Export a plan

Produce drawing files from a .arch plan. 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. archlang compile --help lists every format and flag; archlang spec describes the paper and scale statements.

Steps

1. Check the plan compiles. archlang compile plan.arch --json writes nothing and reports ok and the diagnostics. Do not export a plan with errors; fix it first.
2. Make sure it is a sheet. A plan with no paper statement has no physical size. archlang finish plan.arch --only sheet --dry-run --json shows the sheet statements the plan lacks (paper, scale, dimensions, title block, room schedule, legend). archlang finish plan.arch --only sheet adds them on the smallest sheet the drawing fits.
3. If the user names a paper size or a scale, edit the plan's paper and scale statements to those values and compile again. If the drawing does not fit the sheet the plan declares, archlang finish plan.arch --reissue -o issued.arch writes a copy in which only paper and scale are replaced by ones that fit. Tell the user when the sheet they asked for cannot hold the drawing at that scale.
4. Export. Pick the format by what the file is for:
   • SVG, for the web or further editing: archlang compile plan.arch -o plan.svg --json
   • PDF, for print at true size: archlang compile plan.arch -f pdf -o plan.pdf --install --json
   • PNG, for a document or a chat: archlang compile plan.arch -f png -o plan.png --install --json (-s 2 doubles the raster scale)
   • DXF, for CAD: archlang compile plan.arch -f dxf -o plan.dxf --json
5. Multi-storey plans. A plan written with level blocks compiles to one file per storey, named <stem>.L<level>.<ext>, and the JSON result lists them in outputs[]. To write one storey to one named file, add --level <n>.
6. Many plans at once. Create the output directory first; batch does not create it. Then archlang batch a.arch b.arch -f pdf -o out/ --json renders each input into it and returns one result row per input.
7. Confirm what was written. Read output (or outputs[] for a multi-storey plan) and bytes in the JSON result and list the files for the user. For a PNG you can look at it; for the other formats report the path, the sheet size and the scale.

Report to the user

• Each file written, with its format.
• The paper size and scale of the sheet, and whether you or finish chose them.
• Any storey or input that failed, with its diagnostic.

When the CLI cannot run

Some hosts have no shell, or a shell that cannot reach npm: in ChatGPT's sandbox npx only times out, and a retry ends in ENOTCACHED. Stop after the first such failure and do not substitute another PDF tool. With the ArchLang MCP tools:

1. Set the plan's paper and scale, then check it with the validate tool and render it with the compile tool. W_SCALE_OVERFLOW means the sheet cannot hold the drawing at that scale: choose a smaller scale or a larger sheet, and say which.
2. For SVG, compile returns the drawing.
3. For PDF, PNG or DXF, call the link tool and give the user its playground URL. In the Playground they open Share and press the format under Download.
4. Say plainly that the user downloads the file and that you wrote none. A Playground PDF is an image on a page of the sheet's paper size; a vector PDF needs the CLI.

When something goes wrong

• A missing optional package for PNG or PDF: repeat the command with --install.
• Exit code 2 is a fault in the plan source, not in the export: read the diagnostic. 3 is a wrong flag: run archlang compile --help.
• Text or dimensions too small on the sheet: the scale is too small for the paper. Choose a larger sheet or a larger scale in the plan, or let archlang finish plan.arch --reissue choose.