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The compiler is experimental. Do not fund contracts from it with real funds.
Arkade Script is a contract language for Bitcoin. The compiler, arkadec, turns a contract into a JSON artifact with two kinds of spending path: emulator-enforced paths, which use Arkade opcodes, and consensus-enforceable paths in plain Bitcoin Script. An emulator runs an emulator-enforced path’s script before it cosigns a spend. The operator does not enforce Arkade opcodes. The playground runs the compiler in your browser, with example contracts.

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Install and run

arkadec prints warnings to stderr and exits with a non-zero status on a type or validation error. --no-optimize skips constant folding, static branch removal, and assembly optimization. Prebuilt binaries are on the releases page.

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A first contract

SingleSig.ark
Each function is one way to spend the output:
  • spend has no modifier, so it is a covenant. Its body compiles to Arkade opcodes. The compiler adds a path that needs the operator’s signature and the emulator’s signature: <SERVER_KEY> OP_CHECKSIGVERIFY <EMULATOR_KEY:spend> OP_CHECKSIG. The emulator key is tweaked with the covenant’s script, so it signs only for that covenant.
  • unilateral has the tapscript modifier, so it compiles to one path of plain Bitcoin Script. older(serverExitDelay) waits for the operator’s exit delay. This is the exit path.
The compiler accepts a contract without an exit path and does not warn. Write one, or every spend needs the operator and the emulator.

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The artifact

The artifact lists the constructor inputs, and for each function its Arkade opcodes and its paths, as templates. A wallet fills the templates with the constructor arguments to get the address. Keep the artifact you used for an address: the path order fixes the address. @arkade-os/sdk 0.4 does not read the current artifact format, which fills the exit delay from the <SERVER_EXIT_DELAY> placeholder. The v0.5 docs show how to load an artifact and spend it. The compiler README is the language reference, and examples/ has complete contracts. Arkade Functions lists the built-in functions.