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Basics guide

What are blockchain alerts?

A blockchain alert is a message that tells you something happened on-chain: ETH arrived in a wallet, an NFT was minted, a contract was paused. Instead of refreshing a block explorer, you describe what to watch once and the alert finds you. This guide explains how blockchain alerts work, what you can watch on Ethereum with Alerts on Chain today, and how to set up your first one.

Just want the alert? See all alert types

5 min read
Use the Protect my wallet templateExplore Wallet alerts

How blockchain alerts work

Every Ethereum transaction is public. An alert service follows the addresses you choose, reads each new transaction that touches them, and checks it against your rules. When a rule matches, you get a message.

In Alerts on Chain, a rule says what to watch, when to alert and where to send it. What to watch is the source: a wallet or a smart contract address. When is the event, method or transfer, plus optional conditions. Where is a Telegram chat or group. One address can carry several rules.

Example alert
WalletExample

Received 1.2 ETH from 0x7099…79C8

Wallet 0xf39f…2266 · Rule: Incoming ETH

Ethereum · View on Etherscan09:41

What you can watch

Everything below is live today on Ethereum mainnet:

  • Wallets: ETH, ERC-20 and NFT transfers in or out, filtered by direction, type, asset, amount and counterparty.
  • NFT collections: mints, burns and transfers on ERC-721 and ERC-1155, and Seaport sales without the price.
  • Tokens: every transfer of an ERC-20 token, and approvals with unlimited allowances flagged.
  • DeFi: swaps on Uniswap-style pools, and borrows and liquidations on Aave-style markets.
  • Any smart contract: chosen events or direct method calls, with conditions on their arguments, or every event it emits.
Example alert
NFTExample

NFT Bored Ape Yacht Club #8817 minted to 0x7099…79C8

Contract Bored Ape Yacht Club (0xbc4c…f13d) · Rule: BAYC mints

Ethereum · View on Etherscan09:41

Where alerts arrive

Alerts are only useful if you see them. Telegram puts them on your phone's lock screen and in group chats, and the first line of each message is written to make sense in a notification preview. One message is sent per transaction per rule, so a batch of activity in a single transaction arrives as one message with a line per item.

Discord, Slack, email and webhooks are coming; Telegram is the only live channel today.

Example alert
DeFiExample

Swapped 25,000 USDC for 9.84 WETH on Uniswap V3

Contract Uniswap V3 USDC/WETH pool (0x88e6…5640) · Rule: Pool swaps

Ethereum · View on Etherscan09:41

What alerts are good for

A few common uses:

  • Security: know within seconds when something leaves your wallet, or when a token approval is granted.
  • Payments: hear when a customer's deposit or an invoice payment lands.
  • Operations: watch a treasury, a multisig or the admin functions of a contract you run.
  • Research and trading: follow a whale, a fund or a collector, and see a collection's mints as they happen.

How alerts are counted

An event is one transaction seen on one watched address. It counts once, whether it matches none, one or several of your rules and however many channels it fans out to. An alert is sent only when a rule matches.

The free Beta plan needs no card and includes 1 wallet, 1 contract and 100 events a month. Paid tiers go from 5,000 to 2,000,000 events a month. Busy addresses (a popular collection, a large exchange wallet, a DEX pool) see many transactions, so they suit paid tiers.

What alerts don't do (yet)

It's worth knowing the edges before you rely on alerts:

  • No USD values, token prices, sale prices or floor prices yet. They are coming with Premium.
  • Ethereum mainnet only. More networks are planned, but none is live yet.
  • Alerts arrive within seconds of the transaction being confirmed. Pending (mempool) transactions are not alerted.
  • Alerts report activity; they can't block or reverse a transaction.
  • Alerts on Chain is read-only. It watches public addresses and never asks for a private key or a seed phrase.

Set it up step by step

From sign-in to your first alert, in the actual dashboard.

  1. 1
    Sign in at alertsonchain.com with Google or with your wallet. A wallet sign-in is a signed message, not a transaction, so it costs no gas.
  2. 2
    Open the Channels tab and connect Telegram: start a chat with @alertsonchain_com_bot, send /start, and paste the 8-character code it replies with.
  3. 3
    Pick a template on the Rules tab, such as Protect my wallet, NFT mints or Token transfers.
  4. 4
    Paste the wallet or contract address you want to watch.
  5. Click Create rule. The rule is active straight away, and the next matching transaction sends a Telegram message.
Use the Protect my wallet template

Frequently asked questions

  • Are blockchain alerts free?

    The free Beta plan needs no card and includes 1 wallet, 1 contract and 100 events a month. Paid tiers go from 5,000 to 2,000,000 events a month.

  • Which blockchains are supported?

    Ethereum mainnet. More networks are planned but not live yet.

  • Do I need to write code?

    No. Templates set up the rule for you; you paste an address and pick a chat. Conditions are chosen from lists, by name.

  • Is it safe to connect my wallet?

    Signing in with a wallet is a signed message, not a transaction, and costs no gas. Alerts on Chain is read-only. It watches public addresses and never asks for a private key or a seed phrase.

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