Add external MCP server support (stdio JSON-RPC)

Lets the AI connect to any external stdio MCP server (e.g. safaridriver --mcp) configured in Settings, with tools auto-discovered and prefixed by server slug. Includes crash detection with backoff restart (5s/15s/30s) and a Settings UI to add/enable/disable/remove servers. Fixes the temp-dir allowlist in MCPService.isPathAllowed to also match /tmp and /private/tmp (not just NSTemporaryDirectory(), which resolves to a different per-user Darwin temp dir) so the MCP file tools can actually read files external servers and image generation write there. Also switches the Add Server sheet's argument parsing to a quote-aware tokenizer so args containing spaces survive intact. Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
2026-07-14 08:01:00 +02:00
parent f2949cea3b
commit e6f965ff19
9 changed files with 937 additions and 2 deletions
@@ -0,0 +1,170 @@
+// SPDX-License-Identifier: AGPL-3.0-or-later
+// Copyright (C) 2026 Rune Olsen
+
+import Foundation
+
+// MARK: - Server Configuration
+
+struct ExternalMCPServer: Codable, Identifiable, Sendable {
+    var id: UUID
+    var name: String
+    var command: String
+    var args: [String]
+    var isEnabled: Bool
+    var timeout: TimeInterval
+    var createdAt: Date
+
+    init(id: UUID = UUID(), name: String, command: String, args: [String] = [],
+         isEnabled: Bool = true, timeout: TimeInterval = 30, createdAt: Date = Date()) {
+        self.id = id
+        self.name = name
+        self.command = command
+        self.args = args
+        self.isEnabled = isEnabled
+        self.timeout = timeout
+        self.createdAt = createdAt
+    }
+
+    var slug: String { Self.makeSlug(from: name) }
+
+    static func makeSlug(from name: String) -> String {
+        let s = name
+            .lowercased()
+            .components(separatedBy: CharacterSet.alphanumerics.inverted)
+            .filter { !$0.isEmpty }
+            .joined(separator: "_")
+        return s.isEmpty ? "ext" : s
+    }
+
+    /// Splits a raw arguments string into tokens, respecting single/double-quoted
+    /// segments so arguments containing spaces (e.g. `--root "/Users/x/My Documents"`)
+    /// survive intact instead of being split on every space.
+    static func parseArguments(_ input: String) -> [String] {
+        var args: [String] = []
+        var current = ""
+        var inSingleQuotes = false
+        var inDoubleQuotes = false
+
+        for char in input {
+            if char == "'" && !inDoubleQuotes {
+                inSingleQuotes.toggle()
+            } else if char == "\"" && !inSingleQuotes {
+                inDoubleQuotes.toggle()
+            } else if char.isWhitespace && !inSingleQuotes && !inDoubleQuotes {
+                if !current.isEmpty {
+                    args.append(current)
+                    current = ""
+                }
+            } else {
+                current.append(char)
+            }
+        }
+        if !current.isEmpty { args.append(current) }
+        return args
+    }
+
+    static let reservedSlugs: Set<String> = [
+        "anytype", "paperless", "calendar", "reminders",
+        "contacts", "location", "maps", "bash", "web", "read", "write",
+        "list", "search", "edit", "delete", "create", "move", "copy", "spawn"
+    ]
+
+    var isSlugReserved: Bool { Self.reservedSlugs.contains(slug) }
+}
+
+// MARK: - Client State
+
+enum MCPClientState: Equatable {
+    case idle
+    case connecting
+    case ready
+    case error(String)
+    case crashed
+    case stopped
+}
+
+// MARK: - State Delegate (all callbacks on MainActor)
+
+@MainActor
+protocol ExternalMCPStateDelegate: AnyObject {
+    func clientDidBecomeReady(id: UUID, tools: [MCPToolDefinition], server: ExternalMCPServer)
+    func clientDidChangeState(id: UUID, state: MCPClientState)
+}
+
+// MARK: - Client Errors
+
+enum MCPClientError: LocalizedError {
+    case notConnected
+    case invalidResponse(String)
+    case timeout
+    case processLaunchFailed(String)
+    case handshakeFailed(String)
+    case writeFailed
+
+    var errorDescription: String? {
+        switch self {
+        case .notConnected:               return "MCP server is not connected"
+        case .invalidResponse(let s):     return "Invalid MCP response: \(s)"
+        case .timeout:                    return "MCP request timed out"
+        case .processLaunchFailed(let s): return "Failed to launch MCP server: \(s)"
+        case .handshakeFailed(let s):     return "MCP handshake failed: \(s)"
+        case .writeFailed:                return "Failed to write to MCP server stdin"
+        }
+    }
+}
+
+// MARK: - MCP Protocol Types
+
+struct MCPInitializeResult: Decodable {
+    let protocolVersion: String
+    let capabilities: MCPCapabilities
+    let serverInfo: MCPServerInfo?
+}
+
+struct MCPCapabilities: Decodable {
+    let tools: MCPToolsCapability?
+    struct MCPToolsCapability: Decodable { let listChanged: Bool? }
+}
+
+struct MCPServerInfo: Decodable {
+    let name: String
+    let version: String?
+}
+
+struct MCPToolsListResult: Decodable {
+    let tools: [MCPToolDefinition]
+    let nextCursor: String?
+}
+
+struct MCPToolDefinition: Decodable {
+    let name: String
+    let description: String?
+    let inputSchema: MCPInputSchema
+}
+
+struct MCPInputSchema: Decodable {
+    let type: String
+    let properties: [String: MCPPropertySchema]?
+    let required: [String]?
+}
+
+struct MCPPropertySchema: Decodable {
+    let type: String?
+    let description: String?
+    let `enum`: [String]?
+    let items: MCPItemsSchema?
+    struct MCPItemsSchema: Decodable { let type: String? }
+}
+
+struct MCPToolCallResult: Decodable {
+    let content: [MCPContent]
+    let isError: Bool?
+}
+
+struct MCPContent: Decodable {
+    let type: String
+    let text: String?
+    let data: String?
+    let mimeType: String?
+    let uri: String?
+}