Zavu Functions

Zavu Functions

Zavu Functions let you run TypeScript in our cloud and wire it directly to your WhatsApp/SMS/Email senders. You write the code locally, run npx zavudev deploy, and seconds later your agent is live with tools backed by real business logic.

TypeScriptCopy
import { defineAgent, defineTool } from "@zavudev/functions"

defineAgent({
  senderId: process.env.SENDER_ID!,
  name: "Bella",
  provider: "zavu",
  model: "openai/gpt-5.6-luna",
  prompt: "Eres Bella, anfitriona de la Pizzeria. Sé breve.",
  channels: ["whatsapp"],
})

defineTool({
  name: "check_availability",
  description: "Get free reservation slots for a date and party size.",
  parameters: {
    type: "object",
    properties: {
      date: { type: "string" },
      partySize: { type: "number" },
    },
    required: ["date", "partySize"],
  },
  handler: async ({ date, partySize }) => {
    // your real booking logic — DB, POS, external API, whatever
    return { available: true, slots: ["19:00", "21:00"] }
  },
})

That's the entire integration. One file. npx zavudev deploy. Done.

When to use Functions

How it relates to AI Agents

Zavu has two complementary ways to build agents:

Functions can fully manage an AI Agent: the defineAgent call creates and keeps the agent config in sync with your code. Once your function declares defineAgent, the agent is "managed by the function" — the dashboard surfaces this and disables manual edits to prevent drift.

Mental model

CodeCopy
+----------------+        +--------------------+        +-----------+
| WhatsApp user  | -----> | Zavu sender (WABA) | -----> | AI Agent  |
+----------------+        +--------------------+        +-----------+
                                                              |
                                                       (tool call)
                                                              v
                                            +-------------------------------+
                                            | Your Zavu Function            |
                                            |  defineTool(handler)          |
                                            +-------------------------------+
                                                              |
                                                       (return result)
                                                              v
                                                       Agent answers user

• Fully managed runtime. Each function runs in Zavu's serverless cloud. No consoles to log into — npx zavudev deploy handles bundling, dependencies, and publishing.
• Internal invocation. When the agent calls a tool, we use signed internal invocations — your function is not publicly exposed. No HTTP, no HMAC secrets to rotate, no DDoS surface.
• Native event binding. Functions can also subscribe to Zavu events (message.inbound, broadcast.status_changed, etc) via triggers.
• Auto-provisioned credentials. Every function gets a scoped ZAVU_API_KEY in its environment so it can call our SDK without you handling key distribution.

Quick tour

1. Install the CLI

   terminalCopy
   npx zavudev@latest --version
   # or install it globally: npm install -g zavudev
   # or grab a standalone binary from
   # https://github.com/zavudev/zavu-cli/releases

2. Login (one time)

   terminalCopy
   npx zavudev login

   Opens your browser, lets you pick a project. The API key is saved to ~/.zavu/credentials.json and used by every later command.

3. Scaffold a function

   terminalCopy
   npx zavudev fn init --template restaurant-booking -y
   cd reservations

   Creates index.ts with defineAgent + defineTool boilerplate.

4. Set secrets

   terminalCopy
   npx zavudev fn secrets set SENDER_ID jn76vnxet8g5nq661by3v06y1581bmmn

   The agent will run on this WhatsApp sender. Get the ID from npx zavudev senders list.

5. Deploy

   terminalCopy
   npx zavudev deploy

   Bundle, upload, agent + tools synced to your sender.

6. Try it

   Send a WhatsApp to the sender's number. The agent answers, calls your tool handlers, returns real data.

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