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An SMS AI agent in PulsyAI is a text-based assistant that handles SMS conversations and can be deployed as an embeddable chatbot widget on any website — operating entirely in chat, without any phone calls.

Forgiving channel

No STT errors, no TTS quirks. Leads reply on their own time.

Three surfaces

Standalone SMS, website widget, or fallback for an inbound voice agent.

Same methodology

Capture-first script, never repeat info back, conditional fallbacks.
Before you start: Read Build a Script end-to-end. The principles on that page apply directly to SMS — short messages, fast capture, no useless confirmations, conditional fallback triggers. The SMS channel inherits the methodology with a few channel-specific tweaks called out in the steps below.

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The SMS conversion stack

SMS agents in PulsyAI typically run in one of three configurations: The setup steps below walk you through configuring a standalone SMS agent. For the fallback configuration, see Build an Inbound AI Agent.

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Setup walkthrough

Assign a phone number (or deploy as a widget)

SMS agents need either a phone number capable of sending and receiving SMS, or a website chatbot widget deployment — or both.

Purchase in-app

Buy a new SMS-capable number directly from PulsyAI.

Import from Twilio

Bring a number you already own on Twilio (SMS enabled).

Import from Telnyx

Bring a number you already own on Telnyx (SMS enabled).

Website widget

Deploy as an embeddable chat widget — no phone number required.
For full details on each phone-number option, see the Phone Numbers page. For the website chatbot widget surface, see the Website Chatbot page.

Build the agent and paste your script

Inside your agent builder, create a new agent of type SMS. Paste the script you drafted using the Build a Script methodology into the agent’s prompt.The four-step structure (greeting → need identification → capture → closure) applies as-is for SMS, with the following channel-specific tweaks:

Greeting — keep it short

SMS doesn’t need the “you’re online with Luna the virtual assistant” voice disclosure pattern. A simple "Hi, this is Luna from {company_name} — how can I help?" is enough.

Message length — one or two sentences

Long SMS messages get split into multiple parts and feel robotic. If you need to capture multiple fields, ask for them one at a time across multiple short messages, not all at once.

No read-back — applies to SMS too

The “never repeat user information back” principle from Principle 3 applies to SMS. Acknowledge captures with “noted” or “got it” and move on. The lead can see what they typed in their own message history; repeating it back wastes turns and triggers exit intent.

Knowledge base — inline fits well

Inline knowledge fits well in SMS prompts because there’s no TTS latency to worry about. For larger knowledge bases, use the dedicated Knowledge Base section.

Configure Stale Conversation Recovery

For SMS agents, Stale Conversation Recovery is the single most important integration to configure. It handles the automatic retries when an SMS thread goes silent — the lead opened the message, maybe even responded once or twice, then dropped off without booking or capturing.Configure it in the SMS agent’s Integrations tab:

Trigger condition

Activate when the lead hasn’t responded within a configurable window (1-4 h for warm leads, 24-48 h for colder reactivation).

Relaunch delay

Speed-to-lead: 30 min – 1 h. Database reactivation: 24 h between attempts.

Max attempts

2-3 attempts maximum. Beyond this, recovery becomes spam and damages sender reputation.
For the full configuration walkthrough, see the dedicated Stale Conversations page.
The Call Back integration in the Integrations tab is the trigger that initiates an SMS fallback from a voice agent — it’s how an inbound voice agent decides to switch to SMS when a caller hangs up before completing the capture. Standalone SMS agents don’t need Call Back configured on themselves, because they’re already operating in SMS — there’s no voice-to-SMS transition to trigger.Call Back only becomes relevant for SMS agents in one scenario: when you’re using an SMS agent (either a standalone one, or the voice agent itself acting as its own SMS fallback) as the fallback target for an Inbound voice agent. In that case, the Call Back integration is configured on the Inbound voice agent, not on the SMS agent. The SMS agent simply receives the conversation thread when the inbound trigger fires.For details, see Call Back and the Build an Inbound AI Agent guide.

