Open-source alternatives to Byte Buddy

Powermock is a Java mocking framework and unit testing tool that uses bytecode manipulation to mock static methods, final classes, and private constructors. It includes a Java agent instrumentation tool and a reflection-based testing utility to bypass encapsulation and modify class behavior at runtime. The project distinguishes itself by providing the ability to intercept the instantiation of objects via the new keyword and simulate the behavior of core Java system classes and native methods. It can override final modifiers on classes and methods and bypass signature restrictions for classes

This project is an Android security analysis toolkit and mobile app runtime manipulator designed for reverse engineering and auditing mobile applications. It provides a system for modifying Java classes and method behavior in active mobile processes to bypass security controls. The toolkit includes a web-based interface for controlling the instrumentation engine and a specialized utility for disabling certificate validation to intercept and inspect encrypted network traffic via SSL pinning bypass. It also features an Android file explorer for browsing and managing files within private data di

jvm-sandbox is a bytecode instrumentation framework and plugin container for the Java Virtual Machine. It acts as a runtime application modifier that enables the injection and modification of bytecode in a running process without requiring an application restart or changes to the original source code. The system provides a non-invasive aspect-oriented programming framework to intercept method execution and alter behavior in live processes. It functions as an isolated environment for functional modules, employing a custom class loader hierarchy to prevent dependency conflicts between plugins a

JaCoCo is a Java code coverage tool and bytecode instrumenter that measures which parts of source code are executed during tests. It functions as a runtime agent to monitor application execution on the fly or as a library for offline bytecode instrumentation, allowing it to capture execution data in environments where runtime agents are restricted. The project distinguishes itself by providing both dynamic and static instrumentation paths to track execution. It includes a runtime agent for on-the-fly monitoring and the ability to modify compiled class files before execution. It further enable

btrace is a Java dynamic tracing tool and instrumentation framework designed for real-time diagnostics. It enables the injection of monitoring code into running Java virtual machines to analyze behavior and diagnose processes without requiring an application restart. The platform features a dynamic probe engine for executing single-line debugging commands to print data and trace call stacks. It provides an extensible tracing framework that supports custom functionality and external integrations through isolated implementation modules. The system covers runtime performance monitoring, method

tiny-spring is a Java inversion of control container and aspect-oriented programming framework. It provides a system for managing object lifecycles and dependency injection to decouple application components. The project features a bytecode proxy generator that enables method interception and behavioral modification for classes that do not implement interfaces. It uses pointcut expressions to match specific classes and methods for the execution of cross-cutting logic via dynamic proxies. The framework manages singleton components and resolves object dependencies using lazy initialization. Ap

tModLoader is a modding framework and toolset designed for expanding game content and extending core game logic. It provides a polymorphic content API that allows for the creation of new items, NPCs, projectiles, and world assets through object-oriented inheritance. The project is distinguished by its advanced code modification capabilities, utilizing intermediate language bytecode patching and reflection-based private access to alter internal game behavior. It features a hot-reloading assembly runtime that enables developers to recompile and apply source code changes in real-time without res

Mockito is a Java mocking framework and JUnit testing library used to create simulated objects and stub method calls to isolate components during unit tests. It functions as a dynamic proxy generator and bytecode instrumentation tool, allowing for the creation of runtime substitutes that mimic the behavior of real classes. The framework distinguishes itself by providing the ability to mock final classes and methods, bypassing standard language restrictions through bytecode modification. This capability enables the testing of legacy code that lacks interfaces. The toolset covers behavioral mo

