template_not_found

Status: 404 · Code: template_not_found

The template_id you referenced doesn't exist, belongs to a different workspace, or was deleted.

Common causes

• Typo in the ID (tmpl_ prefix missing, wrong characters)
• The template was deleted
• You're in test mode (sk_test_) pointing at a tmpl_ created in production, or vice versa — templates are per-workspace, not per-mode, but the keys scope which workspace you're hitting

How to fix

List templates and pick the right ID:

curl -H "Authorization: Bearer $SEND0_API_KEY" \
  https://api.send0.dev/v1/templates

Or in the dashboard: app.send0.dev/templates.

If you're using a slug-style name in your code (welcome_v2), look it up once at startup and cache the ID — slugs can change, IDs are stable.

Related

• Templates API