Get Tile Tokens Batch

Generate tile tokens for up to 50 datasets in one request.

The list must hold between 1 and 50 ids, and a request outside that is 422.

One round trip in place of one request per dataset, which is what a map with many layers would otherwise need.

A dataset that cannot be found or cannot be authorized does not fail the batch: that id maps to {"error": "..."} in the response instead, so check each entry for an error key before using it. Duplicate ids are collapsed.

The request as a whole still fails 401 in one case: a request that carried a credential which did not resolve and that no capability authorized answers 401 rather than a body of per-dataset errors. A request carrying no credential is served normally.

X-Embed-Token is accepted as a fallback authorization for the datasets inside that token's scope, so an embedded map can build a terrain source from real bounds and zoom limits.