fal video models vs Luma AI API

fal video models

One key and one queue API reach 137 active text-to-video endpoints, each with a published price, an OpenAPI document and an llms.txt. Billing units, duration formats and audio pricing differ per model, there is no free tier, and a person must sign up in a browser and buy credit.

Luma AI API

Dollar prices per clip, $0.30 for 5 seconds at 720p, no credits to convert. Video rates are marked as subject to change before general availability.

fal video models

1. Submit to queue.fal.run, keep the request_id, then poll status_url or set fal_webhook. Never resubmit to check progress, because each submit is a new billable job
2. Read https://fal.ai/models/<endpoint-id>/llms.txt before a call. duration is the string "5" on Kling, "8s" on Veo 3.1 and an integer on Wan 3.0
3. Set generate_audio on purpose. It defaults to true and raises the Kling v3 Pro price from $0.112 to $0.168 a second and Veo 3.1 from $0.20 to $0.40
4. Check metadata.status in https://api.fal.ai/v1/models before pinning an endpoint. Deprecated endpoints carry no removal date
5. Use an API-scope key, never an ADMIN key. A new account runs 2 requests at once, so long video jobs queue behind each other
6. The MCP relay has no server-side approval gate. Call get_pricing and get the owner's approval before submit_job

Luma AI API

1. Send model ray-3.2 and type video, with resolution and duration inside video. Older model names are rejected
2. Poll GET /v1/generations/{id} until completed or failed, then copy the presigned URL
3. On 429, read detail. Rate limit exceeded means wait Retry-After, Too many concurrent jobs means wait for a job to finish
4. Use keyframes with keyframe_indexes for 10 second clips. start_frame and end_frame only work at 5 seconds