NeMo Flow

nemo-flow-node is the NeMo Flow package for Node.js applications. It gives JavaScript and TypeScript code access to the same execution scopes, middleware, plugins, lifecycle events, and observability model used by the Rust runtime.

The package is implemented as a napi-rs native extension, but Node.js users should install it from npm rather than depend on the Rust crate directly.

Why Use It?

• 🧭 Own execution context in Node.js: Group agent, tool, and LLM work into one scope tree from JavaScript or TypeScript.
• 🛡️ Put policy around callbacks: Register guardrails and intercepts for request rewriting, blocking, sanitization, and execution wrapping.
• 📡 Emit one lifecycle stream: Send runtime events to in-process subscribers, Agent Trajectory Interchange Format (ATIF), OpenTelemetry, or OpenInference workflows.
• 🧩 Use package entry points by need: Import the main runtime surface plus typed, plugin, adaptive, and observability helpers from npm.

What You Get

• ✅ npm package for Node.js: A Node.js 20 or newer package backed by a napi-rs native extension.
• ✅ Managed tool and LLM execution: Helpers that emit lifecycle events and run middleware in a consistent order.
• ✅ Middleware APIs: Guardrails and intercepts for tool and LLM boundaries.
• ✅ Observability exporters: Subscriber and exporter support for common runtime telemetry flows.
• ✅ Additional entry points: nemo-flow-node/typed, nemo-flow-node/plugin, nemo-flow-node/adaptive, and nemo-flow-node/observability.

Installation

Install the npm package in a Node.js 20 or newer project:

npm install nemo-flow-node

Getting Started

Register a subscriber and emit a mark inside a scope:

const {
  ScopeType,
  deregisterSubscriber,
  event,
  registerSubscriber,
  withScope,
} = require("nemo-flow-node");

async function main() {
  registerSubscriber("printer", (runtimeEvent) => {
    console.log(`${runtimeEvent.kind} ${runtimeEvent.name}`);
  });

  await withScope("demo-agent", ScopeType.Agent, async (handle) => {
    event("initialized", handle, { binding: "node" }, null);
  });

  deregisterSubscriber("printer");
}

main().catch((error) => {
  console.error(error);
  process.exitCode = 1;
});

The main runtime API is exported from nemo-flow-node. Additional entry points are available at nemo-flow-node/typed, nemo-flow-node/plugin, nemo-flow-node/adaptive, and nemo-flow-node/observability.

Documentation

NeMo Flow Documentation: https://nvidia.github.io/NeMo-Flow