Setup guide for Express

This page guides you through the steps of configuring your Express application to work with Apitally. If you don’t have an account yet, now would be a good time to sign up.

Once you’re done with this guide, you will be able to:

• Analyze requests to your application
• Keep track of errors, response times and payload sizes
• Understand how individual API consumers use your application
• Log and inspect API requests and responses
• Monitor your application’s uptime and receive alerts when it’s down
• Set up custom alert rules and get notified when they’re triggered

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Create app

To get started, create a new app in the Apitally dashboard and select as your framework.

Here you can also configure the environments (e.g. prod and dev) for your app, or simply accept the defaults.

Take a note of the client ID displayed after submitting. You will need it in the next step.

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Add middleware

Next, install the Apitally SDK in your Express project.

npm install apitally

Add the Apitally middleware to your Express application using the useApitally function and provide the clientId for your app. You’ll find the clientId on the Setup instructions page for your app in the Apitally dashboard, which is displayed immediately after creating the app.

import express from "express";
import { useApitally } from "apitally/express";

const app = express();
app.use(express.json());

useApitally(app, {
  clientId: "your-client-id",
  env: "dev", // or "prod" etc.
});

Deploy your application with these changes, or restart if you're testing locally.

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Identify consumers

To analyze and filter API traffic by consumers, you can associate requests with consumer identifiers in your application.

In most cases, use the authenticated identity to identify the consumer. The identifier should be a string, such as a username, email address, or any other unique identifier.

Optionally, you can also provide a display name and group for each consumer.

Use the setConsumer function to associate requests with consumers, for example in a middleware.

import { setConsumer } from "apitally/express";

app.use(function (req, res, next) {
  if (req.user) {
    setConsumer(req, req.user.username);
  }
  next()
})

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Capture server errors

The Apitally SDK installs an error handler that captures server error details automatically. It is added to the bottom of the middleware stack.

However, if your application already has custom error handlers that return a response and don’t call next(err), you need to add the following line of code for Apitally to capture server error details.

app.use(function (err, req, res, next) {
  res.locals.serverError = err;
  // Your custom error handling logic ...
});

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Configure request logging

Logging of individual requests and responses is disabled by default to protect potentially sensitive data. If you enable it, you can configure in detail what parts of the request and response should be logged. You can also mask sensitive information (e.g. in headers) and exclude certain requests from logging.

The SDK applies default masking rules for common sensitive headers, query parameters and request/response body fields.

import express from "express";
import { useApitally } from "apitally/express";

const app = express();
app.use(express.json());

useApitally(app, {
  clientId: "your-client-id",
  env: "dev", // or "prod" etc.
  requestLogging: {
    enabled: true,
    logRequestHeaders: true,
    logRequestBody: true,
    logResponseBody: true,
  },
});

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Known issues

• @sentry/node v7 is incompatible with Apitally. It’s instrumentation logic erases metadata on Express routers that Apitally requires. To resolve this, please upgrade @sentry/node to v8.