Rich content

This page documents ABL’s rich content output formats: voice configuration, format-specific content (Markdown, Adaptive Cards, HTML, Slack, WhatsApp), carousels, interactive actions, feedback surveys, and reusable templates. For the expression language (operators, functions, {{}} interpolation syntax), see Expressions and functions.

ABL supports multi-format output for delivering responses across different channels (web, mobile, voice, messaging platforms). The VOICE:, RICH_CONTENT:, and ACTIONS: blocks can be attached to any RESPOND statement, COMPLETE condition, or lifecycle handler. A pure reasoning agent (no FLOW:) may also declare top-level RICH_CONTENT: and ACTIONS: blocks that attach to its generated responses.

Overview

A single response can include:

Plain text — the default RESPOND string.
Voice configuration — SSML markup or natural language voice instructions.
Rich content — Markdown, Adaptive Cards, HTML, Slack Block Kit, WhatsApp, or AG-UI.
Carousels — scrollable card collections with images and buttons.
Interactive actions — buttons, select menus, and input fields.
Templates — reusable named response definitions with interpolation.

The runtime selects the appropriate format based on the delivery channel.

Voice configuration

Voice configuration provides channel-specific voice output. The VOICE: block can appear alongside any RESPOND.

Syntax

RESPOND: "Your booking is confirmed for December 15th."
VOICE:
  ssml: |
    <speak>
      Your booking is confirmed for <say-as interpret-as="date" format="mdy">12/15/2025</say-as>.
    </speak>
  instructions: "Speak in a warm, congratulatory tone"
  plain_text: "Your booking is confirmed for December fifteenth."

Voice properties

Property	Type	Required	Default	Description
`provider`	`string`	No	—	TTS provider (for example. `elevenlabs`, `google`, `azure`, `openai`).
`voice_id`	`string`	No	—	Provider-specific voice identifier.
`speed`	`number`	No	`1.0`	Speech-rate multiplier (`1.0` = normal).
`ssml`	`string`	No	—	W3C SSML markup for TTS engines (Google, Azure, Amazon Polly).
`instructions`	`string`	No	—	Natural language voice style instructions (OpenAI Realtime, Gemini Live).
`plain_text`	`string`	No	—	Voice-optimized plaintext. Used by ElevenLabs and as a fallback for all engines.
`pace`	`number`	No	—	Numeric speaking-rate multiplier (authoring alias for speed/pace controls).
`temperature`	`number`	No	—	Provider-specific TTS sampling/variation control.
`auto_tts_language_switch`	`boolean`	No	—	Switch the TTS voice/model to match the detected language of the response.

SSML example

VOICE:
  ssml: |
    <speak>
      <prosody rate="slow" pitch="+2st">
        Your wire transfer of <say-as interpret-as="currency">$50,000 USD</say-as>
        has been executed.
      </prosody>
      <break time="500ms"/>
      The confirmation number is
      <say-as interpret-as="characters">WR-2024-88431</say-as>.
    </speak>

Natural language instructions

For voice platforms that accept style instructions rather than SSML:

VOICE:
  instructions: "Speak slowly and clearly, emphasizing the confirmation number. Use a professional but warm tone."

Rich content formats

The rich-content block provides format-specific variants of a response. The runtime selects the variant matching the delivery channel.

RICH_CONTENT: is the canonical block keyword; FORMATS: is the original spelling, kept as an accepted alias. The .agent.yaml format accepts rich_content: or formats: the same way. Most places a rich-content block is authored — directly under a RESPOND: (in a flow step, ON_START, HOOKS:, or an ON_ACTION/ON_ERROR handler), in a tool’s on_result:/on_error: action block, and in a COMPLETE: condition (including one with no RESPOND: at all) — accept either spelling interchangeably.

