Brief to plan

Turn a written brief into a checked .arch floor plan. Every step is a CLI call; never judge the plan from the SVG markup. If archlang is not on the path, write npx -y @chanmeng666/archlang in its place. Never run a bare arch: on Linux, macOS and Git Bash that name is the coreutils command.

This skill is a workflow, not a language reference. The language is whatever archlang spec prints.

Scope

• Run the archlang CLI commands below and no other program.
• Write one new plan file, plan.arch here or the name the user gives, in the user's working directory, plus the drawings the CLI renders beside it. If a file of that name already exists, ask the user before replacing it.
• The user's explicit instructions take priority over these steps.

Steps

1. Read the language. Run archlang spec and read all of it before writing a line. For one command's flags and examples run archlang <cmd> --help, for example archlang finish --help.
2. List what the brief asks for. Write down each room, each stated area, each stated connection ("opens off the hall"), each stated window, and any outer size. Keep numbers exactly as the brief states them. If two requirements cannot both hold, stop and tell the user which ones; do not quietly change a number.
3. Write plan.arch. Give every room an id, a label and a uses. Attach doors and windows to walls and place furniture by anchor, as archlang spec shows, instead of computing coordinates. Give every room a door or an opening.
4. Compile. archlang compile plan.arch -o plan.svg --json. If ok is false, read each diagnostics[].fix. Preview the mechanical fixes with archlang fix plan.arch --dry-run --json, then apply them with archlang fix plan.arch. Fix the rest by hand and compile again.
5. Check the plan against your list. archlang describe plan.arch --select rooms,doors,windows,totals --json. Compare room count, labels, each area, what each door connects and which rooms have windows with the list from step 2. Edit and repeat from step 4 until they match. area_m2 is measured on wall centrelines; net_area_m2 is the floor no wall stands on.
6. Check soundness. archlang lint plan.arch --json. Fix each warning, or keep it on purpose and say why. If a room cannot be reached or a bedroom has no window, archlang suggest plan.arch --json returns door and window statements you can paste.
7. Finish the drawing. archlang finish plan.arch --dry-run --json shows the furniture and sheet statements it would add; archlang finish plan.arch applies them. Read unresolved: it names each room left empty and each statement left out, with the reason.
8. Gate and show. archlang validate plan.arch --strict --json must exit 0, or you must be able to name each remaining warning as deliberate. Then archlang preview plan.arch -o plan.png to show the user.

Report to the user

• The file you wrote and the drawing you rendered.
• Every requirement of the brief the plan does not meet, or "none".
• Which area you quote: net_area_m2 is the floor no wall stands on, area_m2 the larger centreline figure. If a room has no net_area_m2, say its net area could not be computed.
• Every lint warning still present, with the reason it stays.

When something goes wrong

• Exit code 2 is a fault in the source. Read the diagnostic and fix it; do not run the same command again unchanged. 3 is a wrong flag: run archlang <cmd> --help.
• For an unfamiliar code, run archlang explain <CODE> --json.
• To gate on the brief as data instead of by eye, write it as an intent file and run archlang validate plan.arch --intent intent.json --feedback --json. The archlang-review-plan skill covers this.