An AI agent with its own WhatsApp number that answers questions and books appointments sounds like a weekend project. This free guide says it takes about thirty minutes, and having read it, I believe it.
It runs on Kapso, which connects Claude to WhatsApp's official API. You add their skills to Claude Code, paste one prompt, and Claude writes the thing.
What you need
Claude Code, either in the Claude app or in a terminal. Node.js, for one npx command. And a free Kapso account, which gets you 2,000 messages a month and one connected number.
The setup
First, get a number. Sign up for Kapso and connect one from the Connected numbers page. You can test everything in their sandbox before touching a real number. The free plan also gives you a pre-verified US number to receive the WhatsApp verification code. Make an API key while you're in the dashboard, because you need it in a minute.
Second, add the skills. In your project folder:
npx skills add gokapso/agent-skills
export KAPSO_API_BASE_URL=https://api.kapso.ai
export KAPSO_API_KEY=paste_your_key_here
Keep the key in a .env file. Don't paste it in a screenshot, and please don't commit it.
That installs four skills. They cover connecting and sending messages, workflows and agents, logs and delivery checks, and voice calls.
Third, just ask. Open Claude Code in the same folder and paste this:
Using the Kapso WhatsApp skills, build me a WhatsApp agent for my business that answers questions and books appointments. First ask me for my services, prices, opening hours and booking rules. Then set up the webhook, test it in the Kapso sandbox, and show me how to go live on my number.
Claude asks for your details first, then builds it.
Other prompts to try
An FAQ agent that answers from your own FAQ and, when it doesn't know, says so and hands the chat to you. A lead capture flow that asks new contacts for their name, what they need and their budget, then sends you a summary. And a debug prompt: "Use the observe-whatsapp skill to check my last 20 messages. Did any fail to deliver? Tell me why."
That last one is the quiet winner. Asking why a message failed beats clicking around a dashboard.
Read this before you message anyone
Only message people who agreed to hear from you on WhatsApp. Get opt-in first.
You can reply freely within 24 hours of a customer's last message. After that, only approved templates go through. This catches people out.
Cost comes in two flavours. Kapso counts every message toward your 2,000, incoming and outgoing. Meta bills template messages separately.
And the skills are marked alpha, so test in the sandbox before you go live.
If something's off
If Claude ignores the skills, run it from the folder where you ran npx skills add, or say "the Kapso WhatsApp skills" in your prompt. If you get a 401, check that KAPSO_API_KEY is set in the same terminal you launched Claude from. If messages don't arrive, ask Claude to run the observe-whatsapp checks, and remember that outside the 24-hour window only templates get through.
If you run a small business, or know someone who does, this is a quick way to see an agent doing real work instead of a demo.
Credit to Kapso, the agent skills by gokapso, and Anthropic for Claude. WhatsApp is a Meta trademark. Plans and commands are as of October 2026, so check their pages if anything has moved.