{{fields}}

{{field_name}} is the placeholder syntax used inside a headless template — double braces, deliberately distinct from a flow’s own {variable_name} single-brace variable interpolation so the two never collide inside the same string.

Where fields can appear

Anywhere a template’s flow, hook action, or integration-template configuration expects a string: node text, a webhook body template, an integration credential, a config value. The editor scans the template payload for {{...}} tokens and keeps a field schema in sync automatically — you don’t maintain the field list by hand.

Field values

When creating an instance, you supply a value for every field the target template version declares, validated against the field schema (type, required-ness). Those values are substituted into the template payload before it’s saved as the tenant’s actual flow — by the time a flow exists in the tenant project, it’s a normal, concrete flow with no {{...}} tokens left in it, editable like any other.

Upgrading

When you publish a new template version that adds fields, existing instances are only prompted for the new fields on upgrade — previously-supplied values for unchanged fields are carried forward. See Versioning.