Bring your own syntax

Configorama defaults to ${...} because that is familiar in deployment config. Some projects already use ${...} for CloudFormation, Serverless, Terraform, shell, VTL, or another templating layer. In those projects, change Configorama’s wrapper instead of fighting the other system.

Use buildVariableSyntax(prefix, suffix) to generate the regex for a custom wrapper:

const configorama = require('configorama')
const { buildVariableSyntax } = configorama
 
const config = await configorama('config.yml', {
  syntax: buildVariableSyntax('<<', '>>')
})

Then write Configorama variables with that wrapper:

stage: <<opt:stage, "dev">>
serviceUrl: https://api.example.com/<<stage>>
 
resources:
  Outputs:
    Endpoint:
      Value:
        Fn::Sub: https://${ApiGatewayRestApi}.execute-api.${AWS::Region}.amazonaws.com

With that setup, Configorama resolves <<opt:stage, "dev">> and <<stage>>. The ${...} strings stay untouched for the platform that owns them.

Common wrappers

buildVariableSyntax('<<', '>>')                 // <<opt:stage, "dev">>
buildVariableSyntax('[[', ']]')                 // [[file(./settings.yml):name]]
buildVariableSyntax('#{', '}')                  // #{param:domain}
buildVariableSyntax('{'.repeat(2), '}'.repeat(2)) // double-curly wrapper

Use delimiters that do not already mean something in the files you are resolving. For CloudFormation and Serverless, <<...>> is usually easier to scan than another brace-based wrapper.

Regular expressions

You can pass a custom regular expression when a project already has a wrapper convention.

const config = await configorama('config.yml', {
  syntax: /<<([ ~:a-zA-Z0-9=+!@#%*<>?._'",|\-\/()\\]+?)>>/g
})

Prefer buildVariableSyntax(...) unless you need full control over the character class.

HCL defaults

When loading .tf or .hcl files directly, Configorama uses $[...] by default so Terraform’s native ${...} interpolation remains Terraform’s. If you import HCL from another config format with file(), the parent config’s syntax applies.

See CloudFormation compatibility, formats and semantics, and API reference for related settings.