Documentation Index
Fetch the complete documentation index at: https://redop.useagents.site/docs/llms.txt
Use this file to discover all available pages before exploring further.
Use listen() to start either the HTTP or stdio transport.
For transport selection guidance and common usage patterns, use Listening and Transports.
Overloads
app.listen();
app.listen(3000);
app.listen(3000, "0.0.0.0");
app.listen({
port: 3000,
hostname: "0.0.0.0",
debug: true,
});
Behavior by call shape
| Call shape | Result |
|---|
listen() | Starts stdio |
listen(3000) | Starts http on port 3000 |
listen(3000, "0.0.0.0") | Starts http with an explicit hostname |
listen({ port: 3000 }) | Starts http |
listen({ transport: "stdio" }) | Forces stdio |
listen({ transport: "http" }) | Forces http |
Typical HTTP options
app.listen({
transport: "http",
port: 3000,
hostname: "0.0.0.0",
path: "/mcp",
health: { path: "/health" },
debug: true,
sessionTimeout: 60_000,
onListen: ({ url }) => {
console.log(url);
},
});
Options
Shared options
| Option | Notes |
|---|
transport | "http" or "stdio". Defaults to "http" when port is set, otherwise "stdio". |
HTTP options
| Option | Notes |
|---|
port | HTTP port. Also available through listen(3000). Defaults to 3000 for HTTP. |
hostname | HTTP bind address. Defaults to 127.0.0.1. |
path | MCP endpoint path for HTTP. Defaults to /mcp. |
health | Enable /health or provide { path } for a custom health route. Disabled by default. |
debug | Writes HTTP transport logs to stderr. |
sessionTimeout | HTTP session expiry in milliseconds. Defaults to 60000. |
onListen | Callback fired after the HTTP server starts. Receives { hostname, port, url }. |
cors | Enable permissive CORS or provide the typed CorsOptions shape. |
maxBodySize | Maximum accepted request body size in bytes in the public type surface. |
tls | TLS options in the public type surface. |
Stdio options
| Option | Notes |
|---|
transport | Set to "stdio" to force stdio explicitly. |
Current implementation caveats
These reflect the current HTTP implementation, not just the public type surface:
| Option | Current behavior |
|---|
cors | Present in the type surface. The current HTTP transport always sends a basic permissive CORS response rather than using the full CorsOptions shape. |
maxBodySize | Present in the type surface, but not currently enforced by the HTTP transport. |
tls | Present in the type surface and used when formatting the reported URL, but the current HTTP transport does not start Bun with TLS from this option yet. |
Defaults
- default transport:
stdio without port, otherwise http
- default HTTP hostname:
127.0.0.1
- default HTTP port:
3000
- default MCP path:
/mcp
- default health route: disabled
- default session timeout:
60000
