BLOCK OPEN SOURCE
At Block, we believe open source is at the heart of innovation and community empowerment. Our vision is to nurture a diverse and vibrant open source ecosystem that removes barriers to technology and fosters economic opportunities for all.
By collaborating in the open, we create higher quality software, hardware, and protocols through relentless collective examination, and also ensure our systems, hardware, and protocols evolve to meet real-world needs.
We are committed to building solutions that serve our customers, while enriching the broader developer community with open, accessible tools. Our open source strategy emphasizes transparency, collaboration, and shared progress—because building together empowers everyone.
Goose is your on-machine developer agent, working for you, on your terms. Guided by you, Goose intelligently assesses what you need and generates required code or modifications. You are in charge: Do you prefer Goose to make a draft, or complete the change entirely? Do you prefer to work in a terminal or in your IDE?
Doing our work requires a lot of tools like Jira, GitHub, and Slack, as well APIs for infrastructure and data pipelines. Goose handles all of these, and is extensible. Goose can run anything invocable by a shell command, Python or a plugin.
Like semi-autonomous driving, Goose handles the heavy lifting, allowing you to focus on other priorities. Simply set it on a task and return later to find it completed, boosting your productivity with less manual effort. Read on to get started!
OkHttp is a modern HTTP client designed for efficiency and reliability, ensuring faster load times and reduced bandwidth usage. It supports HTTP/2 to allow multiple requests to share a single connection, uses connection pooling to reduce latency, and leverages features like transparent GZIP compression to shrink downloads and response caching to eliminate redundant network requests. With built-in resilience, OkHttp can recover from common network issues and seamlessly handle services with multiple IP addresses, ensuring robust connectivity across IPv4, IPv6, and redundant data centers. It also supports advanced TLS features, including TLS 1.3, ALPN, and certificate pinning, for secure communication.
Built with developers in mind, OkHttp offers an easy-to-use request/response API with fluent builders and immutability. It supports both synchronous and asynchronous calls, providing flexibility for different use cases. Whether for handling basic requests or navigating complex network conditions, OkHttp simplifies HTTP communication while maintaining high performance and reliability. OkHttp is also the default HTTP client for Android, and is popular in both client and server side development.
Retrofit is a type-safe HTTP client for Java and Android that simplifies API integration by turning RESTful APIs into easy-to-use Java interfaces. It handles all the complexities of network calls, including URL creation, request execution, and response parsing, enabling developers to focus on building features. Retrofit integrates seamlessly with OkHttp for efficient HTTP communication and Gson or Moshi for JSON serialization.
Designed for flexibility and ease of use, Retrofit supports synchronous and asynchronous requests, ensuring compatibility with various application architectures. It also allows customization through annotations for headers, query parameters, and request bodies. With Retrofit, developers can quickly implement reliable, scalable API interactions, reducing boilerplate code and enhancing productivity.
The Lightning Development Kit (LDK) is a flexible, modular library designed to help developers integrate Lightning Network functionality into their applications with ease. It provides core Lightning Network capabilities such as channel management, routing, and transaction signing while giving developers full control over their application’s design and features. LDK supports integration with custom wallets, storage solutions, and networking stacks, ensuring adaptability to diverse use cases.
Built for scalability and security, LDK is written in Rust, offering strong safety guarantees and performance. Its modular architecture allows developers to pick and choose the components they need, enabling seamless integration into existing systems. By empowering developers to build with the Lightning Network, LDK advances Bitcoin adoption and fosters innovation in decentralized financial applications.
Block has a variety of open source projects across our brands. From payment systems to privacy initiatives, from cloud infrastructure to bitcoin hardware wallets, from AI agent frameworks to music streaming, our projects span diverse fields, and each one is open for contributions and collaboration. Visit our GitHub organizations and project pages to learn more.
Whether you're interested in financial services, cryptography, blockchain, AI, or developer tools, there's a project for you to get involved in.
Block has a deep and sustained commitment to open source, contributing to foundational technologies that power our products and the broader developer ecosystem. Our involvement spans across infrastructure, developer tooling, security, and financial innovation, with contributions to both widely adopted community projects and highly specialized tools. From contributions to software ecosystems like MySQL, Android, and Bitcoin to advancing developer productivity and cloud infrastructure with gRPC, Envoy, and LeakCanary, our work has had a lasting impact. Our philosophy is not only about using open source but actively giving back and shaping it—enhancing projects we depend on and sharing our own innovations with the world. This approach aligns with our mission of economic empowerment by fostering transparency, security, and accessibility in technology.
Block has actively contributed to Triton, an open source deep learning compiler that optimizes AI models for efficient deployment. Our work has focused on improving performance for financial and payment-related machine learning applications, ensuring that AI-driven innovations remain accessible and performant at scale.
