diff --git a/container/agent-runner/src/db/connection.ts b/container/agent-runner/src/db/connection.ts
index 31f2fb2..0877531 100644
--- a/container/agent-runner/src/db/connection.ts
+++ b/container/agent-runner/src/db/connection.ts
@@ -90,8 +90,10 @@ export function initTestSessionDb(): { inbound: Database.Database; outbound: Dat
       content        TEXT NOT NULL
     );
     CREATE TABLE delivered (
-      message_out_id TEXT PRIMARY KEY,
-      delivered_at   TEXT NOT NULL
+      message_out_id      TEXT PRIMARY KEY,
+      platform_message_id TEXT,
+      status              TEXT NOT NULL DEFAULT 'delivered',
+      delivered_at        TEXT NOT NULL
     );
   `);
 
diff --git a/container/agent-runner/src/db/messages-out.ts b/container/agent-runner/src/db/messages-out.ts
index 55e078c..3d2f411 100644
--- a/container/agent-runner/src/db/messages-out.ts
+++ b/container/agent-runner/src/db/messages-out.ts
@@ -70,16 +70,37 @@ export function writeMessageOut(msg: WriteMessageOut): number {
 /**
  * Look up a message's platform ID by seq number.
  * Searches both inbound and outbound DBs since seq spans both.
+ *
+ * For inbound messages, the Chat SDK message ID is already the platform message ID
+ * (e.g., "6037840640:42" for Telegram).
+ *
+ * For outbound messages, the internal ID (msg-xxx) won't work for edits/reactions.
+ * Instead, look up the platform_message_id from the delivered table (host writes this
+ * after successful delivery).
  */
 export function getMessageIdBySeq(seq: number): string | null {
-  const inRow = getInboundDb().prepare('SELECT id FROM messages_in WHERE seq = ?').get(seq) as
+  const inbound = getInboundDb();
+
+  // Inbound messages: ID is already the platform message ID
+  const inRow = inbound.prepare('SELECT id FROM messages_in WHERE seq = ?').get(seq) as
     | { id: string }
     | undefined;
   if (inRow) return inRow.id;
+
+  // Outbound messages: look up platform message ID from delivered table
   const outRow = getOutboundDb().prepare('SELECT id FROM messages_out WHERE seq = ?').get(seq) as
     | { id: string }
     | undefined;
-  return outRow?.id ?? null;
+  if (!outRow) return null;
+
+  // Check if host has stored the platform message ID after delivery
+  const deliveredRow = inbound
+    .prepare('SELECT platform_message_id FROM delivered WHERE message_out_id = ?')
+    .get(outRow.id) as { platform_message_id: string | null } | undefined;
+  if (deliveredRow?.platform_message_id) return deliveredRow.platform_message_id;
+
+  // Fallback to internal ID (edits/reactions on undelivered messages won't work)
+  return outRow.id;
 }
 
 /** Get undelivered messages (for host polling — reads from outbound.db). */
diff --git a/container/agent-runner/src/formatter.ts b/container/agent-runner/src/formatter.ts
index 8b0b1e8..87be2d6 100644
--- a/container/agent-runner/src/formatter.ts
+++ b/container/agent-runner/src/formatter.ts
@@ -109,13 +109,7 @@ function formatChatMessages(messages: MessageInRow[]): string {
 
   const lines = ['<messages>'];
   for (const msg of messages) {
-    const content = parseContent(msg.content);
-    const sender = content.sender || content.author?.fullName || content.author?.userName || 'Unknown';
-    const time = formatTime(msg.timestamp);
-    const text = content.text || '';
-    const idAttr = msg.seq != null ? ` id="${msg.seq}"` : '';
-    const attachmentsSuffix = formatAttachments(content.attachments);
-    lines.push(`<message${idAttr} sender="${escapeXml(sender)}" time="${time}">${escapeXml(text)}${attachmentsSuffix}</message>`);
+    lines.push(formatSingleChat(msg));
   }
   lines.push('</messages>');
   return lines.join('\n');
@@ -127,8 +121,9 @@ function formatSingleChat(msg: MessageInRow): string {
   const time = formatTime(msg.timestamp);
   const text = content.text || '';
   const idAttr = msg.seq != null ? ` id="${msg.seq}"` : '';
+  const replyPrefix = formatReplyContext(content.replyTo);
   const attachmentsSuffix = formatAttachments(content.attachments);
-  return `<message${idAttr} sender="${escapeXml(sender)}" time="${time}">${escapeXml(text)}${attachmentsSuffix}</message>`;
+  return `<message${idAttr} sender="${escapeXml(sender)}" time="${time}">${replyPrefix}${escapeXml(text)}${attachmentsSuffix}</message>`;
 }
 
