Onchain monitoring guides

• How to get an alert when a Safe multisig owner or threshold changes
  Watch a Safe (Gnosis Safe) for AddedOwner, RemovedOwner, ChangedThreshold, module and guard changes and get a Discord, Slack, Telegram or phone push alert.
• Get an alert when your wallet grants a token approval (catch phishing approvals fast)
  Most wallet drains start with an ERC-20 approve or setApprovalForAll signed on a phishing site. Get a push alert the moment your wallet grants one, then revoke it.
• Discord or Telegram notification when a wallet receives USDC on Base
  Get a Discord, Slack, Telegram or phone notification every time an address receives USDC (or any ERC-20) on Base, Ethereum, Arbitrum or Optimism. No code needed.
• How to monitor a proxy contract for upgrades (Upgraded, AdminChanged, ownership)
  Get alerted when an ERC-1967 / UUPS / transparent proxy is upgraded, its admin changes, ownership is transferred, or it is paused. Works for any contract you depend on.
• OpenZeppelin Defender Monitor alternatives after the July 2026 shutdown
  OpenZeppelin retired the hosted Defender platform on July 1, 2026. Options for replacing Defender Monitor: self-hosted OpenZeppelin Monitor, or a hosted lightweight alerting service.
• Free phone push notifications for onchain events with ntfy (no account)
  Send blockchain alerts (wallet transfers, approvals, contract events) to your phone for free using ntfy.sh topics. No app account, no Telegram bot, no Discord server.