express-slack-stats

📊 Express middleware to send API request stats and process exit alerts to Slack. Supports endpoint stats, status codes, latency averages, and exit code notifications — all delivered as clean Slack Block Kit messages.

✨ Features

• Tracks:

  • Hits per endpoint (with param normalization, e.g. /users/123 → /users/_)
  • Methods (GET, POST, etc.)
  • Status codes (200, 404, 500, …)
  • Average response time

• Aggregates stats into periodic Slack reports (configurable with cron syntax)

• Reports Node.js process exit codes and uncaught errors

• Lightweight & simple to drop into any Express app

• Written in TypeScript with full type definitions

📦 Installation

npm install express-slack-stats

or

yarn add express-slack-stats

🚀 Usage

import express from "express";
import expressSlackStats from "express-slack-stats";

const app = express();

expressSlackStats(app, {
  webhookUrl: process.env.SLACK_WEBHOOK as string, // required
  schedule: "*/10 * * * *", // optional, default: every 5 min
  includeExitCodes: true,    // optional, default: true
  sendEmptyReports: false,   // optional, default: false
  includeCharts: true,       // optional, default: false
});

app.get("/users/:id/profile", (req, res) => {
  res.json({ ok: true });
});

app.listen(3000, () => console.log("Server running"));

⚙️ Options

| Option | Type | Default | Description | | ------------------ | --------- | --------------- | --------------------------------------------------------------------------- | | webhookUrl | string | required | Slack Incoming Webhook URL | | schedule | string | "*/5 * * * *" | Cron syntax for how often to send stats (e.g. "*/10 * * * *" = every 10m) | | includeExitCodes | boolean | true | Whether to report process exit codes and crashes to Slack | | sendEmptyReports | boolean | false | Whether to send reports when no API activity was recorded | | includeCharts | boolean | false | Whether to include ASCII charts in the Slack reports |

📊 Example Slack Report

Basic Table Format:

📊 API Stats Report

Endpoint                    | Hits | Status       | Avg Time
----------------------------|------|--------------|----------
GET /api/users/:id          |   25 | 200:20,404:5 | 145.2ms
POST /api/users             |   12 | 201:10,400:2 | 89.7ms
GET /api/products/:id       |    8 | 200:8        | 67.3ms
POST /api/login             |   12 | 200:11,401:1 |  89.5ms

With Charts (when includeCharts: true):

📊 API Stats Report

Endpoint                    | Hits | Status       | Avg Time
----------------------------|------|--------------|----------
GET /api/users/:id          |   45 | 200:44,500:1 | 120.3ms
POST /api/login             |   12 | 200:11,401:1 |  89.5ms

API Endpoint Hit Distribution:

GET /api/users/:id        │████████████████████ 45
POST /api/login           │█████████ 12
GET /api/products         │███ 5

Status Code Distribution:

200 OK           │■■■■■■■■■■■■■■■ 50 (80.6%)
401 Unauthorized │■■ 8 (12.9%)
500 Server Error │■ 4 (6.5%)

(Delivered as a Slack Block message with header, table, optional charts, and timestamp.)