Type Alias McpOutcome 

pub type McpOutcome<T> = Outcome<T, McpError>;

Outcome type alias for MCP operations with 4-valued returns.

This is the preferred return type for handler functions as it properly represents all possible states: success, error, cancellation, and panic.

Mapping to JSON-RPC

Outcome	JSON-RPC Response
Ok(value)	{"result": value}
Err(McpError)	{"error": {"code": ..., "message": ...}}
Cancelled	{"error": {"code": -32004, "message": "Request cancelled"}}
Panicked	{"error": {"code": -32603, "message": "Internal error"}}

Aliased Type

pub enum McpOutcome<T> {
    Ok(T),
    Err(McpError),
    Cancelled(CancelReason),
    Panicked(PanicPayload),
}

Variants

Ok(T)

Success with a value.

Err(McpError)

Application-level error.

Cancelled(CancelReason)

The operation was cancelled.

Panicked(PanicPayload)

The operation panicked.