# Accessing Heartbeat data

Heartbeat survey studies return telemetry on user engagement with the survey prompt. The heartbeat pings do not contain the survey responses themselves, which are stored by SurveyGizmo.

The telemetry is received using the heartbeat document type, which is described in the Firefox source tree docs.

## Linking Heartbeat responses to telemetry

Heartbeat responses may be linked to Firefox telemetry if there is a "includeTelemetryUUID": true key in the arguments object of the show-heartbeat recipe.

Heartbeat never reports telemetry client_ids to SurveyGizmo, but, when includeTelemetryUUID is true, the Normandy user_id is reported to SurveyGizmo as the userid URL variable. Simultaneously, a heartbeat ping is sent to Mozilla, containing both the telemetry client_id and the Normandy userid that was reported to SurveyGizmo.

The userid is reported by appending it to the surveyId field of the ping, like:

hb-example-slug::e87bcae5-bb63-4829-822a-85ba41ee5d53


These can be extracted from the ping table for analysis using expressions like:

SPLIT(payload.survey_id,'::')[OFFSET(1)] AS surveygizmo_userid


## Data reference

Heartbeat data is available in the telemetry.heartbeat table in BigQuery.

Its structure matches the heartbeat ping schema.