Migrate from Fly.io to osModa: Firecracker VMs to Dedicated Servers
Fly.io deploys applications as Firecracker micro-VMs across global edge regions with usage-based billing and a complex CLI workflow. For AI agents that need to run 24/7 in a single region with predictable costs, this adds unnecessary complexity and expense. osModa gives you a dedicated NixOS server with root SSH access, flat-rate pricing from $14.99/mo, and purpose-built self-healing infrastructure for autonomous agents.
TL;DR
- • Fly.io uses Firecracker micro-VMs with complex CLI and usage-based billing
- • osModa: dedicated NixOS server with SSH access and flat-rate pricing
- • Migration: note fly.toml config, spawn osModa server, SSH in, deploy code
- • fly.toml and flyctl are replaced by standard SSH + NixOS configuration
- • osmoda-mesh replaces Fly's WireGuard with post-quantum encrypted networking
Step-by-Step Migration from Fly.io
Migrating from Fly.io to osModa takes 30-60 minutes for most applications. The key conceptual shift is moving from a micro-VM platform managed via a CLI to a dedicated server managed via SSH. Your application code does not change.
Step 1: Document Your Fly.io Configuration
Review your fly.toml file to understand your app's configuration: the internal port, health check endpoints, environment variables, and any attached services. Run fly secrets list to see which secrets are set (Fly does not expose secret values, so ensure you have them stored separately). If you use Fly Postgres, note the connection string and consider creating a pg_dump backup.
Step 2: Spawn an osModa Server
Choose a plan that matches your Fly Machine size. If you were running a performance-2x Machine (2 vCPU, 4 GB RAM), the Solo plan ($14.99/mo) is equivalent. Select a region: Frankfurt, Helsinki, Virginia, or Oregon. Spawn via the dashboard or API. The server provisions in 5-10 minutes.
Step 3: SSH In and Deploy
SSH into your server with ssh root@your-server-ip. Clone your repository and install your runtime via NixOS packages. There is no Dockerfile needed (though you can use Docker on NixOS if you prefer). Set your environment variables and secrets directly on the server. Start your application. The osmoda-watch daemon will automatically begin monitoring and restarting it if it crashes.
Step 4: Configure Networking
On Fly.io, your app listens on an internal port and Fly's proxy handles external traffic routing. On osModa, your application binds directly to the server's network interface. If you need multi-server communication (replacing Fly's WireGuard private networking), osmoda-mesh provides encrypted peer-to-peer networking between your osModa nodes automatically.
Step 5: Verify and Cut Over
Test all application endpoints on the osModa server. Verify database connections, external API integrations, and background processes. Once everything works, update DNS records to point to the osModa server IP. After confirming traffic is flowing correctly, destroy your Fly Machine with fly apps destroy to stop Fly billing.
Before and After: Fly.io vs osModa
| Aspect | Fly.io (Before) | osModa (After) |
|---|---|---|
| Infrastructure | Firecracker micro-VMs (shared hosts) | Dedicated NixOS server |
| Management | flyctl CLI + fly.toml + Machines API | SSH + dashboard |
| Pricing | Per-second VM + egress ($62+/mo for 4GB) | $14.99/mo flat (4GB RAM included) |
| Root Access | SSH via flyctl (VM-level) | Yes -- full root on dedicated server |
| Self-Healing | Machine restart | Yes -- Rust watchdog + NixOS rollback |
| Networking | WireGuard private network | osmoda-mesh (post-quantum encrypted) |
| Egress | $0.02/GB outbound | Included in flat rate |
| Audit Trail | No -- no built-in audit logging | Yes -- SHA-256 tamper-proof ledger |
Key Differences: Fly.io vs osModa
Firecracker VMs vs Dedicated Servers
Fly.io runs your application inside Firecracker micro-VMs -- lightweight virtual machines that share physical host hardware with other customers. This provides strong isolation but you are still on shared infrastructure with potential noisy-neighbor effects. osModa provisions a dedicated server where you are the only tenant, giving you full hardware resources and complete OS-level control.