Syntax

RESPOND: "Here are your flight options."
FORMATS:
  MARKDOWN: |
    ## Flight Options
    | Flight | Departure | Arrival | Price |
    |--------|-----------|---------|-------|
    | AA 142 | 8:00 AM   | 11:30 AM | $349 |
    | UA 891 | 10:15 AM  | 1:45 PM  | $289 |

  ADAPTIVE_CARD: |
    {
      "type": "AdaptiveCard",
      "body": [
        {"type": "TextBlock", "text": "Flight Options", "size": "large"}
      ]
    }

  HTML: |
    <div class="flight-results">
      <h2>Flight Options</h2>
      <table>...</table>
    </div>

  SLACK: |
    {
      "blocks": [
        {"type": "header", "text": {"type": "plain_text", "text": "Flight Options"}}
      ]
    }

Rich content properties

Channel-specific string formats:

Property	Type	Required	Default	Description
`MARKDOWN`	`string`	No	—	Formatted markdown text.
`ADAPTIVE_CARD`	`string`	No	—	JSON string conforming to the Microsoft Adaptive Cards schema.
`HTML`	`string`	No	—	HTML content for web-based channels.
`SLACK`	`string`	No	—	JSON string conforming to the Slack Block Kit format.
`AG_UI`	`string`	No	—	JSON string for AG-UI / CopilotKit events.
`WHATSAPP`	`string`	No	—	JSON string for WhatsApp interactive messages.

Structured template formats (channel-neutral; the runtime renders them per channel):

Property	Type	Description
`CAROUSEL`	`object`	Scrollable card collection. See Carousels.
`QUICK_REPLIES`	`array`	Quick-reply chips: each `{ id, label, iconUrl? }`.
`LIST`	`object`	`{ title?, items: [{ title, subtitle?, imageUrl?, defaultActionUrl? }] }`.
`IMAGE`	`object`	`{ url, alt?, thumbnailUrl?, caption? }`.
`VIDEO`	`object`	`{ url, alt?, thumbnailUrl?, caption? }`.
`AUDIO`	`object`	`{ url, alt?, thumbnailUrl?, caption? }`.
`FILE`	`object`	`{ url, filename, sizeBytes?, mimeType? }`.
`KPI`	`object`	`{ label, value, unit?, trend?: up/down/flat, iconUrl? }`.
`TABLE`	`object`	`{ columns: [{ key, header, align?: left/center/right }], rows, maxVisibleRows? }`.
`CHART`	`object`	`{ type: bar/line/pie, title?, data: [{ label, value, color? }] }`.
`FORM`	`object`	`{ title?, fields: [ActionElement], submitLabel? }`.
`PROGRESS`	`object`	`{ label?, value, max?, variant?: bar/circle }`.
`FEEDBACK`	`object`	Rating/feedback survey. `{ FEEDBACK_TEMPLATE?, prompt, type: thumbs/star/scale, max?, submit_label?, pending_message?, success_message?, error_message?, comment_threshold?, comment_prompt?, comment_placeholder?, when?, <field>_rules? }`. See FEEDBACK surveys.

Named templates (in the TEMPLATES: block) may also declare a RENDERABLES: list — customer-owned structured payloads with name, payload, optional targets (api/sdk_websocket/http_async), fallbackText, and schemaRef. Data-rich templates (KPI, TABLE, CHART, LIST, CAROUSEL, …) also support collection binding via from: / template: to render one entry per array item.

Template modifiers

Two cross-cutting modifiers apply to structured templates:

when — a conditional render guard (expression). On an agent-level rich-content block, the template renders only when the expression is truthy at reasoning finalization. Available on the rich-content block and on each structured template. See Expressions and functions for expression syntax.
adaptive — on LIST, KPI, and TABLE templates whose items/rows are bound to a tool variable, set adaptive: true to let the reasoning agent narrow which items/rows/columns render for the user’s request.

FEEDBACK surveys

A FEEDBACK block renders a rating/feedback card. Author it inside a RICH_CONTENT: (or FORMATS:) block.

Inline feedback is deprecated (DEPRECATED_INLINE_FEEDBACK). A FEEDBACK block without a FEEDBACK_TEMPLATE still compiles, but the compiler warns: “Inline feedback is deprecated and will be removed in a future version. Define a survey in the project Surveys area and reference it with FEEDBACK_TEMPLATE.” Prefer referencing a project survey template.

Referencing a survey template

Set FEEDBACK_TEMPLATE to a project survey name. The prompt and type (the survey’s measure) then come from the template, so they become optional here; any copy fields you do set act as per-string overrides (useful for translation):

RICH_CONTENT:
  FEEDBACK:
    FEEDBACK_TEMPLATE: Post_Chat_NPS
    prompt: "How likely are you to recommend us?"   # optional copy override

When a template is named you may not override the measure — type, max, scoring, range, and comment_threshold are owned by the template, and setting them alongside a template is a compile error. Naming a template that doesn’t exist in the project is an error (UNKNOWN_SURVEY_TEMPLATE). expires_after is the one exception to that rule — a numeric answer-window TTL (in seconds) that is overridable per-agent even when a template is referenced:

RICH_CONTENT:
  FEEDBACK:
    FEEDBACK_TEMPLATE: Post_Chat_NPS
    prompt: "How likely are you to recommend us?"
    expires_after: 600    # widen the answer window to 10 minutes for this agent

The effective window is the agent’s expires_after if set, else the template’s own TTL, else a 300-second platform default — clamped to 30–86400 seconds either way. A survey presented to the customer can only be answered within this window; a submission after it expires is rejected.

