Open-source alternatives to Grpcurl

This project is a gRPC framework for Node.js used to implement high-performance remote procedure calls. It provides a client-server communication library that utilizes HTTP/2 for streaming, multiplexing, and binary framing, alongside a protocol buffers implementation for defining structured data and generating service stubs. The framework includes a toolchain to compile protocol buffer files into language-specific objects and supports the generation of static TypeScript type definitions to validate objects at runtime. The library covers distributed system networking and microservices communi

protobuf.js is a JavaScript and TypeScript library for encoding and decoding structured data using the Protocol Buffers binary format. It functions as a dynamic parser that can load and process schemas at runtime, a JSON transcoder for converting messages to human-readable formats, and a framework for building transport-agnostic remote procedure call clients. The project distinguishes itself by offering both dynamic message handling and a static code generator that produces TypeScript declarations and JavaScript modules to reduce runtime overhead. It also provides a reflection API for definin

This project is a .NET implementation of the gRPC framework, providing a system for executing functions on remote servers as if they were local calls. It serves as a high-performance remote procedure call (RPC) framework that utilizes HTTP/2 for service connectivity and binary communication protocols to ensure efficient data exchange. The implementation includes a gRPC-Web proxy, which acts as a translation layer to enable browser-based applications to communicate with gRPC services through web-compatible requests. It further supports the creation of HTTP/2 service meshes to connect distribut

Curl is a command-line tool and portable library for transferring data across a wide range of network protocols. It functions as a unified engine that abstracts diverse communication standards, allowing users and developers to move files and information between servers using a consistent interface. The project provides both a versatile command-line client for terminal-based automation and a stable programmatic interface for integrating complex network operations into applications. The system is distinguished by its protocol-agnostic core and its ability to manage both synchronous and asynchro

Quarkus is a Kubernetes-native Java framework designed for building high-performance, memory-efficient applications. It utilizes ahead-of-time native compilation to transform Java code into standalone, optimized binaries that eliminate the need for a virtual machine, enabling rapid startup and reduced memory consumption. By performing code augmentation during the build phase, it shifts heavy processing tasks away from runtime, ensuring that applications are optimized for cloud-native environments. The framework distinguishes itself through a unified approach to reactive and imperative program

brpc is a high-performance C++ RPC framework and network programming library designed for building distributed systems. It functions as a multi-protocol RPC server capable of hosting and detecting multiple communication protocols, including gRPC, Thrift, HTTP, Redis, and Memcached, on a single TCP port. The project distinguishes itself through high-throughput data transport and memory efficiency, utilizing RDMA-based transport to bypass the kernel TCP stack and zero-copy memory management to eliminate data duplication. It also implements the Raft algorithm for consensus-based state replicatio

Prototool is a development toolkit for Protocol Buffers that provides a suite of tools for linting, formatting, and generating code from schema files. It functions as a system for managing the lifecycle of Protocol Buffer definitions through a command line interface. The toolkit distinguishes itself by providing a breaking change detector that compares different versions of definitions to identify wire or source incompatible changes. It also includes a gRPC client interface capable of invoking endpoints using JSON requests by dynamically compiling Protobuf definitions. The project covers bro

mcp-context-forge is a Model Context Protocol federation gateway that unifies diverse AI tool servers and APIs into a single consistent interface for discovery and execution. It acts as a centralized proxy that aggregates multiple servers and APIs, allowing AI agents to access and invoke a unified set of tools, prompts, and resources. The project distinguishes itself through a multi-protocol translation bridge that converts communication between standard I/O, SSE, gRPC, and REST to enable interoperability between disparate tool servers. It includes a comprehensive LLM evaluation framework for

gRPC is a language-agnostic remote procedure call framework designed for high-performance communication between distributed services. It utilizes a structured interface definition language to generate consistent client stubs and server skeletons, enabling applications to invoke methods on remote servers as if they were local objects. By leveraging the HTTP/2 transport layer, the framework supports efficient binary serialization and multiplexed data exchange across diverse programming environments. The framework distinguishes itself through its support for flexible communication patterns, incl

grpc-go is a Go language implementation of the gRPC framework, providing a remote procedure call library for high-performance service communication. It uses the HTTP/2 protocol to execute functions on remote servers as if they were local methods and utilizes protobuf service bindings to generate type-safe client and server code. The project features a bidirectional streaming transport that supports asynchronous, full-duplex message streams between clients and servers. This networking layer allows for various communication patterns, including client-to-server and server-to-client streaming, to