Our contributions to MySQL have focused on performance improvements and scalability enhancements, particularly in areas related to high-throughput financial transactions. Given the central role MySQL plays in powering Block's payment and financial services, our work helps strengthen this database's reliability and efficiency for businesses worldwide.
The Model Context Protocol (MCP) is an open source protocol built by Anthropic with close collaboration with Block for giving large language models (LLMs) a standard way to access tools and data. MCP has gained wide adoption and industry acceptance, used by proprietary and open source agentic frameworks alike. In addition to being design partners with Anthropic, Block contributed the Rust implementation, and leverages MCP as the foundation for building extensions for codename goose, Block's open source agentic framework.
gRPC, co-created by Block, has become the de-facto standard for high-performance remote procedure calls, enabling efficient, low-latency communication across distributed systems. Our work has been instrumental in shaping its architecture, ensuring it meets the needs of modern cloud applications and microservices. gRPC's widespread adoption across the industry underscores its role in driving scalable, interoperable, and performant service-to-service communication.
Originally created by Square, OkHttp has become a cornerstone of Android networking, providing efficient and secure HTTP communication. Our continued contributions have improved connection pooling, security, and HTTP/2 support, making it a crucial tool for mobile and backend developers worldwide.
Envoy is a high-performance service proxy that Block has contributed to, enhancing its observability, security, and scalability features. Our engineers have worked on improving its integration with cloud-native infrastructure and optimizing performance for high-throughput financial applications. Envoy's role in distributed systems makes it a key enabler of resilient and efficient microservices architectures.
BLOCK OPEN SOURCE
At Block, we believe open source is at the heart of innovation and community empowerment. Our vision is to nurture a diverse and vibrant open source ecosystem that removes barriers to technology and fosters economic opportunities for all.
By collaborating in the open, we create higher quality software, hardware, and protocols through relentless collective examination, and also ensure our systems, hardware, and protocols evolve to meet real-world needs.
We are committed to building solutions that serve our customers, while enriching the broader developer community with open, accessible tools. Our open source strategy emphasizes transparency, collaboration, and shared progress—because building together empowers everyone.
Goose is your on-machine developer agent, working for you, on your terms. Guided by you, Goose intelligently assesses what you need and generates required code or modifications. You are in charge: Do you prefer Goose to make a draft, or complete the change entirely? Do you prefer to work in a terminal or in your IDE?
Doing our work requires a lot of tools like Jira, GitHub, and Slack, as well APIs for infrastructure and data pipelines. Goose handles all of these, and is extensible. Goose can run anything invocable by a shell command, Python or a plugin.
Like semi-autonomous driving, Goose handles the heavy lifting, allowing you to focus on other priorities. Simply set it on a task and return later to find it completed, boosting your productivity with less manual effort. Read on to get started!
OkHttp is a modern HTTP client designed for efficiency and reliability, ensuring faster load times and reduced bandwidth usage. It supports HTTP/2 to allow multiple requests to share a single connection, uses connection pooling to reduce latency, and leverages features like transparent GZIP compression to shrink downloads and response caching to eliminate redundant network requests. With built-in resilience, OkHttp can recover from common network issues and seamlessly handle services with multiple IP addresses, ensuring robust connectivity across IPv4, IPv6, and redundant data centers. It also supports advanced TLS features, including TLS 1.3, ALPN, and certificate pinning, for secure communication.
Built with developers in mind, OkHttp offers an easy-to-use request/response API with fluent builders and immutability. It supports both synchronous and asynchronous calls, providing flexibility for different use cases. Whether for handling basic requests or navigating complex network conditions, OkHttp simplifies HTTP communication while maintaining high performance and reliability. OkHttp is also the default HTTP client for Android, and is popular in both client and server side development.
Retrofit is a type-safe HTTP client for Java and Android that simplifies API integration by turning RESTful APIs into easy-to-use Java interfaces. It handles all the complexities of network calls, including URL creation, request execution, and response parsing, enabling developers to focus on building features. Retrofit integrates seamlessly with OkHttp for efficient HTTP communication and Gson or Moshi for JSON serialization.
Designed for flexibility and ease of use, Retrofit supports synchronous and asynchronous requests, ensuring compatibility with various application architectures. It also allows customization through annotations for headers, query parameters, and request bodies. With Retrofit, developers can quickly implement reliable, scalable API interactions, reducing boilerplate code and enhancing productivity.
The Lightning Development Kit (LDK) is a flexible, modular library designed to help developers integrate Lightning Network functionality into their applications with ease. It provides core Lightning Network capabilities such as channel management, routing, and transaction signing while giving developers full control over their application’s design and features. LDK supports integration with custom wallets, storage solutions, and networking stacks, ensuring adaptability to diverse use cases.
