[#154] Support subagents as a component type

CLAUDE.md

@@ -78,7 +78,7 @@ mcs export <dir> --dry-run       # Preview what would be exported
 - `DependencyResolver.swift` — topological sort of component dependencies with cycle detection
 
 ### External Pack System (`Sources/mcs/ExternalPack/`)
-- `ExternalPackManifest.swift` — YAML `techpack.yaml` schema (Codable models for components, templates, hooks, doctor checks, prompts, configure scripts). Supports **shorthand syntax** (`brew:`, `mcp:`, `plugin:`, `hook:`, `command:`, `skill:`, `settingsFile:`, `gitignore:`, `shell:`) that infers `type` + `installAction` from a single key
+- `ExternalPackManifest.swift` — YAML `techpack.yaml` schema (Codable models for components, templates, hooks, doctor checks, prompts, configure scripts). Supports **shorthand syntax** (`brew:`, `mcp:`, `plugin:`, `hook:`, `command:`, `skill:`, `agent:`, `settingsFile:`, `gitignore:`, `shell:`) that infers `type` + `installAction` from a single key
 - `ExternalPackAdapter.swift` — bridges `ExternalPackManifest` to the `TechPack` protocol
 - `ExternalPackLoader.swift` — discovers and loads packs from `~/.mcs/packs/` (git) or absolute paths (local)
 - `PackFetcher.swift` — Git clone/pull for pack repositories

Sources/mcs/Commands/ExportCommand.swift

@@ -84,6 +84,7 @@ struct ExportCommand: ParsableCommand {
             selectedHookFiles: selection.hookFiles,
             selectedSkillFiles: selection.skillFiles,
             selectedCommandFiles: selection.commandFiles,
+            selectedAgentFiles: selection.agentFiles,
             selectedPlugins: selection.plugins,
             selectedSections: selection.sections,
             includeUserContent: selection.includeUserContent,
@@ -126,6 +127,9 @@ struct ExportCommand: ParsableCommand {
         if !config.commandFiles.isEmpty {
             output.plain("  Commands:      \(config.commandFiles.map(\.filename).joined(separator: ", "))")
         }
+        if !config.agentFiles.isEmpty {
+            output.plain("  Agents:        \(config.agentFiles.map(\.filename).joined(separator: ", "))")
+        }
         if !config.plugins.isEmpty {
             output.plain("  Plugins:       \(config.plugins.joined(separator: ", "))")
         }
@@ -151,6 +155,7 @@ struct ExportCommand: ParsableCommand {
         var hookFiles: Set<String>
         var skillFiles: Set<String>
         var commandFiles: Set<String>
+        var agentFiles: Set<String>
         var plugins: Set<String>
         var sections: Set<String>
         var includeUserContent: Bool
@@ -164,6 +169,7 @@ struct ExportCommand: ParsableCommand {
             hookFiles: Set(config.hookFiles.map(\.filename)),
             skillFiles: Set(config.skillFiles.map(\.filename)),
             commandFiles: Set(config.commandFiles.map(\.filename)),
+            agentFiles: Set(config.agentFiles.map(\.filename)),
             plugins: Set(config.plugins),
             sections: Set(config.claudeSections.map(\.sectionIdentifier)),
             includeUserContent: config.claudeUserContent != nil,
@@ -172,7 +178,7 @@ struct ExportCommand: ParsableCommand {
         )
     }
 
-    private enum ItemCategory { case mcp, hooks, skills, commands, plugins, sections }
+    private enum ItemCategory { case mcp, hooks, skills, commands, agents, plugins, sections }
     private enum SentinelKey { case userContent, gitignore, settings }
 
     private func interactiveSelect(
@@ -233,6 +239,12 @@ struct ExportCommand: ParsableCommand {
             groups.append(SelectableGroup(title: "Commands", items: items, requiredItems: []))
         }
 
+        // Agents
+        if !config.agentFiles.isEmpty {
+            let items = appendItems(config.agentFiles.map { (name: $0.filename, description: "Subagent") }, category: .agents)
+            groups.append(SelectableGroup(title: "Agents", items: items, requiredItems: []))
+        }
+
         // Plugins
         if !config.plugins.isEmpty {
             let items = appendItems(config.plugins.map { (name: $0, description: "Plugin") }, category: .plugins)
@@ -276,6 +288,7 @@ struct ExportCommand: ParsableCommand {
             hookFiles: selectedNames(.hooks),
             skillFiles: selectedNames(.skills),
             commandFiles: selectedNames(.commands),
+            agentFiles: selectedNames(.agents),
             plugins: selectedNames(.plugins),
             sections: selectedNames(.sections),
             includeUserContent: sentinels[.userContent].map { selected.contains($0) } ?? false,

