Twilio for AI provides coding agents with skills and an MCP server for using Twilio services and documentation. The MCP server searches Twilio documentation and API specifications and retrieves full schemas for selected operations, while the skills supply procedural guidance to agents. Its catalogue add-ons are intended for Claude Code, Cursor, Codex, and other tools that support the Agent Skills standard.
Getting it into your agent
One page per mod, every tool's command on it. A separate URL per tool would split the same page into five that compete with each other.
npx skills add twilio/ai --skill twilio-whatsapp-send-messagegit clone --depth 1 https://github.com/twilio/aiWrote this? Show the measurements
A badge with what this costs and how it scanned, read live from this page, so it follows the numbers instead of freezing them. Markdown for a README, HTML for a documentation site or a project page.
[](https://agentmods.dev/skills/twilio/ai/twilio-whatsapp-send-message)<a href="https://agentmods.dev/skills/twilio/ai/twilio-whatsapp-send-message"><img src="https://agentmods.dev/badge/skills/twilio/ai/twilio-whatsapp-send-message/github.svg" alt="Measured on agentmods" height="20"></a>Or the 80×15 button, for a site that already has a row of RSS and ATOM ones. Only the verdict fits; the numbers stay here.
<a href="https://agentmods.dev/skills/twilio/ai/twilio-whatsapp-send-message"><img src="https://agentmods.dev/badge/skills/twilio/ai/twilio-whatsapp-send-message.svg" alt="Reviewed on agentmods" width="80" height="20"></a>- NVIDIA SkillSpector pass
What it costs to keep this loaded
Counted locally with the o200k_base tokenizer, which is exact for GPT models; Claude uses its own tokenizer and its counts differ. Treat this as one consistent yardstick across the catalogue rather than a bill. Prices are per million input tokens.
| Model | Per session | Once invoked |
|---|---|---|
| Fable 5.1 | $0.00083 | $0.01398 |
| Opus 5 | $0.00042 | $0.00699 |
| Sonnet 5 | $0.00017 | $0.00280 |
| Haiku 4.5 | $0.00008 | $0.00140 |
Grade A, and why
twilio-whatsapp-send-message scanned grade A with 0 findings against 26 rules in 11 categories — prompt injection, anti-refusal, data exfiltration, privilege escalation, supply chain, agent snooping, system-prompt leakage, SSRF and excessive agency — measured 11d ago.
A static scan of the body, not an audit. Every finding is printed with the line that produced it so you can judge whether it matters here. A mod is markdown that instructs an agent; that is exactly why what it instructs is worth reading.
Nothing flagged
None of the 26 patterns this scan looks for appear in this file: no shell pipes, no recursive deletes, no credential paths, no hidden text, no instruction-override or anti-refusal phrasing, no agent-config snooping. That is not a guarantee, it is the absence of the things that are checkable.
How it starts
The opening of the file, as written. The whole thing — 169 lines — stays where its author put it; the contents beside it link to each section on GitHub.
Overview
WhatsApp is one channel in Twilio's Messaging platform. All channels share the same messages.create() API — see twilio-messaging-overview for the full channel comparison and onboarding sequence.
Twilio routes WhatsApp through the Programmable Messaging API — all numbers use whatsapp:+E.164 prefix. Two sending modes apply: free-form (within 24 hrs of last inbound) and template (anytime). Sending free-form outside the window causes silent delivery failure — always check which mode is required.
| Mode | When allowed | Parameters |
|---|---|---|
| Free-form | Within 24 hrs of last inbound from user | body, optional mediaUrl |
| Template | Anytime | contentSid + contentVariables |
Prerequisites
- Twilio account with WhatsApp enabled
— New to Twilio? See
twilio-account-setup - Environment variables:
TWILIO_ACCOUNT_SIDTWILIO_AUTH_TOKEN— Seetwilio-iam-auth-setupfor credential setup and best practices
- SDK:
pip install twilio/npm install twilio - Recipient opted in to receive messages from your WhatsApp Business Account
Testing (sandbox): Join by texting join <your-code> to +14155238886. No registration needed — see Console > Messaging > Try it out > Send a WhatsApp message. Sandbox participants must re-join every 3 days.
Production: Register a WhatsApp Business sender first — see twilio-whatsapp-manage-senders.
Quickstart
Python
import os
from twilio.rest import Client
client = Client(os.environ["TWILIO_ACCOUNT_SID"], os.environ["TWILIO_AUTH_TOKEN"])
message = client.messages.create(
from_="whatsapp:+14155238886", # Sandbox sender (or your production number)
to="whatsapp:+15005550006", # Must have joined the sandbox
body="Your order has been confirmed."
)
print(message.sid) # MMxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx
print(message.status) # queued | sent | delivered | failed
What ships with it
3 files beside SKILL.md in the same directory: the scripts, references and assets a skill reads on demand. Not counted in the per-session cost; read them before you install if any of them is executable.
What this file has done since we first saw it
Hashed on every crawl. A supply-chain change to an agent config is a question of when, not whether, so the history is kept rather than the latest state alone.
- 11d ago First seen · 169 lines · 83 tokens per session scan A 04ac30cd716b
twilio-whatsapp-send-message is a skill published in the GitHub repository twilio/ai (32 stars, last pushed 26d ago), licensed MIT. It adds 83 tokens to every session and 1,398 once invoked, about $0.0004 per session on Opus 5. A static security scan graded it A with 0 findings. No closer match exists in the catalogue, so it is treated as the original; first seen 2026-08-30.
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