Ink vs Fly.io
How Ink MCP compares to Fly.io — CLI-dependent microVM platform with experimental MCP versus HTTP-native agent infrastructure
Fly.io runs Firecracker microVMs on bare metal across 18 regions. It's a strong platform for developers who want low-level control. But everything revolves around flyctl, and MCP is still experimental.
Feature comparison
| Ink | Fly.io | |
|---|---|---|
| Agent integration | Skill (prompt-guided), MCP (Streamable HTTP), CLI | MCP only (stdio/SSE/HTTP via flyctl — requires CLI) |
| MCP capabilities | Full read/write: deploy, delete, scale, databases, DNS, logs, metrics | Experimental: apps, machines, orgs, certs, logs, secrets, volumes, status |
| MCP maturity | Production | Experimental ("may still have sharp edges" per Fly docs) |
| Pricing model | Per-minute compute, no seat fees | Usage-based (per-second billing), no seat fees |
| Infrastructure | Bare metal (self-owned) | Firecracker microVMs on bare metal (own hardware) |
| Build system | Railpack auto-detection, Dockerfile, Static | Dockerfile, buildpacks, or auto-detection via fly launch |
| Databases | SQLite via Turso (edge-replicated, managed) | Managed Postgres ($38–$1,922/mo), unmanaged Postgres (self-managed) |
| DNS management | Full programmatic DNS via MCP | No DNS hosting — external provider required |
| Multi-region | Expanding (bare metal regions) | 18 regions with Anycast routing |
| Git-push deploy | Via Ink managed git or GitHub integration | Not supported — fly deploy or GitHub Actions required |
| Private networking | Yes | Yes (WireGuard) |
| GraphQL API | Yes, with introspection | Machines REST API |
Capabilities checklist
| Capability | Ink | Fly.io |
|---|---|---|
| MCP server | ✅ | ✅ |
| Agent Skill (prompt-guided) | ✅ | ❌ |
| CLI | ✅ | ✅ |
| No CLI required for MCP | ✅ | ❌ |
| Multi-agent collaboration | ✅ | ❌ |
| MCP production-ready | ✅ | ❌ |
| Deploy via MCP | ✅ | ✅ |
| Delete services via MCP | ✅ | ✅ |
| Provision databases via MCP | ✅ | ❌ |
| DNS management via MCP | ✅ | ❌ |
| Metrics via MCP | ✅ | ❌ |
| Logs via MCP | ✅ | ✅ |
| GraphQL API | ✅ | ❌ |
| Auto-detect frameworks | ✅ | ✅ |
| Git-push deploy | ✅ | ❌ |
| Per-second/minute billing | ✅ | ✅ |
| Bare metal infrastructure | ✅ | ✅ |
| 18+ global regions | ❌ | ✅ |
| Host third-party MCP servers | ❌ | ✅ |
Where the gap is real
Single integration path. Fly.io's entire workflow centers on flyctl. Deployment is fly deploy. MCP is fly mcp server (which starts a local process). There's no git-push deployment — you either run CLI commands or set up GitHub Actions yourself. Every operation assumes a human (or an agent with CLI access) on a machine with flyctl installed.
Ink gives agents three paths. The Skill teaches agents the CLI through a prompt file (zero infrastructure). The MCP endpoint is an HTTP URL (no CLI needed). The CLI works standalone. Git-push deployment works via Ink managed git or GitHub webhooks.
MCP maturity. Fly.io's MCP is explicitly labeled experimental. Their docs note it "may still have sharp edges." The implementation wraps flyctl commands — powerful but inheriting the CLI's complexity (Machines, volumes, certs, apps v2 abstractions). Fly also offers fly mcp launch to deploy third-party MCP servers to Fly Machines — useful for hosting MCP servers, but separate from managing Fly infrastructure.
Ink's MCP is the production interface. 30+ tools, task-oriented (not CLI-wrapped), stable.
Build system. Fly.io supports Dockerfiles, buildpacks, and auto-detection via fly launch, which scans and configures apps for most common languages and frameworks. However, Fly's detection is tied to fly launch — not the MCP server. Agents operating through MCP don't get automatic framework detection.
Ink auto-detects 30+ frameworks via Railpack, and this works through all integration paths — MCP, Skill, and CLI.
Multi-region advantage (Fly). Fly.io operates in 18 regions with BGP Anycast routing — a genuine strength for latency-sensitive applications. Ink's bare metal infrastructure is expanding but currently has fewer regions. If global edge deployment is your primary requirement, Fly.io has the advantage today.
What Fly.io does well
Firecracker microVMs offer real hardware-level isolation with sub-second start times. WireGuard private networking is elegant. The Machines API gives low-level control that power users want. 18 regions with Anycast routing is excellent for global applications. Usage-based per-second billing with no seat fees is fair. And fly mcp launch for deploying third-party MCP servers is a genuinely useful feature for the MCP ecosystem.