Sources/mcs/Core/Environment.swift

@@ -9,6 +9,7 @@ struct Environment: Sendable {
     let hooksDirectory: URL
     let skillsDirectory: URL
     let commandsDirectory: URL
+    let agentsDirectory: URL
 
     /// mcs-internal state directory (`~/.mcs/`).
     /// Stores pack checkouts, registry, global state, and lock file.
@@ -39,6 +40,7 @@ struct Environment: Sendable {
         self.hooksDirectory = claudeDir.appendingPathComponent("hooks")
         self.skillsDirectory = claudeDir.appendingPathComponent("skills")
         self.commandsDirectory = claudeDir.appendingPathComponent("commands")
+        self.agentsDirectory = claudeDir.appendingPathComponent("agents")
 
         self.mcsDirectory = home.appendingPathComponent(".mcs")
 

Sources/mcs/Export/ConfigurationDiscovery.swift

@@ -15,6 +15,7 @@ struct ConfigurationDiscovery: Sendable {
         var hookFiles: [DiscoveredFile] = []
         var skillFiles: [DiscoveredFile] = []
         var commandFiles: [DiscoveredFile] = []
+        var agentFiles: [DiscoveredFile] = []
         var plugins: [String] = []
         var claudeSections: [DiscoveredClaudeSection] = []
         var claudeUserContent: String?
@@ -25,7 +26,7 @@ struct ConfigurationDiscovery: Sendable {
 
         var isEmpty: Bool {
             mcpServers.isEmpty && hookFiles.isEmpty && skillFiles.isEmpty
-            && commandFiles.isEmpty && plugins.isEmpty && claudeSections.isEmpty
+            && commandFiles.isEmpty && agentFiles.isEmpty && plugins.isEmpty && claudeSections.isEmpty
             && claudeUserContent == nil && gitignoreEntries.isEmpty
             && remainingSettingsData == nil
         }
@@ -78,6 +79,7 @@ struct ConfigurationDiscovery: Sendable {
         let hooksDir: URL
         let skillsDir: URL
         let commandsDir: URL
+        let agentsDir: URL
 
         switch scope {
         case .global:
@@ -86,13 +88,15 @@ struct ConfigurationDiscovery: Sendable {
             hooksDir = environment.hooksDirectory
             skillsDir = environment.skillsDirectory
             commandsDir = environment.commandsDirectory
+            agentsDir = environment.agentsDirectory
         case .project(let projectRoot):
             let claudeDir = projectRoot.appendingPathComponent(Constants.FileNames.claudeDirectory)
             settingsPath = claudeDir.appendingPathComponent("settings.local.json")
             claudeFilePath = projectRoot.appendingPathComponent(Constants.FileNames.claudeLocalMD)
             hooksDir = claudeDir.appendingPathComponent("hooks")
             skillsDir = claudeDir.appendingPathComponent("skills")
             commandsDir = claudeDir.appendingPathComponent("commands")
+            agentsDir = claudeDir.appendingPathComponent("agents")
         }
 
         // 1. Discover MCP servers from ~/.claude.json
@@ -105,6 +109,7 @@ struct ConfigurationDiscovery: Sendable {
         discoverFiles(in: hooksDir, hookCommands: hookCommands, into: &config)
         config.skillFiles = listFiles(in: skillsDir)
         config.commandFiles = listFiles(in: commandsDir)
+        config.agentFiles = listFiles(in: agentsDir)
 
         // 4. Discover CLAUDE.md content
         discoverClaudeContent(at: claudeFilePath, into: &config)

