# Twilio Setup

> Configure Twilio credentials and phone numbers for voice calls

- Skill: `vellum-ai/twilio-setup` (Agent Skill, multi-file: 2 files)
- Install (CLI): `npx skillmds@latest add vellum-ai/twilio-setup`
- Raw SKILL.md: https://api.skillmd.com/api/skills/vellum-ai/twilio-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/twilio-setup

---


You are helping your user configure Twilio for voice calls. Walk through each step below.

## Value Classification

Before you begin, understand how each Twilio value is stored:

| Value        | Type       | Storage method                                                     | Secret? |
| ------------ | ---------- | ------------------------------------------------------------------ | ------- |
| Account SID  | Config     | `assistant config set twilio.accountSid`                           | No      |
| Auth Token   | Credential | `assistant credentials prompt --service twilio --field auth_token` | **Yes** |
| Phone Number | Config     | `assistant config set twilio.phoneNumber`                          | No      |

- **Config values** (Account SID, Phone Number) are non-sensitive identifiers. Collect them via normal conversation -- the user can paste them in chat or you can use `AskUserQuestion`.
  **Auth Token** is a secret. Collect it securely via `assistant credentials prompt` -- never accept it pasted in plaintext chat.

## Retrieving Twilio Credentials

Many steps below require the Account SID and Auth Token. Retrieve them with:

```bash
TWILIO_SID=$(assistant config get twilio.accountSid)
TWILIO_TOKEN=$(assistant credentials reveal --service twilio --field auth_token)
```

# Checking Current Configuration

You can determine whether Twilio has been fully set up by checking to see that all the following config and credential values have been set:

```bash
assistant config get twilio.accountSid
assistant credentials inspect --service twilio --field auth_token --json  # check "hasSecret" field
assistant config get twilio.phoneNumber
```

- If all three config values are non-empty -- Twilio is fully configured. Offer to show status or reconfigure.
- Otherwise, continue to the missing steps.
- If Account SID and Auth Token are already stored (even when you skip Step 2), give the Channel Trust Floors briefing before continuing unless you already gave it in this conversation.

# Twilio Setup Steps

Follow the steps below in order to fully configure Twilio in preparation to make phone calls.

## Step 1: Check Current Configuration

Mark setup as started before doing any read-only checks. This lets a managed gateway begin opening the Velay tunnel WebSocket immediately, so the public Twilio HTTP and WebSocket routes are warming up while the user finishes entering credentials and selecting a phone number:

```bash
assistant config set twilio.setupStarted true
assistant platform status --json
assistant gateway status --json
```

If `assistant platform status --json` reports an available platform assistant but `assistant gateway status --json` returns `{}` (no `tunnel` URL yet), continue with setup and check status again before configuring webhooks. Do not treat this as an ngrok setup problem unless the assistant is local/self-hosted without Velay.

Refer to "Checking Current Configuration" above to see the current state of the user's Twilio setup. If Twilio appears to be fully configured, offer to show status or reconfigure. If they are asking about inbound access or an unexpected first greeting, go to "Channel Trust Floors" and the matching Troubleshooting section. Otherwise, continue to the missing steps below.

## Step 2: Collect and Store Credentials

Tell the user: **"You'll need a Twilio account. Sign up at https://www.twilio.com/try-twilio -- it's free to start and includes trial credit."**

They need two values from the Twilio Console dashboard (https://console.twilio.com):

- **Account SID** -- visible on the dashboard, starts with `AC` (this is not a secret value and can be collected conversationally)
- **Auth Token** -- click "Show" to reveal (this is a secret value and should be collected securely)

### Collect Account SID

Ask the user for their Account SID. This is NOT a secret value, so the user should be encouraged to comfortable paste it into the chat directly. Once they have, store it as a config value:

```bash
assistant config set twilio.accountSid "<Account SID from user>"
```

### Collect Auth Token

Ask the user for their Auth Token. This IS a secret value, so the user should be prompted to enter the value securely. Do NOT ask them to provide it in the chat. Once they have, store it as a credential:

- Run (via the bash tool):

  ```bash
  assistant credentials prompt --service twilio --field auth_token \
    --label "Twilio Auth Token" --placeholder "your_auth_token" \
    --description "Enter your Auth Token from the Twilio Console dashboard (click 'Show' to reveal it)"
  ```

Confirm it has been stored successfully:

```bash
assistant credentials inspect --service twilio --field auth_token
```

If credentials are invalid, Twilio API calls in Step 3 will fail -- ask the user to re-enter.

