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Variables

Variable interpolation is used to pass dynamic data within Bot runtimes.

It allows values produced in one part of the system to be reused in another.

Voxtronics uses a unified syntax for variable interpolation across routing, adapters, transcripts, and pipelines.

Supported interpolation syntax​

  • ${variable} → interpolate a variable value
  • ${a.b.c} → interpolate a nested value
  • $${variable} → escape interpolation and produce the literal value ${variable}

Examples​

inputs = { payload = "${arguments}" }
inputs = {
  payload = "${arguments}"
  validation = "${validation}"
  process_result = "${process_result}"
}
url = "https://example.com/hooks/${tenant_id}"

To render a literal interpolation expression, prefix it with an extra $:

value = "$${tenant_id}"

This resolves to the literal string:

${tenant_id}

Behavior​

Variable interpolation:

  • Supports nested paths, such as ${a.b.c}
  • Works across objects and sequences
  • Is resolved at all levels, including nested values
  • Preserves non-string values when the whole value is an interpolation expression

For example:

inputs = { payload = "${arguments}" }

If arguments is an object, payload receives that object, not a stringified version.

When interpolation appears inside a larger string, the resolved value is inserted into that string:

url = "https://api.example.com/users/${user.id}"

Scope​

Variable interpolation is supported in:

  • Adapters, such as passing intent data to external APIs
  • Pipelines, such as passing results between steps
  • Routing, such as using extracted values for decisions
  • Transcripts, such as extracting and reusing user input

JSONPath extraction​

Variable interpolation is separate from JSONPath extraction.

Use ${variable} when referencing an existing runtime variable.

Use $.field when extracting a value from the current response payload, such as a pipeline step service response.

For example:

[[adapters.multi_webhook_workflow.steps]]
id = "validate_request"
service = "validate"
inputs = { payload = "${arguments}" }
outputs = { validation = "$.data" }

Pipelines​

Pipeline steps should use ${variable} for inputs and $.field for outputs.