 function formatTaskMessage(msg: MessageInRow): string {
@@ -153,13 +148,26 @@ function formatSystemMessage(msg: MessageInRow): string {
   return `[SYSTEM RESPONSE]\n\nAction: ${content.action || 'unknown'}\nStatus: ${content.status || 'unknown'}\nResult: ${JSON.stringify(content.result || null)}`;
 }
 
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
+function formatReplyContext(replyTo: any): string {
+  if (!replyTo) return '';
+  const sender = replyTo.sender || 'Unknown';
+  const text = replyTo.text || '';
+  const preview = text.length > 100 ? text.slice(0, 100) + '…' : text;
+  return `\n<reply-to sender="${escapeXml(sender)}">${escapeXml(preview)}</reply-to>\n`;
+}
+
 // eslint-disable-next-line @typescript-eslint/no-explicit-any
 function formatAttachments(attachments: any[] | undefined): string {
   if (!Array.isArray(attachments) || attachments.length === 0) return '';
   const parts = attachments.map((a) => {
     const name = a.name || a.filename || 'attachment';
     const type = a.type || 'file';
+    const localPath = a.localPath ? `/workspace/${a.localPath}` : '';
     const url = a.url || '';
+    if (localPath) {
+      return `[${type}: ${escapeXml(name)} — saved to ${escapeXml(localPath)}]`;
+    }
     return url ? `[${type}: ${escapeXml(name)} (${escapeXml(url)})]` : `[${type}: ${escapeXml(name)}]`;
   });
   return '\n' + parts.join('\n');
diff --git a/container/agent-runner/src/index.ts b/container/agent-runner/src/index.ts
index 8f91e6e..1513f5c 100644
--- a/container/agent-runner/src/index.ts
+++ b/container/agent-runner/src/index.ts
@@ -76,20 +76,36 @@ async function main(): Promise<void> {
     CLAUDE_CODE_AUTO_COMPACT_WINDOW: '165000',
   };
 
+  // Build MCP servers config: nanoclaw built-in + any additional from host
+  const mcpServers: Record<string, { command: string; args: string[]; env: Record<string, string> }> = {
+    nanoclaw: {
+      command: 'node',
+      args: [mcpServerPath],
+      env: {
+        SESSION_INBOUND_DB_PATH: process.env.SESSION_INBOUND_DB_PATH || '/workspace/inbound.db',
+        SESSION_OUTBOUND_DB_PATH: process.env.SESSION_OUTBOUND_DB_PATH || '/workspace/outbound.db',
+        SESSION_HEARTBEAT_PATH: process.env.SESSION_HEARTBEAT_PATH || '/workspace/.heartbeat',
+      },
+    },
+  };
+
+  // Merge additional MCP servers from host configuration
+  if (process.env.NANOCLAW_MCP_SERVERS) {
+    try {
+      const additional = JSON.parse(process.env.NANOCLAW_MCP_SERVERS) as Record<string, { command: string; args: string[]; env: Record<string, string> }>;
+      for (const [name, config] of Object.entries(additional)) {
+        mcpServers[name] = config;
+        log(`Additional MCP server: ${name} (${config.command})`);
+      }
+    } catch (e) {
+      log(`Failed to parse NANOCLAW_MCP_SERVERS: ${e}`);
+    }
+  }
+
   await runPollLoop({
     provider,
     cwd: CWD,
-    mcpServers: {
-      nanoclaw: {
-        command: 'node',
-        args: [mcpServerPath],
-        env: {
-          SESSION_INBOUND_DB_PATH: process.env.SESSION_INBOUND_DB_PATH || '/workspace/inbound.db',
-          SESSION_OUTBOUND_DB_PATH: process.env.SESSION_OUTBOUND_DB_PATH || '/workspace/outbound.db',
-          SESSION_HEARTBEAT_PATH: process.env.SESSION_HEARTBEAT_PATH || '/workspace/.heartbeat',
-        },
-      },
-    },
+    mcpServers,
     systemPrompt,
     env,
     additionalDirectories: additionalDirectories.length > 0 ? additionalDirectories : undefined,
diff --git a/container/agent-runner/src/mcp-tools/agents.ts b/container/agent-runner/src/mcp-tools/agents.ts
index 54e50b6..a9443de 100644
--- a/container/agent-runner/src/mcp-tools/agents.ts
+++ b/container/agent-runner/src/mcp-tools/agents.ts
@@ -1,6 +1,7 @@
 /**
- * Agent-to-agent MCP tools: send_to_agent.
+ * Agent-to-agent MCP tools: send_to_agent, create_agent.
  */
+import { findQuestionResponse, markCompleted } from '../db/messages-in.js';
 import { writeMessageOut } from '../db/messages-out.js';
 import type { McpToolDefinition } from './types.js';
 
