Reference

What is written here is what is true. This volume is for looking things up, not for reading through. To learn the notation, start with Your first .muro; to work from a goal, use the how-to guides.

The volumes follow koyu's surfaces — the words you write, the messages the tools return, the commands, the server, the library, and the form that is derived. Look it up from the surface you are touching.

Writing

Volume	What it answers
Every .muro construct	How is this word spelled? What may it carry, and what happens if you leave it out?

One page per declaration: space, zone, boundary, door, window, column, import, over/drop and the rest. Each declaration's page owns its attributes and defaults; rules that span layers live in composition.

Checking

Volume	What it answers
Diagnostic code index	What does this koyu check code mean, and what do I change? (65 codes)
koyu validate	Architectural judgement. Not what check guarantees. (15 rules)

They are two different surfaces. check and validate explains why.

Running

Volume	What it answers
The koyu command	Arguments, flags, output and exit codes for all 14 subcommands
koyu-mcp	The surface an agent touches: 12 tools and the JSON-RPC contract
TypeScript API	The public names of @kensnzk/koyu (59 runtime values, 77 types) and the four entry points

What comes out

Volume	What it answers
Form	How a written composition becomes one unambiguous form. Derivation constants and tolerances
Canonical JSON	The machine form: the byte-level norms and the stability rules

The extent of the promise

Page	What it answers
What check guarantees	What a green check means, and what it does not
Frozen surfaces	What you may depend on across versions. The language version and the implementation version
Identity	uid — where you may write it, when you need it, what it guarantees
What koyu does not hold	What is deliberately impossible

If a word is unfamiliar, see the glossary.