Minimal model

Every model declares the YAML format version and a model name. This model has one entity type, Task, with two events. Events are emitted at most once per entity instance unless the model says otherwise.

YAML model

quent: alpha
model: minimal

entities:
  Task:
    events:
      started: {}
      ended: {}

Instrumentation API

The context provides an observer for each entity type. Calling .handle() on an observer creates a handle for a new entity instance and assigns it a fresh UUID. The handle exposes one method per event.

Every context is created with an exporter, which determines where emitted events go. This example uses Noop, an exporter that discards every event. It keeps the example focused on the generated API without creating files or starting another service. Applications replace Noop with an exporter that stores or sends their events.

// SPDX-FileCopyrightText: Copyright (c) 2026, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
// SPDX-License-Identifier: Apache-2.0

#[allow(unused)]
mod instrumentation {
    include!(concat!(env!("OUT_DIR"), "/minimal.rs"));
}

use instrumentation::{Context, Minimal, Noop, Task};

fn main() -> Result<(), Box<dyn std::error::Error>> {
    let context = Context::<Minimal>::try_new(Noop)?;
    let mut task = context.observer::<Task>().handle();

    task.started()?;
    task.ended()?;

    Ok(())
}