Code Execution Sandbox Pricing 2026: Cost, Cold Starts, and Persistence for AI Agents
If you’re building AI agents that execute code — whether it’s a coding agent running tests, a data analysis pipeline spinning up Python interpreters, or a multi-agent system that needs isolated environments per task — the sandbox you pick directly determines your cost structure, your latency profile, and how much state management code you have to write yourself. Three providers dominate this space in 2026: E2B, Modal, and Fly.io. Each one has a fundamentally different pricing model, cold start story, and persistence strategy. I’ve been running production agent workloads on all three for the past six months, and the differences are bigger than the marketing suggests. ...