Response Format

Every API response — success or error — uses a consistent JSON envelope. You never have to guess the shape.

Success

{
  "success": true,
  "message": "ok",
  "updatedAt": "2026-05-31T10:00:00.000Z",
  "expiresAt": "2026-05-31T11:00:00.000Z",
  "data": {
    ...
  }
}

Field	Type	Description
success	boolean	Always true for successful responses
message	string	Human-readable status message
updatedAt	string	ISO 8601 timestamp of when the data was last scraped from the RSI website. Omitted when not available
expiresAt	string	ISO 8601 timestamp after which the cached data is re-scraped by the next request. Omitted when not available
data	any	The actual response payload

tip

HTTP headers carry the same freshness info.

The Last-Modified and Expires HTTP response headers are set to the same timestamps as updatedAt and expiresAt, in HTTP-date format. Use them for HTTP-level conditional caching — or read the body fields for application-level freshness checks. An X-Data-Source header (cache or live) tells you where the data came from. See HTTP Caching (ETags) for details.

Error

{
  "success": false,
  "message": "Unauthorized",
  "code": 401
}

Field	Type	Description
success	boolean	Always false for error responses
message	string	Human-readable description of the error
code	number	HTTP status code of the error

warning

Check success, not message.

Check the HTTP status code (or success) to detect errors. Do not branch on message — its wording may change without notice.

Key rules

• Errors always use a non-2xx HTTP status; code repeats it in the body.
• data is omitted entirely on error responses (there is no "data": null).
• updatedAt and expiresAt are omitted for endpoints that do not cache (e.g. GET /v2/me).

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Response headers

Header	When	Description
ETag	Successful responses	Weak fingerprint of the body (W/"...") — send it back in If-None-Match to get a 304. See HTTP Caching (ETags)
Last-Modified / Expires	Cached RSI data	Same moments as updatedAt / expiresAt, in HTTP-date format
X-Data-Source	Cached RSI data	cache or live
X-Quota-Consumed	Successful responses	Daily requests used by this call — 0 unless it was a billed ?refresh=true
X-RateLimit-Limit / X-RateLimit-Remaining / X-RateLimit-Reset	Every response	Per-minute request limit — see Rate Limits & Quota

For the full list of error codes and what causes them, see Error Codes.