Inline FEEDBACK (deprecated)

Without a template, prompt and type are required:

Field	Type	Description
`prompt`	`string`	The question (aliases: `question`, `label`).
`type`	`"thumbs"` \| `"star"` \| `"scale"`	Rating measure. `stars` is an accepted alias for `star`.
`max`	`number`	Maximum rating value (for `star`/`scale`).
`submit_label`	`string`	Submit-button label.
`pending_message` / `success_message` / `error_message`	`string`	Status copy.
`comment_prompt` / `comment_placeholder`	`string`	Free-text comment field copy.
`comment_threshold`	`number`	Rating at/below which the comment field is requested.
`when`	`string`	Conditional render guard (expression).

Condition-based wording (`<field>_rules`)

To vary wording by condition — the second way to translate a survey, kept next to the source copy — add a <field>_rules list. Each rule has a when expression and the field’s replacement text (the field key, or the alias value). Rules are ordered, first match wins:

FEEDBACK:
  FEEDBACK_TEMPLATE: Post_Chat_NPS
  prompt: "How likely are you to recommend us?"
  prompt_rules:
    - when: "language == 'es'"
      prompt: "¿Nos recomendaría?"          # or:  value: "¿Nos recomendaría?"
  comment_placeholder_rules:
    - when: "language == 'es'"
      value: "Cuéntenos más..."

Only wording fields accept rules: prompt, submit_label, pending_message, success_message, error_message, comment_prompt, comment_placeholder. There is no type_rules/max_rules — the measure is never rule-selectable.

Copy rules are evaluated before the customer answers, so a when expression may reference max, language, channel, and session (as session.<name>) but not rating. An invalid condition is a compile error (INVALID_SURVEY_CONDITION).

Carousels

Carousels display a horizontal scrollable collection of cards, each with a title, subtitle, image, and action buttons.

Syntax

FORMATS:
  CAROUSEL:
    - title: "Economy Class"
      subtitle: "$289 - UA 891"
      imageUrl: "https://cdn.example.com/economy.jpg"
      defaultActionUrl: "https://booking.example.com/ua891"
      buttons:
        - id: select_economy
          type: button
          label: "Select"
          value: "ua891_economy"

    - title: "Business Class"
      subtitle: "$1,249 - UA 891"
      imageUrl: "https://cdn.example.com/business.jpg"
      buttons:
        - id: select_business
          type: button
          label: "Select"
          value: "ua891_business"

Carousel card properties

Property	Type	Required	Default	Description
`title`	`string`	Yes	—	Card title.
`subtitle`	`string`	No	—	Card subtitle or description.
`imageUrl`	`string`	No	—	URL for the card image.
`defaultActionUrl`	`string`	No	—	URL opened when the card itself is tapped.
`buttons`	`array`	No	—	Action buttons. See Interactive actions.

Interactive actions

Interactive actions add buttons, select menus, and input fields to a response. Users interact with these elements, and the agent handles the interactions via ON_ACTION blocks.

Syntax

RESPOND: "How would you like to proceed?"
ACTIONS:
  - id: confirm_wire
    type: button
    label: "Confirm Wire"
    value: "confirmed"

  - id: modify_amount
    type: button
    label: "Modify Amount"
    value: "modify"

  - id: cancel
    type: button
    label: "Cancel"
    value: "cancelled"

Action element properties

Property	Type	Required	Default	Description
`id`	`string`	Yes	—	Unique action identifier. Referenced in `ON_ACTION` handlers.
`type`	`string`	Yes	—	Element type: `button`, `select`, or `input`.
`label`	`string`	Yes	—	Display label.
`value`	`string`	No	—	Hidden value sent when the user interacts with this element.
`url`	`string`	No	—	For `button` type only: clicking opens this link instead of posting the value back to the agent. (Aliases: `link`, `web_url`.)
`description`	`string`	No	—	Subtitle or help text (for list items).
`options`	`array`	No	—	Options for `select` type. Each has `id`, `label`, `description`.
`inputType`	`string`	No	—	Input type for `input` elements: `text`, `number`, `date`, `time`, `email`.
`placeholder`	`string`	No	—	Placeholder text for `input` elements.
`required`	`boolean`	No	—	Whether the input is required before submission.

