Semaphore: P2P Crowdfunding with Bitcoin

"Semaphore is a crowdfunding app that uses bitcoin's smart contracting functionality to let contributors recover their funds if the fundraiser does not reach its goal."

Semaphore: P2P Crowdfunding with Bitcoin
  • "My latest invention is Semaphore: peer to peer crowdfunding with bitcoin," announced @super_testnet.
  • "Semaphore gives contributors two ways to give someone money: irreversible and reversible. If you choose irreversible, it sends the money straight to the recipient's bitcoin address and there are no "takebacks" after the money confirms."
"If you choose reversible, it sends the money to a bitcoin smart contract with two spending paths: one lets the contributor take their money back at any time, the other is a "multisig" path that can only spend the money if the contributor and the recipient both cosign a transaction."
  • "After sending money to this smart contract, the contributor creates a bitcoin transaction that sends the money to the recipient but only if the fundraiser reaches the goal amount."
  • "The contributor signs this transaction and publishes their signature, and thus the recipient can only take the money if he gets enough signatures on valid contributions that he reaches his goal."
  • Try it at: or check out an existing fundraiser for Super Testnet.

Video explainer

  • "Alternative fundraising platforms like don't let contributors take your money back. Contributors send their money directly to the recipient and that's that. I wanted modern "refund" features like platforms like gofundme have, so that's what I made. And all my software is free and open source so companies like geyser are free to use it if they like it," wrote the developer in the project description.

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