Tokens are placeholders written as {{name}} that IVR Studio fills in during a call: the caller's number, the key just pressed, the menu option chosen, a spoken answer, or a variable you passed when starting the call. Prompts accept {{var.*}} tokens; HTTP Request and Email nodes accept every token. Variables come from the outbound API or a test call.

All tokens#

Token	Value
`{{caller}}`	The caller's number (on an outbound call, the number dialled)
`{{did}}`	The other number on the call (your IVR number on an inbound call)
`{{digits}}`	The key just pressed in a Menu, e.g. `2`
`{{menu_choice}}`	The label of that menu option, e.g. `Support`
`{{answer.<question key>}}`	A spoken answer captured by an Ask node, e.g. `{{answer.city}}`
`{{var.<name>}}`	A per-call variable, e.g. `{{var.order_id}}`
`{{voicemail_url}}`	Link to the voicemail recorded on this call
`{{reference_id}}`	Your `reference_id` from the outbound API
`{{call_sid}}`	The call's ID
`{{flow_id}}`	The flow's ID
`{{time}}`	Now, in IST, readable
`{{time_iso}}`	Now, in UTC, RFC 3339

Where tokens work#

Place	Tokens allowed
Say text, Menu prompt, Ask question	`{{var.<name>}}` only
HTTP Request URL (path and query), header values, body	All tokens
Email subject and message	All tokens
Order Action tag and note	Tokens allowed

A {{var.*}} the call doesn't have is spoken as nothing. In an HTTP request or email, an unknown token is sent unchanged, so typos are easy to spot.

Passing variables#

Variables come from:

the variables object of POST/v1/ivr/calls;
the Variables (JSON, optional) box of a test call;
an order automation, which fills order variables such as customer_name and cod_amount.

{ "variables": { "order_id": "A123", "name": "Ravi", "amount": 499 } }

Variable limits#

Limit	Value
Variables per call	20
Name	Letters, digits and `_`, starting with a letter or `_`, up to 64 characters (`[a-zA-Z_][a-zA-Z0-9_]{0,63}`)
Value	String, number or boolean (stored as a string), up to 512 characters. Objects and arrays are rejected
Total size	4 KB

Safe substitution#

In HTTP requests, token values are escaped for where they land. A value can't break out of a JSON string, add a query parameter, add a header line or change the host. For JSON bodies, put tokens inside string values: {"order_id": "{{var.order_id}}"}.

Variables in logs#

Each call's variables are shown in Call Logs and returned by GET/v1/ivr/calls/{call_sid} and the status callback.