Complex CLI vs SSH
Managing Fly.io applications requires learning the flyctl CLI, the fly.toml configuration format, the Machines API, and Fly-specific concepts like volumes, regions, and machine placement. On osModa, you have one interface: SSH. You manage your server the same way you would manage any Linux machine. The osModa dashboard provides a GUI for monitoring, logs, and key management, but SSH is the primary management tool.
What You Gain
Moving from Fly.io to osModa gives you flat-rate pricing with no per-second metering or egress fees, a dedicated server with full root access, purpose-built self-healing with crash-loop detection and atomic rollback, SHA-256 tamper-proof audit logging, and post-quantum encrypted mesh networking. You also eliminate the flyctl CLI dependency and Fly-specific configuration.
What Requires Manual Work
Fly.io excels at multi-region edge deployment -- if you need your application running in 30+ regions simultaneously, Fly is purpose-built for that. osModa offers 4 regions and is designed for persistent workloads, not edge distribution. Fly's scale-to-zero capability has no osModa equivalent; osModa servers are always-on. If you relied on Fly's built-in Postgres or Redis, you will need to set up your own database on the osModa server or use a managed service.
Explore More Migration Guides
- Migrate from Heroku -- dynos to dedicated NixOS servers
- Migrate from Railway -- usage-based PaaS to flat-rate hosting
- Migrate from Render -- shared instances to dedicated servers
- osModa vs Fly.io (full comparison) -- detailed feature-by-feature breakdown
- All migration guides -- complete list of platform migration guides
Frequently Asked Questions
How do I export my Fly.io app configuration?
Your Fly.io configuration lives in fly.toml in your project root. This file defines your app name, build settings, services, ports, health checks, and environment. Export your secrets with 'fly secrets list' (note that Fly does not let you read secret values, so you will need to have them stored elsewhere). For Fly Postgres, create a backup using pg_dump connected to your Fly database's connection string.
What replaces fly.toml on osModa?
There is no direct equivalent of fly.toml because osModa gives you a full server, not a container platform. Your app's port configuration, environment variables, and start commands are set directly on the server. If you want declarative configuration, NixOS's configuration.nix serves a similar purpose but for the entire system -- not just a single application container. The osModa daemons handle health checking and process supervision automatically.
Does osModa support Fly.io's multi-region deployment?
osModa offers four regions: Frankfurt, Helsinki, Virginia, and Oregon. You can deploy separate servers in different regions and connect them via osmoda-mesh for encrypted cross-region communication. This is architecturally different from Fly's approach of replicating a single app across edge regions, but it gives you full control over each node and eliminates the complexity of Fly's multi-region state management.
What about Fly.io Machines and auto-scaling?
Fly Machines are Firecracker micro-VMs that can scale to zero and start on demand. osModa servers are always-on dedicated machines -- they do not scale to zero. If your workload is an AI agent that needs to run 24/7, always-on is what you want. If you need burst capacity, you can spawn additional osModa servers via the API and connect them via osmoda-mesh. The trade-off is that you pay a flat rate for always-on capacity rather than per-second for on-demand VMs.
How does Fly.io's WireGuard networking compare to osmoda-mesh?
Fly.io uses WireGuard for its private networking between Fly Machines, which provides encrypted tunnels between your VMs. osmoda-mesh uses Noise_XX + ML-KEM-768 for post-quantum encrypted peer-to-peer networking between osModa servers. Both provide encrypted inter-node communication, but osmoda-mesh adds automatic peer discovery, agent-level routing, and post-quantum cryptographic protection.
Is Fly.io's pricing actually cheaper for small workloads?
For very small, intermittent workloads that can scale to zero, Fly.io can be cheaper because you only pay when the Machine is running. However, for always-on AI agents, Fly's pricing adds up quickly. A shared-cpu-1x Machine with 256 MB RAM costs approximately $1.94/mo, but an AI agent typically needs more resources. A performance-2x Machine with 4 GB RAM costs approximately $62/mo running 24/7, plus $0.02/GB for outbound data transfer. osModa's Solo plan at $14.99/mo provides 2 CPU and 4 GB RAM with no per-second metering and no egress fees.
Simpler Infrastructure. Predictable Pricing.
Replace Firecracker VMs and flyctl with a dedicated NixOS server you manage via SSH. Self-healing, audit logging, and mesh networking included. From $14.99/mo.
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Last updated: March 2026