Get template

Retrieve one message template variant by name.

Meta stores one template per name + language, so a name identifies a family of variants, each with its own Meta id. Pass language to address one variant. Without it, a name with a single variant resolves to that variant; a name with several returns 409 ambiguous_template with details.languages. A bare language (es) matches a single regional variant (es_ES); if the family has several regional variants for it, that is also a 409. A full code (es_ES) must match exactly. Variants in PENDING_DELETION are not part of the family.