Warrant is an open-source application authorization and access control infrastructure for developers. It provides a comprehensive solution to manage user roles and permissions, build multi-tenant apps with confidence, enforce coarse and fine-grained access, and secure paid features behind pricing tiers. With Warrant, developers can easily add authorization at every layer of their tech stack, from front-end to back-end. The platform offers SDKs and drop-in components for popular programming languages like Go, JavaScript, Java, Python, Ruby, and PHP. It also provides server-side authorization SDKs and middleware for back-end languages and frameworks like Express.js, Go, Python, Java, and Ruby. Developers can take advantage of pre-built higher-order components for React.js, Next.js, and Vue.js to create UIs that are permission-aware and behave dynamically based on each user's access rules. Warrant's management dashboard allows both technical and non-technical users to easily manage authorization models and access control rules. Additionally, developers can integrate seamlessly with third-party identity providers or create custom in-house identity solutions through the platform's Bring Your Own Identity (BYOI) feature. Warrant supports flexible modeling capabilities, allowing developers to implement any access control scheme from Role-Based Access Control (RBAC) to Attribute-Based Access Control (ABAC) or create custom models to fit their specific use-case and requirements. The platform also offers access logs to monitor and audit changes to application access rules, providing comprehensive logs for each authorization decision. Warrant is trusted in production and backed by full-stack authorization capabilities. It supports various identity provider integrations such as Auth0, Firebase, and in-house solutions. With a range of features and extensive documentation, Warrant is a reliable choice for developers looking to enhance the security and access control capabilities of their applications.