The placeholders
Every hole a template may carry, what it fills, and what it resolves to
right now. {{ '{{prompt}}' }} is required — without it every
image would be the same one, whatever anybody typed.
{# The current value beside each name, the way /admin/prompts shows a
variable's. A legend that lists names and not values answers "what may I
write" and not "what will happen", and the second is the question
somebody has while looking at a workflow that came out wrong. #}
{% for name, kind, what, current in placeholder_help %}
{{ '{{' ~ name ~ '}}' }}
{{ what }}
{% if name == "prompt" %}Required.{% endif %}
{{ current }}
{% endfor %}
Two of these are not spelled the way ComfyUI spells them, which is the
mistake that costs an afternoon: {{ '{{model}}' }} fills
ckpt_name and {{ '{{sampler}}' }} fills
sampler_name.
The right-hand column is what an omitted placeholder resolves to today —
the instance defaults from the image settings page, falling back to the
built-in floor. A model may override any of them except
{{ '{{batch}}' }}, which is yours alone.