@@ -20,6 +21,10 @@ function err(text: string) {
   return { content: [{ type: 'text' as const, text: `Error: ${text}` }], isError: true };
 }
 
+function sleep(ms: number): Promise<void> {
+  return new Promise((resolve) => setTimeout(resolve, ms));
+}
+
 export const sendToAgent: McpToolDefinition = {
   tool: {
     name: 'send_to_agent',
@@ -55,4 +60,56 @@ export const sendToAgent: McpToolDefinition = {
   },
 };
 
-export const agentTools: McpToolDefinition[] = [sendToAgent];
+export const createAgent: McpToolDefinition = {
+  tool: {
+    name: 'create_agent',
+    description: 'Create a new agent group dynamically. Returns the new agent group ID.',
+    inputSchema: {
+      type: 'object' as const,
+      properties: {
+        name: { type: 'string', description: 'Agent display name' },
+        instructions: { type: 'string', description: 'CLAUDE.md content (agent instructions/personality)' },
+        folder: { type: 'string', description: 'Folder name (default: auto-generated from name)' },
+      },
+      required: ['name'],
+    },
+  },
+  async handler(args) {
+    const name = args.name as string;
+    if (!name) return err('name is required');
+
+    const requestId = generateId();
+
+    writeMessageOut({
+      id: requestId,
+      kind: 'system',
+      content: JSON.stringify({
+        action: 'create_agent',
+        requestId,
+        name,
+        instructions: (args.instructions as string) || null,
+        folder: (args.folder as string) || null,
+      }),
+    });
+
+    log(`create_agent: ${requestId} → "${name}"`);
+
+    // Poll for host response
+    const deadline = Date.now() + 30_000;
+    while (Date.now() < deadline) {
+      const response = findQuestionResponse(requestId);
+      if (response) {
+        const parsed = JSON.parse(response.content);
+        markCompleted([response.id]);
+        if (parsed.status === 'success') {
+          return ok(`Agent created: ${parsed.result.agentGroupId} (name: ${parsed.result.name}, folder: ${parsed.result.folder})`);
+        }
+        return err(parsed.result?.error || 'Failed to create agent');
+      }
+      await sleep(1000);
+    }
+    return err('Timed out waiting for agent creation response');
+  },
+};
+
+export const agentTools: McpToolDefinition[] = [sendToAgent, createAgent];
diff --git a/container/agent-runner/src/mcp-tools/index.ts b/container/agent-runner/src/mcp-tools/index.ts
index 254d802..f98143d 100644
--- a/container/agent-runner/src/mcp-tools/index.ts
+++ b/container/agent-runner/src/mcp-tools/index.ts
@@ -14,12 +14,13 @@ import { coreTools } from './core.js';
 import { schedulingTools } from './scheduling.js';
 import { interactiveTools } from './interactive.js';
 import { agentTools } from './agents.js';
+import { selfModTools } from './self-mod.js';
 
