BitVM

Tree++

Tree++ is a language for smarter Bitcoin contracts. The following summarizes the vision.

Advanced Scripting

At the core of Tree++ there is a templating language which can express complex Bitcoin Scripts.

• Evaluate constant expressions
• Parametrized templates
• Unroll loops
• Compose opcodes
• Library of composed opcodes
  • E.g., multiplication, bitwise XOR, bitwise shifts, Blake3, …
• Hints
  • E.g. reduce: division to a multiplication, square root to a multiplication, modulo to a multiplication., …
• Lookup tables
• Statefulness
  • Lamport signatures (message sizes: u8, u32, u160, …)
  • Also Winternitz signatures
  • In the future maybe OP_CHECKSIGFROMSTACK

Graphs of Transactions

• Compose Tree++ scripts into potentially large Taptrees
• Model contract logic in form of sequences and graphs of transactions
• Statefulness
  • Presigned transactions (also sighashes!)
  • Connector outputs
  • Trigger transactions
  • Timeouts
• Library of parametrizable sub-graphs
  • E.g. BitVM, zkp verifier, bridge

Tooling

• Documentation and Tutorials
• Online editor with examples (like https://ide.scriptwiz.app)
• Package manager (Cargo)