Most agents spend their day waiting.

A build takes twenty minutes. A review takes an afternoon. An approval comes tomorrow.

And the whole time, the agent loop just sits there. Holding a process. Holding memory. Holding its breath.

A waiting agent shouldn't cost the same as a working one.

On October 23, 2026 , AWS introduced Infinity , an Apache 2.0 research runtime from the Hydro project, a collaboration between AWS and UC Berkeley. AWS says: "When an agent calls a tool, Infinity dispatches the call, saves the conversation, and suspends the agent. When the tool result arrives, the runtime resumes the agent from its saved state."

The headline number is that AWS fit 75,000 concurrent agents in the 8 GB of a Raspberry Pi 5. On serverless, the function can simply end while a tool runs, "even if a tool call takes days."

The idea comes from programming languages. Infinity treats a tool call like an await in a stackless coroutine.…