RWS Docs

Interpolation replaces placeholders with actual values at runtime, enabling integrations that adapt to different contexts, time periods, and data.

Type	Syntax	Use Case
Simple Variables	`{{ variableName }}`	Insert values from parameters
DateTime	`{{ now.format(YYYY-MM-DD) }}`	Current date/time with formatting

When to use

Use interpolation when you need to:

Insert parameter values into API URLs or paths
Add dynamic dates to requests (today, yesterday, last week)
Reference dates from extraction datapoints
Generate file names with timestamps
Build parameterized query strings

Simple Variables

Replace placeholders with values from your integration’s parameters. The variable name must match exactly.

// Input
"users/{{ userId }}/orders"
// Params
{ "userId": "123" }
// Output
"users/123/orders"

Using datapoints with simple variables

To interpolate a datapoint value, add a query param with the datapoint field name. The param name becomes available as a variable.

// Query Params
{ "userId": "{{ userId }}" }
// Path
"users/{{ userId }}/orders"
// If datapoint has userId = "456", output becomes
"users/456/orders"

DateTime Interpolation

Insert current dates, calculate relative dates, and format output for API requirements. DateTime interpolation supports three prefixes:

Prefix	Description	Example
`now`	Current date and time	`{{ now.format(YYYY-MM-DD) }}`
`today`	Alias for `now`	`{{ today.format(YYYY-MM-DD) }}`
`date()`	Date from a data field	`{{ date(order.createdAt).format(YYYY-MM-DD) }}`

Format Patterns

Use .format(pattern) to control output. Patterns follow dayjs format tokens.

Pattern	Output Example
`YYYY-MM-DD`	2026-01-12
`DD/MM/YYYY`	12/01/2026
`YYYY-MM-DDTHH:mm:ss`	2026-01-12T15:30:00
`HH:mm:ss`	15:30:00
`MMMM D, YYYY`	January 12, 2026

Timezone Conversion

Use .timezone(tz) to convert to a specific timezone before formatting. The default timezone is America/Sao_Paulo.

{{ now.timezone(UTC).format(YYYY-MM-DDTHH:mm:ss) }}
{{ now.timezone(America/New_York).format(YYYY-MM-DD) }}
{{ now.timezone(Europe/London).format(HH:mm:ss) }}

Date Arithmetic

Add or subtract time using .add(amount, unit) and .subtract(amount, unit). Available units: days, weeks, months, years, hours, minutes, seconds

{{ now.subtract(1, days).format(YYYY-MM-DD) }} // Yesterday
{{ now.subtract(7, days).format(YYYY-MM-DD) }} // One week ago
{{ now.add(1, months).format(YYYY-MM-DD) }} // Next month
{{ now.add(2, weeks).format(YYYY-MM-DD) }} // Two weeks from now

Using Data Fields

Reference dates from your extraction datapoints with the date() function. Pass the field path as the argument.

{{ date(order.createdAt).format(YYYY-MM-DD) }}
{{ date(user.lastLogin).add(30, days).format(YYYY-MM-DD) }}
{{ date(invoice.dueDate).subtract(7, days).format(YYYY-MM-DD) }}

This is useful when you need to calculate dates relative to data values rather than the current time.

When a parameter is missing

If a {{ parameter }} referenced in a URL, header, or body has no value at runtime, the request is not sent. It fails with a clear parsing error naming the missing parameter. An empty string counts as missing: sending it would produce a malformed request (e.g. /items//details) that the target API would misroute instead of reject. Parameter names are case-sensitive and must match the data field exactly.

Connections

Business Rules

Extract

Load

Monitoring

Dynamic Parameters

When to use

Simple Variables

Using datapoints with simple variables

DateTime Interpolation

Format Patterns

Timezone Conversion

Date Arithmetic

Using Data Fields

When a parameter is missing

​When to use

​Simple Variables

​Using datapoints with simple variables

​DateTime Interpolation

​Format Patterns

​Timezone Conversion

​Date Arithmetic

​Using Data Fields

​When a parameter is missing

When to use

Simple Variables

Using datapoints with simple variables

DateTime Interpolation

Format Patterns

Timezone Conversion

Date Arithmetic

Using Data Fields

When a parameter is missing