This example demonstrates a counter application, written in WebAssembly directly. The compiled Wasm module is only 389 bytes.
It can be a good way to learn and experiment with the IC system API.
Install the wat2wasm tool, which is part of WABT.
For example, on Mac, you can run the following command:
$ brew install wabt
$ dfx start [--background]
$ dfx deploy [--no-wallet] counter
$ dfx canister call counter get
(0 : int64)
$ dfx canister call counter inc
()
$ dfx canister call counter get
(1 : int64)
$ dfx canister call counter set '(42)'
()
$ dfx canister call counter get
(42 : int64)