👋 Hello
We are currently exploring an efficient on-chain mechanism to enable multi-output payments within a single Bitcoin transaction – without custody, without PSBT workflows for the sender, and without additional interaction for the main recipient.
🔹 Core Concept:
A dynamically generated P2WSH address acts as the payment recipient.
Two predefined outputs are established when creating this address:
Output 1 = Main recipient (e.g., merchant, service provider, seller).
Output 2 = Flexible instance (multi-sig capable, automated signature).
The sender (input) simply sends a standard Bitcoin transaction to this address – no PSBT required.
The signing logic ensures BTC is automatically distributed on-chain without requiring the recipient to manually sign anything.
🛠 Technical Mechanism:
✅ P2WSH as a Native Splitting Mechanism
The P2WSH address is created based on two fixed outputs.
Input payments go directly to this address, and the distribution is enforced through the script.
✅ No Interaction Required from the Main Recipient (Output 1)
Output 1 receives BTC directly, no multi-sig requirement for merchants.
If multi-sig is used, only Output 2 acts as the flexible signing instance.
✅ Automated Signing & Security Mechanism through Output 2
If a 1-of-2 signature scheme is used, Output 2 handles validation.
If a 2-of-3 multi-sig scheme is used, Output 2 can be flexible (e.g., an HSM that signs within seconds).
✅ No Wallet Restrictions for Sender & Recipient
Sender (Input): Only needs a standard wallet that can send BTC.
Recipient (Output 1): Only needs a wallet that can receive BTC.
Only Output 2 needs to be multi-sig capable, if an automated mechanism is used.
🔥 Advantages of this Approach:
✔ On-Chain UTXO Efficiency → No unnecessary transfers; BTC is directly split.
✔ Full User Control → No custody, no centralized holding of funds.
✔ Fast Execution Without PSBT Overhead → Merchants do not need to interact, no manual signing required.
✔ No Wallet Limitations for Sender & Merchant → Works with standard Bitcoin wallets.
Could This Be MiCA-Free?
One of the biggest advantages of this approach is that, if structured correctly, it could fall outside of MiCA regulation.
Since the platform never holds BTC, it could avoid being classified as a custodian.
The entire transaction process is self-executing on-chain, meaning no funds are ever controlled by a third party.
The flexible Output 2 mechanism ensures security without creating an intermediary risk.
However, before we finalize this approach, we’d like to get insights from Bitcoin developers on the technical feasibility of the system.
Open Technical Questions for the Community:
1️⃣ Can the sender’s normal P2WSH transaction be automatically counted as the first signature?
2️⃣ Would a 1-of-2 signature setup work, where Output 2 acts as the flexible validation instance?
3️⃣ Can RBF be fully disabled for this specific transaction to prevent any modifications post-signing?
4️⃣ Are there alternatives to PSBT/HSM for the second signature that remain secure, scalable, and non-custodial?
We are excited to hear your feedback – does this concept have potential, or are there technical limitations we may have overlooked?
Best regards and thanks!
