qos-sdk Reference

The Q-OS host ABI exposes a minimal set of extern "C" functions that your WASM module can import. There is no separate library to link — the host runtime injects these symbols at instantiation time.

__qos_state_get

fn __qos_state_get(key_ptr: *const u8, key_len: u32, out_ptr: *mut u8) -> u32

Reads a value from the Sled K/V store by key. Returns the byte length written into out_ptr. Returns 0 if the key does not exist.

Example Usage

rust

fn state_get(key: &str) -> Option<String> {
    let key_bytes = key.as_bytes();
    let mut buf = vec![0u8; 4096];
    let len = unsafe {
        __qos_state_get(key_bytes.as_ptr(), key_bytes.len() as u32, buf.as_mut_ptr())
    };
    if len == 0 { return None; }
    String::from_utf8(buf[..len as usize].to_vec()).ok()
}

__qos_state_set

fn __qos_state_set(key_ptr: *const u8, key_len: u32, val_ptr: *const u8, val_len: u32)

Writes a key-value pair to the Sled store. Writes are atomic and immediately durable. The change is broadcast to all WebSocket subscribers as a STATE_MUTATION event.

Example Usage

rust

fn state_set(key: &str, value: &str) {
    let k = key.as_bytes();
    let v = value.as_bytes();
    unsafe {
        __qos_state_set(k.as_ptr(), k.len() as u32, v.as_ptr(), v.len() as u32)
    };
}

More ABI functions — coming soon

__qos_broadcast, __qos_log, __qos_timestamp are on the roadmap.