Rust plugins¶

A single-file plugin needs no Cargo project. Save greetings.rs in your plugins directory:

/// Say hello.
#[make_action]
fn greet() {
    println!("Hello from Rust!");
}

Run mrsm greet. Meerschaum builds the plugin when needed; a Rust toolchain is required for the first build and after edits.

Supply rows¶

Save readings.rs:

fn register() -> Value {
    json!({"columns": {"id": "id"}})
}

fn fetch() -> Vec<Value> {
    vec![json!({"id": 1, "temperature": 21.5})]
}

mrsm register pipe -c plugin:readings -m readings -i sql:local
mrsm sync pipes -c plugin:readings -i sql:local

Single-file plugins receive Value, json!, and the marker macros from their host. For connectors, hooks, packaged plugins, or host calls, continue to the Rust plugin guide and SDK reference.