# Add Password to PDF — 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://protect-pdf.yeezhan.com
Skill definition: https://protect-pdf.yeezhan.com/skill/SKILL.md
API documentation: https://protect-pdf.yeezhan.com/api/docs

## What this tool does
Encrypt a PDF with AES-256 — nobody opens it without the password you set.

## Typical user problems
- Confidential documents travel by email unprotected every day. One line of defense you can add in a minute: AES-256 encryption that requires the password to even open.
- Salary sheets, contracts, medical results — sending them by email unprotected is a risk you take only when forced. Set a password and share it over a different channel.

## Parameters
- user_password: string, required. 打开密码（≥4 位）
- owner_password: string, optional. 权限密码（可选，缺省随机）

## 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 input 200 MB
- AES-256, print allowed / modify & extract blocked
- Lose the password = lose the file