 function log(msg: string): void {
   console.error(`[mcp-tools] ${msg}`);
 }
 
-const allTools: McpToolDefinition[] = [...coreTools, ...schedulingTools, ...interactiveTools, ...agentTools];
+const allTools: McpToolDefinition[] = [...coreTools, ...schedulingTools, ...interactiveTools, ...agentTools, ...selfModTools];
 
 const toolMap = new Map<string, McpToolDefinition>();
 for (const t of allTools) {
diff --git a/container/agent-runner/src/mcp-tools/self-mod.ts b/container/agent-runner/src/mcp-tools/self-mod.ts
new file mode 100644
index 0000000..9a0ef18
--- /dev/null
+++ b/container/agent-runner/src/mcp-tools/self-mod.ts
@@ -0,0 +1,155 @@
+/**
+ * Self-modification MCP tools: install_packages, add_mcp_server, request_rebuild.
+ *
+ * These tools request changes to the agent's container configuration.
+ * install_packages and request_rebuild require admin approval.
+ * add_mcp_server takes effect on next container restart without approval.
+ */
+import { findQuestionResponse, markCompleted } from '../db/messages-in.js';
+import { writeMessageOut } from '../db/messages-out.js';
+import type { McpToolDefinition } from './types.js';
+
+function log(msg: string): void {
+  console.error(`[mcp-tools] ${msg}`);
+}
+
+function generateId(): string {
+  return `msg-${Date.now()}-${Math.random().toString(36).slice(2, 8)}`;
+}
+
+function ok(text: string) {
+  return { content: [{ type: 'text' as const, text }] };
+}
+
+function err(text: string) {
+  return { content: [{ type: 'text' as const, text: `Error: ${text}` }], isError: true };
+}
+
+function sleep(ms: number): Promise<void> {
+  return new Promise((resolve) => setTimeout(resolve, ms));
+}
+
+async function pollForResponse(requestId: string, timeoutMs: number) {
+  const deadline = Date.now() + timeoutMs;
+  while (Date.now() < deadline) {
+    const response = findQuestionResponse(requestId);
+    if (response) {
+      const parsed = JSON.parse(response.content);
+      markCompleted([response.id]);
+      if (parsed.status === 'success') {
+        return ok(JSON.stringify(parsed.result || 'Success'));
+      }
+      return err(parsed.result?.error || parsed.selectedOption || 'Request denied');
+    }
+    await sleep(2000);
+  }
+  return err(`Request timed out after ${timeoutMs / 1000}s`);
+}
+
+export const installPackages: McpToolDefinition = {
+  tool: {
+    name: 'install_packages',
+    description:
+      'Request installation of system (apt) or Node.js (npm) packages in the container. Requires admin approval. Takes effect after container rebuild.',
+    inputSchema: {
+      type: 'object' as const,
+      properties: {
+        apt: { type: 'array', items: { type: 'string' }, description: 'apt packages to install' },
+        npm: { type: 'array', items: { type: 'string' }, description: 'npm packages to install globally' },
+        reason: { type: 'string', description: 'Why these packages are needed' },
+      },
+    },
+  },
+  async handler(args) {
+    const apt = (args.apt as string[]) || [];
+    const npm = (args.npm as string[]) || [];
+    if (apt.length === 0 && npm.length === 0) return err('At least one apt or npm package is required');
+
+    const requestId = generateId();
+    writeMessageOut({
+      id: requestId,
+      kind: 'system',
+      content: JSON.stringify({
+        action: 'install_packages',
+        requestId,
+        apt,
+        npm,
+        reason: (args.reason as string) || '',
+      }),
+    });
+
+    log(`install_packages: ${requestId} → apt=[${apt.join(',')}] npm=[${npm.join(',')}]`);
+    return await pollForResponse(requestId, 300_000);
+  },
+};
+
+export const addMcpServer: McpToolDefinition = {
+  tool: {
+    name: 'add_mcp_server',
+    description:
+      "Add an MCP server to this agent's configuration. Takes effect on next container restart (no rebuild needed, no approval required).",
+    inputSchema: {
+      type: 'object' as const,
+      properties: {
+        name: { type: 'string', description: 'MCP server name (unique identifier)' },
+        command: { type: 'string', description: 'Command to run the MCP server' },
+        args: { type: 'array', items: { type: 'string' }, description: 'Command arguments' },
+        env: { type: 'object', description: 'Environment variables for the server' },
+      },
+      required: ['name', 'command'],
+    },
+  },
+  async handler(args) {
+    const name = args.name as string;
+    const command = args.command as string;
+    if (!name || !command) return err('name and command are required');
+
+    const requestId = generateId();
+    writeMessageOut({
+      id: requestId,
+      kind: 'system',
+      content: JSON.stringify({
+        action: 'add_mcp_server',
+        requestId,
+        name,
+        command,
+        args: (args.args as string[]) || [],
+        env: (args.env as Record<string, string>) || {},
+      }),
+    });
+
+    log(`add_mcp_server: ${requestId} → "${name}" (${command})`);
+    return await pollForResponse(requestId, 30_000);
+  },
+};
+
+export const requestRebuild: McpToolDefinition = {
+  tool: {
+    name: 'request_rebuild',
+    description:
+      'Request a container rebuild to apply pending package installations. Requires admin approval. The current container will be stopped and restarted with the new image.',
+    inputSchema: {
+      type: 'object' as const,
+      properties: {
+        reason: { type: 'string', description: 'Why the rebuild is needed' },
+      },
+    },
+  },
+  async handler(args) {
+    const requestId = generateId();
+    writeMessageOut({
+      id: requestId,
+      kind: 'system',
+      content: JSON.stringify({
+        action: 'request_rebuild',
+        requestId,
+        reason: (args.reason as string) || '',
+      }),
+    });
+
+    log(`request_rebuild: ${requestId}`);
+    return await pollForResponse(requestId, 300_000);
+  },
+};
+
+export const selfModTools: McpToolDefinition[] = [installPackages, addMcpServer, requestRebuild];
diff --git a/groups/global/CLAUDE.md b/groups/global/CLAUDE.md
index b3c44c6..d2b2658 100644
--- a/groups/global/CLAUDE.md
+++ b/groups/global/CLAUDE.md
@@ -77,6 +77,34 @@ Standard Markdown works: `**bold**`, `*italic*`, `[links](url)`, `# headings`.
 
