0xBASIC

Structured BASIC for Chia smart contracts. Compiled directly to CLVM.

0xBASIC brings the readable, beginner-friendly style of Microsoft QuickBASIC 4.5 to smart contract development on the Chia blockchain. It uses named functions, structured conditionals, explicit types, and EMIT statements—no line numbers. A Rust compiler translates familiar BASIC constructs into functional CLVM code.

The goal is to make contract development easier to learn without hiding how Chia's coin and condition model works.

Early development · compiler 0.1.0-m3.6b · Apache-2.0

The compiler and local runner work today, but the language is incomplete and has not been audited for production use. Current execution checks CLVM behavior; it does not validate a blockchain spend. Do not use this development version to secure funds.

A small working example

CONTRACT HeightLock(earliestHeight AS INTEGER)
    EMIT ASSERT_HEIGHT_ABSOLUTE(earliestHeight)
END CONTRACT

earliestHeight is fixed when the contract is bound into a puzzle. With earliestHeight = 100, this contract returns a condition requiring an absolute height of at least 100. Contracts execute using supplied data; they never prompt or wait for interactive input. EMIT adds a condition to the result; the blockchain enforces that condition when validating a spend.

What works today

• Case-insensitive names, AS declarations, constants, local reassignment, assertions, and IF / ELSEIF / ELSE.
• Pure, nonrecursive functions and typed INTEGER, BOOLEAN, BYTES, STRING, AMOUNT, PUZZLEHASH, PUBLICKEY, PAIR, LIST, and CONDITION values inside programs.
• Byte operations, SHA256, integer encodings, strict UTF-8 conversion, and collection operations.
• INTEGER, BOOLEAN, BYTES, STRING, AMOUNT, PUZZLEHASH, PUBLICKEY, and nested PAIR/LIST fixed parameters and solution fields, with JSON conversion and generated CLVM boundary validation.
• check, build, and run commands; reproducible artifacts, tree hashes, structured diagnostics, and execution-cost reporting.

Only ASSERT_HEIGHT_ABSOLUTE is currently implemented as a blockchain condition constructor. Payment conditions, signatures, and simulator spend validation are upcoming work. The specifications describe the intended language as well as features still being implemented; see the status and roadmap.

Try it

You need Git, Rust installed through rustup, and a native C/C++ build toolchain. On Windows, use Visual Studio Build Tools with Desktop development with C++; on Linux, install your distribution's C compiler and build tools. The repository pins Rust 1.95.0. Windows and Linux are tested; macOS has not yet been verified.

git clone https://github.com/steppsr/0xBASIC.git
cd 0xBASIC
cargo build --workspace --locked
cargo run --locked -p oxbasic-cli -- check examples/height-lock.bas
cargo run --locked -p oxbasic-cli -- build examples/height-lock.bas --bindings examples/height-lock.bindings.json --out height-lock-build
cargo run --locked -p oxbasic-cli -- run height-lock-build/manifest.json --json

These commands work in PowerShell and Linux shells. The output directory height-lock-build must not already exist. A build produces binary CLVM, hex files, and a manifest recording the template and bound puzzle identities. The runner returns the raw condition tree corresponding to ((83 100)) and labels its result clvm-execution-only.

Dependency downloads require internet access initially. Compilation and local execution then work with cached dependencies; no wallet or running Chia node is required. Python is only needed for the verification scripts.

Explore and contribute

• Examples: small programs demonstrating implemented features. height-locked-payment.bas is a future conformance example and does not compile yet.
• Architecture and language specification.
• ABI, CLI and artifact format, and pinned target profile.
• Development status and roadmap.
• Contribution and testing guide.

Feedback, bug reports, and small focused contributions are welcome through GitHub issues and pull requests. Language and artifact formats may change during development.

Visit 0xBASIC.com for the project introduction.

License

Apache License 2.0. 0xBASIC is an independent project and is not affiliated with or endorsed by Chia Network or Microsoft.