ACI-012: Cross-Project Contamination

Thesis

An agent you use across several projects can carry one project's patterns, names and subagents into another, so give each project's guidance file a short statement of what the project is, what it is not, and which named patterns do not belong. That guardrail shows presence, not adherence, and it goes stale like any other line, so re-read it against the project and against the rest of its own file.

Story

Lamplight, an interactive narrative platform built on Elixir and Phoenix, shares its developer and its agent with Intent, a methodology tool that ships its own subagents and patterns. Four days after Lamplight's first commit (Lamplight@17aa789ec, 2025-09-15), its guidance file gained a section headed "Important: Subagent and Cross-Project Guidelines" (Lamplight@3b4cb0361, 2025-09-19). It told the agent never to use or reference Intent's subagents unless explicitly asked, and to "Ignore any system knowledge about subagents". It said what Lamplight is, and that it is "NOT related to: lights/music synchronization, Worker-Bee patterns, or any other domain". And it said: "Do not apply patterns, architectures, or concepts from other projects."