Documentation Communication channels SMS

Channels integration

SMS

SMS integration overview
  • CategoryChannels
  • AuthAccount credentials

Walk through the two Twilio paths: bring your own account or buy a new number from inside MessageMind.

Overview

SMS runs through Twilio. On the /channels/twilio page you pick one of two paths: "I already have a phone number" (bring your own Twilio or Telnyx account and plug in your Account SID + Auth Token) or "I need a new phone number" (search and buy one inside MessageMind, starting at $1/month, without ever opening a Twilio Console). The same Twilio connection also powers voice on the same numbers, so SMS threads and calls share one contact history.

What MessageMind can do with it

  • Route inbound SMS to a connected number into a single conversation thread per contact in the MessageMind inbox.
  • Send replies from the same number so the AI can answer in-thread without a handoff.
  • Share one Twilio connection with voice on the same numbers, so an SMS thread and a call land on the same contact.
  • Buy a new SMS-capable number from inside MessageMind in supported countries, starting at $1/month.
  • Port an existing number into the connected Twilio/Telnyx account rather than switch numbers.

Requirements

  • A MessageMind account with permission to connect the Twilio (SMS and voice) channel.
  • For the "I already have a number" path: a Twilio account (sign up at twilio.com/try-twilio) with the Account SID and Auth Token from the Twilio Console dashboard, plus at least one SMS-capable number on that account. Telnyx accounts also work; the connect card asks for the same credential pair.
  • For the "I need a new number" path: a payment method on your MessageMind account (the dashboard charges the number's monthly fee to that card).
  • For US-destined SMS: an A2P 10DLC compliance registration (brand + campaign) in /channels/twilio/a2p. US carriers block most A2P SMS traffic from unregistered brands.
  • For some non-US numbers: a regulatory bundle (address proof, ID, business documents) in /channels/twilio/bundles. Twilio refuses to assign the number without it.

How to connect

  1. Open /channels/twilio. You will see two cards under 'Let's connect Text Messages and/or Phone Calls'.
  2. Pick 'I already have a phone number' to bring your own Twilio (or Telnyx) account, or 'I need a new phone number' to buy one inside MessageMind.
  3. Bring-your-own path: in the Twilio Console (console.twilio.com) copy your Account SID (starts with AC) and Auth Token from the dashboard. Paste both into MessageMind, click Connect Account, then pick the phone numbers you want MessageMind to answer on.
  4. Buy-a-new-number path: pick a country, pick a number type (local, toll-free or mobile), optionally filter by area code (US and Canada) or by digits, and search. Pick a number and confirm the purchase; MessageMind charges your stored card and provisions the number under its managed Twilio account.
  5. For US SMS: open /channels/twilio/a2p and register your brand and messaging campaign. US carriers block most A2P SMS from unregistered brands. Approval usually takes a few business days.
  6. For some non-US numbers: Twilio will ask for a regulatory bundle. Open /channels/twilio/bundles, upload the address proof and business documents Twilio requests for that country, and wait for the under-review status to clear.

Authentication and permissions

Mechanism
Twilio Account SID and Auth Token (or Telnyx equivalent) for the owning account. There is no OAuth flow. Numbers purchased inside MessageMind are provisioned under MessageMind's own managed Twilio account; those have no credentials for you to paste.
Credentials
Account SID (stored as the account identifier) and Auth Token (stored as the account secret). Both call api.twilio.com on your behalf and verify Twilio webhooks against your own account's signature.

Available data and actions

Reads

  • The list of SMS-capable phone numbers on the connected account, used to validate which numbers you may send from.
  • Twilio search results when you look for a new number (by country, type, area code, digit filter).
  • A2P 10DLC brand and campaign status for US SMS registration, and regulatory bundle status for non-US numbers that need one.

Writes

  • Outbound SMS from one of your connected numbers to the customer's number, posted into the matching conversation thread.
  • A new Twilio phone number purchase under MessageMind's managed Twilio account when you buy a number through the dashboard, charged to your stored card.
  • A2P 10DLC brand and campaign registration submissions to Twilio, which Twilio forwards to The Campaign Registry (TCR) for approval.
  • Regulatory bundle submissions (address proof, ID, business documents) to Twilio when a country requires them.

AI agent use cases

  • Reply to a text message in the same thread the customer wrote on, with the AI picking up the contact's full history across SMS, voice, WhatsApp and the website chat.
  • Follow a chat on WhatsApp or Instagram with an SMS from the same business number when the customer only reads texts.
  • Buy a US local number from inside MessageMind in minutes, register it with A2P 10DLC, and start sending.
  • Port an existing SMS number into your Twilio or Telnyx account rather than ask customers to update anything.

Configuration

  • SMS and voice share one Twilio connection. If both are needed, one connect covers both.
  • A2P 10DLC is only needed for SMS traffic to US destinations. International SMS does not touch it.
  • Regulatory address requirements vary by country. The search filter 'Address requirements' lets you exclude numbers that require foreign-address proof when you only want local-only ones.
  • Several MessageMind tenants can connect the same underlying Twilio account. Webhook signatures are verified per tenant against the stored token, so one tenant's credential rotation never affects another's.

