The Redis URL That Leaked Its Own Password Into AI Agent Context

This is a submission for DEV's Summer Bug Smash: Clear the Lineup powered by Sentry.

Project Overview

ContextOS is a context operating system for AI coding agents: it scans a repo, ranks the relevant files, and builds a context pack under a token budget for the agent to work from. Before anything goes into that pack, a secret detector redacts API keys, tokens, and credentials so agents never see live secrets, published on PyPI with 980+ automated tests and an 80% coverage gate.

Bug Fix or Performance Improvement

The database_url secret-detection pattern was supposed to catch connection strings like postgres://user:password@host and redact the password. It required at least one character for the username segment before it would match. That's fine for Postgres and MySQL, which always have a username. It's not fine for Redis, where the standard URI convention is redis://:password@host, no username at all, just a password. That empty-username shape silently failed the pattern's [^:@/\s]+ requirement, so detection was skipped entirely. The password sailed straight into the context pack, unredacted, ready to be handed to an LLM agent.