Sources/mcs/Export/ManifestBuilder.swift

@@ -45,6 +45,7 @@ struct ManifestBuilder {
         let selectedHookFiles: Set<String>
         let selectedSkillFiles: Set<String>
         let selectedCommandFiles: Set<String>
+        let selectedAgentFiles: Set<String>
         let selectedPlugins: Set<String>
         let selectedSections: Set<String>
         let includeUserContent: Bool
@@ -182,6 +183,8 @@ struct ManifestBuilder {
              { "\($0.filename) skill" }),
             (config.commandFiles, options.selectedCommandFiles, "cmd", .command, .command,
              { "/\($0.filename.hasSuffix(".md") ? String($0.filename.dropLast(3)) : $0.filename) command" }),
+            (config.agentFiles, options.selectedAgentFiles, "agent", .agent, .agent,
+             { "\($0.filename) subagent" }),
         ]
 
         for spec in copyFileSpecs {
@@ -332,6 +335,7 @@ struct ManifestBuilder {
                 ("Hooks", { $0.type == .hookFile }),
                 ("Skills", { $0.type == .skill }),
                 ("Commands", { $0.type == .command }),
+                ("Agents", { $0.type == .agent }),
                 ("Plugins", { $0.type == .plugin }),
                 ("Configuration", { $0.type == .configuration }),
             ]
@@ -383,6 +387,7 @@ struct ManifestBuilder {
         yaml.comment("  hook:       → checks if hook file exists")
         yaml.comment("  skill:      → checks if skill directory exists")
         yaml.comment("  command:    → checks if command file exists")
+        yaml.comment("  agent:      → checks if agent file exists")
         yaml.comment("  shell:      → NO auto-check (add doctorChecks: manually)")
         yaml.comment("")
         yaml.comment("Add pack-level checks for prerequisites not tied to a component:")
@@ -484,6 +489,7 @@ struct ManifestBuilder {
             case .hook: key = "hook"
             case .skill: key = "skill"
             case .command: key = "command"
+            case .agent: key = "agent"
             case .generic, .none:
                 preconditionFailure("Export does not produce .generic file components")
             }

Sources/mcs/ExternalPack/ExternalPackManifest.swift

@@ -313,6 +313,7 @@ struct ExternalComponentDefinition: Codable, Sendable {
         case hook          // Map — CopyFileShorthand (fileType: .hook)
         case command       // Map — CopyFileShorthand (fileType: .command)
         case skill         // Map — CopyFileShorthand (fileType: .skill)
+        case agent         // Map — CopyFileShorthand (fileType: .agent)
         case settingsFile  // String — source path
         case gitignore     // [String] — gitignore entries
     }
@@ -420,6 +421,10 @@ struct ExternalComponentDefinition: Codable, Sendable {
             let config = try shorthand.decode(CopyFileShorthand.self, forKey: .skill)
             return ResolvedShorthand(type: .skill, action: .copyPackFile(config.toExternalConfig(fileType: .skill)))
         }
+        if shorthand.contains(.agent) {
+            let config = try shorthand.decode(CopyFileShorthand.self, forKey: .agent)
+            return ResolvedShorthand(type: .agent, action: .copyPackFile(config.toExternalConfig(fileType: .agent)))
+        }
         if shorthand.contains(.settingsFile) {
             let source = try shorthand.decode(String.self, forKey: .settingsFile)
             return ResolvedShorthand(type: .configuration, action: .settingsFile(source: source))
@@ -478,6 +483,7 @@ enum ExternalComponentType: String, Codable, Sendable {
     case skill
     case hookFile
     case command
+    case agent
     case brewPackage
     case configuration
 
@@ -489,6 +495,7 @@ enum ExternalComponentType: String, Codable, Sendable {
         case .skill: return .skill
         case .hookFile: return .hookFile
         case .command: return .command
+        case .agent: return .agent
         case .brewPackage: return .brewPackage
         case .configuration: return .configuration
         }
@@ -649,6 +656,7 @@ enum ExternalCopyFileType: String, Codable, Sendable {
     case skill
     case hook
     case command
+    case agent
     case generic
 }
 

Sources/mcs/TechPack/Component.swift

@@ -7,6 +7,7 @@ enum ComponentType: String, Sendable, CaseIterable {
     case skill = "Skills"
     case hookFile = "Hooks"
     case command = "Commands"
+    case agent = "Agents"
     case brewPackage = "Dependencies"
     case configuration = "Configurations"
 }
@@ -75,6 +76,7 @@ enum CopyFileType: String, Sendable {
     case skill
     case hook
     case command
+    case agent
     case generic
 }
 
