# Prompt402

> Pay-per-request Higgsfield video API with Seedance 2.5 text-to-video, x402 payments and live upstream pricing plus a fixed 10% markup. No subscription.

Prompt402 is independent and is not affiliated with Higgsfield or ByteDance. It accepts an explicit allowlist of text-to-video operations, not arbitrary model slugs.

## Documentation
- [API guide](https://prompt402.com/docs): quote, x402 payment, retries, polling and failures.
- [Pricing](https://prompt402.com/pricing): live upstream estimate plus a fixed 10% service markup, rounded up to micro-USDC; no subscription.
- [Seedance 2.5](https://prompt402.com/models/seedance-2.5): supported text-to-video settings and official upstream mode sources.

## Machine-readable discovery
- [OpenAPI](https://prompt402.com/openapi.json): authoritative model-specific input schemas.
- [x402 discovery](https://prompt402.com/.well-known/x402): x402 v2 exact payment resource.
- [Storefront](https://prompt402.com/api/storefront): API and payment behavior.
- [Pricing JSON](https://prompt402.com/pricing.json): pricing policy, not a live quote.
- [Pricing Markdown](https://prompt402.com/pricing.md): human and agent-readable policy.
- [Consolidated guide](https://prompt402.com/llms-full.txt): request guide, model scope, pricing and FAQs.

## Request lifecycle
POST /api/v1/quote accepts the same generation body without payment or submission.
POST /api/v1/generations requires an 8–255 character Idempotency-Key. Inspect the 402 challenge and retry the same request with PAYMENT-SIGNATURE using an x402 client.
Payment settles upfront; rejected submissions require refund review, not an automatic refund. Completed submission replays return the original job without another charge.
GET /api/v1/generations/{id} polls only IDs submitted and recorded by this service. Poll no more than once every two seconds.
Production uses Base mainnet USDC; development and previews use Base Sepolia test USDC. The challenge specifies the active network and payable amount.

## Model scope
Supported: bytedance/seedance-2.0/text-to-video, bytedance/seedance-2.5/text-to-video.
Seedance 2.5 image-to-video, reference-to-video, video-edit and video-extend are not supported by Prompt402.
Official model sources last verified: 2026-09-17. Integration checks are hermetic, not real generation or payment tests.

## Complete request settings
Both operations require a nonblank prompt (maximum 2,000 characters). Unknown fields are stripped.
Seedance 2.5 text-to-video: duration integer 4–30 (default 5); resolution 480p or 720p (default 720p); aspect_ratio 16:9, 4:3, 1:1, 3:4, 9:16, 21:9 (default 16:9); output_format mp4 or mov (default mp4); generate_audio boolean (default true).
Seedance 2.0 text-to-video: duration 5 or 10 (default 5); resolution 480p, 720p or 1080p (default 720p); aspect_ratio 16:9, 9:16, 1:1 (default 16:9); generate_audio boolean (default false).

Quote response fields: upstreamUsd, priceUsdc, priceMicros, expiresInSeconds. Quotes are cached for up to 60 seconds; not a price lock.
Submission response: HTTP 202 with generation and relative poll URL. A queued job is not a finished video.
Limits: 10 quotes and 10 generation attempts in separate buckets, plus 30 status polls per IP per minute; process-local.
Errors: invalid input 400; unpaid request 402; conflicting/in-progress key 409; rate limit 429 with Retry-After. Generation submission errors after payment: 502 requires refund review; 500 requires reconciliation. Unknown status ID: 404. Status upstream failure: 502.
Keep the original key and response details for uncertain outcomes; do not start a new paid request to recover them. Keys are stored durably without expiry. No client wallet custody.

# Prompt402 pricing

Live Higgsfield upstream pricing plus a fixed 10% service markup. No subscription. Pay per request in USDC.

- Calculation: ceil(ceil(upstreamUsd * 1000000) * 110 / 100)
- Result unit: micro-USDC
- Rounding: Round the upstream USD estimate up to micro-USD, apply 10%, then round up to micro-USDC.
- Quote cache: up to 60 seconds for the same normalized request.
- The x402 402 challenge contains the payable amount. A prior quote is not a price lock.
- Settlement: Upfront, before upstream submission. Rejected submissions are recorded for refund review; refunds are not automatic.
- Production: Base (eip155:8453); development and preview: Base Sepolia (eip155:84532), test USDC.
- Supported operations: bytedance/seedance-2.0/text-to-video, bytedance/seedance-2.5/text-to-video.
- No hardcoded model price or universal lowest-price claim.

[Pricing page](https://prompt402.com/pricing) | [Pricing JSON](https://prompt402.com/pricing.json) | [API docs](https://prompt402.com/docs#quote)

Policy reviewed: 2026-09-17. Model availability and upstream prices may change.

## Frequently asked questions
### What is Prompt402?
Prompt402 is an independent Higgsfield API proxy for developers and AI agents. It exposes an asynchronous video generation API with x402 v2 exact payments in USDC. Request a live quote, authorize payment with your wallet, submit a supported request, and poll its status. No Prompt402 subscription is required.

### How much does Prompt402 cost?
Each request uses the live Higgsfield upstream estimate plus a fixed 10% service markup, rounded up to micro-USDC. There is no subscription or fixed model price list. The upstream estimate is first rounded up to micro-USD. Check the x402 payment challenge for the exact payable amount.

### Can I use Seedance 2.5 through Prompt402?
The Prompt402 request contract supports Seedance 2.5 text-to-video: 4–30 seconds, 480p or 720p, optional generated audio, and MP4 or MOV output. Seedance 2.0 text-to-video remains supported. Image, reference, video-edit, and video-extend operations are available upstream but are not supported by this proxy.

### Can an agent send any Higgsfield model slug?
No. Prompt402 validates an explicit model allowlist before payment. Only the text-to-video operations documented in its OpenAPI schema are accepted. Use the model-specific settings in the API reference; an upstream catalog listing does not automatically add a model or mode to Prompt402.

### When is payment taken, and what if submission fails?
Payment settles before the request is submitted to Higgsfield. A rejected submission is recorded for refund review, not automatically refunded. Keep your Idempotency-Key: replaying a completed submission returns the original job without a new charge. Avoid submitting a new paid request to recover an uncertain outcome.

## Verified upstream modes and sources
- Text-to-video: prompt-driven video with optional audio. Supported by Prompt402. https://console.higgsfield.ai/models/bytedance/seedance-2.5/text-to-video/playground
- Parameter reference: https://console.higgsfield.ai/models/bytedance%2Fseedance-2.5%2Ftext-to-video/api-reference
- Image-to-video: image URL, optional end image and prompt. Not supported by Prompt402. https://console.higgsfield.ai/models/bytedance/seedance-2.5/image-to-video/playground
- Reference-to-video: image, video or audio inputs. Not supported by Prompt402. https://console.higgsfield.ai/models/bytedance/seedance-2.5/reference-to-video/playground
- Video edit: prompt-based editing of existing video. Not supported by Prompt402. https://console.higgsfield.ai/models/bytedance/seedance-2.5/video-edit/playground
- Video extend: extend video from a URL and prompt. Not supported by Prompt402. https://console.higgsfield.ai/models/bytedance/seedance-2.5/video-extend/playground
- Current Higgsfield video catalog: https://console.higgsfield.ai/explore/video

Upstream capabilities do not imply proxy support. No fixed upstream price, guaranteed output quality, universal market leadership or affiliate relationship is claimed.