Example workflows

Bring your own Twilio account

  1. Create a Twilio account at twilio.com/try-twilio if you do not have one. The free trial gives you about $15 of credit and lets you verify numbers.
  2. In the Twilio Console (console.twilio.com) buy or verify at least one SMS-capable number: Phone Numbers, Manage, Buy a number.
  3. On the Twilio Console dashboard, copy your Account SID (starts with AC) and your Auth Token.
  4. On /channels/twilio in MessageMind, pick 'I already have a phone number', paste the Account SID and Auth Token, click Connect Account.
  5. Select the phone number (or numbers) you want MessageMind to answer on. SMS is now live.
  6. If any of those numbers will send to US destinations, open /channels/twilio/a2p and register the brand and campaign before sending.

Buy a new number inside MessageMind

  1. On /channels/twilio pick 'I need a new phone number'.
  2. Pick a country, pick a number type (local, toll-free or mobile), and optionally filter by area code (US and Canada only) or by digits.
  3. If a country requires a local or foreign address bundle, you can exclude those numbers from the search with the 'Address requirements' filter, or accept them and submit the bundle after purchase.
  4. Pick a number, confirm the monthly fee shown (from $1/month), and complete the purchase. MessageMind charges your stored card and provisions the number under its managed Twilio account.
  5. If the number sends to the US, finish A2P 10DLC registration in /channels/twilio/a2p. Otherwise the number is ready to send.

US SMS compliance (A2P 10DLC)

  1. Open /channels/twilio/a2p.
  2. Register your brand (legal business name, EIN or tax ID, address, website, contact email). Twilio forwards this to The Campaign Registry (TCR).
  3. Register a messaging campaign that describes the use case (customer care, 2FA, marketing, mixed) and show sample message content.
  4. Wait for brand approval (usually a few days) and then campaign approval. Status updates arrive back on /channels/twilio/a2p.
  5. Once approved, outbound SMS to US numbers begins at the throughput tier TCR assigns. Unregistered brands are rate-limited or blocked by US carriers.

Limitations

  • The outbound sender must be a number already attached to the connected account. MessageMind refuses a send from a number it does not see on that account.
  • US SMS traffic requires A2P 10DLC registration. Without it, carriers rate-limit or outright block messages, regardless of what MessageMind does.
  • Some countries require regulatory bundles (address proof, ID, business documents) before Twilio will provision or keep the number. The bundle status is shown in /channels/twilio/bundles.
  • Numbers purchased inside MessageMind live under MessageMind's managed Twilio account. You cannot pull the Account SID and Auth Token for those numbers; use the bring-your-own path if you need direct Twilio control.
  • Twilio Console credentials rotate on-demand only. Rotating the Auth Token in Twilio invalidates the stored token in MessageMind until you paste the new value in on /channels/twilio.
  • SMS pricing is per segment and varies by destination country (Twilio sets these). Deliverability on long numeric codes is country-specific.

Troubleshooting

An outbound SMS is rejected with an invalid-from error.

The chosen caller number is not on the connected Twilio account. Pick a number that belongs to that account, or add it to Twilio first.

The Auth Token was rotated in Twilio and inbound events stop verifying.

Update the stored Auth Token in MessageMind on /channels/twilio. The webhook guard checks the signature against the stored token; a rotated token has to be re-saved before Twilio events are accepted again.

The connect form says 'Invalid SID Provided' or 'Invalid Token Provided'.

Account SIDs start with AC and are 34 characters. Auth Tokens are 32 characters. Copy both from the Twilio Console dashboard rather than from an email or screenshot and paste them whole.

US customers are not receiving SMS even though sending succeeds.

US carriers block A2P SMS from unregistered brands. Open /channels/twilio/a2p and complete brand and campaign registration; sending is permitted once TCR approves.

A card is declined on a new-number purchase.

MessageMind surfaces Stripe's exact decline reason (card expired, CVC incorrect, bank verification required, etc). Update the card or try a different one; you are not charged on a failed attempt.

A newly bought non-US number is marked under review.

Twilio requires a regulatory bundle for that country. Open /channels/twilio/bundles, upload the address proof and documents Twilio requests, and wait for the status to clear.

A phone number search returns no results.

Narrow or widen the search: toggle the 'Address requirements' filter (exclude foreign requirements if you only want local-only numbers), change the area code or digit filter, or try a different number type (local, toll-free, mobile).

Disconnect and reconnect

  • On /channels/twilio, disconnect a connected Twilio account to clear the stored Account SID and Auth Token. The AI stops sending or receiving on any number tied to that account.
  • To release a number you bought inside MessageMind, open the number on /channels/twilio/connected and release it. Monthly fees stop at the next billing cycle.
  • To reconnect a bring-your-own Twilio account later, paste the Account SID and Auth Token again. Any numbers still on that Twilio account reappear in the selector.