Select element example

ACTIONS:
  - id: select_account
    type: select
    label: "Choose Account"
    options:
      - id: checking
        label: "Checking ****4521"
        description: "Available: $12,340.50"
      - id: savings
        label: "Savings ****8872"
        description: "Available: $45,200.00"

Input element example

ACTIONS:
  - id: amount_input
    type: input
    label: "Transfer Amount"
    inputType: number
    placeholder: "Enter amount"
    required: true

  - id: reference_input
    type: input
    label: "Reference (optional)"
    inputType: text
    placeholder: "Invoice number, memo, etc."
    required: false
  submitLabel: "Submit"
  submitId: "submit_transfer"

Form submission

When the ACTIONS block contains input elements, you can specify a submitLabel and submitId for the form submission button:

Property	Type	Required	Default	Description
`submitLabel`	`string`	No	—	Label for the form submit button.
`submitId`	`string`	No	—	Action ID emitted when the form is submitted.

ON_ACTION handlers

Handle user interactions with action elements in flow steps:

FLOW:
  review_wire:
    RESPOND: "Ready to proceed?"
    ACTIONS:
      - id: confirm
        type: button
        label: "Confirm"
      - id: cancel
        type: button
        label: "Cancel"
    ON_ACTION:
      confirm:
        DO:
          - SET: user_confirmed = true
          - RESPOND: "Executing your wire transfer."
            FORMATS:
              MARKDOWN: "**Executing your wire transfer.**"
          - GOTO: execute_wire_step
      cancel:
        RESPOND: "Wire transfer cancelled."
        GOTO: cleanup

The ON_ACTION handler properties are described below.

Property	Type	Required	Default	Description
`ACTION_ID`	`string`	Yes	—	Which action element triggered this handler.
`CONDITION`	`string`	No	—	Optional condition based on the action value.
`DO`	ordered action list	No	—	Preferred form when order or nested rich `FORMATS:` matters.
`RESPOND`	`string`	No	—	Response message; supports nested `FORMATS:` inside a `DO` action.
`SET`	`Record<string,string>`	No	—	Variable assignments.
`CLEAR`	`string[]`	No	—	Session variables to clear.
`CALL`	`string`	No	—	Tool call; use `AS result_key` to store the result.
`GOTO` / `TRANSITION` / `THEN`	`string`	No	—	Flow step to transition to.
`HANDOFF`	`string`	No	—	Declared handoff target agent.
`DELEGATE`	`string`	No	—	Declared delegate target agent; supports nested `RETURN` and `ON_RETURN`.
`COMPLETE`	`boolean`	No	`true`	Complete the current flow.

If a handler RESPOND includes rich FORMATS: before terminal routing, that payload is forwarded as the fallback final channel payload. The terminal target’s own rich payload takes precedence.

Reusable handlers (`ACTION_HANDLERS:`)

ON_ACTION inside a flow step handles actions for that step only. To define reusable action handlers available across the whole agent, declare a top-level ACTION_HANDLERS: section. Each entry is keyed by the action element id and uses the same grammar as ON_ACTION (an optional CONDITION, shorthand RESPOND/SET/TRANSITION, or a canonical DO: block of ordered actions — SET, CLEAR, LOG, RESPOND, CALL, GOTO/TRANSITION/THEN, HANDOFF, DELEGATE, COMPLETE).

ACTION_HANDLERS:
  open_summary:
    DO:
      - SET: selected_action = "open_summary"
      - RESPOND: TEMPLATE(account_summary)
      - TRANSITION: display_summary

  contact_support:
    CONDITION: user.tier == "premium"
    DO:
      - RESPOND: "Connecting you to premium support."
      - HANDOFF: Support_Agent

Templates

Templates are named, reusable response definitions declared in the TEMPLATES: block. They support {{}} interpolation and multi-format variants.

