Configuration
Variables
Use variables to personalize the message:{{firstName}}, {{lastName}}, {{email}}, {{phone}}, {{businessName}}, plus any trigger data or previous step outputs.
Compliance
The first SMS sent to a new phone number automatically includes an opt-out footer with your workspace info and instructions to reply STOP. This is required for compliance and happens automatically — you don’t need to add it to your message. Two independent toggles control this, under Phone Numbers → Compliance: the company/sender name and the opt-out notice. Both are on by default. You can disable either one per workspace (for example, if your carrier already appends opt-out language), but leaving them on is strongly recommended — opt-out text is generally an A2P/carrier requirement and turning it off makes compliance your responsibility.Opt-out enforcement
If the contact repliedSTOP (or any of STOPALL, UNSUBSCRIBE, CANCEL, END, QUIT) to the workspace number you’re sending from, the action fails with an opt-out error and the SMS is not sent. The check is per (contact, phone number) — a contact opted out from one number can still be reached from another.
A contact who later replies START, UNSTOP, or YES is opted back in automatically and the workflow can send again. Carrier-level opt-outs (received via Telnyx webhooks) are enforced the same way.
See Unibox → SMS opt-out handling for full opt-out behavior.
Limits
Messages longer than one segment are sent as multi-part SMS and count as multiple segments.
Checks
Before sending, the action verifies:- The contact has a phone number
- The contact is not on the Do Not Call (DNC) list
- The contact has not opted out from the selected workspace number
- The phone number is active in your workspace
- The daily SMS limit hasn’t been reached
Example
Follow-up after a call:- Trigger: Conversation ended → Agent Type: voice
- Condition: Outcome equals “completed”
- Action: Send SMS
- Phone number: Your workspace number
- Recipient: Contact
- Message: “Hi
{{firstName}}, great speaking with you! As discussed, here’s the link to get started: https://example.com/signup”
