Configure Interpolations

Interpolations let you insert dynamic values into questionnaire text using {{placeholder}} syntax. This is useful for showing region names, thresholds, user answers, or constants directly in questions and descriptions — without hardcoding values.

How interpolation works

In Strapi, write text with {{placeholder}} tokens. When the questionnaire renders, these placeholders are replaced with actual values from:

• Constants — values defined in the questionnaire’s metadata constants
• Shared config — global values like featherName or privateHealthInsuranceThreshold
• Answers — the user’s previous answers in the current flow
• Region data — region-specific names and info

Syntax

Syntax	Source	Example
{{constants.myConstant}}	Questionnaire metadata constants	{{constants.expatLongTermLastSupportedStartDate}}
{{featherName}}	Shared config (global)	Resolves to “Feather”
{{privateHealthInsuranceThreshold}}	Shared config	Resolves to the current threshold amount
{{miniJobThreshold}}	Shared config	Resolves to the current mini-job income limit
{{answers.startDate}}	User’s answer to the startDate question	Shows the date the user selected
{{answers.variantData.name}}	Variant-specific data (e.g., provider name)	“AOK”, “Barmer”, “TK”
{{regionName}}	The human-readable name of the selected region	“Germany”, “Spain”, “France”

Examples

Show a region name in a question

In Strapi, set the screen question text to:

What is your address in {{regionName}}?

When the user selects Spain as their region, this renders as:

What is your address in Spain?

Show a constant threshold in a description

First, define a constant in the questionnaire’s metadata:

1. Go to the metadata section
2. In the constants repeatable field, add:
   • key: miniJobThreshold
   • value: 538

Then use it in a question’s screen description:

If your income is below {{constants.miniJobThreshold}}€ per month, you qualify for reduced rates.

Renders as:

If your income is below 538€ per month, you qualify for reduced rates.

Tip

Constants from shared config (like miniJobThreshold and privateHealthInsuranceThreshold) are available globally — you don’t need to define them in the questionnaire’s constants. They’re automatically injected.

Reference a user’s previous answer

Use the answers prefix to show what the user entered earlier:

To sign up with a start date of {{answers.startDate}}, please reach out to our customer support.

Renders as:

To sign up with a start date of 2026-08-01, please reach out to our customer support.

Show variant-specific content

For multi-variant questionnaires (e.g., public health with multiple providers):

Apply for your new public health insurance with {{answers.variantData.name}}.

Renders differently per variant:

Apply for your new public health insurance with AOK.
Apply for your new public health insurance with TK.
Apply for your new public health insurance with Barmer.

Use in rule comparison values

Constants can also be referenced inside rule comparison values:

{{constants.privateHealthInsuranceThreshold}}

This lets you compare against a dynamic value instead of hardcoding a number. If the threshold changes, you only update the constant — all rules using it update automatically.

Where interpolations work

Field	Works?	Notes
screen.question	Yes	Main question title
screen.description	Yes	Description below the title
screen.continueButtonText	Yes	Submit button text
Blocker/success text	Yes	Screen text on standalone layouts
props.mapValue labels	Yes	Radio/checkbox option labels
Rule comparison values	Yes	Dynamic thresholds in rules
Quote-page content	Yes	Text in quote-page components

Common patterns

Region-aware questionnaires

For multi-region questionnaires (e.g., expat insurance available in DE, ES, FR):

1. Add a region question early in the flow (typically a COUNTRY_SINGLE type)
2. Use {{regionName}} in subsequent questions to personalize the text
3. The framework resolves regionName from the selected region automatically

Shared thresholds

Instead of hardcoding financial thresholds that change yearly:

1. Define them as constants in the questionnaire metadata (or rely on shared config)
2. Reference them with {{constants.threshold}} or {{threshold}}
3. When the value changes, update the constant once — all references update

Caution

Interpolation happens at render time, not in Strapi. You won’t see the resolved values in the Strapi admin — you’ll see the raw {{placeholder}} text. Use Preview to see the actual rendered result.

See also

• Translation System — how t() and interpolate() work under the hood
• Questionnaire Metadata — where to define constants
• Configure Rules — using constants in rule values
• Syncing & Previewing — previewing interpolated content