diff --git a/notepad.md b/notepad.md
index e53266f..db1238e 100644
--- a/notepad.md
+++ b/notepad.md
@@ -225,3 +225,94 @@ All tasks execution STARTED: Thu Dec 4 16:52:57 KST 2025
 
 ---
 
+## [2025-12-09 16:24] - Task 4: Add claude-code-agent-loader feature
+
+### DISCOVERED ISSUES
+- None - straightforward file copy task
+
+### IMPLEMENTATION DECISIONS
+- Copied 3 files from opencode-cc-plugin: `index.ts`, `loader.ts`, `types.ts`
+- Import path `../../shared/frontmatter` unchanged - already compatible with oh-my-opencode structure
+- No `log()` usage in source files - no logger integration needed
+
+### PROBLEMS FOR NEXT TASKS
+- None identified - agent-loader is self-contained
+
+### VERIFICATION RESULTS
+- Ran: `bun run typecheck` → exit 0, no errors
+- Directory structure verified: `claude-code-agent-loader/` created with 3 files
+- Functions exported: `loadUserAgents()`, `loadProjectAgents()`
+
+### LEARNINGS
+- Source location: `~/local-workspaces/opencode-cc-plugin/src/features/agent-loader/`
+- Agent loader uses `parseFrontmatter` from shared module
+- Agent configs loaded from `~/.claude/agents/` (user) and `.claude/agents/` (project)
+- Scope is appended to description: `(user)` or `(project)`
+
+소요 시간: ~1분
+
+---
+
+## [2025-12-09 16:25] - Task 5: Add claude-code-mcp-loader feature
+
+### DISCOVERED ISSUES
+- None - straightforward file copy task
+
+### IMPLEMENTATION DECISIONS
+- Copied 5 files from opencode-cc-plugin: `index.ts`, `loader.ts`, `transformer.ts`, `env-expander.ts`, `types.ts`
+- Import path `../../shared/logger` unchanged - already compatible with oh-my-opencode structure
+- Kept `Bun.file()` usage - oh-my-opencode targets Bun runtime
+- Environment variable expansion supports `${VAR}` and `${VAR:-default}` syntax
+
+### PROBLEMS FOR NEXT TASKS
+- None identified - mcp-loader is self-contained
+- Does NOT conflict with src/mcp/ (builtin MCPs are separate)
+
+### VERIFICATION RESULTS
+- Ran: `bun run typecheck` → exit 0, no errors
+- Directory structure verified: `claude-code-mcp-loader/` created with 5 files
+- Functions exported: `loadMcpConfigs()`, `formatLoadedServersForToast()`, `transformMcpServer()`, `expandEnvVars()`, `expandEnvVarsInObject()`
+
+### LEARNINGS
+- Source location: `~/local-workspaces/opencode-cc-plugin/src/features/mcp-loader/`
+- MCP configs loaded from:
+  - `~/.claude/.mcp.json` (user scope)
+  - `.mcp.json` (project scope)
+  - `.claude/.mcp.json` (local scope)
+- Later scope overrides earlier scope for same server name
+- Supports stdio, http, and sse server types
+
+소요 시간: ~1분
+
+---
+
+## [2025-12-09 16:24] - Task 6: Add claude-code-session-state feature
+
+### DISCOVERED ISSUES
+- None - straightforward file copy task
+
+### IMPLEMENTATION DECISIONS
+- Copied 4 files from opencode-cc-plugin: `types.ts`, `state.ts`, `detector.ts`, `index.ts`
+- No import path changes needed - files are completely self-contained
+- No external dependencies - types are defined locally
+
+### PROBLEMS FOR NEXT TASKS
+- Task 7 should import from `./features/claude-code-session-state` in src/index.ts
+- Task 7 should remove local session variables and use the module's getter/setters
+
+### VERIFICATION RESULTS
+- Directory created: `src/features/claude-code-session-state/` (4 files confirmed)
+- Exports available: sessionErrorState, sessionInterruptState, subagentSessions, sessionFirstMessageProcessed (Maps/Sets)
+- Exports available: currentSessionID, currentSessionTitle, mainSessionID (state vars)
+- Exports available: setCurrentSession(), setMainSession(), getCurrentSessionID(), getCurrentSessionTitle(), getMainSessionID() (getters/setters)