@@ -86,6 +88,7 @@ extension CopyFileType {
         case .skill: return "skills/"
         case .hook: return "hooks/"
         case .command: return "commands/"
+        case .agent: return "agents/"
         case .generic: return ""
         }
     }
@@ -95,6 +98,7 @@ extension CopyFileType {
         case .skill: return environment.skillsDirectory
         case .hook: return environment.hooksDirectory
         case .command: return environment.commandsDirectory
+        case .agent: return environment.agentsDirectory
         case .generic: return environment.claudeDirectory
         }
     }
@@ -110,6 +114,7 @@ extension CopyFileType {
         case .skill: return claudeDir.appendingPathComponent("skills")
         case .hook: return claudeDir.appendingPathComponent("hooks")
         case .command: return claudeDir.appendingPathComponent("commands")
+        case .agent: return claudeDir.appendingPathComponent("agents")
         case .generic: return claudeDir
         }
     }

Tests/MCSTests/ComponentExecutorTests.swift

@@ -115,4 +115,35 @@ struct ComponentExecutorTests {
         #expect(!content.contains("__PROJECT_DIR_NAME__"))
         #expect(!content.contains("__REPO_NAME__"))
     }
+
+    @Test("installProjectFile with agent fileType installs to .claude/agents/")
+    func installProjectFileAgentType() throws {
+        let tmpDir = try makeTmpDir()
+        defer { try? FileManager.default.removeItem(at: tmpDir) }
+
+        let projectPath = tmpDir.appendingPathComponent("project")
+        try FileManager.default.createDirectory(at: projectPath, withIntermediateDirectories: true)
+
+        let agentFile = tmpDir.appendingPathComponent("code-reviewer.md")
+        try "---\nname: Code Reviewer\n---\nReview code".write(
+            to: agentFile,
+            atomically: true, encoding: .utf8
+        )
+
+        var exec = makeExecutor()
+        let paths = exec.installProjectFile(
+            source: agentFile,
+            destination: "code-reviewer.md",
+            fileType: .agent,
+            projectPath: projectPath,
+            resolvedValues: [:]
+        )
+
+        #expect(!paths.isEmpty)
+
+        let installed = projectPath.appendingPathComponent(".claude/agents/code-reviewer.md")
+        #expect(FileManager.default.fileExists(atPath: installed.path))
+        let content = try String(contentsOf: installed, encoding: .utf8)
+        #expect(content.contains("Code Reviewer"))
+    }
 }

Tests/MCSTests/DerivedDoctorCheckTests.swift

@@ -152,6 +152,7 @@ struct DerivedDoctorCheckTests {
             (.skill, "/tmp/proj/.claude/skills/test.md"),
             (.hook, "/tmp/proj/.claude/hooks/test.md"),
             (.command, "/tmp/proj/.claude/commands/test.md"),
+            (.agent, "/tmp/proj/.claude/agents/test.md"),
             (.generic, "/tmp/proj/.claude/test.md"),
         ]
         for (fileType, expectedPath) in cases {

Tests/MCSTests/ExternalPackAdapterTests.swift

@@ -171,6 +171,37 @@ struct ExternalPackAdapterTests {
         }
     }
 
+    @Test("Adapter converts copyPackFile component with agent type")
+    func copyPackFileAgentComponent() throws {
+        let manifest = manifestWithComponents([
+            ExternalComponentDefinition(
+                id: "test-pack.agent",
+                displayName: "Code Reviewer",
+                description: "A subagent",
+                type: .agent,
+                dependencies: nil,
+                isRequired: nil,
+                hookEvent: nil,
+                installAction: .copyPackFile(ExternalCopyPackFileConfig(
+                    source: "agents/code-reviewer.md",
+                    destination: "code-reviewer.md",
+                    fileType: .agent
+                )),
+                doctorChecks: nil
+            ),
+        ])
+        let (adapter, packPath) = try makeAdapter(manifest: manifest)
+        let component = adapter.components[0]
+        #expect(component.type == .agent)
+        if case .copyPackFile(let source, let destination, let fileType) = component.installAction {
+            #expect(source == packPath.appendingPathComponent("agents/code-reviewer.md"))
+            #expect(destination == "code-reviewer.md")
+            #expect(fileType == .agent)
+        } else {
+            Issue.record("Expected .copyPackFile action")
+        }
+    }
+
     @Test("Adapter sets packIdentifier on components")
     func packIdentifierSet() throws {
         let manifest = manifestWithComponents([