Once both the Account SID and Auth Token are stored, tell the user how Phone access works before continuing. Do not skip this briefing, even if they already have a number.

> Connecting Twilio does not open the line to everyone. Phone starts on **Verified contacts**: you and people you have verified can talk. Anyone else who calls hears that I don't recognize the number, is asked for their name, and you get a request so you can decide.
>
> Change this any time on the **Channels** page: select **Phone**, then **Who can message**. The options are **No one**, **Only you**, **Verified contacts**, **Any contact**, and **Strangers** (anyone who dials can talk immediately).

See "Channel Trust Floors" below if they want more detail or want to change the floor.

## Step 3: Get a Phone Number

The assistant needs a phone number for voice calls. Three options:

### Option A: Use an Existing Number

You should assume this option if the user had just created their Twilio account. Trial accounts come with one free number.

Retrieve credentials, then list numbers on the account:

```bash
curl -s -u "$TWILIO_SID:$TWILIO_TOKEN" \
  "https://api.twilio.com/2010-04-01/Accounts/$TWILIO_SID/IncomingPhoneNumbers.json"
```

Present the `incoming_phone_numbers` array. Let the user choose.

### Option B: Provision a New Number

Retrieve credentials (see "Retrieving Twilio Credentials" above), then:

**Search for available numbers:**

```bash
curl -s -u "$TWILIO_SID:$TWILIO_TOKEN" \
  "https://api.twilio.com/2010-04-01/Accounts/$TWILIO_SID/AvailablePhoneNumbers/US/Local.json?VoiceEnabled=true&AreaCode=415"
```

- `AreaCode` is optional -- ask the user if they have a preference
- Replace `US` with another country code if needed

Present the first few results from the `available_phone_numbers` array (show `phone_number` and `friendly_name`).

**Purchase the chosen number:**

```bash
curl -s -u "$TWILIO_SID:$TWILIO_TOKEN" -X POST \
  "https://api.twilio.com/2010-04-01/Accounts/$TWILIO_SID/IncomingPhoneNumbers.json" \
  -d "PhoneNumber=+14155551234"
```

Note the `sid` field (starts with `PN`) from the response -- needed for webhook setup in Step 4.

### Option C: Manual Entry

If the user already has a number and knows it, skip the API calls. They can paste it directly in chat.

### Save the phone number

After choosing a number via any option, store it as a config value:

```bash
assistant config set twilio.phoneNumber "+14155551234"
```

## Step 4: Set Up Public Ingress and Webhooks

### Verify Public Ingress is Set Up

Twilio needs publicly reachable HTTP webhooks and, for live calls, a publicly reachable WebSocket path. First check managed/platform status:

```bash
assistant platform status --json
assistant gateway status --json
```

If `assistant platform status --json` reports an available platform assistant and `assistant gateway status --json` reports a `tunnel` URL (a `{ "tunnel": "..." }` object), do not load `public-ingress` or install ngrok. Use the managed Velay route for the WebSocket leg. If it returns `{}`, restart or re-hatch the assistant/gateway and check gateway logs for `Velay tunnel registered`; do not treat that as an ngrok setup problem.

For local/self-hosted assistants without Velay, load the `public-ingress` skill to determine whether `ingress.publicBaseUrl` is configured and walk the user through setting one up if not.

### Configure Twilio Webhooks

Set webhook URLs on the phone number so Twilio routes traffic to the assistant.

Retrieve credentials and config values:

```bash
TWILIO_SID=$(assistant config get twilio.accountSid)
TWILIO_TOKEN=$(assistant credentials reveal --service twilio --field auth_token)
PUBLIC_URL=$(assistant config get ingress.publicBaseUrl)
PHONE_NUMBER=$(assistant config get twilio.phoneNumber)
```

Look up the phone number's SID:

```bash
curl -s -u "$TWILIO_SID:$TWILIO_TOKEN" \
  "https://api.twilio.com/2010-04-01/Accounts/$TWILIO_SID/IncomingPhoneNumbers.json?PhoneNumber=$PHONE_NUMBER"
```

Note the `sid` field (starts with `PN`) from the matching entry, then update webhooks:

```bash
curl -s -u "$TWILIO_SID:$TWILIO_TOKEN" -X POST \
  "https://api.twilio.com/2010-04-01/Accounts/$TWILIO_SID/IncomingPhoneNumbers/$PHONE_SID.json" \
  -d "VoiceUrl=$PUBLIC_URL/webhooks/twilio/voice" \
  -d "StatusCallback=$PUBLIC_URL/webhooks/twilio/status"
```

