speak/command returns 400 'Input failed to validate'

[cmadden-cirqul]

Description

After successful authentication (devices and history work fine), the speak and command functions return:

Error: API error 400: {"message":"Input failed to validate."}

Environment

• macOS ARM64 (Apple Silicon)
• alexacli v0.3.0 (Homebrew)
• Authenticated via alexa-cookie-cli v5.0.1

Steps to Reproduce

1. alexacli auth <token> - succeeds, shows 14 devices
2. alexacli devices - works
3. alexacli history - works
4. alexacli speak "test" -d "Kitchen dot" - fails with 400
5. alexacli speak "test" --announce - fails with 400
6. alexacli command "turn on lights" -d Kitchen - fails with 400

Suspected Cause

Amazon may have changed the /api/behaviors/preview endpoint payload format.

Working Commands

• alexacli devices
• alexacli devices --json
• alexacli history
• alexacli history --limit 5