Hosting
Build (one-time, amortized)
Ongoing maintenance
Cost by scale
Hosting and build cost barely change with call volume until you outgrow one instance — maintenance and the amortized build are the lines that dominate at low-to-mid traffic.
| Tool calls/mo | Hosting | Build (amortized) | Total/mo |
|---|
MCP wraps existing API cost — it doesn't replace it
An MCP server is a protocol adapter: it exposes tools to any MCP-compatible client (Claude Code, Claude Desktop, other agents) instead of writing custom integration code per client. That reuse is the entire value proposition, and it's also why "how much does an MCP server cost" has two very different answers depending on what it's connected to. This calculator prices the adapter itself — hosting, build, maintenance — not the downstream API or LLM calls it triggers, which you should price separately with the API cost forecast calculator or the relevant provider guide.
Most MCP servers cost nothing to host: they run as local stdio subprocesses spawned directly by the client on whatever machine it's already running on. The moment you need a remote, always-reachable server for a team or a hosted product, you're choosing between a serverless platform (Cloudflare Workers has a generous free tier, then pay-per-request) and an always-on instance (Fly.io, Railway, Render — roughly $5-15/mo per instance, plus more for high availability). Compare those platforms directly on the Railway vs Render vs Fly.io calculator.
The build cost is the number most people miss. A read-only, single-client MCP server exposing a handful of tools is a days-to-weeks job. An actions-capable server that writes to production systems needs real validation and testing. A fully agent-resident server with broad autonomous permissions is the most expensive and highest-scrutiny tier. Spreading that one-time build cost over 12 months of amortization — the default here — turns a five-figure build into a monthly number you can actually compare against hosting and maintenance, which is usually the bigger ongoing line for a low-traffic internal tool.