🔗 Instant transaction notifications

Bitcoin Safe (starting from version 1.5.0) supports instant notification of incoming Bitcoin transactions relevant to your wallet. Here’s how it works under the hood:

🔗 1. 📡 Listening to the Bitcoin P2P Network

Bitcoin Safe connects directly to one or more Bitcoin Core nodes, which participate in the global peer-to-peer (P2P) network. These nodes continuously exchange newly broadcasted transactions intended for inclusion in the mempool.

Bitcoin Safe listens passively to these broadcast messages and checks whether:

• any transaction involves addresses or UTXOs from your wallet.

✅ Privacy Preserving This method is completely private. It does not reveal anything about your wallet to the outside world. Bitcoin Safe behaves just like a regular Bitcoin Core node: it only listens to public P2P traffic — never announcing or requesting anything specific to your wallet.

🔗 2. 🧠 Match Found — What Happens Next?

If a matching transaction is found, Bitcoin Safe will react differently depending on the backend you’re using:

🔗 Option A: ⚡ Electrum or Esplora Backend

• Bitcoin Safe will trigger a background sync to fetch the full transaction and wallet state from the server.

🔗 Option B: 🔍 Compact Block Filters (Neutrino Mode)

• The wallet will directly add the unconfirmed transaction to your local wallet data — no further lookup needed.

🔗 ⚙️ Opt-In / Opt-Out Behavior

To respect user preferences and privacy settings:

• 🔒 For existing users upgrading to version 1.5.0 or later, this feature is opt-in by default — you can enable it manually in network settings.
• 🚀 For new users, this feature is enabled (opt-out) by default, since it is both privacy-preserving and highly useful for tracking wallet activity in real-time.

You remain in full control and can toggle this feature at any time.

🔗 ⚠️ Only confirmed transactions can be trusted

Bitcoin Safe cannot not validate that a broadcast transaction is valid. An attacker — especially one controlling both your Electrum server and the Bitcoin node you’re connected to — could:

• Craft a fake transaction involving your address
• Broadcast it to trigger a wallet notification
• Ensure it never confirms, because it’s invalid or conflicts with consensus rules

🔗 ✅ Summary

From version 1.5.0, Bitcoin Safe supports instant transaction notifications by:

• Listening passively to the P2P Bitcoin network (like Bitcoin Core)
• Matching transactions involving your wallet’s addresses or UTXOs
• Fetching full details via Electrum/Esplora or adding directly via Compact Block Filters
• Never revealing any wallet data to the outside world