Coming from fal, Replicateor WaveSpeed

Not a base-URL swap

Changing the base URL and the key is not enough on any of the three. Every request also changes in these ways:

• The key: Authorization: Bearer with a key that starts with sk_test_ or sk_live_.
• The model id goes in the body as model, and one id covers text, a first frame and references.
• An Idempotency-Key header on every generation request.
• A price cap: max_credits, or a quote_id from POST /v1/quotes.
• The result is a job: poll GET /v1/jobs/{id} or receive our signed webhook.

fal

Closest to ours: most Seedance field names are fal's. Also rename image_urls to reference_image_urls, send duration as a number, and move fal_webhook into the body as webhook_url.

Replicate

Take the fields out of input. Also rename image to image_url, reference_images to reference_image_urls and webhook to webhook_url.

WaveSpeed

Also rename image to image_url and reference_images to reference_image_urls, and move standard_webhook into the body as webhook_url. Read results from GET /v1/jobs/{id}.

Authentication

Where requests go and how they are signed.

Developer API access is by application: request it in the studio under API keys. A key is shown once. A developer key spends the developer API balance, and the same key works as a Bearer header on the MCP server.

Model ids

Theirs go in the URL; ours goes in the body as model. One of our ids covers text, a first frame and references: the fields you send decide.

For AI agents

Plain text for AI agents: inputs, legal values, every price and a request exampleseedance-2.0-fastseedance-2.0-miniqwen-image-2512-lightningqwen-image-2512qwen-image-edit-2511-lightningqwen-image-edit-2511

Seedance 2.0, field by field

Our names follow fal's where fal has the field, and the notes say where they differ. Fields sit at the top level of the JSON body; Replicate wraps them in input.

Their Seedance fields with no counterpart here. Sent as they are, they are refused as unknown fields (400 invalid_request).

fal

end_image_urlvideo_urlsaudio_urlsbitrate_modecodec

Replicate

last_frame_imagereference_videosreference_audios

WaveSpeed

last_imagereference_videosreference_audiosenable_web_search

Qwen-Image, field by field

Our image body is smaller than theirs: a size and an aspect ratio instead of free pixels, one image per job, and no sampler settings.

Their Qwen-Image fields with no counterpart here. Sent as they are, they are refused as unknown fields (400 invalid_request).

fal

negative_promptnum_inference_stepsguidance_scalenum_imagesoutput_formataccelerationenable_safety_checkersync_modeloras

Replicate

negative_promptstrengthwidthheightguidancenum_inference_stepsgo_fastoutput_formatoutput_qualitydisable_safety_checkerlora_weightslora_scale

WaveSpeed

widthheightoutput_formatenable_base64_outputenable_sync_mode

Async jobs and webhooks

All four run jobs in the background. What each one calls the steps:

Our webhook body is the job itself, and the signature is ours: code that verifies their webhooks will reject ours. How to verify ours

Idempotency

Every generation request needs an Idempotency-Key header, 1 to 255 visible ASCII characters. The same key within 24 hours returns the same job with HTTP 200, so a retry after a timeout never creates or charges a second job.

None of the three documents an idempotency key for creating a job (2026-10-22): fal suggests deduplicating webhooks by request_id, and WaveSpeed asks you to submit once and look for the task before you resubmit. Give each job one key and reuse it on every retry.

What is not compatible

Sent as they are, these fail or are refused here:

• Their client libraries (fal_client, replicate, wavespeed) do not call /v1. Use plain HTTP, the OpenAPI document or the MCP server.
• Their response shapes: a job here is a Job with outputs[].url, not a fal result, a Replicate prediction or a WaveSpeed data wrapper.
• Last frames: fal end_image_url, Replicate last_frame_image, WaveSpeed last_image.
• Reference videos and reference audio: fal video_urls and audio_urls, Replicate and WaveSpeed reference_videos and reference_audios.
• An automatic length or ratio, the ratios 4:3, 3:4 and 21:9, and 1080p or 4K renders. Higher resolutions here are a separate step, enhance, labeled AI Enhanced.
• A first frame together with reference images. Replicate refuses that too.
• Waiting for the result in one call (fal.run, Replicate's Prefer: wait, WaveSpeed's enable_sync_mode): every job here is async.
• Several images per job, PNG or WebP output, free width and height, several source images for an edit, LoRAs and sampler settings.
• Their webhook verification: our deliveries carry X-Signature, an HMAC-SHA256 with your whsec_ secret, not fal's ED25519 signature or the webhook-signature header.
• Paying after use: credits are prepaid, every job has a cap, and a job above max_credits is refused, not charged.
• Long-lived output links: ours last 24 hours. Read the job again for a fresh one.

Before and after

The same Seedance 2.0 Fast request with a first frame, as each platform documents it, then on /v1. The price cap comes from our price engine.

curl -X POST https://queue.fal.run/bytedance/seedance-2.0/fast/image-to-video \
  -H "Authorization: Key $FAL_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "prompt": "Slow dolly-in on a ceramic mug on a wooden table, morning window light",
    "image_url": "https://example.com/first-frame.jpg",
    "duration": "5",
    "resolution": "720p",
    "aspect_ratio": "16:9",
    "generate_audio": true
  }'

curl https://api.pershot.app/v1/videos/generations \
  -H "Authorization: Bearer $API_KEY" \
  -H "Idempotency-Key: $(uuidgen)" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "seedance-2.0-fast",
    "prompt": "Slow dolly-in on a ceramic mug on a wooden table, morning window light",
    "image_url": "https://example.com/first-frame.jpg",
    "duration": 5,
    "resolution": "720p",
    "aspect_ratio": "16:9",
    "generate_audio": true,
    "max_credits": 34
  }'

Prices are ours

Every job here is quoted in credits before it runs (US$1 = 100 credits) and never costs more than its quote or max_credits.

What fal, Replicate and WaveSpeed charge is on their own pages. Our comparison pages list their published Seedance 2.0 prices, each with the date it was read.