Open source · Built by PaXa

Small tools for
real engineering work.

PaXa Labs

Useful tools built from problems I’ve encountered while developing, deploying and maintaining production systems.

Simple by design. Useful in the browser. Open for other developers to learn from and improve.

LAB / 01Available now

Invoice Generator

Create clean, client-ready invoices in the browser without handing your billing data to a third party.

PDFPrivacy-first
Open Tool GitHub
LAB / 02Available now

Maintenance Work Order Generator

Turn maintenance details into a structured work order that technicians and operations teams can use.

CMMSOperations
Open Tool GitHub
LAB / 03Available now

API Request Builder

Build a request starter for Flutter, Node.js, or cURL that you can adapt and use in your project.

RESTTypeScriptDio
Open Tool GitHub
LAB / 04Live

Modbus Toolkit

Decode Modbus registers, integers, Float32 values, hexadecimal data and byte ordering.

ModbusFloat32Edge / IoT
Open Tool GitHub
LAB / 05Available now

Systemd Service Generator

Generate Linux systemd service files, installation commands and common service-management commands.

LinuxDeployment
Open Tool GitHub
LAB / 06Available now

Log Inspector

Paste noisy application logs and quickly surface errors, repeated events and useful patterns.

DebuggingObservability
Open Tool GitHub
LAB / 07Available now

Mobile Capability Generator

Generate native Android, iOS and Flutter setup for common device capabilities and permissions.

FlutterAndroid / iOS
Open Tool
LAB / 08Available now

Payment Integration Playground

Explore payment APIs, webhooks, transaction states, and failure scenarios using simulated payments.

PaymentsREST APIWebhooksBackend
Launch Playground
LAB / 09Available now

BMS Point & Alarm Simulator

Manipulate live building points, tune alarm thresholds, explore deadband and acknowledge a realistic alarm lifecycle.

BMSAlarmsTrendsSimulation
Open Tool
LAB / 10Available now

Facility Explorer

Walk through a synthetic 3D facility, inspect engineering equipment, simulate faults, trace systems and locate alarms in space.

Three.js3DBMSEngineering
Open Tool
LAB / 11Available now

SQL Security Playground

Explore unsafe query construction, Boolean logic and parameterized statements in a controlled browser-only simulation.

SQLSecurityNode.jsEducation
Open Tool
LAB / 12Available now

Rate Limit Playground

Overload a fictional API and compare fixed window, token bucket, sliding window and leaky bucket decisions in real time.

Rate limitingHTTP 429APISimulation
Open Tool
LAB / 13Available now

CI/CD Pipeline Playground

Explore a simplified software delivery pipeline. Run builds, break tests, approve deployments, and see how failures and rollbacks affect the release process.

CI/CDTestingDeploymentRollback
Open Playground
LAB / 14Available now

QR Code Generator

Generate customizable QR codes with your own logo or image. Everything stays in your browser.

QR CodePrivacy-firstClient-side
Open Tool
LAB / 15Client-side

JWT Inspector

Decode and inspect JWT headers, claims, expiry and structure directly in your browser.

JWTSecurityClient-side
Open Tool
LAB / 16Interactive

Event Loop Visualiser

Watch JavaScript tasks move through the call stack, microtask queue and event loop step by step.

JavaScriptNode.jsInteractive
Open Visualiser