Built for scalability and security, LDK is written in Rust, offering strong safety guarantees and performance. Its modular architecture allows developers to pick and choose the components they need, enabling seamless integration into existing systems. By empowering developers to build with the Lightning Network, LDK advances Bitcoin adoption and fosters innovation in decentralized financial applications.
Block has a variety of open source projects across our brands. From payment systems to privacy initiatives, from cloud infrastructure to bitcoin hardware wallets, from AI agent frameworks to music streaming, our projects span diverse fields, and each one is open for contributions and collaboration. Visit our GitHub organizations and project pages to learn more.
Whether you're interested in financial services, cryptography, blockchain, AI, or developer tools, there's a project for you to get involved in.
Block has a deep and sustained commitment to open source, contributing to foundational technologies that power our products and the broader developer ecosystem. Our involvement spans across infrastructure, developer tooling, security, and financial innovation, with contributions to both widely adopted community projects and highly specialized tools. From contributions to software ecosystems like MySQL, Android, and Bitcoin to advancing developer productivity and cloud infrastructure with gRPC, Envoy, and LeakCanary, our work has had a lasting impact. Our philosophy is not only about using open source but actively giving back and shaping it—enhancing projects we depend on and sharing our own innovations with the world. This approach aligns with our mission of economic empowerment by fostering transparency, security, and accessibility in technology.
Block has actively contributed to Triton, an open source deep learning compiler that optimizes AI models for efficient deployment. Our work has focused on improving performance for financial and payment-related machine learning applications, ensuring that AI-driven innovations remain accessible and performant at scale.
The Model Context Protocol (MCP) is an open source protocol built by Anthropic with close collaboration with Block for giving large language models (LLMs) a standard way to access tools and data. MCP has gained wide adoption and industry acceptance, used by proprietary and open source agentic frameworks alike. In addition to being design partners with Anthropic, Block contributed the Rust implementation, and leverages MCP as the foundation for building extensions for codename goose, Block's open source agentic framework.
Our contributions to MySQL have focused on performance improvements and scalability enhancements, particularly in areas related to high-throughput financial transactions. Given the central role MySQL plays in powering Block's payment and financial services, our work helps strengthen this database's reliability and efficiency for businesses worldwide.
Originally created by Square, OkHttp has become a cornerstone of Android networking, providing efficient and secure HTTP communication. Our continued contributions have improved connection pooling, security, and HTTP/2 support, making it a crucial tool for mobile and backend developers worldwide.
gRPC, co-created by Block, has become the de-facto standard for high-performance remote procedure calls, enabling efficient, low-latency communication across distributed systems. Our work has been instrumental in shaping its architecture, ensuring it meets the needs of modern cloud applications and microservices. gRPC's widespread adoption across the industry underscores its role in driving scalable, interoperable, and performant service-to-service communication.
Envoy is a high-performance service proxy that Block has contributed to, enhancing its observability, security, and scalability features. Our engineers have worked on improving its integration with cloud-native infrastructure and optimizing performance for high-throughput financial applications. Envoy's role in distributed systems makes it a key enabler of resilient and efficient microservices architectures.
We highly encourage you to join us in our work. Each project comes with a contribution guide, which has details on how to communicate with contributors and maintainers of that project, including best practices for filing bugs, requesting features, or brainstorming on ideas.
In addition, Block Open Source also runs a Discord server, where you can get in touch with the Block Open Source team. Drop in and say hello!
We care deeply about fostering a safe, inclusive, and productive open source community. We want every contributor to feel welcome and confident in collaborating with us, whether you’re fixing a typo or proposing a new feature. Here are the principles and policies that guide our work:
Block proudly sponsors and collaborates with numerous foundations that are pushing technology forward. Our involvement is rooted in our belief that the open source community thrives when we invest in collective progress. We contribute to the sustainability and growth of open technologies by supporting:
We highly encourage you to join us in our work. Each project comes with a contribution guide, which has details on how to communicate with contributors and maintainers of that project, including best practices for filing bugs, requesting features, or brainstorming on ideas.
In addition, Block Open Source also runs a Discord server, where you can get in touch with the Block Open Source team. Drop in and say hello!
We care deeply about fostering a safe, inclusive, and productive open source community. We want every contributor to feel welcome and confident in collaborating with us, whether you’re fixing a typo or proposing a new feature. Here are the principles and policies that guide our work:
Block proudly sponsors and collaborates with numerous foundations that are pushing technology forward. Our involvement is rooted in our belief that the open source community thrives when we invest in collective progress. We contribute to the sustainability and growth of open technologies by supporting: