Helio Node SDK

Send application runtime logs from Node.js and Express apps to Helio.

Install

npm install @zynnodehq/helio

Express

import express from "express";
import { createExpressMiddleware, createLogger } from "@zynnodehq/helio";

const app = express();

const logger = createLogger({
  apiKey: process.env.HELIO_API_KEY!,
  service: "todo-api",
  environment: process.env.NODE_ENV ?? "development",
});

app.use(createExpressMiddleware(logger));

app.get("/todos", (_req, res) => {
  logger.info("Fetched todos", { route: "GET /todos" });
  res.json([]);
});

process.on("SIGTERM", async () => {
  await logger.close();
  process.exit(0);
});

app.listen(3000);

Manual Logs

import { createLogger } from "@zynnodehq/helio";

const logger = createLogger({
  apiKey: process.env.HELIO_API_KEY!,
  service: "billing-api",
  environment: "production",
});

logger.info("Checkout started", {
  requestId: "req_123",
  userId: "user_123",
  route: "POST /checkout",
});

try {
  throw new Error("Payment provider timeout");
} catch (error) {
  logger.captureException(error as Error, {
    requestId: "req_123",
    traceId: "checkout.flow",
    tags: ["payments"],
  });
}

await logger.close();

Test Logs

By default, the SDK sends production logs to:

https://ingest.helio.zynnode.com/v1/logs/batch

To send test logs, use a test API key and the test ingestion endpoint:

const logger = createLogger({
  apiKey: process.env.HELIO_TEST_API_KEY!,
  service: "todo-api",
  environment: "test",
  endpoint: "https://ingest-test.helio.zynnode.com/v1/logs/batch",
});

Configuration

createLogger({
  apiKey: "helio_live_...",
  service: "api",
  environment: "production",
  endpoint: "https://ingest.helio.zynnode.com/v1/logs/batch",
  batchSize: 20,
  flushIntervalMs: 5000,
  maxRetries: 3,
  redactKeys: ["password", "token", "authorization"],
  onError: (error) => {
    console.error("Helio logging failed", error);
  },
});

Notes

• Logs are batched before being sent.
• Logging failures do not crash your application.
• Common sensitive keys are redacted from metadata.
• Call logger.close() during shutdown so queued logs are flushed.