 ---
 
+## Installing Packages & Tools
+
+Your container is ephemeral — anything installed via `apt-get` or `npm install -g` is lost on restart. To install packages that persist, use the self-modification tools:
+
+1. **`install_packages`** — request system (apt) or global npm packages. Requires admin approval.
+2. **`request_rebuild`** — rebuild your container image so approved packages are baked in. Always call this after `install_packages` to apply the changes.
+
+Example flow:
+```
+install_packages({ apt: ["ffmpeg"], npm: ["@xenova/transformers"], reason: "Audio transcription" })
+# → Admin gets an approval card → approves
+request_rebuild({ reason: "Apply ffmpeg + transformers" })
+# → Admin approves → image rebuilt with the packages
+```
+
+**When to use this vs workspace npm install:**
+- `npm install` in `/workspace/agent/` persists on disk (it's mounted) but isn't on the global PATH — use it for project-level dependencies
+- `install_packages` is for system tools (ffmpeg, imagemagick) and global npm packages that need to be on PATH
+
+### MCP Servers
+
+Use **`add_mcp_server`** to add an MCP server to your configuration, then **`request_rebuild`** to apply. Browse available servers at https://mcp.so — it's a curated directory of high-quality MCP servers. Most Node.js servers run via `npx`, e.g.:
+
+```
+add_mcp_server({ name: "memory", command: "npx", args: ["@modelcontextprotocol/server-memory"] })
+request_rebuild({ reason: "Add memory MCP server" })
+```
+
 ## Task Scripts
 
 For any recurring task, use `schedule_task`. Frequent agent invocations — especially multiple times a day — consume API credits and can risk account restrictions. If a simple check can determine whether action is needed, add a `script` — it runs first, and the agent is only called when the check passes. This keeps invocations to a minimum.
diff --git a/src/channels/adapter.ts b/src/channels/adapter.ts
index 23271ed..d02f62c 100644
--- a/src/channels/adapter.ts
+++ b/src/channels/adapter.ts
@@ -67,8 +67,8 @@ export interface ChannelAdapter {
   teardown(): Promise<void>;
   isConnected(): boolean;
 
