Substitute-day intro clip: a 20-second avatar per class period

A 20-second talking-avatar clip for a substitute day costs $3.68 at Sume's Standard quality, using the $0.184 per second rate on the rate card read 2026-10-04, and $4.90 at Plus ($0.245 per second). Make one clip per class period, each saying what that class does today, and the sub only has to press play.

The reason to do this per period, not once, is that the instructions differ: the second-period class is in the library and the fifth-period class has a quiz. A clip that names the page, the task and the time limit is easier to follow than a note on the desk.

What does each clip say?

About 50 words: a greeting, the task, where the materials are, how long, and who to ask. At speaking pace that is near 20 seconds. Avatar Video accepts scripts that Sume estimates at 4 to 60 seconds, so keep each period inside it and split anything longer (Avatar videos).

Which aspect ratio for a projector?

The default is 9:16, which suits a phone. For a classroom projector set aspect_ratio to 16:9 or 4:3 yourself. The supported values are 1:1, 3:4, 9:16, 4:3 and 16:9, and resolution is currently 720p.

import os, requests

periods = {
    "p2": "Good morning, period two. Today you finish the lab report in the library. Your group folder is on the front table. You have thirty minutes. Ask the library aide if you need anything.",
    "p5": "Hello, period five. Please clear your desks for the chapter quiz. It is twenty minutes. Turn it in face down when you finish, then read quietly.",
}
for k, script in periods.items():
    r = requests.post(
        "https://api.sume.com/v1/avatar-1.0/talking-video",
        headers={
            "Authorization": f"Bearer {os.environ['SUME_API_KEY']}",
            "Idempotency-Key": f"sub-day-{k}",
        },
        json={
            "avatar_handle": os.environ["AVATAR_HANDLE"],
            "aspect_ratio": "16:9",
            "quality": "standard",
            "script": script,
        },
        timeout=60,
    )
    print(k, r.status_code, r.json())

What does a full day cost?

The rate card lists Avatar Standard, Plus and Max without a product image at $0.184, $0.245 and $0.55 per second (API pricing). A day with five class periods at 20 seconds each is 100 seconds of video.

What should I do before the day?

Watch each clip with the sound on and check the words against your plan, then send the files to the person who will play them. Poll GET /v1/jobs/{id}/status until completed, and do not resubmit a paid request because your own client timed out (Jobs and results). Check your school's rules on AI-generated video before you use one with students.