How to Add Audit Logs to Your App (The Complete Guide for Developers)

#systemdesign #monitoring #tutorial #security

Modern apps generate a huge amount of user activity — sign-ins, CRUD operations, API calls, admin changes, billing updates, and more.
But most teams still rely on console logs or random database timestamps to debug issues.

That works… until you absolutely need to know “WHO did WHAT and WHEN.”

That’s where audit logs come in.

In this guide, I'll show:

What audit logs actually are
Why every SaaS and internal tool needs them
How to design audit logging correctly
A simple way to add audit logs in minutes (local or cloud)

What Are Audit Logs?

Audit logs are structured, immutable records that track:

User actions
Application events
Admin changes
Security-sensitive operations

Unlike console logs, audit logs are legal and compliance-friendly, designed to answer:

“What happened? Who did it? How did it impact the system?”

Why Every App Needs Audit Logging

Whether you're building:

A SaaS dashboard
A fintech platform
A productivity / workflow app
An internal admin tool
A cloud API service

Audit logs solve important problems:

Debugging

You can track strange user behaviour, API failures, or unexpected state changes.

Security & Compliance

Ideal for GDPR, SOC2, ISO standards.

Transparency for Customers

Teams love seeing "who changed what" in their organization.

Preventing Data Tampering

Immutable logs create a trusted event history.

Usage Tracking

You can track how users interact with your product.

What Should a Good Audit Log Contain?

A simple schema:

{
  "timestamp": 1732857951234,
  "user_id": "123",
  "actor_name": "shreya"
  "action_type": "create:project",
  "resource_id": "project_789",
  "ip": "192.168.1.1",
  "metadata": {
    "previousValue": null,
    "newValue": {
      "name": "New Marketing Project"
    }
  }
}

How to Add Audit Logs (Locally or Cloud)

Most tutorials tell you to:

create a DB table
write your own log middleware
build filtering
build exporting
build querying
build a UI for logs That’s days (or weeks) of work.

Instead… use an audit-logging SDK

A plug-and-play auditing system lets you:

log events
store them locally or in the cloud
view them in a visual dashboard
track events per project/user
export filtering + search

LogMint SDK does this with just:

  const { init, log} = require("@logmint/audit");

  await init({
    mode: "cloud",
    apiKey: "<YOUR_API_KEY>",
    secretKey: "<YOUR_SECRET_KEY>",
  });

  await log({
    event_type: "user.paid.first.order",
    actor_name: "shreya",
    actor_id: "1",
    resource_id: "#1",
    resource_type: "mobile app",
    metadata: { old_column: "old", new_column: "new" },
  }, <API_ENDPOINT>);