Error Codes

All endpoints return application/json unless stated otherwise.

Status codes

Code	Meaning	What to do
`200`	Success (may include empty results)	Process the response
`401`	Missing or invalid API key	Check the `X-API-Key` header
`404`	Unknown `deviceId`	Verify the device ID
`500`	Internal server error	Retry with backoff; contact support if persistent

Error response shape

Errors return a single error field:

{
  "error": "Device not found"
}

Empty states are not errors

When a device has no data for the requested day, the endpoint still returns 200. List fields come back as an empty array and summary values as null:

{
  "deviceId": "863758060992848",
  "date": "2026-06-11",
  "series": [],
  "average": null,
  "max": null,
  "min": null
}

Treat empty arrays and null summaries as “no reading for this period,” not as a failure. This is common for intermittently measured metrics such as ECG, metabolic markers, and body composition.

Retry guidance

For 500, retry with exponential backoff (for example 1s, 2s, 4s) up to a few attempts.
For 401 and 404, do not retry — fix the request first.
If 500 responses persist for an endpoint, contact support@stealthera.in.

Overview

API Reference

Guides

Status codes

Error response shape

Empty states are not errors

Retry guidance

​Status codes

​Error response shape

​Empty states are not errors

​Retry guidance

Status codes

Error response shape

Empty states are not errors

Retry guidance