1package transport
 2
 3import (
 4	"context"
 5	"encoding/json"
 6
 7	"github.com/mark3labs/mcp-go/mcp"
 8)
 9
10// HTTPHeaderFunc is a function that extracts header entries from the given context
11// and returns them as key-value pairs. This is typically used to add context values
12// as HTTP headers in outgoing requests.
13type HTTPHeaderFunc func(context.Context) map[string]string
14
15// Interface for the transport layer.
16type Interface interface {
17	// Start the connection. Start should only be called once.
18	Start(ctx context.Context) error
19
20	// SendRequest sends a json RPC request and returns the response synchronously.
21	SendRequest(ctx context.Context, request JSONRPCRequest) (*JSONRPCResponse, error)
22
23	// SendNotification sends a json RPC Notification to the server.
24	SendNotification(ctx context.Context, notification mcp.JSONRPCNotification) error
25
26	// SetNotificationHandler sets the handler for notifications.
27	// Any notification before the handler is set will be discarded.
28	SetNotificationHandler(handler func(notification mcp.JSONRPCNotification))
29
30	// Close the connection.
31	Close() error
32
33	// GetSessionId returns the session ID of the transport.
34	GetSessionId() string
35}
36
37// RequestHandler defines a function that handles incoming requests from the server.
38type RequestHandler func(ctx context.Context, request JSONRPCRequest) (*JSONRPCResponse, error)
39
40// BidirectionalInterface extends Interface to support incoming requests from the server.
41// This is used for features like sampling where the server can send requests to the client.
42type BidirectionalInterface interface {
43	Interface
44
45	// SetRequestHandler sets the handler for incoming requests from the server.
46	// The handler should process the request and return a response.
47	SetRequestHandler(handler RequestHandler)
48}
49
50type JSONRPCRequest struct {
51	JSONRPC string        `json:"jsonrpc"`
52	ID      mcp.RequestId `json:"id"`
53	Method  string        `json:"method"`
54	Params  any           `json:"params,omitempty"`
55}
56
57type JSONRPCResponse struct {
58	JSONRPC string          `json:"jsonrpc"`
59	ID      mcp.RequestId   `json:"id"`
60	Result  json.RawMessage `json:"result,omitempty"`
61	Error   *struct {
62		Code    int             `json:"code"`
63		Message string          `json:"message"`
64		Data    json.RawMessage `json:"data"`
65	} `json:"error,omitempty"`
66}