diff --git a/Sources/ExarotonWebSocket/Models.swift b/Sources/ExarotonWebSocket/Models.swift
index 0613055..3c02b5b 100644
--- a/Sources/ExarotonWebSocket/Models.swift
+++ b/Sources/ExarotonWebSocket/Models.swift
@@ -7,6 +7,18 @@
 
 import Foundation
 
+/// exaroton 服务器状态码（https://developers.exaroton.com/ → "Server status"）。
+///
+/// ```
+/// 0 = OFFLINE   1 = ONLINE   2 = STARTING   3 = STOPPING   4 = RESTARTING
+/// 5 = SAVING    6 = LOADING  7 = CRASHED    8 = PENDING    9 = TRANSFERRING
+/// 10 = PREPARING
+/// ```
+///
+/// ⚠️ **必须覆盖全部官方取值**：这个枚举参与 WebSocket `status` 消息的解码，
+/// 少一个值就意味着"整个状态消息解码失败 → 状态更新被丢掉"（实测漏了 9 = TRANSFERRING，
+/// 服务器启动/停止期间的迁移阶段状态会卡住不动）。
+/// 另外解码是**宽容**的：将来 exaroton 新增状态码时退化成 `.UNKNOWN`，而不是让整条消息失败。
 public enum ServerStatus: Int, CaseIterable, Codable {
     case OFFLINE = 0
     case ONLINE = 1
@@ -17,7 +29,16 @@ public enum ServerStatus: Int, CaseIterable, Codable {
     case LOADING = 6
     case CRASHED = 7
     case PENDING = 8
+    case TRANSFERRING = 9
     case PREPARING = 10
+
+    /// 未知/未来新增的状态码。调用方应把它当成"过渡态"处理（不允许动作，等状态稳定）。
+    case UNKNOWN = -1
+
+    public init(from decoder: any Decoder) throws {
+        let raw = try decoder.singleValueContainer().decode(Int.self)
+        self = ServerStatus(rawValue: raw) ?? .UNKNOWN
+    }
 }
 
 public struct Server: Codable, Identifiable {
diff --git a/Tests/ExarotonWebSocketTests/ServerStatusDecodingTests.swift b/Tests/ExarotonWebSocketTests/ServerStatusDecodingTests.swift
new file mode 100644
index 0000000..0df042a
--- /dev/null
+++ b/Tests/ExarotonWebSocketTests/ServerStatusDecodingTests.swift
@@ -0,0 +1,45 @@
+import Foundation
+import Testing
+@testable import ExarotonWebSocket
+
+/// 状态码解码：文档里的每个取值都必须能解出来。
+///
+/// 回归背景：枚举曾漏掉 `9 = TRANSFERRING`，导致服务器启动/停止迁移期间的
+/// `status` 消息**整条解码失败**，上层看到的就是"状态卡住不动"。
+@Suite(.tags(.unit, .websocket, .codec))
+final class ServerStatusDecodingTests {
+
+    private func serverJSON(status: Int) -> Data {
+        Data("""
+        {"id":"X","name":"demo","address":"demo.exaroton.me","motd":"hi","status":\(status),
+         "players":{"max":20,"count":0,"list":[]},
+         "software":{"id":"1","name":"Paper","version":"1.0"},"shared":false}
+        """.utf8)
+    }
+
+    @Test(arguments: [
+        (0, ServerStatus.OFFLINE),
+        (1, ServerStatus.ONLINE),
+        (2, ServerStatus.STARTING),
+        (3, ServerStatus.STOPPING),
+        (4, ServerStatus.RESTARTING),
+        (5, ServerStatus.SAVING),
+        (6, ServerStatus.LOADING),
+        (7, ServerStatus.CRASHED),
+        (8, ServerStatus.PENDING),
+        (9, ServerStatus.TRANSFERRING),
+        (10, ServerStatus.PREPARING),
+    ])
+    func decodesEveryDocumentedCode(raw: Int, expected: ServerStatus) throws {
+        let server = try JSONDecoder().decode(Server.self, from: serverJSON(status: raw))
+        #expect(server.status == expected)
+        #expect(server.status.rawValue == raw)
+    }
+
+    /// 将来 exaroton 新增状态码时不能把整条消息炸掉，退化成 `.UNKNOWN`。
+    @Test
+    func unknownCodeDegradesInsteadOfThrowing() throws {
+        let server = try JSONDecoder().decode(Server.self, from: serverJSON(status: 99))
+        #expect(server.status == .UNKNOWN)
+    }
+}