Kitex is a high-performance remote procedure call framework for building distributed microservices in Go. It provides a communication system compatible with gRPC and Protobuf standards and includes a suite of tools for microservices governance. The framework features proxyless service mesh integration, which allows it to manage network traffic and governance directly without adding sidecar proxy latency. It optimizes data throughput through a high-performance communication library that minimizes memory copies. The system covers a broad surface of distributed capabilities, including service d

NATS Server is a high-performance, lightweight messaging system designed for cloud-native applications, edge computing, and distributed microservices. It functions as a distributed publish-subscribe broker that routes messages using hierarchical, dot-separated subject strings, enabling decoupled communication between services without requiring centralized broker lookups. The system supports core messaging patterns including asynchronous publish-subscribe, request-reply, and load-balanced queue processing. The platform distinguishes itself through a decentralized architecture that eliminates t

RoadRunner is a high-performance application server and process manager designed to serve PHP applications using a persistent worker model. It eliminates bootload overhead and initialization time by keeping application processes alive between requests, acting as a protocol-agnostic proxy that routes traffic to a pool of supervised workers. The server is built with a plugin-based modular architecture, allowing it to be extended with custom Go plugins and compiled into tailored binaries. It distinguishes itself by providing a unified execution model for a wide array of communication protocols,

grpc-rust is a native gRPC framework for Rust designed for building high-performance remote procedure call clients and servers. It provides an asynchronous communication stack and a protocol buffers implementation for encoding, decoding, and generating type-safe code from service definitions. The project enables the implementation of unary and bi-directional data streaming over the HTTP/2 protocol. It includes specialized support for gRPC-Web integration, allowing browser-based clients to communicate with services through protocol translation. The infrastructure covers a broad range of distr

OkHttp is an HTTP client for the JVM and Android that enables network communication via synchronous and asynchronous requests. It provides a core identity as a comprehensive networking toolkit featuring a WebSocket client for bidirectional data synchronization, a TLS security toolkit for encrypted communication, and a programmable HTTP mock server for simulating backend responses. The project distinguishes itself through a specialized security and performance architecture. It implements mutual TLS, certificate pinning, and DNS over HTTPS to secure data in transit, while utilizing connection p

This project is an end-to-end type-safe API framework designed to synchronize data structures between frontend and backend codebases without the need for manual code generation. By leveraging TypeScript’s type inference, it allows developers to invoke server-side functions directly from the client as if they were local methods. This remote procedure call approach abstracts away the complexities of HTTP verbs and URL structures, streamlining the full-stack development workflow into a unified experience. The framework distinguishes itself through a modular router architecture that organizes bac

Comlink is a remote procedure call library that transforms message-based communication into asynchronous function calls between the main thread and web workers. It provides a proxy-based interface that allows multiple threads to interact with a single object instance without manual message handling. The project enables the execution of functions across separate browser windows, iframes, and web workers, making external calls behave like local asynchronous operations. It supports the transfer of non-cloneable data through custom serialization handlers and allows for the movement of ownership f

