ESP32 Http Client

A lightweight, low-allocation, high-performance HTTP client library for ESP32.

Internet of Things (IoT)C++GPL-3.0

Abstract

ESP32 Http Client is an open-source Internet of Things (IoT) project. A lightweight, low-allocation, high-performance HTTP client library for ESP32. It is built using C++, Arduino, ESP32. Key capabilities include: Fluent chaining — build requests naturally: .get().query().getBody(), .soap().soapAction().body().getBody(), or .graphql().query().getData(); Direct injection — JSON, XML, and GraphQL values are written straight into standard C types (int, float, bool, char) or C++ structs; Zero buffering — the response stream is parsed in place; the full payload is never stored in memory. The complete source code is publicly available on GitHub under the GNU General Public License v3.0, making it a useful reference for students building an Internet of Things (IoT) mini project or final-year project.

1. Introduction

A lightweight, low-allocation, high-performance HTTP client library for ESP32.

2. Objective

A lightweight, low-allocation, high-performance HTTP client library for ESP32.

This project demonstrates how C++, Arduino, ESP32 can be applied to a real-world Internet of Things (IoT) problem.

3. Key Features / Modules

  • Fluent chaining — build requests naturally: .get().query().getBody(), .soap().soapAction().body().getBody(), or .graphql().query().getData().
  • Direct injection — JSON, XML, and GraphQL values are written straight into standard C types (int, float, bool, char) or C++ structs.
  • Zero buffering — the response stream is parsed in place; the full payload is never stored in memory.
  • Native SOAP 1.1 & 1.2 support — automatic envelopes, SOAPAction/Content-Type headers, streaming XML response parsing, and SOAP Fault handling.
  • Struct JSON mapping — direct bidirectional struct serialization/deserialization without dynamic document allocations.
  • Full REST support — GET, POST, PUT, PATCH, and DELETE are all first-class citizens.
  • IoT ready — designed for connecting ESP32 devices to cloud backends, Firebase, AWS API Gateway, GraphQL endpoints, SOAP web services, or custom servers.

4. Technology Stack

C++ArduinoESP32
  • Open Arduino IDE and go to Sketch → Include Library → Manage Libraries....
  • Search for ESP32-HTTP-Client.
  • Click Install.

5. System Requirements

General requirements for this technology stack — check the README for exact versions.

  • Arduino IDE / PlatformIO or a C++ compiler (g++)
  • Target board (e.g. Arduino, ESP32) where applicable
  • Git (to clone the repository)

6. Installation & Setup

git clone https://github.com/PedroFnseca/esp32-http-client.git
cd esp32-http-client

Full setup instructions are in the project README.

7. Future Enhancements

Suggested extensions you can add to make this your own project.

  • Add a mobile dashboard using Blynk or Firebase
  • Store readings in a cloud database for history charts
  • Add alerts via SMS / Telegram when thresholds are crossed

8. Viva / Review Questions

Common questions examiners ask for projects in this domain.

  1. Which microcontroller / board and sensors are used and why?
  2. How does the device send data (Wi-Fi, MQTT, HTTP, Bluetooth)?
  3. Where is the sensor data stored and visualised?
  4. How is power consumption managed?
  5. How would you secure the device and its communication?

9. Source Code & License

This project is developed by PedroFnseca and published on GitHub under the GNU General Public License v3.0. Please follow the license terms and credit the original author when you use or modify this code.

View Source on GitHubDownload ZIP

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