Booster is an Android app build optimizer and bytecode manipulator designed to reduce binary size, fix system-level crashes, and improve application performance. It functions as an extensible build process plugin that modifies compiled class files and build artifacts to inject stability fixes and optimizations without altering the original source code. The project differentiates itself through low-level bytecode manipulation to patch OS-level bugs and manage thread pools during the compilation phase. It also provides a performance profiling toolkit to identify main-thread blocking operations

apk.sh is a mobile application patching framework and reverse engineering tool designed to inject custom instrumentation and logic into compiled Android binaries. It serves as a workflow manager for modifying application packages without requiring access to the original source code. The toolkit focuses on automating the process of injecting the Frida gadget into Android packages, enabling dynamic analysis and function hooking on non-rooted devices. It handles the end-to-end lifecycle of deconstructing, modifying, and resigning binaries to facilitate security research, malware analysis, and be

This library provides a toolkit for instrumenting Go applications to track performance data, including counters, gauges, and timers. It serves as a centralized facility for collecting, storing, and exporting runtime metrics to external monitoring and telemetry platforms. The project distinguishes itself through a pluggable architecture that decouples application instrumentation from specific output formats. It manages metric data through a registry that supports concurrent updates and provides granular control over data volume by filtering metric labels before transmission. To support operati

This project provides a collection of patches and modification sets for Android applications. It focuses on enhancing media consumption through the removal of advertisements and sponsored segments, while enabling deep customization of application interfaces and internal behaviors. The project employs system-level modifications, including binary hooking, bytecode manipulation, and dynamic memory patching, to override default application restrictions. These capabilities allow for the restoration of push notifications via signature spoofing, the suppression of screenshot alerts, and the automati

This project is a structured tracing framework for Rust that serves as an async-aware instrumentation library and telemetry data collector. It provides a structured logging facade and the tools necessary to record, filter, and route event-based diagnostic data from both standard applications and embedded systems. The framework distinguishes itself through a core implementation that supports bare-metal and no-standard-library environments without requiring a dynamic memory allocator. It specifically handles the complexities of asynchronous workflows by propagating diagnostic contexts across fu

Aliucord is a modified version of the Discord Android application that functions as a plugin-based app extender. It allows for the installation of third-party plugins and deep customization of the mobile client without requiring a full rebuild of the binary. The project provides a framework for loading external code modules at runtime and includes a management system for installing and updating these extensions. It features a dedicated telemetry blocker designed to prevent the application from sending tracking and analytics data to remote servers. Additional capabilities include a crash logg

Lombok is a Java annotation processor and boilerplate reduction library designed to automatically generate repetitive source code. It intercepts the compilation process to inject methods and fields directly into Java classes, acting as a source code generator that eliminates the need to manually write common class patterns. The project distinguishes itself through deep integration with the Java compiler and various integrated development environments. It provides IDE plugins that allow editors to recognize and navigate generated methods, preventing false compilation errors and maintaining syn

Hugo is an annotation-based debugging tool and Java method logging library. It functions as a method execution tracker that records method arguments, return values, and execution durations during application runtime. The project differentiates itself by using annotation-driven instrumentation and bytecode-level aspect injection to capture telemetry without requiring manual print statements. It employs post-compilation bytecode manipulation and aspect-oriented wrapping to insert interception logic around annotated method boundaries. The library covers observability and monitoring capabilities

Prometheus client_golang is the official Go client library for instrumenting applications with Prometheus metrics. It provides a metric registry that manages and exposes custom application metrics like counters, gauges, histograms, and summaries in Prometheus format for HTTP scraping by a Prometheus server. The library also includes a remote read client that sends PromQL queries to a Prometheus server over HTTP and retrieves time series data programmatically. The library supports creating separate registries to isolate metric namespaces and control which metrics are exposed per scrape endpoin

This project provides a collection of extensions for the OpenTelemetry Go software development kit, serving as a toolkit for automated instrumentation, context propagation, and telemetry pipeline management. It enables the capture of traces, metrics, and logs across distributed systems by providing unified interfaces that decouple data collection from specific backend storage or analysis platforms. The project distinguishes itself through its ability to inject telemetry collection into popular frameworks and libraries without requiring manual source code modifications. It maintains request co

