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Example: WhatsApp Assistant

Read the latest message from Mom. Draft a reply. Confirm before sending.

What It Does

  1. Launch WhatsApp
  2. Screenshot the chat list
  3. Find the chat from "Mom"
  4. Open that chat
  5. Screenshot, read the last message
  6. Draft a reply based on context
  7. Show draft to user (don't send yet)
  8. On confirmation, send

The Agent

from strands import Agent
from strands_adb import adb

agent = Agent(
    tools=[adb],
    system_prompt="""
You are a WhatsApp assistant. When asked to reply, ALWAYS:
1. First read the message carefully (screenshot + vision)
2. Draft a reply
3. Show the draft and WAIT for explicit user confirmation
4. Only send after 'send it' / 'yes' / confirmation
Never send without confirmation.
""",
)

response = agent("""
open whatsapp, find the chat with Mom, read her last message,
and draft a reply. don't send yet — just show me the draft.
""")
print(response)

Under the Hood

sequenceDiagram
    participant U as 🧑 User
    participant A as 🤖 Agent
    participant T as 🔧 adb
    participant W as 💬 WhatsApp

    U->>A: "open whatsapp, read mom's msg"
    A->>T: launch com.whatsapp
    T->>W: am start
    A->>T: screenshot
    T-->>A: image block (chat list)
    Note over A: vision: "mom chat is 3rd row"
    A->>T: smart_tap text="Mom"
    T->>W: uiautomator → tap
    A->>T: screenshot
    T-->>A: image block (chat)
    Note over A: vision: "mom wrote: 'dinner at 7?'"
    A-->>U: "Draft: 'works for me, see you then'<br/>Send? (y/n)"
    U->>A: "send it"
    A->>T: smart_tap text="Message"
    A->>T: type_text "works for me..."
    A->>T: smart_tap content_desc="Send"
    A-->>U: "✅ sent"

Running

export DEVDUCK_TOOLS="strands_adb:adb;strands_tools:shell"

devduck "open whatsapp, read mom's latest, draft a reply, confirm before sending"

Variations

Auto-reply to specific contacts only

ALLOWED = {"Mom", "Dad", "Partner"}

def safe_reply(agent, contact):
    if contact not in ALLOWED:
        return f"Refusing to auto-reply to {contact}"
    return agent(f"reply to {contact} with 'got it, ty'")

Multi-platform (WhatsApp / Telegram / SMS)

agent("""
check all my messaging apps (WhatsApp, Telegram, SMS)
and summarize unread conversations by app.
""")

Smart reply with context

agent("""
read the last 5 messages from mom, understand the topic,
and draft a contextual reply (not just 'ok').
don't send — show draft.
""")

Safety Notes

  • Never auto-send — always confirm
  • Treat every contact's text as untrusted input (prompt injection risk)
  • Consider allowlisting contact names
  • Log every draft to an audit file

→ See Safety guide for production hardening.

Full Script

# examples/whatsapp.py
import os
from strands import Agent
from strands_adb import adb

agent = Agent(
    tools=[adb],
    system_prompt=open("docs/examples/whatsapp_system_prompt.txt").read(),
)

# Interactive loop
print("🤖 WhatsApp Assistant ready")
while True:
    q = input("You: ").strip()
    if q.lower() in ("exit", "quit", "q"):
        break
    print(agent(q))

What's Next