+- Exports available: detectInterrupt() function
+
+### LEARNINGS
+- Session state module is completely self-contained - no external dependencies
+- Uses barrel export pattern: index.ts re-exports everything from types, state, detector
+- Source directory: `~/local-workspaces/opencode-cc-plugin/src/features/session-state/`
+
+소요 시간: ~1분
+
+---
+
diff --git a/src/features/claude-code-agent-loader/index.ts b/src/features/claude-code-agent-loader/index.ts
new file mode 100644
index 0000000..644158c
--- /dev/null
+++ b/src/features/claude-code-agent-loader/index.ts
@@ -0,0 +1,2 @@
+export * from "./types"
+export * from "./loader"
diff --git a/src/features/claude-code-agent-loader/loader.ts b/src/features/claude-code-agent-loader/loader.ts
new file mode 100644
index 0000000..27425d5
--- /dev/null
+++ b/src/features/claude-code-agent-loader/loader.ts
@@ -0,0 +1,93 @@
+import { existsSync, readdirSync, readFileSync } from "fs"
+import { homedir } from "os"
+import { join, basename } from "path"
+import type { AgentConfig } from "@opencode-ai/sdk"
+import { parseFrontmatter } from "../../shared/frontmatter"
+import type { AgentScope, AgentFrontmatter, LoadedAgent } from "./types"
+
+function parseToolsConfig(toolsStr?: string): Record<string, boolean> | undefined {
+  if (!toolsStr) return undefined
+
+  const tools = toolsStr.split(",").map((t) => t.trim()).filter(Boolean)
+  if (tools.length === 0) return undefined
+
+  const result: Record<string, boolean> = {}
+  for (const tool of tools) {
+    result[tool.toLowerCase()] = true
+  }
+  return result
+}
+
+function isMarkdownFile(entry: { name: string; isFile: () => boolean }): boolean {
+  return !entry.name.startsWith(".") && entry.name.endsWith(".md") && entry.isFile()
+}
+
+function loadAgentsFromDir(agentsDir: string, scope: AgentScope): LoadedAgent[] {
+  if (!existsSync(agentsDir)) {
+    return []
+  }
+
+  const entries = readdirSync(agentsDir, { withFileTypes: true })
+  const agents: LoadedAgent[] = []
+
+  for (const entry of entries) {
+    if (!isMarkdownFile(entry)) continue
+
+    const agentPath = join(agentsDir, entry.name)
+    const agentName = basename(entry.name, ".md")
+
+    try {
+      const content = readFileSync(agentPath, "utf-8")
+      const { data, body } = parseFrontmatter<AgentFrontmatter>(content)
+
+       const name = data.name || agentName
+       const originalDescription = data.description || ""
+
+       const formattedDescription = `(${scope}) ${originalDescription}`
+
+       const config: AgentConfig = {
+         description: formattedDescription,
+         mode: "subagent",
+         prompt: body.trim(),
+       }
+
+       const toolsConfig = parseToolsConfig(data.tools)
+      if (toolsConfig) {
+        config.tools = toolsConfig
+      }
+
+      agents.push({
+        name,
+        path: agentPath,
+        config,
+        scope,
+      })
+    } catch {
+      continue
+    }
+  }
+
+  return agents
+}
+
+export function loadUserAgents(): Record<string, AgentConfig> {
+  const userAgentsDir = join(homedir(), ".claude", "agents")
+  const agents = loadAgentsFromDir(userAgentsDir, "user")
+
+  const result: Record<string, AgentConfig> = {}
+  for (const agent of agents) {
+    result[agent.name] = agent.config
+  }
+  return result
+}
+
+export function loadProjectAgents(): Record<string, AgentConfig> {
+  const projectAgentsDir = join(process.cwd(), ".claude", "agents")
+  const agents = loadAgentsFromDir(projectAgentsDir, "project")
+
