Best suited for: API wrappers and lightweight that connect to external services.Not designed for: Heavy compute workloads, ML inference, large file processing, or long-running background jobs.
Resource Limits
Hosted MCP servers run on Smithery’s edge runtime — a high-performance JavaScript environment without access to the Node.js filesystem or native OS APIs.| Resource | Limit |
|---|---|
| Memory | 128 MB |
| CPU time | 30 seconds per request |
CPU time is the time your code is actively executing—not time spent waiting on external API calls, database queries, or other I/O. Most MCP servers that wrap APIs will use minimal CPU time since they’re primarily waiting on network responses.
Runtime Limitations
The edge runtime does not support:- Native Node.js modules - No
fs,child_process,net, or other system-level APIs - Dynamic requires of Node built-ins - Packages using
require("util"),require("stream"), etc. at runtime - Native bindings - Packages with C/C++ addons won’t work (e.g.,
sharp,bcrypt) - Filesystem access - No reading/writing local files
- Spawning processes - Cannot execute shell commands or subprocesses
What This Means for Your Server
Your MCP server should:- Be stateless - Don’t rely on in-memory state between requests; use session state cache, or external databases to maintain state
- Wrap APIs, not run compute - Ideal for calling external services, not processing data locally
- Avoid loading large files or datasets into memory - Process data in chunks or stream from external sources
- Use streaming for large responses - Return data incrementally rather than buffering entire responses
- Keep dependencies minimal - Smaller dependency footprint means faster cold starts and less memory overhead
When to Publish Your Own MCP
Consider publishing your MCP (bring your own infrastructure) if you need:- More than the above resource limitations
- Native Node.js APIs (
fs,child_process, etc.) - Native bindings or C/C++ addons
- GPU access or heavy compute
- Persistent local storage
- Long-running background processes