JPEX Software is a comprehensive reverse engineering suite for SWF binary files, serving as an ActionScript decompiler and editor. It provides a toolkit for decompiling, analyzing, and modifying the internal structure of compiled Flash content, including the extraction of scripts and media assets. The project is distinguished by its ability to perform direct binary modification, allowing users to edit bytecode and replace embedded resources without reverting to high-level source code. It includes a runtime ActionScript bytecode debugger for variable inspection and call stack analysis, as well

HotswapAgent is a Java runtime instrumentation agent and bytecode redefinition tool designed to apply code changes to running applications instantly. It functions as a hot swap utility and classloader extender that modifies method bodies and updates class definitions without requiring a process restart. The project distinguishes itself as a framework state synchronizer, ensuring that beans, caches, and configurations remain consistent after class redefinitions. It provides specialized mechanisms to refresh managed beans, dependency injection points, and persistence factories, allowing logic c

nyc is a JavaScript code coverage tool and command-line interface that instruments source files to track the execution of lines, branches, and functions during test runs. It acts as a wrapper for Node.js test runners, intercepting the module loading process to collect coverage data. The tool functions as a coverage data merger and build gating tool, allowing users to combine results from multiple independent test runs or child processes into a single unified report. It can automatically fail the build process if code coverage percentages fall below defined minimum thresholds. The project sup

This project is a collection of practical scripts and reference guides that demonstrate advanced Python language features and idioms. It provides code implementations for mastering concepts such as concurrency, metaprogramming, and data structure design. The repository includes examples of the Python object model, covering custom attribute access, descriptor protocols, and special method overrides. It also features implementations of design patterns that utilize first-class functions and decorators to reduce object-oriented boilerplate. The codebase covers a broad range of capabilities, incl

ChaosBlade is an open-source chaos engineering platform that injects faults into applications, containers, Kubernetes clusters, and host systems to test resilience. It functions as a multi-layer fault injection tool, capable of disrupting system resources, Java, C++, NodeJS, and Golang applications, Docker containers, and Kubernetes pods and nodes from a single interface. The platform distinguishes itself through its architecture, which defines chaos experiments as Kubernetes Custom Resource Definitions for native cluster integration, and supports multiple fault injection mechanisms including

Robust is an Android hotfix framework and runtime application updater designed for patching bugs in production environments. It functions as a bytecode patcher and dynamic code injection tool, allowing for the modification of application logic without requiring a full app update or device reboot. The project enables the remediation of Android defects by injecting new classes and methods into existing builds and modifying the implementations of existing methods. It utilizes a toolchain to generate binary patch files that update application behavior and introduce workarounds on the fly. The sy

Kit is a microservices architectural framework and toolkit for Go. It provides a set of standardized primitives and abstractions for implementing service, endpoint, and transport layers in a decoupled manner. The framework focuses on system instrumentation through integrated distributed request tracing and a service instrumentation toolkit that utilizes counters and gauges to export performance data to external monitoring backends. It includes a structured logging library that records system events as key-value pairs to ensure compatibility with log aggregation tools. The project covers a br

OpenCensus-go is an observability instrumentation library designed to capture and export telemetry data from distributed systems. It functions as a framework for application performance monitoring and distributed request tracing, allowing developers to track system health, latency, and the progression of requests across service boundaries. The project distinguishes itself through a modular architecture that decouples data collection from storage. By utilizing a pluggable exporter interface, it enables the transmission of metrics and trace data to a variety of external monitoring and analysis

Istanbul is a JavaScript code coverage tool and instrumentation engine that measures the execution of statements, lines, functions, and branches. It functions as a test coverage analysis tool capable of monitoring code across unit, functional, and browser tests to identify untested areas of a codebase. The project distinguishes itself through a transparent instrumentation engine that uses module loader hooks to inject tracking code without requiring manual source modifications. It supports distributed test reporting by aggregating fragmented coverage data from multiple concurrent processes in