whatsapp-agent-builder

WhatsApp Agent Builder by Jack Vidal

> Build, deploy & maintain your own WhatsApp AI agent — no coding required. > Hebrew-first. Wasender-powered. Runs on Claude Code.

A Claude Code plugin that walks non-technical users through the entire lifecycle of a WhatsApp AI agent, in plain Hebrew, one decision at a time. You make the choices; Claude Code does the work.

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What it builds

A live WhatsApp number that:

• Replies to messages with Claude (or OpenAI / Gemini) as its brain
• Has a personality, scope, and audience you define
• Can integrate with Google Calendar, Gmail, persistent reminders, human handoff, group chat, and voice transcription
• Runs 24/7 on Render.com (free tier works for personal use)
• Stores conversation history in SQLite or Postgres

Stack of the generated bot: Python 3.12 + FastAPI + httpx + Anthropic SDK, deployed to Render.com, connected to WhatsApp via Wasender.

Install

# In Claude Code:
/plugin marketplace add jackvidal/whatsapp-agent-builder
/plugin install whatsapp-agent-builder@jack-vidal-plugins

Then start the flow:

/wa

That's it. Claude Code reads .wa-state.json in the current directory, figures out what stage you're at, and routes you to the right skill.

The seven stages

1. wa-setup — Sign up at Wasender, generate a Personal Access Token, create a WhatsApp session, scan a QR with your phone, verify the connection. 2. wa-characterize — A short Hebrew Q&A that produces spec.json: name, tone, audience whitelist, in/out scope, knowledge base, tools wishlist. 3. wa-build — Generates the entire FastAPI bot from spec.json (no templates — fresh code traces directly to your spec). 4. wa-deploy — Pushes to GitHub, deploys to Render, registers the webhook URL with Wasender, runs a real round-trip test. 5. wa-connect — Adds tools one at a time: Calendar, Gmail, persistent reminders, human handoff, groups, voice notes. 6. wa-persistence — Choose where the bot's memory lives: ephemeral SQLite, Render Disk, Supabase, or Render Postgres. 7. wa-maintain — Forever-stage. Tweak personality, refresh tokens, diagnose "the bot is acting weird," reconnect after disconnect.

The plugin tracks state in .wa-state.json so you can stop and resume any time.

Why Wasender (and the trade-offs)

Wasender is a Baileys-based WhatsApp gateway — not the official WhatsApp Business Cloud API. That means:

✅ Cheap — $6/month for 1 number, no per-message fees, 3-day free trial. ✅ Simple — no Meta Business verification, no 24-hour reply window, full inbox visibility. ✅ Fast to launch — connect via QR scan in under a minute.

❌ Unofficial — there's a theoretical risk of WhatsApp banning the connected number. Always enable account_protection: true (the plugin defaults this on) and use a dedicated/secondary number for production. ❌ Rate-limited — with account protection: 1 message per 5 seconds. Fine for personal/small-business, not for mass marketing (which you shouldn't do anyway).

For most personal-assistant and small-business use cases, this is the right trade-off.

Design principles

• "I do, you decide." Claude Code runs every command, edits every file, makes every API call. The user makes decisions.
• Hebrew throughout the user-facing dialog. Internal architectural notes stay in English.
• No templates. Every file is generated from the user's spec.json, so reading the code teaches you what each choice did.
• Diagnose before changing. wa-maintain has a 7-step ladder for debugging. Redeploy is rarely the fix.
• Fast first win. wa-build wires only one tool (reminders) initially, so the bot replies on Wasender end-to-end before any OAuth complexity.

Repo structure

whatsapp-agent-builder/
├── .claude-plugin/
│   ├── plugin.json
│   └── marketplace.json
├── commands/
│   └── wa.md                     # /wa orchestrator
├── skills/
│   ├── wa-setup/SKILL.md
│   ├── wa-characterize/SKILL.md
│   ├── wa-build/SKILL.md
│   ├── wa-deploy/SKILL.md
│   ├── wa-connect/SKILL.md
│   ├── wa-persistence/SKILL.md
│   └── wa-maintain/SKILL.md
├── .env.example
├── .gitignore
├── LICENSE
└── README.md

The plugin generates a separate bot/ folder in the user's project directory — that's the actual runtime code that gets deployed.

Costs

Realistic monthly cost for a personal WhatsApp agent:

• Wasender: $6 (Basic, 1 number)
• Render: $0 (free tier, sleeps after 15min idle) or $7 (always-on)
• Anthropic API: $1–5 (Haiku 4.5 for typical personal-assistant usage)
• Supabase / Postgres: $0 (free tier) or $25 (Supabase Pro)

So roughly $7–18/month for a hobby bot, $30–50/month for an always-on production bot.

Credits

• Architectural inspiration: Asher-pro/wa-whatsapp-agent (the GreenAPI version)
• WhatsApp gateway: Wasender
• Built for Claude Code

License

MIT — see LICENSE.

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Author: Jack Vidal · jack@jackvidal.com