# x402 Video Gateway

> Pay-per-call AI video generation over the x402 payment protocol.
> No accounts, no API keys, no credit cards: HTTP 402 -> pay USDC on Base -> generate.

## How to buy (for agents)

1. POST to a generation endpoint below. You get HTTP 402 with payment requirements.
2. Pay with any x402 client (e.g. `@x402/fetch` wrapping your wallet) and retry.
3. The paid response returns `{ job_id, status_url }` immediately (async).
4. Poll `GET /jobs/:id` (free) until `status: succeeded`; download `video_url` within 24h.
5. Optional: send an `Idempotency-Key` header — retrying with the same key returns the
   original job instead of charging again (keys live 24h).

## Fixed SKUs

### seedance-5s-720p

- Endpoint: `POST /generate/seedance/5s-720p`
- Model: seedance-2.0 (seedance family)
- Output: 5s 720p MP4
- Price: $0.96 USDC per call (x402 exact scheme, network eip155:8453)
- Body: `{"prompt": "<text>", "ratio": "<optional, default 16:9>"}`

### seedance-fast-5s-720p

- Endpoint: `POST /generate/seedance-fast/5s-720p`
- Model: seedance-2.0-fast (seedance family)
- Output: 5s 720p MP4
- Price: $0.91 USDC per call (x402 exact scheme, network eip155:8453)
- Body: `{"prompt": "<text>", "ratio": "<optional, default 16:9>"}`

## Parametric endpoints (you choose duration/resolution/...)

### seedance-custom (parametric)

- Endpoint: `POST /generate/seedance/custom`
- Model: seedance-2.0 (seedance family)
- You choose: duration 4-15s, resolution (480p|720p|1080p), ratio, seed, generate_audio, camera_fixed
- Price: retail_per_second × duration + $0.00 fee, rounded up to the cent (480p=$0.112/s, 720p=$0.192/s, 1080p=$0.48/s)
- generate_audio=true multiplies the per-second rate ×1.25
- The HTTP 402 quote always shows the exact price for YOUR params before you pay.
- Body: `{"prompt": "<text>", "duration": 8, "resolution": "720p", "ratio": "16:9", "generate_audio": true}`

### seedance-fast-custom (parametric)

- Endpoint: `POST /generate/seedance-fast/custom`
- Model: seedance-2.0-fast (seedance family)
- You choose: duration 4-15s, resolution (480p|720p), ratio, seed, generate_audio, camera_fixed
- Price: retail_per_second × duration + $0.00 fee, rounded up to the cent (480p=$0.065/s, 720p=$0.182/s)
- generate_audio=true multiplies the per-second rate ×1.25
- The HTTP 402 quote always shows the exact price for YOUR params before you pay.
- Body: `{"prompt": "<text>", "duration": 8, "resolution": "720p", "ratio": "16:9", "generate_audio": true}`

## Free endpoints

- `GET /` — machine-readable storefront (JSON)
- `GET /jobs/:id` — job status + result URL
- `GET /status` — live success rate, p50 generation time, delivered count
- `GET /openapi.json` — OpenAPI 3.1 spec with x402 payment metadata

## Limits (fair use)

- Max 20 generation POSTs per minute per IP (429 past that).
- Max 5 jobs in flight per wallet — poll /jobs/:id, retry when one finishes.
- Request body up to 16384 bytes; prompt up to 2000 chars.
- At service capacity, new requests get 503 BEFORE payment (you are never charged).
- Repeatedly sending prompts that get rejected temporarily blocks your IP.

## Content policy

Prompts are screened BEFORE payment — rejected requests are never charged.
Hard red lines: content involving minors, real-person likeness/deepfakes.
Also rejected: sexually explicit content, graphic violence, and `--flag`
parameter directives inside prompts.

## Reliability

Generation auto-retries twice with upstream failover. All outcomes are recorded
in an append-only audit log. Live stats: GET /status.