The bridge

The one process that holds the board's serial port, plus the checks that say whether what it reads can be trusted. The workbench (apps/web) starts it for you; run it on its own when another app wants the stream.

pip install pyserial          # optional — only the acquisition half needs it
python3 apps/server/serve.py 8140 127.0.0.1

Acquisition. Arduino + Olimex SHIELD-EKG-EMG → serial CSV → ring buffer → SSE. One process owns the port; every project is a client. The flashed firmware source lives at apps/olimex-shield/eeg_stream/eeg_stream.ino — cross-checked against the live board 2026-09-14 (see ../olimex-shield/README.md and RIG.md).

<script src="http://localhost:8140/eeg-client.js"></script>
<script>
  const eeg = new EEGClient({ base: 'http://localhost:8140' });
  await eeg.connect();
  eeg.onData(() => eeg.scope(document.getElementById('scope')));
</script>

Experimental: the Auditory Response Atlas and the extraction layer. With the optional companion tools installed ($OLIMEX_TOOLS, see ../../docs/experimental.md), this process also serves experimental routes (experimental.py): describe what you are about to play into each ear and get back which evoked responses should exist and where to put the electrodes, or run a lock-in at a known frequency. Every response says "experimental": true.

curl -s localhost:8140/montage -H 'Content-Type: application/json' -d '{
  "stimulus": {"transducer":"insert_earphone",
    "left":{"kind":"am_tone","carrier_hz":500,"am_rate_hz":40,"level_db_spl":70},
    "right":{"kind":"am_tone","carrier_hz":500,"am_rate_hz":40,"level_db_spl":70}},
  "channels": 3 }'

Without the companion tools those routes answer 503 "not installed"; acquisition is unaffected.

• Integrating either half into another project → INTEGRATION.md
• Architecture, firewalls and honesty rules → CLAUDE.md
• Self-tests: python3 dev_check.py

Acquisition survives browser reloads (the server owns the port), recordings survive browser/OS crashes (server-side black box), malformed lines and dropped samples are counted from the board's t_us and never repaired, and CORS allows loopback origins (plus $OLIMEX_ALLOWED_ORIGINS) so local apps on other ports can consume it. The atlas predicts and measures nothing — its scalp maps are a forward model from published anatomy, never source localisation.