How to post to a channel in Python with the Wapito WhatsApp API

"""Post to Channel with the Wapito WhatsApp API.

Send to the channel id like any recipient, upload media once and reuse it, prefer link posts for traffic, and confirm from the status event.

Run it with:
    export WAPITO_TOKEN="wpt_..."
    python post-to-channel.py
"""
import os

import requests

BASE_URL = "https://api.wapito.com/v1"
TOKEN = os.environ["WAPITO_TOKEN"]

# --- Publish a text post ---
url = BASE_URL + "/messages/text"

payload = {
    "to": "+15551234567",
    "body": "Your order #4182 has shipped. Track it here: https://acme.example/t/4182",
    "typing_time": 3
}
headers = {
    "Authorization": "Bearer " + TOKEN,
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.json())

# --- Post an image with a caption ---
url = BASE_URL + "/messages/image"

payload = {
    "to": "+15551234567",
    "media": "https://acme.example/labels/4182.png",
    "caption": "Your shipping label for order #4182"
}
headers = {
    "Authorization": "Bearer " + TOKEN,
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.json())

# --- Share a link with a preview ---
url = BASE_URL + "/messages/link"

payload = {
    "to": "+15551234567",
    "url": "https://acme.example/t/4182",
    "title": "Track order #4182",
    "description": "Out for delivery, arriving before 18:00.",
    "image": "https://acme.example/og/tracking.png",
    "body": "Your parcel is on the van:"
}
headers = {
    "Authorization": "Bearer " + TOKEN,
    "Content-Type": "application/json"
}

response = requests.post(url, json=payload, headers=headers)

print(response.json())

import hashlib
import hmac
import os
import time

from fastapi import FastAPI, Header, HTTPException, Request

app = FastAPI()
SECRET = os.environ["WAPITO_WEBHOOK_SECRET"].encode()
EVENTS = ["messages", "messages.status"]


def verify(raw: bytes, header: str | None) -> bool:
    """Checks the X-Wapito-Signature header: t=<ms>,v1=<hex hmac-sha256>."""
    if not header:
        return False
    parts = dict(p.split("=", 1) for p in header.split(",") if "=" in p)
    ts, sig = parts.get("t"), parts.get("v1")
    if not ts or not sig:
        return False
    if abs(time.time() * 1000 - int(ts)) > 300_000:  # 5 minute clock skew
        return False
    expected = hmac.new(SECRET, ts.encode() + b"." + raw, hashlib.sha256).hexdigest()
    return hmac.compare_digest(expected, sig)


@app.post("/wapito")
async def wapito(request: Request, signature: str | None = Header(default=None, alias="X-Wapito-Signature")):
    raw = await request.body()
    if not verify(raw, signature):
        raise HTTPException(status_code=401, detail="bad signature")
    payload = await request.json()
    if payload["event"] in EVENTS:
        print(payload["event"], payload["data"])
    return {"ok": True}  # answer 2xx fast; do the real work in a queue