Enum Connection 

#[non_exhaustive]
pub enum Connection {
    Stdio {
        command: String,
        args: Vec<String>,
        env: HashMap<String, String>,
    },
    Sse {
        url: String,
        auth_token: Option<String>,
        timeout_secs: Option<u64>,
    },
    StreamableHttp {
        url: String,
        auth_token: Option<String>,
        timeout_secs: Option<u64>,
    },
    WebSocket {
        url: String,
        auth_token: Option<String>,
    },
}

Configuration for connecting to a single MCP server.

Each variant describes a different transport mechanism.

Variants (Non-exhaustive)

Non-exhaustive enums could have additional variants added in future. Therefore, when matching against variants of non-exhaustive enums, an extra wildcard arm must be added to account for any future variants.

Stdio

Launch a subprocess and communicate over its stdin/stdout.

Fields

command: String

Executable path.

args: Vec<String>

Command-line arguments.

env: HashMap<String, String>

Environment variables.

Sse

Connect via Server-Sent Events (SSE) transport.

Fields

url: String

SSE endpoint URL.

auth_token: Option<String>

Optional Bearer token.

timeout_secs: Option<u64>

Connection timeout in seconds.

StreamableHttp

Connect via Streamable HTTP (MCP 2025-03-26 spec).

Fields

url: String

HTTP endpoint URL.

auth_token: Option<String>

Optional Bearer token.

timeout_secs: Option<u64>

Connection timeout in seconds.

WebSocket

Connect via WebSocket.

Fields

url: String

WebSocket URL (ws:// or wss://).

auth_token: Option<String>

Optional Bearer token.

Implementations

impl Connection

pub fn into_transport( self, name: &str, ) -> Result<Box<dyn McpTransport>, AgentError>

Creates a transport for this connection configuration.

Returns a Box<dyn McpTransport> suitable for use with McpClientSession.

Errors

Returns an error if the underlying transport cannot be initialised (e.g. HTTP client TLS failure).

Trait Implementations

impl Clone for Connection

fn clone(&self) -> Connection

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Connection

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.