vact-server

Server-only VACT client for Python. No dependencies — standard library only.

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pip install vact-server

Your backend is the only place the App Secret ever lives. It authenticates your own user, then asks VACT for a short-lived token scoped to them.

from vact_server import VactServer

vact = VactServer(
    app_id=os.environ["VACT_APP_ID"],
    app_secret=os.environ["VACT_APP_SECRET"],
)

# After YOUR login has decided who this is:
token = vact.create_access_token(
    user_id=current_user.id,
    allowed_callee_ids=["user_42"],   # optional: restrict who they may call
)
return {"accessToken": token["accessToken"]}

Verifying webhooks

Pass the raw request bytes. Re-serializing parsed JSON changes the bytes and the signature will not match.

from vact_server import verify_vact_webhook, VactServerError

@app.post("/webhooks/vact")
async def webhook(request):
    try:
        event = verify_vact_webhook(
            await request.body(),          # raw bytes, not the parsed dict
            dict(request.headers),
            os.environ["VACT_WEBHOOK_SECRET"],
        )
    except VactServerError:
        return Response(status_code=400)   # never process an unverified body

    # Deduplicate on event["eventId"] — delivery is retried.
    if event["type"] == "incoming_call":
        send_push(event["data"]["toUserId"], event["data"])
    return Response(status_code=200)

Signature verification is timing-safe and rejects deliveries whose timestamp is more than five minutes old, which stops replay.

Deleting a user's data

result = vact.delete_user_data(user_id)   # pages internally until complete

Full documentation: https://vact.online/docs.html