Drawing your montage

1. Import it

import sys
from pathlib import Path
sys.path.insert(0, str(Path("apps/web/placement").resolve()))  # wherever this folder lives
import placement

2. Hand it the montage you already have

placement wants a list of {role, site, note?} — the shape readouts.py already uses for its EEG, ECG and EMG montages.

montage = [   # bipolar surface EMG over one belly, along the fibres (SENIAM)
    {"role": "active",    "site": "FDI belly, distal"},
    {"role": "reference", "site": "FDI belly, proximal"},
    {"role": "ground",    "site": "ulnar styloid (wrist)"},
]
svg  = placement.render(montage, "hand-dorsal-right", title="FDI, bipolar")
list_ = placement.checklist(montage, "hand-dorsal-right")

render returns a self-contained SVG string; drop it straight into a page. It draws in currentColor, so it inherits your theme rather than fighting it.

Roles: active reference ground sham aux marker. Anything else draws as a plain dot.

3. Maps available

placement.maps() lists them with their sites; placement.sites(map_id) lists one map's.

4. Expect it to refuse

placement.render([{"role": "active", "site": "FDI belly"}], "hand-dorsal-right")
# PlacementError: this montage has no GROUND …

Both refusals are deliberate — see CLAUDE.md. Pass require_ground=False only if your hardware genuinely has no ground connection.

5. Adding a site or a map

Edit bodymaps.json. A landmark needs x, y, label_dx, label_dy, anchor and a note saying where the place is — never what goes there, because the same site gets reused for different roles and dev_check.py fails a note containing a role word. Put labels out in the gutter; the canvas sizes itself around them.