Swell is an API development and testing client designed for interacting with modern network protocols, executing GraphQL operations, and running local mock servers. It provides a unified interface for connecting to endpoints served over HTTP/2, WebSockets, Server-Sent Events, gRPC, tRPC, and WebRTC, enabling live messaging, monitoring, and debugging. The platform includes a concurrent load testing engine that spawns parallel worker threads to evaluate endpoint performance under heavy traffic, alongside a local mock server engine for simulating backend responses during frontend development. It

open62541 is an open-source implementation of the OPC Unified Architecture standard, providing a complete stack for industrial automation and data exchange. It functions as both an OPC UA server and client, enabling the creation of an object-oriented address space to model physical industrial assets and their relationships. The project is designed for versatility across diverse hardware, offering a C99 library that can be deployed to both cloud servers and resource-constrained embedded environments. It distinguishes itself through a pluggable network layer and interface-based security backend

Merlin is a cross-platform command and control framework and remote access tool. It provides a server and agent system for post-exploitation coordination, utilizing an HTTP/2 framework for secure communication and the execution of commands across multiple operating systems. The project features an in-memory code execution engine that runs assemblies and shellcode directly within a process to avoid writing files to disk. It implements a decentralized communication architecture through a peer-to-peer network, allowing agents to exchange data via direct bind or reverse connections. To evade det

rustls is a memory-safe implementation of the Transport Layer Security protocol written in Rust. It provides a cryptographic stack for secure network communication, supporting both TLS 1.3 and 1.2 standards for client and server implementations. The project is designed as a modular cryptographic library that allows swapping underlying cryptographic backends and primitive providers to meet specific security or performance requirements. It incorporates a post-quantum cryptography stack, utilizing hybrid key exchanges and signatures to protect data against future quantum computing threats. The

This project provides a collection of practical implementations and code references for establishing secure network communications using transport layer security protocols. It serves as a guide for developers to implement public key infrastructure and enforce encryption standards within client and server applications. The repository focuses on cryptographic certificate management, including the generation of public and private key pairs and the creation of self-signed certificates for local testing environments. It covers the configuration of secure web servers, offering methods to harden ser

Armeria is a Netty-based microservice framework used for building high-performance asynchronous services. It functions as a multi-protocol RPC server capable of exposing gRPC, Thrift, and REST services on a single unified port. The project is distinguished by its ability to run diverse communication protocols simultaneously and its integrated RPC debugging web console, which allows for the discovery and invocation of remote procedure calls via JSON. It also includes a gRPC to JSON transcoder to enable web client compatibility with Protobuf services. The framework provides a comprehensive sui

This project is a Protocol Buffers implementation for Go, providing a binary serialization framework to convert native data structures into a compact binary format for efficient network transmission and storage. It functions as a language bindings generator, utilizing a compiler plugin to create Go source code from platform-neutral protocol buffer definitions. The implementation includes a JSON data mapper that transforms structured binary messages into JSON format to facilitate compatibility with web services and external APIs. It also enables cross-language data exchange by using a common s

grpc-spring is a framework for integrating gRPC servers and clients into Spring applications. It provides a suite of tools for managing the lifecycle of remote procedure call servers, automating client stub injection, and implementing request interception within a Java environment. The project enables high-performance remote procedure call communication through annotation-driven service registration and automatic configuration of client stubs. It includes a specialized interceptor library for modifying requests and responses, as well as a telemetry tool for exporting performance metrics and d

Mailu is a complete email distribution system deployed as a suite of containerized images. It provides a self-hosted email infrastructure that integrates a webmail client interface with a centralized administration dashboard for managing domains, user accounts, and storage quotas. The system focuses on email deliverability and security through a framework that implements identity verification records and digital certificates. This includes the use of identity signatures and encryption to secure mail transport and prevent domain spoofing. The platform includes layered spam and malware filteri

mcp-agent is a framework for building AI agents that integrate with Model Context Protocol servers to execute tools and access data. It functions as a multi-agent orchestrator and protocol-compliant server, enabling the creation of agents that can discover and invoke tools from connected external servers. The project distinguishes itself through a durable workflow engine that supports long-running tasks capable of pausing, resuming, and surviving restarts. It implements complex orchestration patterns, including iterative evaluator-optimizer loops, hierarchical workflow nesting, and specialist