Camera observation

The participant turns on their camera and carries on as normal for a couple of minutes. Their browser measures what the camera sees: blinks, where they look, head movement, mouth and smile, posture, and how active they are. It sends only the numbers. Staff read them on the evaluation as context.

The numbers are descriptive. They never change the assessment score, and Synapse never labels them as emotions, personality, honesty or suitability.

Turn it on

Set SYNAPSE_OBSERVATION_ENABLED=true on the API and on the web app. You can restrict it to some apps with SYNAPSE_OBSERVATION_APP_IDS. To turn it off for one experience, set "observation": { "enabled": false }. The same block sets target_seconds (60–180), min_seconds, prompt_text and show_participant_results.

Participant API

The participant’s own spt_ token authenticates every call. The session needs its own camera_observation consent; record it like any consent event, using the notice from getObservation().

const offer = await participant.getObservation();
await participant.sendEvents([{
  client_event_id: crypto.randomUUID(),
  type: "consent_accepted",
  occurred_at: new Date().toISOString(),
  metadata: { purpose: offer.consent.purpose, notice_version: offer.consent.notice_version },
}]);
await participant.startObservation();
// ... the browser analyses the camera and builds { summary, timeline, client } ...
const saved = await participant.finishObservation(numbers, undefined, `observation-${attemptId}`);

finishObservation refuses any field it doesn’t know, and refuses a duration longer than the session has actually been running. discardObservation() deletes the numbers. Withdrawing the consent deletes them too.

Read it as staff

const record = await synapse.evaluations.getObservation(organizationId, appId, environmentId, evaluationId);
record.summary?.eyes.blinks_per_min;
record.summary?.gaze.on_screen_pct;
record.timeline; // one row per analysed second

record = client.evaluations.get_observation(organization_id, app_id, environment_id, evaluation_id)
record.summary.head.nods

A 404 means the evaluation has no camera session.

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SDKs

Direct API

API endpoints

Guides

Camera observation

Camera observation

Turn it on

Participant API

Read it as staff

​Camera observation

​Turn it on

​Participant API

​Read it as staff

Camera observation

Turn it on

Participant API

Read it as staff