Set up campaigns (for standalone SMS agents)

Standalone SMS agents support SMS Campaigns — exactly the same mechanics as Outbound Campaigns but over SMS. Upload an Excel (XLSX) file with a PHONE_NUMBER column and any additional columns you want as dynamic variables ({first_name}, {email_address}, {last_purchase}, etc.), schedule the campaign for a chosen date, time, and timezone, and PulsyAI fires the SMS sequence on schedule.Use cases where SMS Campaigns shine:
  • Database reactivation — Re-engage cold leads from the client’s existing CRM database with a personalized SMS sequence. A casual SMS (“Hey {first_name}, it’s been a while — still interested in {service}?”) combined with Stale Conversation Recovery converts dormant database entries into booked appointments at a fraction of the cost of paid ads.
  • Promo and offer campaigns — One-off blasts tied to a specific offer, time window, or event. Excel column for the promo code, the offer expiration, or any other dynamic content the agent should reference.
  • Follow-up nurture sequences — Scheduled multi-touch SMS sequences for leads who engaged once but didn’t convert. The Excel file holds the contact list, Stale Conversation Recovery handles the retries between touches.
  • Speed-to-lead via SMS — When voice is not appropriate for the audience (younger demographics, B2C verticals where texting is the dominant channel), running speed-to-lead over SMS instead of voice can outperform voice on response rate.
  • Appointment reminders — A batch reminder to upcoming appointment holders, with the agent ready to handle reschedule requests inline.
The Excel format, the strict PHONE_NUMBER column rule, dynamic variable syntax, scheduling, and lifecycle states are identical to Outbound Campaigns. For the full walkthrough, see Outbound Campaigns — every detail there applies to SMS Campaigns, just over text instead of voice.

Connect integrations and test

The last step is wiring up where the captured leads should land. SMS agents typically integrate with:

CRM connectors

HubSpot, GoHighLevel, and other native connectors push lead data directly into your client’s CRM.

Webhooks

Custom destinations for clients with bespoke systems.

Email or Slack

Simple notification channels for smaller operations.
For the full list of available integrations and setup guides, see the Integrations section.
Final test: send a test SMS to the agent’s number (or open the widget on the client’s site), run through the full capture flow, and verify two things:
  1. The captured data lands correctly in the configured destination.
  2. If you deliberately stop replying mid-thread, the Stale Conversation Recovery SMS arrives at the expected interval.

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Common SMS use cases

Database reactivation

Re-engage cold leads sitting in the client’s CRM. A casual SMS sequence (“Hey, it’s been a while — still interested in ?”) combined with Stale Conversation Recovery converts dormant database entries into booked appointments at a fraction of the cost of paid ads.

Website chatbot widget

Deploy the SMS agent as an embeddable chat widget on the client’s website. Visitors who wouldn’t have picked up the phone or filled out a form will engage in chat — capturing leads from the same traffic the client is already paying to attract.

Inbound voice agent SMS fallback

Configured via Call Back on the Inbound voice agent. Catches callers who hung up before completing the capture and follows up via text, where they’re far more likely to respond than to a second call.

Speed-to-lead via SMS

For paid-ad lead forms where SMS converts better than voice. The agent texts the lead within seconds of form submission, captures intent and contact info, and books the human callback.

Customer support intake

Handle first-line support questions via SMS, deflect repetitive queries using the inline knowledge base, and escalate complex cases to the human team with full conversation context attached.

Multi-touch nurture sequences

Scheduled multi-message sequences for leads who engaged once but didn’t convert. The agent paces the touches over days or weeks, with Stale Conversation Recovery handling silent-thread retries between touches.

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Next step

Build an Inbound AI Agent

The implementation guide for inbound voice agents — pre-call intro, Verify User Information, and the Call Back + Stale Recovery fallback stack.

Build an Outbound AI Agent

The implementation guide for outbound agents — speed-to-lead, the greeting variant, Auto Call Back, and SMS fallback.