Fly.io vs Temporal AI

Temporal and Fly.io solve fundamentally different problems. Temporal is a durable execution platform: you write workflows in Go, Java, Python, TypeScript, .NET, PHP, Ruby, or Rust, and its service persists every step — crashed workers, timed-out API calls, even abandoned sessions resume exactly where they stopped. Activities retry automatically with backoff, four timeout classes, and heartbeating. Signals, Queries, and Updates let you read and mutate running workflows mid-flight, and Workflow Streams add real-time interactivity. Durable AI agents via the OpenAI Agents SDK or Google ADK run LLM and tool calls as Activities, with built-in humans-in-the-loop orchestration and Saga-pattern compensating transactions. Recent additions include Projects for organizing Temporal Cloud resources (pre-release), Serverless Workers for GCP Cloud Run (pre-release) and AWS Lambda (public preview), Custom Roles (pre-release), and Temporal Cloud on Azure (invite-only pre-release).

Fly.io provides the machine underneath. Its Sprites are hardware-isolated Linux VMs with automatic checkpointing: agents like Claude or Codex can crash, sleep, and resume mid-task without external state management. Sprites boot in under a second across 18+ global regions, deploy in ~500ms, and bill per second of active CPU/memory — dropping to zero when idle. The Sprite Block Device (private beta) offers up to 100 GB of object-storage-backed disk; you can roll back to any checkpoint in seconds. Sprites Connectors integrate GitHub, Slack, and OpenRouter, with egress control and a clean baseline per request for untrusted code. Fly.io also offers general-purpose Machines, managed Postgres, private networking, and zero-downtime deploys.

The overlap is that both touch AI agents — but Temporal orchestrates them, Fly.io hosts them.

Both products use a freemium model, but they charge for entirely different resources. Temporal's pricing (as reflected in its freemium tier and Cloud offerings) typically bundles durable execution, workflow history retention, and actions; the open-source server is free to self-host, while Temporal Cloud adds audit logging, SSO, SOC 2/HIPAA compliance, and SLA-backed support on higher tiers. You pay for orchestration capacity and enterprise controls rather than raw compute. Fly.io bills per second for active CPU and memory, plus storage that tiers as hot or cold — and the bill goes to zero when your Sprites are idle. That idle-zero property is a core selling point for agent builders running bursty, interactive workloads: you don't pay for a VM that's waiting for the next user prompt. Fly.io also charges for Sprite Block Device storage (up to 100 GB, currently private beta) and managed Postgres. If your cost driver is compute time, Fly.io's per-second model is the lever; if it's workflow executions and compliance features, Temporal's tiers are where the money goes. There is no apples-to-apples comparison because the units are different — Temporal sells orchestration, Fly.io sells machine time.