# Add / Replace Background Music — yeezhan.com
> One-time pay-per-task emergency tool to make your file ready for submission.
> No credits, no balance. One payment unlocks one task result, valid for 24 hours.

Tool domain: https://video-audio-replace.yeezhan.com
Skill definition: https://video-audio-replace.yeezhan.com/skill/SKILL.md
API documentation: https://video-audio-replace.yeezhan.com/api/docs

## What this tool does
Put BGM under a video — mix over the original audio or replace it, auto-looped to length.

## Typical user problems
- Raw footage sounds dead and royalty-free tracks are rarely the exact length. The BGM is looped to cover the whole video at your chosen volume — mixed under the original audio when there is one, or used on its own when there is not. The video stream is never re-encoded.

## Parameters
- loop_bgm: enum, required. BGM 不够长时自动循环
- bgm_volume: number (range 0-2), required. BGM 音量倍率

## Pricing
- Watermarked preview: free, no login required
- Final clean output: $0.99 one-time per task
- Require login (email/phone OTP) to complete payment
- Result available for download 24 hours after payment

## Limitations
- Max 200 MB
- 1 video + 1 audio file