Captioning API · v1

Picute Captioning API

Submit a video URL, receive a captioned MP4, signed SRT, and transcript JSON. The full v1 surface is documented below — Quick Start, interactive reference, and webhook verification.

Quick start

Pick your language. The snippets below submit a caption job using your API key — replace the placeholder before running.

curl -X POST https://picute.net/api/v1/captions \
  -H "Authorization: Bearer pk_live_<your_key>" \
  -H "Content-Type: application/json" \
  -d '{
    "video_url": "https://cdn.example.com/clip.mp4",
    "language": "auto",
    "preset": "default",
    "callback_url": "https://api.your-app.com/webhooks/picute"
  }'

API reference

All endpoints, request schemas, and error codes for v1. Click any operation to expand request and response schemas.

Webhooks

Picute POSTs a signed webhook to your callback URL when a caption job reaches a terminal state. Verify the X-Picute-Signature header before trusting the payload.

Events

  • caption.completed — Caption job succeeded. data is the full Caption resource with output URLs populated.
  • caption.failed — Caption job failed. data.error has the error code and message.

Verify the signature

Compute HMAC-SHA256 over the raw 'timestamp.body' string with your webhook secret, then constant-time compare against the hex digest in the v1= field of the header.

import hmac, hashlib, time
from flask import Flask, request, abort

app = Flask(__name__)
SECRET = "<your_webhook_secret_from_dashboard>"
TOLERANCE_SECONDS = 5 * 60

def verify(req):
    header = req.headers.get("X-Picute-Signature", "")
    parts = dict(p.split("=", 1) for p in header.split(",") if "=" in p)
    timestamp = int(parts.get("t", "0"))
    received = parts.get("v1", "")
    if abs(time.time() - timestamp) > TOLERANCE_SECONDS:
        return False
    signed = f"{timestamp}.{req.get_data(as_text=True)}".encode("utf-8")
    expected = hmac.new(SECRET.encode("utf-8"), signed, hashlib.sha256).hexdigest()
    return hmac.compare_digest(expected, received)

@app.post("/webhooks/picute")
def hook():
    if not verify(request):
        abort(401)
    payload = request.get_json()
    print(payload["event"], payload["data"]["id"])
    return "", 204