Essays on systems, artificial intelligence and infrastructure

Capturing real browser traffic to feed an agent: the Network Listener extension

Before writing the first client for an API, there is a source of truth almost nobody consults: the Network tab itself. That is where the headers documentation forgot live, along with the exact POST body and the error the frontend received. Network Listener came from that: a Chrome extension that records this traffic into a local SQLite file, with filters, session marks, findings and replay, plus an MCP server that lets an agent query everything by capture id.