dataset_version

dataset_version identifies what the API is serving: the loaded data and the code that turns it into responses. Every response carries it in the envelope, and it’s the value behind the ETag header on every response:

{"dataset_version": "e9c25a6", "data": {}}

curl -D - -o /dev/null https://truefloat.app/api/v1/meta

etag: "e9c25a6"

Treat it as an opaque string: compare it for equality, never parse or order it.

What moves it, what doesn’t

change	dataset_version
a guide or item added, corrected or removed	changes
a fix to how responses are derived from the data (places, counts, aliases, response content)	changes
a docs, formatting or infrastructure deploy, this site included	unchanged

That split matters for caching: a client’s ETag stays valid, and If-None-Match keeps returning 304, across deploys that don’t change what the API returns. When a response body can differ, the version changes with it. See Caching & conditional requests for how to use it in a poller.

GET /v1/meta

The cheapest way to check the current version and when it last loaded:

curl https://truefloat.app/api/v1/meta

{
  "dataset_version": "e9c25a6",
  "data": {
    "dataset_version": "e9c25a6",
    "loaded_at": "2026-09-25T16:31:05.095031+00:00",
    "counts": {
      "items": 298,
      "guides": 308,
      "aliases": 1312,
      "systems": 536,
      "gradings": 83836
    }
  }
}

counts.items counts (def_index, paint_index) pairs. The counts above are the dataset as of 2026-09-25; /v1/meta always has the current ones.