ByteDance's Doubao Phone Agent Goes MCP/A2A-First With GUI Fallback

ByteDance's consumer Doubao phone assistant is rolling out with an agent architecture that prefers structured MCP and A2A protocol calls, falling back to GUI-agent screen control in Beta. The SAEP protocol lets developers declare page-, intent- and action-level automation boundaries, with a 30-day window limiting automation to system, ByteDance and opt-in apps.

• Doubao prioritizes MCP and A2A calls, GUI agent stays in Beta
• SAEP sets page-, intent- and action-level automation boundaries
• 30-day window limits automation to system and opt-in apps
• Payments and content publishing still need user confirmation