-  // Outbound delivery
-  deliver(platformId: string, threadId: string | null, message: OutboundMessage): Promise<void>;
+  // Outbound delivery — returns the platform message ID if available
+  deliver(platformId: string, threadId: string | null, message: OutboundMessage): Promise<string | undefined>;
 
   // Optional
   setTyping?(platformId: string, threadId: string | null): Promise<void>;
diff --git a/src/channels/channel-registry.test.ts b/src/channels/channel-registry.test.ts
index 2fc183b..25ceab3 100644
--- a/src/channels/channel-registry.test.ts
+++ b/src/channels/channel-registry.test.ts
@@ -54,8 +54,9 @@ function createMockAdapter(
       return setupConfig !== null;
     },
 
-    async deliver(_platformId: string, _threadId: string | null, message: OutboundMessage) {
+    async deliver(_platformId: string, _threadId: string | null, message: OutboundMessage): Promise<string | undefined> {
       delivered.push(message);
+      return undefined;
     },
 
     async setTyping() {},
@@ -213,8 +214,8 @@ describe('channel + router integration', () => {
     setDeliveryAdapter({
       async deliver(channelType, platformId, threadId, kind, content) {
         const adapter = getChannelAdapter(channelType);
-        if (!adapter) return;
-        await adapter.deliver(platformId, threadId, { kind, content: JSON.parse(content) });
+        if (!adapter) return undefined;
+        return adapter.deliver(platformId, threadId, { kind, content: JSON.parse(content) });
       },
     });
 
diff --git a/src/channels/chat-sdk-bridge.ts b/src/channels/chat-sdk-bridge.ts
index 1d84b00..9f8f9d2 100644
--- a/src/channels/chat-sdk-bridge.ts
+++ b/src/channels/chat-sdk-bridge.ts
@@ -30,11 +30,23 @@ interface GatewayAdapter extends Adapter {
   ): Promise<Response>;
 }
 
+/** Reply context extracted from a platform's raw message. */
+export interface ReplyContext {
+  text: string;
+  sender: string;
+}
+
+/** Extract reply context from a platform-specific raw message. Return null if no reply. */
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
+export type ReplyContextExtractor = (raw: Record<string, any>) => ReplyContext | null;
+
 export interface ChatSdkBridgeConfig {
   adapter: Adapter;
   concurrency?: ConcurrencyStrategy;
   /** Bot token for authenticating forwarded Gateway events (required for interaction handling). */
   botToken?: string;
+  /** Platform-specific reply context extraction. */
+  extractReplyContext?: ReplyContextExtractor;
 }
 
 export function createChatSdkBridge(config: ChatSdkBridgeConfig): ChannelAdapter {
@@ -53,11 +65,50 @@ export function createChatSdkBridge(config: ChatSdkBridgeConfig): ChannelAdapter
     return map;
   }
 
