Build an msens cell tile URL template — cell_tile

Returns an XYZ tile URL template (with {z}/{x}/{y} placeholders) for the msens TiTiler factory. The SQL is canonicalized (whitespace collapsed) then base64url-encoded. Consistent canonicalization is critical so repeated calls with equivalent SQL produce identical URLs — Varnish keys on the full URL.

Usage

cell_tile_url(
  sql = NULL,
  colormap = "spectral_r",
  rescale = NULL,
  color = NULL,
  mtime = NULL,
  mdl_key = NULL,
  base = "https://titiler-v8.marinesensitivity.org"
)

Arguments

sql: character(1); SELECT returning cell_id and value columns
colormap: character; rio-tiler colormap name (default: "spectral_r")
rescale: numeric length-2 c(min, max) for normalization; NULL lets the server auto-compute from the SQL result on each tile request (prefer a client-side value from cell_stats() for cache stability)
color: character(1); hex #rrggbb or #rrggbbaa for a single-color mask. When set, the server renders every valid pixel in this flat color (ignoring colormap + rescale) — useful for binary "cell is present / cell is outside X" overlays.
mtime: character; optional cache-bust tag, typically the mtime of the source DuckDB file (e.g. from file.info(sdm_db)$mtime). Distinct from the data version tag (v6, v7, ...) used in paths.
mdl_key: character(1); the STABLE model key fast-path. When given (and sql NULL), the tile reads exactly one serving partition by exact path — the merged-model equivalent of a dense SQL point query, with no S3 LIST. titiler resolves mdl_key -> the internal integer partition id from the model registry, so this URL keeps referencing the same model across releases even as that internal id is renumbered.
base: character; base URL of the tile service. Defaults to the v8 titiler-v8 factory, which accepts ?mdl_key=. (The legacy titilecache Varnish caches the v7 titiler, whose API takes ?sql= and 422s on mdl_key — so it must not be used for v8 tiles.)

Value

character(1) tile URL template