8bae517eec
OpenCADStudio --serve --port <N> listens on 127.0.0.1:<N> and serves the same line-based JSON protocol over the socket (one client at a time; the document session persists across reconnects), as an alternative to stdin/stdout. ocs.py grows a port= option to connect either way. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
73 lines
3 KiB
Markdown
73 lines
3 KiB
Markdown
# Headless automation API
|
|
|
|
Open CAD Studio can run without a GUI and be driven over a line-based JSON
|
|
protocol — for scripts, batch jobs, or AI agents.
|
|
|
|
```sh
|
|
OpenCADStudio --serve # stdin/stdout transport
|
|
OpenCADStudio --serve --port 4242 # listen on 127.0.0.1:4242 instead
|
|
```
|
|
|
|
It reads one JSON request per line and writes one JSON response per line — over
|
|
**stdin/stdout**, or over a **local TCP socket** with `--port`. The active
|
|
document persists across requests (and, on the socket, across reconnects), so a
|
|
caller can act → observe → act.
|
|
|
|
## Protocol
|
|
|
|
| Request | Response |
|
|
|---------|----------|
|
|
| `{"op":"new"}` | `{"ok":true,"total":0,"by_type":{}}` |
|
|
| `{"op":"open","path":"plan.dwg"}` | entity summary |
|
|
| `{"op":"run","cmd":"LAYER Walls"}` | `{"ok":true,"cmd":...,"entities":N,"added":D}` |
|
|
| `{"op":"entities"}` | `{"ok":true,"total":N,"by_type":{"Line":42,...}}` |
|
|
| `{"op":"query","type":"Line","layer":"Walls"}` | per-entity `{handle,type,layer,…geometry}` (Line/Circle/Arc/Point/Ellipse/Text/MText/Polyline/Insert; filters + `limit` optional) |
|
|
| `{"op":"layers"}` | layers `{name,color,off,frozen,locked}` + the current layer |
|
|
| `{"op":"header"}` | drawing variables (units, PDMODE/PDSIZE, LTSCALE, …) |
|
|
| `{"op":"select","handles":["2B"]}` | set the selection (by `handles`, `type`, or `layer`; `clear` to deselect) → `{"ok":true,"selected":N}` |
|
|
| `{"op":"undo"}` / `{"op":"redo"}` | step the document history → entity summary |
|
|
| `{"op":"save","path":"out.dwg"}` | `{"ok":true,"saved":"out.dwg"}` (path optional once opened/saved) |
|
|
|
|
Selection drives modify commands — `select` the targets (e.g. the handles a
|
|
`query` returned), then `run("ERASE")`:
|
|
|
|
```python
|
|
ocs.select(type="Line"); ocs.run("ERASE") # erase every line
|
|
ids = [e["handle"] for e in ocs.query(layer="Walls")["entities"]]
|
|
ocs.select(handles=ids); ocs.run("ERASE")
|
|
```
|
|
|
|
Every response has `"ok"`; failures carry `"error"`. `run` drives Open CAD
|
|
Studio's **own** command system — no separate bindings to maintain — so its
|
|
coverage grows with the app.
|
|
|
|
Interactive draw commands take their points as coordinate tokens; the tool is
|
|
started, the points are fed, and it is terminated as if Enter were pressed:
|
|
|
|
```
|
|
{"op":"run","cmd":"LINE 0,0 10,10 10,20"} → two Line segments
|
|
{"op":"run","cmd":"CIRCLE 5,5 3"} → centre 5,5 radius 3
|
|
```
|
|
|
|
Coordinates are `x,y` or `x,y,z`; `@dx,dy` is relative to the previous point.
|
|
Inline-argument commands (`PDMODE 3`, `LAYER Walls`) are passed through as-is.
|
|
|
|
> Coverage is growing: commands whose options are typed keywords or coordinates
|
|
> work; ones that still rely on on-screen picking (object selection by clicking)
|
|
> are being wired next.
|
|
|
|
## Python client
|
|
|
|
[`ocs.py`](ocs.py) is a ~100-line client — nothing to compile:
|
|
|
|
```python
|
|
from ocs import Ocs
|
|
|
|
with Ocs(binary="OpenCADStudio") as ocs: # spawns `--serve`
|
|
ocs.open("plan.dwg")
|
|
ocs.run("LAYER Walls")
|
|
print(ocs.entities())
|
|
ocs.save("plan_out.dwg")
|
|
```
|
|
|
|
Any language can speak the same protocol over a subprocess pipe.
|