+  const result: Record<string, AgentConfig> = {}
+  for (const agent of agents) {
+    result[agent.name] = agent.config
+  }
+  return result
+}
diff --git a/src/features/claude-code-agent-loader/types.ts b/src/features/claude-code-agent-loader/types.ts
new file mode 100644
index 0000000..4ffd9de
--- /dev/null
+++ b/src/features/claude-code-agent-loader/types.ts
@@ -0,0 +1,17 @@
+import type { AgentConfig } from "@opencode-ai/sdk"
+
+export type AgentScope = "user" | "project"
+
+export interface AgentFrontmatter {
+  name?: string
+  description?: string
+  model?: string
+  tools?: string
+}
+
+export interface LoadedAgent {
+  name: string
+  path: string
+  config: AgentConfig
+  scope: AgentScope
+}
diff --git a/src/features/claude-code-mcp-loader/env-expander.ts b/src/features/claude-code-mcp-loader/env-expander.ts
new file mode 100644
index 0000000..b3edf89
--- /dev/null
+++ b/src/features/claude-code-mcp-loader/env-expander.ts
@@ -0,0 +1,27 @@
+export function expandEnvVars(value: string): string {
+  return value.replace(
+    /\$\{([^}:]+)(?::-([^}]*))?\}/g,
+    (_, varName: string, defaultValue?: string) => {
+      const envValue = process.env[varName]
+      if (envValue !== undefined) return envValue
+      if (defaultValue !== undefined) return defaultValue
+      return ""
+    }
+  )
+}
+
+export function expandEnvVarsInObject<T>(obj: T): T {
+  if (obj === null || obj === undefined) return obj
+  if (typeof obj === "string") return expandEnvVars(obj) as T
+  if (Array.isArray(obj)) {
+    return obj.map((item) => expandEnvVarsInObject(item)) as T
+  }
+  if (typeof obj === "object") {
+    const result: Record<string, unknown> = {}
+    for (const [key, value] of Object.entries(obj)) {
+      result[key] = expandEnvVarsInObject(value)
+    }
+    return result as T
+  }
+  return obj
+}
diff --git a/src/features/claude-code-mcp-loader/index.ts b/src/features/claude-code-mcp-loader/index.ts
new file mode 100644
index 0000000..20f4972
--- /dev/null
+++ b/src/features/claude-code-mcp-loader/index.ts
@@ -0,0 +1,11 @@
+/**
+ * MCP Configuration Loader
+ *
+ * Loads Claude Code .mcp.json format configurations from multiple scopes
+ * and transforms them to OpenCode SDK format
+ */
+
+export * from "./types"
+export * from "./loader"
+export * from "./transformer"
+export * from "./env-expander"
diff --git a/src/features/claude-code-mcp-loader/loader.ts b/src/features/claude-code-mcp-loader/loader.ts
new file mode 100644
index 0000000..d75cb57
--- /dev/null
+++ b/src/features/claude-code-mcp-loader/loader.ts
@@ -0,0 +1,89 @@
+import { existsSync } from "fs"
+import { homedir } from "os"
+import { join } from "path"
+import type {
+  ClaudeCodeMcpConfig,
+  LoadedMcpServer,
+  McpLoadResult,
+  McpScope,
+} from "./types"
+import { transformMcpServer } from "./transformer"
+import { log } from "../../shared/logger"
+
+interface McpConfigPath {
+  path: string
+  scope: McpScope
+}
+
+function getMcpConfigPaths(): McpConfigPath[] {
+  const home = homedir()
+  const cwd = process.cwd()
+
+  return [
+    { path: join(home, ".claude", ".mcp.json"), scope: "user" },
+    { path: join(cwd, ".mcp.json"), scope: "project" },
+    { path: join(cwd, ".claude", ".mcp.json"), scope: "local" },
+  ]
+}
+
+async function loadMcpConfigFile(
+  filePath: string
+): Promise<ClaudeCodeMcpConfig | null> {
+  if (!existsSync(filePath)) {
+    return null
+  }
+
+  try {
+    const content = await Bun.file(filePath).text()
+    return JSON.parse(content) as ClaudeCodeMcpConfig
+  } catch (error) {
