> ## Documentation Index
> Fetch the complete documentation index at: https://docs.voiceflow.com/llms.txt
> Use this file to discover all available pages before exploring further.
# Variables
> Store and reuse context throughout a conversation.
Variables let your agent remember and reuse information during a conversation — things like a user's name, account details, or selections they've made. They act as your agent's short-term memory, letting it personalize responses, make decisions, and pass data between steps.
Variables are scoped to individual users via `user_id`. If ten users are talking to your agent simultaneously, their variable values are completely independent.
## Creating variables
You can create a variable from anywhere your can insert them — type `{` in most text inputs across Voiceflow to see your existing variables or create a new one inline.
You can also manage variables from the **Variables** tab in the sidebar. Click **New variable** in the top right to create one, or click an existing variable to edit it. When creating a variable, you can optionally set a default value — this gives your agent a fallback if the variable hasn't been set yet during a conversation. By default, variables are initialized automatically and set to 0.
## Using variables
Reference a variable by typing `{` and selecting it from the searchable menu. Variables work inside playbook instructions, API tool URLs and headers, condition steps, response messages, and more. If you're in a place where you need to use a variable, type `{` and it the menu will pop up.
## Setting variable values
| Method | How it works |
| ------------------------------------------------ | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| [**Set step**](/documentation/build/steps/set) | Assign a value directly in a workflow |
| [**Code step**](/documentation/build/steps/code) | Set values using JavaScript logic |
| **Tool responses** | Capture the response from an [API tool](/documentation/build/tools/api-tool) or [function](/documentation/build/tools/function-tool) and store it in a variable |
| **Playbook exit conditions** | Variables attached as [exit conditions](/documentation/build/playbooks) on a playbook are filled by the agent during the conversation, then passed back when the playbook completes via a [playbook step](/documentation/build/steps/playbook) |
## Built-in variables
Every project has access to built-in variables that are automatically set when a conversation begins or when certain events occur.
| Variable | Description | Example |
| ------------------ | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ------------------------------------------------------------------ |
| `user_id` | The user's unique ID, set via the [web chat widget](/documentation/deploy/widget/embedding-the-chat-widget) or [API](/api-reference/api-overview). For [phone](/documentation/deploy/phone/connect-a-phone-number) integrations, this is the caller's phone number. | `example_user` or `+16471234567` |
| `last_utterance` | The previous message sent by the user | `My name is Braden and I like cookies.` |
| `last_response` | The agent's most recent response | `Hello, I'm an agent! How can I help today?` |
| `last_event` | The last [event](/documentation/building-agents/behaviour) the user triggered (object, not string) | `{"type":"event","payload":{"event":{"name":"buySyrup"}}}` |
| `vf_memory` | The last ten user inputs and agent responses as a string, including tool calls | `agent: Hey what's up?`
`nuser: I want to order maple syrup.` |
| `vf_now` | Current date and time. Timezone configurable in **Settings** → **General** | `Monday, Jan 1, 2025, 16:37` |
| `vf_date` | Current date | `Jan 1, 2025` |
| `vf_time` | Current time | `16:37` |
| `vf_month` | Current month | `January` |
| `vf_day` | Current day of the month | `1` |
| `vf_year` | Current year | `2025` |
| `vf_user_timezone` | The user's timezone. Defaults to project timezone if unavailable | `America/Toronto` |
| `sessions` | Number of times this user has opened the agent | `8` |
| `timestamp` | [UNIX timestamp](https://en.wikipedia.org/wiki/Unix_time) of when the conversation began | `873700668` |
| `locale` | The user's [locale](https://learn.microsoft.com/en-us/globalization/locale/standard-locale-names), detected from their browser | `en-CA` |
| `platform` | The platform your agent is running on | `voiceflow` |