building-myco-disciplinelisted

# Building Myco the Myco Way This skill is the operational codex for non-trivial work in Myco. It is the *how*; `AGENTS.md` is the *what* and *why*. Read both before starting work that touches more than one file. ## When to apply - Any feature work that spans more than one module - Any refactor (especially when the diff DELETES code that looks like cleanup) - Any work touching paths in the [Capabilities table](../../../AGENTS.md#capabilities-single-writers-for-shared-state) — `daemon.json`, `<projectRoot>/.myco/`, `myco.yaml`, symbiont agent config - Any work that adds a new entry point — HTTP handler, MCP tool, CLI command, intelligence task - Any work that takes more than ~3 commits Do NOT skip this skill because the change "feels small." The recurring bug class in this codebase is: a small change that looked clean compounded into a regression because a load-bearing invariant lived in convention, not in structure. ## Tenets These are the lessons paid for in production bugs, code reviews, and review cycles. ### 1. Capability-first for shared state If your change writes to a path or resource that *anything else* writes to, the first question is: **is there a capability that owns this?** Check [AGENTS.md's Capabilities table](../../../AGENTS.md#capabilities-single-writers-for-shared-state). - **If yes:** route through it. Do not call the lower-level primitives. - **If no but the resource is shared:** stop and design a capability before writing the second writer. *"I'l