Brownstone AI Access Control for Express

This `brownstone-middleware` package, currently at version 0.1.4, integrates with Express.js applications to manage and monetize AI agent access. It operates by detecting known AI crawlers and bots based on their user-agents. The middleware offers capabilities for logging AI hits (metering), enforcing access policies by blocking unauthorized agents with a 403 status, and injecting licensing metadata into HTML responses via a `<meta name="ai-usage">` tag. This allows AI systems to directly read usage terms. A key differentiator is its reliance on an external Brownstone API for comprehensive analytics, centralized licensing configuration, and robust bot detection, providing developers with granular control over how their content is accessed and used by AI models. The project is actively maintained, with ongoing updates to agent detection and API features.