+    log(`Failed to load MCP config from ${filePath}`, error)
+    return null
+  }
+}
+
+export async function loadMcpConfigs(): Promise<McpLoadResult> {
+  const servers: McpLoadResult["servers"] = {}
+  const loadedServers: LoadedMcpServer[] = []
+  const paths = getMcpConfigPaths()
+
+  for (const { path, scope } of paths) {
+    const config = await loadMcpConfigFile(path)
+    if (!config?.mcpServers) continue
+
+    for (const [name, serverConfig] of Object.entries(config.mcpServers)) {
+      if (serverConfig.disabled) {
+        log(`Skipping disabled MCP server "${name}"`, { path })
+        continue
+      }
+
+      try {
+        const transformed = transformMcpServer(name, serverConfig)
+        servers[name] = transformed
+
+        const existingIndex = loadedServers.findIndex((s) => s.name === name)
+        if (existingIndex !== -1) {
+          loadedServers.splice(existingIndex, 1)
+        }
+
+        loadedServers.push({ name, scope, config: transformed })
+
+        log(`Loaded MCP server "${name}" from ${scope}`, { path })
+      } catch (error) {
+        log(`Failed to transform MCP server "${name}"`, error)
+      }
+    }
+  }
+
+  return { servers, loadedServers }
+}
+
+export function formatLoadedServersForToast(
+  loadedServers: LoadedMcpServer[]
+): string {
+  if (loadedServers.length === 0) return ""
+
+  return loadedServers
+    .map((server) => `${server.name} (${server.scope})`)
+    .join(", ")
+}
diff --git a/src/features/claude-code-mcp-loader/transformer.ts b/src/features/claude-code-mcp-loader/transformer.ts
new file mode 100644
index 0000000..f94e504
--- /dev/null
+++ b/src/features/claude-code-mcp-loader/transformer.ts
@@ -0,0 +1,53 @@
+import type {
+  ClaudeCodeMcpServer,
+  McpLocalConfig,
+  McpRemoteConfig,
+  McpServerConfig,
+} from "./types"
+import { expandEnvVarsInObject } from "./env-expander"
+
+export function transformMcpServer(
+  name: string,
+  server: ClaudeCodeMcpServer
+): McpServerConfig {
+  const expanded = expandEnvVarsInObject(server)
+  const serverType = expanded.type ?? "stdio"
+
+  if (serverType === "http" || serverType === "sse") {
+    if (!expanded.url) {
+      throw new Error(
+        `MCP server "${name}" requires url for type "${serverType}"`
+      )
+    }
+
+    const config: McpRemoteConfig = {
+      type: "remote",
+      url: expanded.url,
+      enabled: true,
+    }
+
+    if (expanded.headers && Object.keys(expanded.headers).length > 0) {
+      config.headers = expanded.headers
+    }
+
+    return config
+  }
+
+  if (!expanded.command) {
+    throw new Error(`MCP server "${name}" requires command for stdio type`)
+  }
+
+  const commandArray = [expanded.command, ...(expanded.args ?? [])]
+
+  const config: McpLocalConfig = {
+    type: "local",
+    command: commandArray,
+    enabled: true,
+  }
+
+  if (expanded.env && Object.keys(expanded.env).length > 0) {
+    config.environment = expanded.env
+  }
+
+  return config
+}
diff --git a/src/features/claude-code-mcp-loader/types.ts b/src/features/claude-code-mcp-loader/types.ts
new file mode 100644
index 0000000..838ff61
--- /dev/null
+++ b/src/features/claude-code-mcp-loader/types.ts
@@ -0,0 +1,42 @@
+export type McpScope = "user" | "project" | "local"
+
+export interface ClaudeCodeMcpServer {
+  type?: "http" | "sse" | "stdio"
+  url?: string
+  command?: string
+  args?: string[]
+  env?: Record<string, string>
+  headers?: Record<string, string>
+  disabled?: boolean
+}
+
+export interface ClaudeCodeMcpConfig {
+  mcpServers?: Record<string, ClaudeCodeMcpServer>
+}
+
