Provision and manage devices in Memfault using the REST API: create devices, assign cohorts, and query fleet metrics

Steps

1. Generate a Memfault organization API key or user API key from the console under Settings > API Keys; include it as the Memfault-Email and Memfault-Password headers or use the bearer token scheme as documented for your authentication method
2. Create a device via the Memfault REST API: POST /api/v0/organizations/<org>/projects/<project>/devices with a JSON body containing device_serial, hardware_version, and optionally nickname and notes
3. Assign the device to a cohort: PATCH /api/v0/organizations/<org>/projects/<project>/devices/<device_serial> with {"cohort": {"slug": "<cohort_slug>"}}
4. List devices in a cohort: GET /api/v0/organizations/<org>/projects/<project>/devices?cohort=<cohort_slug> and paginate through results using the cursor parameter
5. Retrieve fleet metric aggregates: GET /api/v0/organizations/<org>/projects/<project>/metrics with filters for metric key, time range, and cohort; the response provides aggregate statistics (mean, p50, p95) across the queried devices
6. Use the metrics endpoint to build a health dashboard: track crash-free hours, OTA success rate, and custom heartbeat metrics defined in device firmware