@wassist/eve

The Wassist channel for Vercel eve to add WhatsApp to any eve agent in 60 seconds.

Backed by the official WhatsApp Business API via Wassist. Receive inbound WhatsApp messages as eve turns, reply with typing indicators, and ship outbound messages back to the user

Want to skip the README? Deploy on Vercel

Before you click Deploy, grab two values from wassist.app — Vercel will prompt for both during clone:

1. WASSIST_API_KEY — at Settings → API keys, click Create API key and copy the value.
2. WASSIST_WEBHOOK_SECRET — at Settings → Webhooks, click Create webhook. Use any placeholder URL (e.g. https://placeholder.example.com/eve/v1/wassist) — you'll update it after deploying. Copy the signing secret it generates.

Now deploy:

Once deployed, head back to the dummy webhook in the Wassist dashboard and replace the placeholder URL with https://<your-deployment>.vercel.app/eve/v1/wassist. Done.

Quickstart

In your eve project, install the package and create the channel file.

Requires an eve project (npx eve@latest init my-agent if you're starting from scratch) and Node.js >= 18.

1. Install

npm install @wassist/eve
pnpm install @wassist/eve

2. Create the channel file

Add agent/channels/whatsapp.ts to your eve project:

import { wassistChannel } from "@wassist/eve";

export default wassistChannel({
  credentials: {
    apiKey: process.env.WASSIST_API_KEY!,
    webhookSecret: process.env.WASSIST_WEBHOOK_SECRET!,
  },
});

That's it — eve auto-loads everything in agent/channels/, so your agent now answers WhatsApp.

3. Get your Wassist credentials

Sign up at wassist.app, then grab two values from the dashboard:

Env var	How to get it
WASSIST_API_KEY	Settings → API keys → Create API key → copy the value.
WASSIST_WEBHOOK_SECRET	Settings → Webhooks → Create webhook. The signing secret is generated when you create the webhook, so you need to create one before you can deploy. Use a placeholder URL like https://placeholder.example.com/eve/v1/wassist for now — you'll update it in step 5.

Drop both into your .env.local (and your hosting provider's environment variables).

4. Expose your agent over HTTPS

Wassist needs a public URL to POST signed webhooks to.

Production / staging — deploy your eve agent anywhere that gives you a public HTTPS URL. The Vercel one-click above is the fastest path:

Local dev — run your agent and tunnel it with ngrok or cloudflared:

# Terminal 1 — start the agent
npm run dev

# Terminal 2 — expose port 3000 (or whatever your agent uses)
ngrok http 3000

ngrok prints a public URL like https://abc123.ngrok.app. Note that it changes every restart unless you have a reserved domain — you'll need to update the Wassist webhook URL each time.

5. Register the webhook URL in Wassist

In the Wassist dashboard → Settings → Webhooks, set the webhook URL to:

https://<your-public-url>/eve/v1/wassist

For example: https://my-agent.vercel.app/eve/v1/wassist or https://abc123.ngrok.app/eve/v1/wassist.

(Override the path via the route config option if you need something else — see below.)

6. Subscribe your phone number to the webhook

The channel listens for subscription.message.received — Wassist's "this conversation is routed to my webhook" event. Without a subscription, inbound messages stay on the broadcast message.received event and never reach the channel.

In the Wassist dashboard, open the phone number you want the agent to answer and subscribe it to the webhook you registered in step 5. You can also subscribe individual conversations instead of the whole number — see the routing guide.

7. Send your bot a WhatsApp message

Open WhatsApp, message your connected number, and watch your eve agent reply.

How it works

flowchart LR
    Phone[WhatsApp user] -->|inbound msg| Wassist[Wassist platform]
    Wassist -->|signed webhook| Channel["POST /eve/v1/wassist"]
    Channel -->|send| Eve[eve runtime]
    Eve -->|message.completed| Channel
    Channel -->|messages.send| Wassist
    Wassist -->|outbound msg| Phone

Loading

1. A WhatsApp user messages your number.
2. Wassist POSTs a signed webhook to POST /eve/v1/wassist.
3. The channel verifies the X-Wassist-Signature header with your webhook secret.
4. On subscription.message.received — the event Wassist emits when a conversation has been routed to your webhook via phoneNumbers.subscribe or conversations.subscribe — the channel dispatches the message into eve via send(), keyed by the Wassist conversation ID as the eve continuation token. The legacy message.received broadcast event is intentionally ignored to avoid double-handling.
5. eve runs its turn. When the turn emits message.completed, the channel ships the reply text back to Wassist with wassist.conversations.messages.send(...).
6. eve's turn.started triggers a WhatsApp typing indicator via wassist.conversations.typing(...).

Configuration

wassistChannel({
  credentials: {
    apiKey: process.env.WASSIST_API_KEY!,
    webhookSecret: process.env.WASSIST_WEBHOOK_SECRET!,
  },
  senderWhitelist: ["+1 415 555 0100", "+447700900123"],
  route: "/eve/v1/wassist",
  baseUrl: "https://backend.wassist.app",
});

Option	Type	Default	Description
credentials.apiKey	string	process.env.WASSIST_API_KEY	Wassist API key.
credentials.webhookSecret	string	process.env.WASSIST_WEBHOOK_SECRET	Webhook signing secret.
senderWhitelist	string[]	undefined (all senders allowed)	Phone numbers permitted to message the agent. Inbound messages from any other sender are rejected with HTTP 401. Entries are compared after stripping whitespace and + symbols, so "+1 415 555 0100", "+14155550100", and "14155550100" are all equivalent.
route	string	"/eve/v1/wassist"	HTTP path the channel listens on. Must match the webhook URL you set in the Wassist dashboard.
baseUrl	string	"https://backend.wassist.app"	Wassist API base URL. Only override for self-hosted Wassist or non-prod backends.

If both credentials.apiKey and WASSIST_API_KEY are missing the channel throws a descriptive error at construction time — your agent won't boot with a misconfigured channel.

Troubleshooting

Missing Wassist API key at startup. Set WASSIST_API_KEY in your environment or pass it explicitly via credentials.apiKey. Get a key at wassist.app → Settings → API keys.

Invalid Wassist webhook signature (HTTP 400). The WASSIST_WEBHOOK_SECRET in your environment doesn't match the signing secret in the Wassist dashboard. Copy it again from Settings → Webhooks → Signing secret.

Wassist dashboard shows webhook deliveries failing with 404. Your route config and the webhook URL in the Wassist dashboard are out of sync. Defaults assume /eve/v1/wassist.

ngrok URL changed. Free ngrok URLs rotate on every restart. Update the webhook URL in the Wassist dashboard, or reserve a domain.

Examples

• quickstart-whatsapp — minimal deployable eve agent wired to @wassist/eve. One-click deploy on Vercel.

Links

• Wassist documentation
• @wassist/sdk — the TypeScript client this channel uses under the hood
• @wassist/cli — manage your WhatsApp agents from the terminal
• Vercel eve — the framework for building agents

License

MIT