Syntax

TEMPLATES:
  wire_confirmation:
    DEFAULT: |
      **Wire Confirmation -- {{confirmation_number}}**
      From: ****{{source_last4}} | To: {{beneficiary_name}}
      Amount: {{amount}} {{currency}} | Fees: {{fees}} | Total: {{total_debit}}
      Status: {{status}} | ETA: {{estimated_arrival}}
    MARKDOWN: |
      ## Wire Transfer Confirmation
      | Field | Value |
      |-------|-------|
      | Confirmation | {{confirmation_number}} |
      | Amount | {{amount}} {{currency}} |
      | Status | {{status}} |

  fee_breakdown:
    DEFAULT: |
      **Fee Breakdown for {{transfer_type}} wire**
      Wire fee: {{wire_fee}} {{currency}}
      {{#if intermediary_fee}}Intermediary fee: {{intermediary_fee}} {{currency}}{{/if}}
      **Total fees: {{total_fees}} {{currency}}**

Template properties

Property	Type	Required	Default	Description
`name`	`string`	Yes	—	Template name (the YAML key). Referenced via `TEMPLATE(name)`.
`DEFAULT`	`string`	Yes	—	Default template body with `{{}}` interpolation.
`MARKDOWN`	`string`	No	—	Markdown variant.
`ADAPTIVE_CARD`	`string`	No	—	Adaptive Card JSON variant.
`ACTIONS`	`object`	No	—	Interactive actions attached to this template.
`VOICE`	`object`	No	—	Voice (TTS) overrides for this template. Same shape as Voice configuration.
`RENDERABLES`	`object[]`	No	—	Customer-owned structured payload contracts (`name`, `payload`, `targets`, `fallbackText`, `schemaRef`).

Referencing templates

Use TEMPLATE(name) in any RESPOND value:

RESPOND: TEMPLATE(wire_confirmation)

Template interpolation

Template bodies use the same {{variable_name}} interpolation and {{#if variable}}...{{/if}} conditional-section syntax as any other ABL string — see Template strings in Expressions and functions for the full syntax, including calling built-in functions inside {{}}.

DEFAULT: |
  Hello, {{customer_name}}.
  {{#if has_loyalty}}Your loyalty tier: {{loyalty_tier}}.{{/if}}
  How can I help you today?

Channel selection

The runtime selects the response format based on the delivery channel.

Channel	Priority format	Fallback
Web/SDK	`RICH_CONTENT` (Markdown, HTML, AG-UI)	Plain text
Mobile	`RICH_CONTENT` (Adaptive Card, Carousel)	Plain text
Voice	`VOICE` (SSML, instructions, plain_text)	RESPOND text
Slack	`RICH_CONTENT` (SLACK)	Markdown
WhatsApp	`RICH_CONTENT` (WHATSAPP)	Plain text

If the preferred format isn’t available, the runtime falls back through the priority chain until it finds a defined format. Plain text (RESPOND) is always the final fallback.

Related articles:

Expressions and functions — operators, built-in functions, {{}} template-string syntax, and type coercion rules
Lifecycle and hooks — ON_START and hooks that support rich content
Multi-Agent and supervisor — COMPLETE conditions with rich responses
Data Types and utilities — types used in rich content and template fields

​Rich content

​Overview

​Voice configuration

​Syntax

​Voice properties

​SSML example

​Natural language instructions

​Rich content formats

​Syntax

​Rich content properties

​Template modifiers

​FEEDBACK surveys

​Referencing a survey template

​Inline FEEDBACK (deprecated)

​Condition-based wording (<field>_rules)

​Carousels

​Syntax

​Carousel card properties

​Interactive actions

​Syntax

​Action element properties

​Select element example

​Input element example

​Form submission

​ON_ACTION handlers

​Reusable handlers (ACTION_HANDLERS:)

​Templates

​Syntax

​Template properties

​Referencing templates

​Template interpolation

​Channel selection

Rich content

Overview

Voice configuration

Syntax

Voice properties

SSML example

Natural language instructions

Rich content formats

Syntax

Rich content properties

Template modifiers

FEEDBACK surveys

Referencing a survey template

Inline FEEDBACK (deprecated)

Condition-based wording (`<field>_rules`)

Carousels

Syntax

Carousel card properties

Interactive actions

Syntax

Action element properties

Select element example

Input element example

Form submission

ON_ACTION handlers

Reusable handlers (`ACTION_HANDLERS:`)

Templates

Syntax

Template properties

Referencing templates

Template interpolation

Channel selection