httpjail is a tool designed to provide fine-grained HTTP filtering for coding agents, aiming to mitigate risks such as destructive actions, data leaks, and excessive authority during development. It implements an HTTP(S) interceptor and process-level network isolation, allowing flexible rule creation using JavaScript, while also addressing TLS interception for secure traffic inspection. The tool's design acknowledges the challenges of maintaining security in agentic development, offering solutions for both weak and strong isolation modes.