockchain Events Subscriptions | `GET /blockchain-events/{blockchain}/{network}` | Bitcoin, Ethereum, XRP Ledger, Ethereum Classic, Bitcoin Cash, Dash, Litecoin, Dogecoin, Zcash, BNB Smart Chain, Polygon, Tron, Solana, Tezos, Avalanche, Arbitrum, Optimism, Base, Kaspa | [Docs](https://developers.cryptoapis.io/v-2.2024-12-12-175/RESTapis/manage-subscriptions/list-blockchain-events-subscriptions/get) | | Delete Blockchain Event Subscription | `DELETE /blockchain-events/{blockchain}/{network}/{referenceId}` | Bitcoin, Ethereum, XRP Ledger, Ethereum Classic, Bitcoin Cash, Dash, Litecoin, Dogecoin, Zcash, BNB Smart Chain, Polygon, Tron, Solana, Tezos, Avalanche, Arbitrum, Optimism, Base, Kaspa | [Docs](https://developers.cryptoapis.io/v-2.2024-12-12-175/RESTapis/delete-blockchain-event-subscription/delete-blockchain-event-subscription/delete) | | Get Blockchain Event Subscription Details By Reference ID | `GET /blockchain-events/{blockchain}/{network}/{referenceId}` | Bitcoin, Ethereum, XRP Ledger, Ethereum Classic, Bitcoin Cash, Dash, Litecoin, Dogecoin, Zcash, BNB Smart Chain, Polygon, Tron, Solana, Tezos, Avalanche, Arbitrum, Optimism, Base, Kaspa | [Docs](https://developers.cryptoapis.io/v-2.2024-12-12-175/RESTapis/delete-blockchain-event-subscription/get-blockchain-event-subscription-details-by-reference-id/get) | | Activate Blockchain Event Subscription | `POST /blockchain-events/{blockchain}/{network}/{referenceId}/activate` | Bitcoin, Ethereum, XRP Ledger, Ethereum Classic, Bitcoin Cash, Dash, Litecoin, Dogecoin, Zcash, BNB Smart Chain, Polygon, Tron, Solana, Tezos, Avalanche, Arbitrum, Optimism, Base, Kaspa | [Docs](https://developers.cryptoapis.io/v-2.2024-12-12-175/RESTapis/manage-subscriptions/activate-blockchain-event-subscription/post) | | New Confirmed Coins Transactions | `POST /blockchain-events/{blockchain}/{network}/address-coins-transactions-confirmed` | Bitcoin, Ethereum, XRP Ledger, Ethereum Classic, Bitcoin Cash, Dash, Litecoin, Dogecoin, Zcash, BNB Smart Chain, Polygon, Tron, Solana, Tezos, Avalanche, Arbitrum, Optimism, Base, Kaspa | [Docs](https://developers.cryptoapis.io/v-2.2024-12-12-175/RESTapis/create-subscriptions-for/new-confirmed-coins-transactions/post) | | New Confirmed Coins Transactions And Each Confirmation | `POST /blockchain-events/{blockchain}/{network}/address-coins-transactions-confirmed-each-confirmation` | Bitcoin, Ethereum, XRP Ledger, Ethereum Classic, Bitcoin Cash, Dash, Litecoin, Dogecoin, Zcash, BNB Smart Chain, Polygon, Tron, Tezos, Avalanche, Arbitrum, Optimism, Base | [Docs](https://developers.cryptoapis.io/v-2.2024-12-12-175/RESTapis/create-subscriptions-for/new-confirmed-coins-transactions-and-each-confirmation/post) | | New Unconfirmed Coins Transactions | `POST /blockchain-events/{blockchain}/{network}/address-coins-transactions-unconfirmed` | Bitcoin, Bitcoin Cash, Dash, Litecoin, Dogecoin, Zcash | [Docs](https://developers.cryptoapis.io/v-2.2024-12-12-175/RESTapis/create-subscriptions-for/new-unconfirmed-coins-transactions/post) | | New Confirmed Internal Transactions | `POST /blockchain-events/{blockchain}/{network}/address-internal-transactions-confirmed` | Ethereum, Ethereum Classic, BNB Smart Chain, Polygon, Tron, Avalanche, Arbitrum, Optimism, Base | [Docs](https://developers.cryptoapis.io/v-2.2024-12-12-175/RESTapis/create-subscriptions-for/new-confirmed-internal-transactions/post) | | New Confirmed Internal Transactions And Each Confirmation | `POST /blockchain-events/{blockchain}/{network}/address-internal-transactions-confirmed-each-confirmation` | Ethereum, Ethereum Classic, BNB Smart Chain, Polygon, Tron, Avalanche, Arbitrum, Optimism, Base | [Docs](https://developers.cryptoapis.io/v-2.2024-12-12-175/RESTapis/create-subscriptions-for/new-confirmed-internal-transactions-and-each-confirmation/post) | | New Confirmed Tokens Transactions | `POST /blockchain-events/{blockchain}/{network}/address-tokens-transactions-confirmed` | Ethereum, Ethereum Classic, BNB Smart Chain, Polygon, Tron, Solana, Avalanche, Arbitrum, Optimism, Base | [Docs](https://developers.cryptoapis.io/v-2.2024-12-12-175/RESTapis/create-subscriptions-for/new-confirmed-tokens-transactions/post) | | New Confirmed Tokens Transactions And Each Confirmation | `POST /blockchain-events/{blockchain}/{network}/address-tokens-transactions-confirmed-each-confirmation` | Bitcoin, Ethereum, Ethereum Classic, BNB Smart Chain, Polygon, Tron, Avalanche, Arbitrum, Optimism, Base | [Docs](https://developers.cryptoapis.io/v-2.2024-12-12-175/RESTapis/create-subscriptions-for/new-confirmed-tokens-transactions-and-each-confirmation/post) | | New Block | `POST /blockchain-events/{blockchain}/{network}/block-mined` | Bitcoin, Ethereum, XRP Ledger, Ethereum Classic, Bitcoin Cash, Dash, Litecoin, Dogecoin, Zcash, BNB Smart Chain, Polygon, Tron, Solana, Tezos, Avalanche, Arbitrum, Optimism, Base | [Docs](https://developers.cryptoapis.io/v-2.2024-12-12-175/RESTapis/create-subscriptions-for/new-block/post) | ## Blockchain Events works on 19 blockchains Mainnets, and test networks where the chain has one. Open a chain for its own endpoints and quick start. - [Bitcoin](/chains/bitcoin) - [Ethereum](/chains/ethereum) - [XRP Ledger](/chains/ripple) - [Ethereum Classic](/chains/ethereum-classic) - [Bitcoin Cash](/chains/bitcoin-cash) - [Dash](/chains/dash) - [Litecoin](/chains/litecoin) - [Dogecoin](/chains/doge) - [Zcash](/chains/zcash) - [BNB Smart Chain](/chains/binance-smart-chain) - [Polygon](/chains/polygon) - [Tron](/chains/tron) - [Solana](/chains/solana) - [Tezos](/chains/tezos) - [Avalanche](/chains/avalanche) - [Arbitrum](/chains/arbitrum-one) - [Optimism](/chains/optimism) - [Base](/chains/base) - [Kaspa](/chains/kaspa) ## Build the rest of the flow - [Address Latest](/products/blockchain-api/address-latest) — Balance and recent transactions of any address, no setup - [HD Wallets Management](/products/blockchain-api/hd-wallets-management) — xPub wallets: derive, sync and read, keys stay with you - [Broadcast Transactions](/products/blockchain-api/broadcast-transactions) — Send a transaction you signed yourself ## Blockchain Events questions **Which blockchains does Blockchain Events support?** Blockchain Events works on 19 blockchains: Bitcoin, Ethereum, XRP Ledger, Ethereum Classic, Bitcoin Cash, Dash, Litecoin, Dogecoin, Zcash, BNB Smart Chain, Polygon, Tron, Solana, Tezos, Avalanche, Arbitrum, Optimism, Base, Kaspa. Each chain's page lists its networks and its own endpoints. **Can I try Blockchain Events for free?** Yes, for 14 days. The Blockchain API free trial includes Blockchain Events and every other feature, with no card. It ends after 14 days or when its credits run out; after that, calls need a subscription, listed on the [pricing page](/pricing). **Does the Blockchain Events API support Solana?** Yes. Solana is a supported chain for Blockchain Events on both mainnet and devnet, alongside XRP and Kaspa. You can subscribe to events and receive callbacks for Solana activity through the same unified subscription flow used for the EVM and UTXO chains. **What blockchain event types can I subscribe to?** You can subscribe to confirmed coin (native) transactions, unconfirmed coin transactions, internal transactions, and token transactions for an address, as well as newly mined blocks. Confirmed coin, internal, and token transaction events also offer an each-confirmation variant that fires on every confirmation. For UTXO chains, callbacks report direction (incoming or outgoing) based on input/output address matching. **How are event notifications delivered, and are the callbacks secure?** Events are delivered as HTTPS POST callbacks (webhooks) to a URL you register. The callback URL must use HTTPS and match a domain you verify in the Dashboard beforehand. You can optionally set a callback secret key so each request carries an HMAC-SHA256 x-signature header you can verify, and every callback includes an idempotencyKey so you can safely deduplicate. **What happens if my callback endpoint is down when an event fires?** CryptoAPIs retries failed callbacks with exponential backoff. Each callback allows a 5-second response timeout, and up to 5 retries follow roughly a 5, 10, 20, 40, and 80-minute schedule. If all retries fail, every subscription sharing that event type and callback URL is marked disabled, so you should monitor delivery and re-activate subscriptions as needed. ## Pointers - [Blockchain API](/products/blockchain-api) - [All networks](/what-we-support) - [Pricing](/pricing) - [Developer portal](https://developers.cryptoapis.io/)