Local vs remote MCP servers: stdio, Streamable HTTP and SSE
Of the servers we can write a config for, 85,194 run locally and 37,838 remotely.
| How it runs | What happens | Servers |
|---|---|---|
| Local (stdio) | The client starts the package on your machine and talks to it over standard input and output. | 85,194 |
| Remote, Streamable HTTP | The client posts to one HTTPS address; the current transport. | 30,876 |
| Remote, Streamable HTTP with a key | The same, with a key the client sends in a header. | 3,204 |
| Remote, HTTP+SSE | The client opens an event stream and posts to the address it names; the older transport. | 3,711 |
| Remote, HTTP+SSE with a key | The same, with a key the client sends in a header. | 47 |
What the clients support
Of the 24 clients we write a config for, 24 start local servers, 21 connect over Streamable HTTP, 14 over HTTP+SSE, and 18 can send a key in a header.