+export interface McpLocalConfig {
+  type: "local"
+  command: string[]
+  environment?: Record<string, string>
+  enabled?: boolean
+}
+
+export interface McpRemoteConfig {
+  type: "remote"
+  url: string
+  headers?: Record<string, string>
+  enabled?: boolean
+}
+
+export type McpServerConfig = McpLocalConfig | McpRemoteConfig
+
+export interface LoadedMcpServer {
+  name: string
+  scope: McpScope
+  config: McpServerConfig
+}
+
+export interface McpLoadResult {
+  servers: Record<string, McpServerConfig>
+  loadedServers: LoadedMcpServer[]
+}
diff --git a/src/features/claude-code-session-state/detector.ts b/src/features/claude-code-session-state/detector.ts
new file mode 100644
index 0000000..9cb8178
--- /dev/null
+++ b/src/features/claude-code-session-state/detector.ts
@@ -0,0 +1,21 @@
+export function detectInterrupt(error: unknown): boolean {
+  if (!error) return false
+
+  if (typeof error === "object") {
+    const errObj = error as Record<string, unknown>
+    const name = errObj.name as string | undefined
+    const message = errObj.message as string | undefined
+
+    if (name === "MessageAbortedError" || name === "AbortError") return true
+    if (name === "DOMException" && message?.includes("abort")) return true
+    const msgLower = message?.toLowerCase()
+    if (msgLower?.includes("aborted") || msgLower?.includes("cancelled") || msgLower?.includes("interrupted")) return true
+  }
+
+  if (typeof error === "string") {
+    const lower = error.toLowerCase()
+    return lower.includes("abort") || lower.includes("cancel") || lower.includes("interrupt")
+  }
+
+  return false
+}
diff --git a/src/features/claude-code-session-state/index.ts b/src/features/claude-code-session-state/index.ts
new file mode 100644
index 0000000..665b542
--- /dev/null
+++ b/src/features/claude-code-session-state/index.ts
@@ -0,0 +1,3 @@
+export * from "./types"
+export * from "./state"
+export * from "./detector"
diff --git a/src/features/claude-code-session-state/state.ts b/src/features/claude-code-session-state/state.ts
new file mode 100644
index 0000000..d0a57b9
--- /dev/null
+++ b/src/features/claude-code-session-state/state.ts
@@ -0,0 +1,31 @@
+import type { SessionErrorState, SessionInterruptState } from "./types"
+
+export const sessionErrorState = new Map<string, SessionErrorState>()
+export const sessionInterruptState = new Map<string, SessionInterruptState>()
+export const subagentSessions = new Set<string>()
+export const sessionFirstMessageProcessed = new Set<string>()
+
+export let currentSessionID: string | undefined
+export let currentSessionTitle: string | undefined
+export let mainSessionID: string | undefined
+
+export function setCurrentSession(id: string | undefined, title: string | undefined) {
+  currentSessionID = id
+  currentSessionTitle = title
+}
+
+export function setMainSession(id: string | undefined) {
+  mainSessionID = id
+}
+
+export function getCurrentSessionID(): string | undefined {
+  return currentSessionID
+}
+
+export function getCurrentSessionTitle(): string | undefined {
+  return currentSessionTitle
+}
+
+export function getMainSessionID(): string | undefined {
+  return mainSessionID
+}
diff --git a/src/features/claude-code-session-state/types.ts b/src/features/claude-code-session-state/types.ts
new file mode 100644
index 0000000..4939871
--- /dev/null
+++ b/src/features/claude-code-session-state/types.ts
@@ -0,0 +1,8 @@
+export interface SessionErrorState {
+  hasError: boolean
+  errorMessage?: string
+}
+
+export interface SessionInterruptState {
+  interrupted: boolean
+}