-  function messageToInbound(message: ChatMessage): InboundMessage {
+  async function messageToInbound(message: ChatMessage): Promise<InboundMessage> {
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    const serialized = message.toJSON() as Record<string, any>;
+
+    // Download attachment data before serialization loses fetchData()
+    if (message.attachments && message.attachments.length > 0) {
+      const enriched = [];
+      for (const att of message.attachments) {
+        // eslint-disable-next-line @typescript-eslint/no-explicit-any
+        const entry: Record<string, any> = {
+          type: att.type,
+          name: att.name,
+          mimeType: att.mimeType,
+          size: att.size,
+          width: (att as unknown as Record<string, unknown>).width,
+          height: (att as unknown as Record<string, unknown>).height,
+        };
+        if (att.fetchData) {
+          try {
+            const buffer = await att.fetchData();
+            entry.data = buffer.toString('base64');
+          } catch (err) {
+            log.warn('Failed to download attachment', { type: att.type, err });
+          }
+        }
+        enriched.push(entry);
+      }
+      serialized.attachments = enriched;
+    }
+
+    // Extract reply context via platform-specific hook
+    if (config.extractReplyContext && message.raw) {
+      // eslint-disable-next-line @typescript-eslint/no-explicit-any
+      const replyTo = config.extractReplyContext(message.raw as Record<string, any>);
+      if (replyTo) serialized.replyTo = replyTo;
+    }
+
+    // Drop raw to save DB space (can be very large)
+    serialized.raw = undefined;
+
     return {
       id: message.id,
       kind: 'chat-sdk',
-      content: message.toJSON(),
+      content: serialized,
       timestamp: message.metadata.dateSent.toISOString(),
     };
   }
@@ -83,20 +134,20 @@ export function createChatSdkBridge(config: ChatSdkBridgeConfig): ChannelAdapter
       // Subscribed threads — forward all messages
       chat.onSubscribedMessage(async (thread, message) => {
         const channelId = adapter.channelIdFromThreadId(thread.id);
-        setupConfig.onInbound(channelId, thread.id, messageToInbound(message));
+        setupConfig.onInbound(channelId, thread.id, await messageToInbound(message));
       });
 
       // @mention in unsubscribed thread — forward + subscribe
       chat.onNewMention(async (thread, message) => {
         const channelId = adapter.channelIdFromThreadId(thread.id);
-        setupConfig.onInbound(channelId, thread.id, messageToInbound(message));
+        setupConfig.onInbound(channelId, thread.id, await messageToInbound(message));
         await thread.subscribe();
       });
 
       // DMs — always forward + subscribe
       chat.onDirectMessage(async (thread, message) => {
         const channelId = adapter.channelIdFromThreadId(thread.id);
-        setupConfig.onInbound(channelId, null, messageToInbound(message));
+        setupConfig.onInbound(channelId, null, await messageToInbound(message));
         await thread.subscribe();
       });
 
@@ -108,6 +159,17 @@ export function createChatSdkBridge(config: ChatSdkBridgeConfig): ChannelAdapter
         const questionId = parts[1];
         const selectedOption = event.value || '';
         const userId = event.user?.userId || '';
+
+        // Update the card to show the selected answer and remove buttons
+        try {
+          const tid = event.threadId;
+          await adapter.editMessage(tid, event.messageId, {
+            markdown: `❓ **Question**\n\n${selectedOption ? `✅ **${selectedOption}**` : '(clicked)'}`,
+          });
+        } catch (err) {
+          log.warn('Failed to update card after action', { err });
+        }
+
         setupConfig.onAction(questionId, selectedOption, userId);
       });
 
@@ -161,7 +223,7 @@ export function createChatSdkBridge(config: ChatSdkBridgeConfig): ChannelAdapter
       log.info('Chat SDK bridge initialized', { adapter: adapter.name });
     },
 
-    async deliver(platformId: string, threadId: string | null, message) {
+    async deliver(platformId: string, threadId: string | null, message): Promise<string | undefined> {
       // platformId is already in the adapter's encoded format (e.g. "telegram:6037840640",
       // "discord:guildId:channelId") — use it directly as the thread ID
       const tid = threadId ?? platformId;
@@ -190,24 +252,36 @@ export function createChatSdkBridge(config: ChatSdkBridgeConfig): ChannelAdapter
             Actions(options.map((opt) => Button({ id: `ncq:${questionId}:${opt}`, label: opt, value: opt }))),
           ],
         });
-        await adapter.postMessage(tid, { card, fallbackText: `${content.question}\nOptions: ${options.join(', ')}` });
-        return;
+        const result = await adapter.postMessage(tid, {
+          card,
+          fallbackText: `${content.question}\nOptions: ${options.join(', ')}`,
+        });
+        return result?.id;
       }
 
