Templates (Handlebars)

Overview

component-templates renders Handlebars text from the current flow payload and message envelope. It is a small, deterministic component for formatting replies, reports, prompts, labels, and notification text before routing to the next flow step.

Use it when a flow needs string rendering, not when it needs a full HTML/email templating system. The current component exposes one operation, text, and one config object, templates.

Flow Shape

Use the component through component.exec or through the dev flow generated by greentic-flow:

format_answer:
  component.exec:
    component: ai.greentic.component-templates
    operation: text
    input:
      config:
        templates:
          text: "Hello {{payload.name}}. Your order #{{payload.order_id}} is ready."
          routing: out
      msg: "{{msg}}"
      payload: "{{payload}}"
  routing:
    - out: true

The component manifest defines this config:

Field	Required	Default	Purpose
`templates.text`	Yes	-	Handlebars template to render.
`templates.routing`	No	`out`	Optional routing target returned with the component output.
`templates.output_path`	No	`text`	Dot path where the rendered string is stored when wrapping output.
`templates.wrap`	No	`true`	When true, return an object; when false, return the rendered string directly.

Template Context

The runtime input gives the template two top-level objects:

Object	Meaning
`payload`	Incoming node payload. Use `{{payload.name}}`, `{{payload.items}}`, and similar paths.
`msg`	Channel message envelope. Use this for message metadata such as tenant, session, channel, and provider values when present.

{{payload}} is normalized to compact JSON for debugging. Use triple braces to avoid HTML escaping:

Debug payload: {{{payload}}}

Supported Handlebars Syntax

Standard Handlebars variables and built-in control flow work:

{{payload.user.name}}

{{#if payload.active}}
  Active
{{else}}
  Inactive
{{/if}}

{{#each payload.items}}
  - {{this.name}} x {{this.quantity}}
{{/each}}

The current component does not register custom helpers such as uppercase, currency, formatDate, remote template loading, or partial files. If a workflow needs those, create a custom component with greentic-component wizard and add the helper behavior there.

Output Examples

Default wrapped output:

{
  "payload": {
    "text": "Hello Ada"
  },
  "routing": "out"
}

Custom output path:

config:
  templates:
    text: "Hello {{payload.name}}"
    output_path: "reply.body"

{
  "payload": {
    "reply": {
      "body": "Hello Ada"
    }
  },
  "routing": "out"
}

Raw string output:

config:
  templates:
    text: "Hello {{payload.name}}"
    wrap: false

{
  "payload": "Hello Ada",
  "routing": "out"
}

Create a Custom Template Component

Start from the wizard instead of copying this component by hand:

greentic-component wizard --schema
greentic-component wizard --answers component-template-answers.json

For a pack-owned component, use the top-level launcher:

gtc wizard --schema
gtc wizard --answers pack-with-template-component.answers.json

Set operation_names to the operations you need, for example render_text,render_email. Turn on advanced_setup when the component needs HTTP, state, secrets, events, messaging, filesystem access, or custom config fields. The wizard writes the manifest, WIT bindings, QA scaffolding, i18n keys, build/test wiring, and default operation metadata.