Before rendering, confirm the template exists and read its manifest so your data keys bind. Two
canonical, key-authenticated read endpoints make this a fast pre-flight check.
List templates
GET /v1/templates returns every template in your key’s project
with its publish state — lightweight, no manifest.
Read one template’s manifest
GET /v1/templates/:slug returns the template plus its published
manifest and an auto-generated JSON Schema you can use for client-side validation.
Distinguish “missing” from “unpublished”
Cache the manifest and treat it as a contract. If a render returns invalid_input_data, re-read
the manifest — the published version may have changed which keys or types it expects.