# Scopes and Placeholders

Every scope maintains its own memory bank. Variables are stored in the memory bank by functions such as [Set Variable](function-reference.md#set-variable), by triggers, or by application events (e.g. call forwarding).

The memory bank is deleted when the scope is invalidated — for example, when a call ends, the call's scope is discarded.

Scope variables can be used in [conditions](conditions.md) and in placeholder resolution using the `scope[myVariableName]` syntax.

## Smart Link Scope

There is a special scope for handling [Smart Links](smart-links.md). When a Smart Link invokes a function, any arbitrary data included in the link URL is populated into the scope that executes the function.

## Supported Placeholders

Functions that perform in-app navigation, web navigation, or HTTP requests can use placeholders from the following sources:

- **Global parameters** — app-wide values such as `%platform%`.
- **Account parameters** — account-level values accessed via `%account[key]%`.
- **Scope variables** — values from the current scope's memory, accessed via `%scope[myVarName]%`.
- **Scope-specific parameters** — context-dependent values (see below).

### Call Screen Scope

The following placeholders are available within a call screen scope:

| Placeholder | Description |
|------------|-------------|
| `callId` | SIP call ID. |
| `groupId` | Call Group ID. |
| `callerTransportUri` | Remote caller transport URI. |
| `callState` | Call state at the moment the function is invoked (see Call FSM). |
| `callDirection` | Call direction: `Outgoing`, `Incoming`, or `Unknown`. |
| `callDuration` | Call duration in milliseconds, measured from call object creation to function invocation. |
| `callIncomingRingingDuration` | Ringing duration in milliseconds, measured from ringer start until the call is established, rejected, cancelled, or errors. |
| `callDeliveryMethod` | How the call was delivered: `pushed` (via push notification), `direct` (via SIP INVITE), or `unknown`. |
| `sipHeader[X-my-header]` | Value of a custom SIP header (headers starting with `X-`). |
| `callDate` | Call datetime in standard UTC format. |