# Variables

How {{...}} tokens are filled in when a step runs, what trigger, data and step outputs hold, and what happens when a value is missing.

Updated Oct 28, 2026. Source: https://smallbusinesschatbot.com/docs/workflows/variables

## What this does

A variable is a path between double curly braces, such as `{{trigger.email}}`. When a step runs, Small Business Chatbot replaces each variable with the value at that path in the run's data. Every text field of every step takes variables.

- **Where:** any text field in a step, or the tag button at its left
- **Format:** `{{root.key.key}}`, with a number for a list item, such as `{{trigger.messages.0}}`

## Inserting a variable

The tag button at the left of a text field opens the **Reference picker**. It lists the data of the run chosen under **Execution** in the step's runtime data inspector, the latest run by default: **Trigger** first, then **Variables** when the run has saved any, each step's output by name, **Last Output** and **Execution**. **+** opens a branch and **Insert** adds the path as `{{...}}` where you are typing.

![The Reference picker with the trigger's contact branch open on email, first_name and phone, each with an Insert button](https://smallbusinesschatbot.com/static/images/docs/workflows/variables-ref-picker-2026-10-28.webp)
*Workflows › Reference picker, October 2026*

With no run yet, **Trigger** is empty, except in a workflow with an appointment trigger, which shows a sample appointment. Type the path by hand until a run exists.

## The roots

| Root | What it holds | Example |
|---|---|---|
| `trigger` | What the trigger carried. For an Inbound Webhook with mapping rules, only the mapped fields. | `{{trigger.email}}`, `{{trigger.contact.phone}}`, `{{trigger.appointment.start_at_iso}}` |
| `data.trigger_raw` | What the trigger carried, before any mapping rules | `{{data.trigger_raw.customer.name}}` |
| `data.variables` | Values saved by Variable steps, under their **Variable name** | `{{data.variables.customer_name}}` |
| `node_outputs_by_name` | Each finished step's output, under its **Node name** | `{{node_outputs_by_name.http_request.response.status_code}}` |
| `data.last_output` | The output of the step that ran before this one | `{{data.last_output.contact_id}}` |
| `workflow` | The workflow's ID and name | `{{workflow.name}}` |
| `execution` | The run's ID and state | `{{execution.execution_id}}` |

What each trigger carries is on its page under [Triggers](https://smallbusinesschatbot.com/docs/workflows). What each step saves is on its page under Steps.

### Step names in paths

A step's **Node name** becomes its key under `node_outputs_by_name`: lowercase, with each run of spaces and other characters turned into one underscore.

| Node name | Key |
|---|---|
| HTTP Request | `http_request` |
| AI Agent | `ai_agent` |
| Send 24-hour reminder | `send_24_hour_reminder` |

Only steps that have already run in this run are there. When two steps share a name, one of them gets `_2` at the end, so give each step its own name. Renaming a step changes its key, so update the variables that use it.

## How a variable is filled in

| The field holds | It becomes |
|---|---|
| Only one variable, such as `{{trigger.number_of_messages}}` | The value with its own type: a number, a list or an object stays one |
| A variable inside text, such as `Hi {{trigger.first_name}}` | Text |
| A variable whose path has no value | Empty text |
| A path with a typo | Empty text. Insert paths from the **Reference picker** to avoid typos. |

To fall back to another value, use an [If](https://smallbusinesschatbot.com/docs/workflows/steps/branch) step on the empty value, or a default in the webhook's mapping rules. To do arithmetic or change text, use an AI Agent, Date Formatter or Text Extractor step.

A field that ends up empty can fail its step. A Send Text with an empty **Recipient phone** fails, and so does a Send Email with an empty **To**.

### In an HTTP Request's JSON body

Quote every token, such as `"email": "{{trigger.email}}"`. A token alone inside quotes keeps its type, so a number stays a number. [HTTP Request](https://smallbusinesschatbot.com/docs/workflows/steps/http-request#variables-in-the-request) has the full rules, including tokens without quotes.

### In an If step

The **Left side** keeps the value's type when it is one variable. The **Right side** reads `true`, `yes`, `false`, `no` and numbers as values, not text. [If](https://smallbusinesschatbot.com/docs/workflows/steps/branch#how-the-sides-are-read) has the details.

## The Variable step

**Variable** saves one value under a name, for later steps to read from `data.variables`.

| Field | What it does | Default or options |
|---|---|---|
| **Variable name** | The name to save under, such as `customer_name`. | Empty |
| **Value** | The value. It can hold variables, which are filled in when the step runs. | Empty |

A later Variable step with the same name replaces the value. A new step added with **+** starts as a Variable step until you change its **Node type**.