max / makenotwork

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1	//! MCP JSON-RPC 2.0 protocol types for the Streamable HTTP transport.
2	//!
3	//! Only the subset needed for `initialize`, `tools/list`, and `tools/call`.
4
5	use serde::{Deserialize, Serialize};
6	use serde_json::Value;
7
8	pub const MCP_PROTOCOL_VERSION: &str = "2025-06-18";
9
10	#[derive(Debug, Deserialize)]
11	pub struct JsonRpcRequest {
12	#[allow(dead_code)]
13	pub jsonrpc: String,
14	#[serde(default)]
15	pub id: Option<Value>,
16	pub method: String,
17	#[serde(default)]
18	pub params: Option<Value>,
19	}
20
21	#[derive(Debug, Serialize)]
22	pub struct JsonRpcResponse {
23	pub jsonrpc: &'static str,
24	pub id: Value,
25	#[serde(skip_serializing_if = "Option::is_none")]
26	pub result: Option<Value>,
27	#[serde(skip_serializing_if = "Option::is_none")]
28	pub error: Option<JsonRpcError>,
29	}
30
31	impl JsonRpcResponse {
32	pub fn ok(id: Value, result: Value) -> Self {
33	Self {
34	jsonrpc: "2.0",
35	id,
36	result: Some(result),
37	error: None,
38	}
39	}
40
41	pub fn err(id: Value, code: i32, message: impl Into<String>) -> Self {
42	Self {
43	jsonrpc: "2.0",
44	id,
45	result: None,
46	error: Some(JsonRpcError {
47	code,
48	message: message.into(),
49	data: None,
50	}),
51	}
52	}
53	}
54
55	#[derive(Debug, Serialize)]
56	pub struct JsonRpcError {
57	pub code: i32,
58	pub message: String,
59	#[serde(skip_serializing_if = "Option::is_none")]
60	pub data: Option<Value>,
61	}
62
63	pub mod codes {
64	pub const PARSE_ERROR: i32 = -32700;
65	pub const METHOD_NOT_FOUND: i32 = -32601;
66	pub const INVALID_PARAMS: i32 = -32602;
67	pub const INTERNAL_ERROR: i32 = -32603;
68	/// MCP-defined: a `resources/read` (or subscribe) named an unknown uri.
69	pub const RESOURCE_NOT_FOUND: i32 = -32002;
70	/// An in-flight request was cancelled before it completed. Same code LSP
71	/// uses for `ContentModified`/cancellation.
72	pub const REQUEST_CANCELLED: i32 = -32800;
73	}
74
75	#[derive(Debug, Serialize)]
76	pub struct InitializeResult {
77	#[serde(rename = "protocolVersion")]
78	pub protocol_version: &'static str,
79	pub capabilities: ServerCapabilities,
80	#[serde(rename = "serverInfo")]
81	pub server_info: ServerInfo,
82	}
83
84	#[derive(Debug, Serialize)]
85	pub struct ServerCapabilities {
86	pub tools: ToolsCapability,
87	/// Only advertised when the server was configured with a resource
88	/// registry. `subscribe` stays `false` until the push layer lands.
89	#[serde(skip_serializing_if = "Option::is_none")]
90	pub resources: Option<ResourcesCapability>,
91	}
92
93	#[derive(Debug, Serialize)]
94	pub struct ToolsCapability {
95	#[serde(rename = "listChanged")]
96	pub list_changed: bool,
97	}
98
99	#[derive(Debug, Serialize)]
100	pub struct ResourcesCapability {
101	pub subscribe: bool,
102	#[serde(rename = "listChanged")]
103	pub list_changed: bool,
104	}
105
106	#[derive(Debug, Serialize)]
107	pub struct ServerInfo {
108	pub name: String,
109	pub version: String,
110	}
111
112	#[derive(Debug, Deserialize)]
113	pub struct CallToolParams {
114	pub name: String,
115	#[serde(default)]
116	pub arguments: Value,
117	}
118
119	/// `resources/subscribe` and `resources/unsubscribe` param object.
120	#[derive(Debug, Deserialize)]
121	pub struct SubscribeParams {
122	pub uri: String,
123	}
124
125	/// `notifications/cancelled` param object (client → server). `requestId` is the
126	/// id of the request being cancelled; `reason` is optional free text.
127	#[derive(Debug, Deserialize)]
128	pub struct CancelledParams {
129	#[serde(rename = "requestId")]
130	pub request_id: Value,
131	#[serde(default)]
132	#[allow(dead_code)]
133	pub reason: Option<String>,
134	}
135