Simplicity Unchained brings Simplicity to Bitcoin networks. It acts as an oracle that executes Simplicity programs and, on success, produces side effects such as co-signing Bitcoin transactions, triggering events, or performing any other action a server is capable of.
The primary target is Bitcoin (including Bitcoin testnets), with additional support for Elements-based networks such as Liquid.
⚠️ Warning: Project Under DevelopmentThis project is still in active development and conceptualization. It is not safe for use in production environments at this time. Features and functionality may change, and there may be critical bugs or incomplete implementations.
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core: Contains the fundamental logic for executing Simplicity programs and interacting with Bitcoin and Elements environments. (Note: In the future, parts of this logic may be migrated to hal-simplicity) -
service: Implements a web service providing endpoints to interact with Simplicity Unchained. Currently, it supports a 2-of-2 multisig co-signing flow on Bitcoin and Elements, triggered by the successful execution of a Simplicity program. -
cli: Command-line interface for communicating with the Simplicity Unchained service and accessing various ecosystem utilities. (Note: In the future, parts of this CLI will use hal-simplicity)
Each component of the project has its own README file with more detailed information.
A live testnet demo is hosted at testnet.simplicity-unchained.blockstream.com. It provides a browser interface for writing Simplicity programs, compiling them, generating a P2WSH address, and sending co-signed transactions on Bitcoin Testnet4 or Liquid Testnet — no CLI or local setup required.
You can explore the Bitcoin capabilities by running the Bitcoin demo script. This demo guides you through:
- Tweaking a public key with a Simplicity program via the Simplicity Unchained service.
- Creating a 2-of-2 multisig P2WSH address on Bitcoin Testnet4.
- Funding the address and creating a PSBT spending transaction.
- Using the Simplicity Unchained service to co-sign the PSBT after successful Simplicity program execution.
- Broadcasting the fully signed transaction to Bitcoin Testnet4.
The Elements demo script demonstrates the same 2-of-2 multisig co-signing flow on the Liquid Testnet.
To run either demo, follow the instructions in the CLI readme.
See the LICENCE file for details.
This project is inspired by Smart Contracts Unchained, a concept proposed by ZmnSCPxj in 2019.