## Channel Trust Floors

Phone access is a channel trust floor, separate from Twilio credentials. Credentials decide whether calls can reach the assistant. The floor decides **who** is allowed to talk once a call arrives.

| Floor                           | Who can talk                                                                                           |
| ------------------------------- | ------------------------------------------------------------------------------------------------------ |
| **No one**                      | Nobody, including you. Inbound calls are rejected.                                                     |
| **Only you**                    | Only the verified owner.                                                                               |
| **Verified contacts** (default) | You and people you have verified. Everyone else is asked to identify themselves, and you are notified. |
| **Any contact**                 | You and any known contact, including unverified ones. Strangers still request access.                  |
| **Strangers**                   | Anyone who dials the number, including complete strangers.                                             |

The control lives on the **Channels** page. Select **Phone** (it must be connected) and use **Who can message**. Only the guardian can change this setting. Point them there; do not treat this as a webhook or ingress repair.

Unknown callers on **Verified contacts** or **Any contact** hear a scripted greeting: the assistant does not recognize the number, will let the owner know, and asks for a name. After a name, the caller is held while you decide. That greeting means the call reached the assistant and the floor is doing its job.

## Clearing Credentials

To disconnect Twilio:

```bash
assistant credentials delete --service twilio --field auth_token
assistant config set twilio.accountSid ""
```

Phone number assignments are preserved. Voice calls will stop until credentials are reconfigured.

## Troubleshooting

### "Twilio credentials not configured"

Run Steps 2 and 3.

### "No phone number assigned"

Run Step 3.

### Phone number provisioning fails

- Verify credentials are correct
- Trial accounts may already have a free number -- check "Active Numbers" in the Console
- Ensure the account has sufficient balance

### Calls fail after setup

- Verify ingress is running: `assistant config get ingress.publicBaseUrl`
- For calls, ensure `calls.enabled` is `true`
- Trial accounts can only reach verified numbers

### Inbound call greeting asks for a name / "I don't recognize this number"

If the user complains about the **first thing callers hear** (asked for their name, "I don't recognize this number", "I'll let them know and see if I have permission", or held after giving a name), this is **who can contact the assistant on Phone**, not a Twilio, webhook, or voice-setup failure. The call reached the assistant. The Phone trust floor (default **Verified contacts**) is keeping unknown callers out of a normal conversation.

Identify it that way. Then:

1. Explain the default floor and that the greeting is expected for unrecognized numbers.
2. Point them to **Channels → Phone → Who can message**.
3. Ask what they want: keep the gate, verify specific people in Contacts, verify themselves (`guardian-verify-setup`), or change **Who can message** to **Strangers** on Channels → Phone. Only the guardian can change that setting.
4. Do not retune webhooks, ingress, or TTS unless the call never answered, Twilio reported an application error, or the spoken message named a missing speech credential and hung up.

The same floor applies if the user calls from their own unverified number and hears that greeting. Offer `guardian-verify-setup` so their number is recognized.

### Incoming calls not reaching the assistant

Webhooks on the Twilio phone number may not match the current ingress URL. This happens when ngrok restarts with a new URL or webhooks were never configured. Use this path only when the call does not connect or Twilio reports an application error. If the call connects and speaks the "I don't recognize this number" greeting, see the trust-floor case above.

**Diagnose** -- fetch the number's current webhooks and compare to the expected URL:

```bash
TWILIO_SID=$(assistant config get twilio.accountSid)
TWILIO_TOKEN=$(assistant credentials reveal --service twilio --field auth_token)
PUBLIC_URL=$(assistant config get ingress.publicBaseUrl)
PHONE_NUMBER=$(assistant config get twilio.phoneNumber)

curl -s -u "$TWILIO_SID:$TWILIO_TOKEN" \
  "https://api.twilio.com/2010-04-01/Accounts/$TWILIO_SID/IncomingPhoneNumbers.json?PhoneNumber=$PHONE_NUMBER"
```

Check that `voice_url` and `status_callback` start with the current `ingress.publicBaseUrl`. If they don't match, update them:

```bash
PHONE_SID=<PN sid from the response above>
curl -s -u "$TWILIO_SID:$TWILIO_TOKEN" -X POST \
  "https://api.twilio.com/2010-04-01/Accounts/$TWILIO_SID/IncomingPhoneNumbers/$PHONE_SID.json" \
  -d "VoiceUrl=$PUBLIC_URL/webhooks/twilio/voice" \
  -d "StatusCallback=$PUBLIC_URL/webhooks/twilio/status"
```