Quantumplations has an API.

Quickstart

curl -X POST https://quantumplations.ai/api/v1/videos \
  -H "Authorization: Bearer $QP_API_KEY" \
  -H "Content-Type: application/json" \
  -H "Idempotency-Key: $(uuidgen)" \
  -d '{"prompt": "Explain how a Kalman filter works.", "duration_seconds": 60}'

{
  "id": "425e4bbe-5d63-4343-b0ad-8d90dc5805b4",
  "status": "queued",
  "cost_credits": 60,
  "duration_seconds": 60,
  "credits_remaining": 940,
  "video": null
}

curl https://quantumplations.ai/api/v1/videos/$RENDER_ID \
  -H "Authorization: Bearer $QP_API_KEY"

"video": {
  "url": "https://…/425e4bbe….mp4?token=…",
  "poster_url": "https://…/425e4bbe….jpg?token=…",
  "duration_seconds": 59.8,
  "expires_in": 3600
}

Endpoints

Render options

Everything but prompt has a default. Anything else you send is ignored.

Errors

Every failure is {"error": "<code>", "message": "…"} with a matching status.

Webhooks

Give callback_url and we post once, when the render settles: { event, id, status, error, completed_at }, with X-Quantumplations-Signature: t=<unix>,v1=<hex>. There's no retry, so keep polling as your fallback.

The signature is an HMAC-SHA256 of "<t>.<raw body>" keyed with the webhook secret shown beside your key. Verify against the raw bytes, before parsing:

import { createHmac, timingSafeEqual } from 'node:crypto';

export function verifyWebhook(rawBody, header, secret,
                              nowS = Math.floor(Date.now() / 1000)) {
  const parts = Object.fromEntries(String(header || '').split(',').map((p) => {
    const i = p.indexOf('=');
    return i < 0 ? ['', ''] : [p.slice(0, i).trim(), p.slice(i + 1).trim()];
  }));

  // Reject a replay of anything older than five minutes.
  const t = Number(parts.t);
  if (!/^[0-9]+$/.test(parts.t || '') || Math.abs(nowS - t) > 300) return false;

  const expected = createHmac('sha256', secret).update(`${parts.t}.${rawBody}`).digest();
  const given = Buffer.from(String(parts.v1 || ''), 'hex');
  // timingSafeEqual throws on a length mismatch, so check length first.
  return given.length === expected.length && timingSafeEqual(given, expected);
}

Answer with a 2xx quickly. Nothing you return is read.

Use it from an agent

There's an MCP server at https://quantumplations.ai/api/mcp, so Claude Code, Cursor and anything else that speaks MCP can order a film without leaving the conversation. It's the same API and the same key.

claude mcp add --transport http quantumplations https://quantumplations.ai/api/mcp \
  --header "Authorization: Bearer $QP_API_KEY"

Or, in a client that takes JSON:

{
  "mcpServers": {
    "quantumplations": {
      "type": "http",
      "url": "https://quantumplations.ai/api/mcp",
      "headers": { "Authorization": "Bearer qp_live_…" }
    }
  }
}

Five tools: generate_video, answer_questions, get_video, list_videos and get_credits. The one worth knowing about is answer_questions: the agent making your film stops and asks when a brief is ambiguous, and get_video reports awaiting_answers with the questions and how long is left to answer. Only generate_video spends anything, and it's annotated so your client asks before it does. There's deliberately no cancel tool — an agent that can cancel renders it didn't order is a footgun, and cancelling stays on the REST surface where a person presses the button.

A key in an MCP config is still a secret key. It sits on the machine running the client, which is a server-side place, but treat the config file the way you'd treat any file holding a credential.

Your API keys

Keys belong to your Quantumplations account and carry your credits, your plan and your beta access. Mint one per application, so you can revoke one without breaking the rest. Twenty live keys is the ceiling; revoke one to make room for another.

Credits

A render ordered through the API costs 1.5 credits per second of film, rounded up — so a 60-second film is 90 credits. The same film ordered from the website costs 60. cost_credits on the render always says exactly what was charged, so you never have to work it out. API and website renders draw on the same balance, every plan includes the API, and a render that fails or is cancelled refunds itself. See the plans.