# Sms Setup > Set up the SMS channel with the user's own Twilio account and number so the assistant can send and receive texts. After the credentials are stored, save and verify the user's SMS handle on their guardian contact if it is missing. Use when the user wants to text the assistant, when a send fails with a missing credential or 401, or when the channel reports it is idle. - Skill: `vellum-ai/sms-setup` (Agent Skill, multi-file: 2 files) - Install (CLI): `npx skillmds@latest add vellum-ai/sms-setup` - Raw SKILL.md: https://api.skillmd.com/api/skills/vellum-ai/sms-setup/raw - Safety review: pending - Works with: Claude Code, Claude.ai, OpenAI Codex - Category: Coding & Dev Tools - Author: vellum-ai (https://skillmd.com/u/vellum-ai) - Updated: 2026-09-17 - Page: https://skillmd.com/skills/vellum-ai/sms-setup --- Connects the SMS channel to the user's own [Twilio](https://www.twilio.com) account. Twilio is the only provider. ## Set expectations first Say this before starting, because it is usually not what people picture: - The user creates their **own** Twilio account and buys or ports their own number. There is no number provided for them. - People reach the assistant by texting **that number**, not the user's own mobile number. - The assistant does **not** read the user's personal text messages or history. Inbound arrives only on the Twilio line. - Twilio bills per message (roughly fractions of a cent in the US, more elsewhere), plus the number's monthly fee. A2P registration may be required for US traffic before carriers will deliver — see step 4. ## 1. Get the credentials All three come from the Twilio Console (https://console.twilio.com): - **Account SID** — on the dashboard, starts with `AC`. - **Auth Token** — on the dashboard, next to the Account SID. The **live** credentials, not the test pair: test credentials cannot send to real numbers. - **From Number** — a number on the account that can send SMS. Buy one under Phone Numbers if the account has none (a US number with SMS capability is the straightforward choice). ## 2. Store the credentials **The assistant performs this step.** Do not tell the user to run a terminal command, send them to Settings, or ask them to paste any of these values into chat. Tell them what the next secure field is for, then invoke each command below through the bash tool. Each command blocks until the user submits or dismisses its secure prompt. Run the prompts one at a time, in this order: ```bash assistant credentials prompt --service sms --field account_sid \ --label "Twilio Account SID" \ --placeholder "AC..." \ --description "Paste the live Account SID from your Twilio Console dashboard" \ --usage-description "Connect your Twilio account to the SMS channel" ``` ```bash assistant credentials prompt --service sms --field auth_token \ --label "Twilio Auth Token" \ --placeholder "Twilio Auth Token" \ --description "Paste the live Auth Token shown next to your Account SID in the Twilio Console" \ --usage-description "Send and verify SMS messages through your Twilio account" ``` ```bash assistant credentials prompt --service sms --field from_number \ --label "Twilio SMS Number" \ --placeholder "+15551234567" \ --description "Paste the Twilio number with SMS capability that should send and receive assistant messages" \ --usage-description "Send and receive SMS messages through your Twilio account" ``` Exit code `0` means the value was stored. Exit code `130` means the user dismissed that prompt, which is a valid choice: ask whether to retry or stop. Any other non-zero exit is an error to investigate before continuing. Never put a secret in `config.json` and never paste one into chat. The plugin reads these values from the credential store at call time, so rotating one later needs no restart. ## 3. Inbound The channel programs the number's SMS webhook itself on every start, so once the credentials are stored and the assistant is reachable (a public `ingress.publicBaseUrl` or a platform connection), inbound needs no manual step. A credential save is enough: the restart that follows it programs the number. If the assistant has no public URL, inbound SMS cannot arrive until a public ingress URL is available. The settings app reports the last registration attempt, including which step failed. "no webhook could be registered" with a URL reason means the assistant has no public address; a "not found on this Twilio account" reason means the from number does not match the account. ## 4. A2P and carrier registration US carriers require A2P 10DLC registration for traffic from Twilio numbers, and unregistered traffic is filtered. If the user's messages are not being delivered, check the messaging compliance section of the Twilio Console before debugging the plugin: the send will succeed from Twilio's side and silently fail at the carrier. A trial account can only text verified numbers added to the console — that restriction lifts on upgrade. ## 5. Save and verify the user's SMS handle Inbound from a handle that is not a verified identity on the guardian is classified unknown and denied under the default plugin floor. A number that is only verified on Phone Calling is still unknown on this channel — plugin channels keep their own contact records. A number that only appeared in chat history is not on the contact graph. After the credentials are stored, check: ```bash bun skills/sms-setup/scripts/guardian-sms.ts ``` The script prints one of: - `{ "found": true, "address": "+15551234567", "verified": true }` — already attested. Say so and skip the rest of this step. - `{ "found": true, "address": "+15551234567", "verified": false }` — stored but not attested. Open the prompt below with `--default-value` set to `address`. - `{ "found": false, "suggested": "+15551234567" }` — no SMS row yet. A Phone Calling number is only a prefill. Open the prompt with `--default-value` set to `suggested` unless this conversation already has their number. - `{ "found": false }` — nothing to prefill. Open the prompt. If this conversation already has their number, pass it as `--default-value` in E.164. Do not invent a number. Then save the handle as a guardian SMS channel (the prompt the contacts skill documents; replace `` with the value above): ```bash assistant contacts prompt-channel --type sms --address --role guardian ``` and tell the user to reply **STOP** unwanted-sender style or text the line from their phone so verification can complete the next time they message the assistant — the verified state is what admits them past the floor. ## 6. Confirm Have the user text the line. The turn runs, the reply arrives on their phone, and the settings app's inbound report confirms the delivery. If nothing arrives: the number's webhook (Twilio Console, Phone Numbers, the number, Messaging), the assistant's public URL, and step 4's A2P note, in that order.