       // Normal message
       const text = (content.markdown as string) || (content.text as string);
       if (text) {
         // Attach files if present (FileUpload format: { data, filename })
-        const fileUploads = message.files?.map((f) => ({ data: f.data, filename: f.filename }));
+        const fileUploads = message.files?.map((f: { data: Buffer; filename: string }) => ({
+          data: f.data,
+          filename: f.filename,
+        }));
         if (fileUploads && fileUploads.length > 0) {
-          await adapter.postMessage(tid, { markdown: text, files: fileUploads });
+          const result = await adapter.postMessage(tid, { markdown: text, files: fileUploads });
+          return result?.id;
         } else {
-          await adapter.postMessage(tid, { markdown: text });
+          const result = await adapter.postMessage(tid, { markdown: text });
+          return result?.id;
         }
       } else if (message.files && message.files.length > 0) {
         // Files only, no text
-        const fileUploads = message.files.map((f) => ({ data: f.data, filename: f.filename }));
-        await adapter.postMessage(tid, { markdown: '', files: fileUploads });
+        const fileUploads = message.files.map((f: { data: Buffer; filename: string }) => ({
+          data: f.data,
+          filename: f.filename,
+        }));
+        const result = await adapter.postMessage(tid, { markdown: '', files: fileUploads });
+        return result?.id;
       }
     },
 
diff --git a/src/channels/discord.ts b/src/channels/discord.ts
index 01ed4c5..d23a1e2 100644
--- a/src/channels/discord.ts
+++ b/src/channels/discord.ts
@@ -5,9 +5,19 @@
 import { createDiscordAdapter } from '@chat-adapter/discord';
 
 import { readEnvFile } from '../env.js';
-import { createChatSdkBridge } from './chat-sdk-bridge.js';
+import { createChatSdkBridge, type ReplyContext } from './chat-sdk-bridge.js';
 import { registerChannelAdapter } from './channel-registry.js';
 
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
+function extractReplyContext(raw: Record<string, any>): ReplyContext | null {
+  if (!raw.referenced_message) return null;
+  const reply = raw.referenced_message;
+  return {
+    text: reply.content || '',
+    sender: reply.author?.global_name || reply.author?.username || 'Unknown',
+  };
+}
+
 registerChannelAdapter('discord', {
   factory: () => {
     const env = readEnvFile(['DISCORD_BOT_TOKEN', 'DISCORD_PUBLIC_KEY', 'DISCORD_APPLICATION_ID']);
@@ -17,6 +27,11 @@ registerChannelAdapter('discord', {
       publicKey: env.DISCORD_PUBLIC_KEY,
       applicationId: env.DISCORD_APPLICATION_ID,
     });
-    return createChatSdkBridge({ adapter: discordAdapter, concurrency: 'concurrent', botToken: env.DISCORD_BOT_TOKEN });
+    return createChatSdkBridge({
+      adapter: discordAdapter,
+      concurrency: 'concurrent',
+      botToken: env.DISCORD_BOT_TOKEN,
+      extractReplyContext,
+    });
   },
 });
diff --git a/src/channels/telegram.ts b/src/channels/telegram.ts
index c4ae5fe..345419f 100644
--- a/src/channels/telegram.ts
+++ b/src/channels/telegram.ts
@@ -5,9 +5,19 @@
 import { createTelegramAdapter } from '@chat-adapter/telegram';
 
 import { readEnvFile } from '../env.js';
-import { createChatSdkBridge } from './chat-sdk-bridge.js';
+import { createChatSdkBridge, type ReplyContext } from './chat-sdk-bridge.js';
 import { registerChannelAdapter } from './channel-registry.js';
 
+// eslint-disable-next-line @typescript-eslint/no-explicit-any
+function extractReplyContext(raw: Record<string, any>): ReplyContext | null {
+  if (!raw.reply_to_message) return null;
+  const reply = raw.reply_to_message;
+  return {
+    text: reply.text || reply.caption || '',
+    sender: reply.from?.first_name || reply.from?.username || 'Unknown',
+  };
+}
+
 registerChannelAdapter('telegram', {
   factory: () => {
     const env = readEnvFile(['TELEGRAM_BOT_TOKEN']);
@@ -16,6 +26,6 @@ registerChannelAdapter('telegram', {
       botToken: env.TELEGRAM_BOT_TOKEN,
       mode: 'polling',
     });
-    return createChatSdkBridge({ adapter: telegramAdapter, concurrency: 'concurrent' });
+    return createChatSdkBridge({ adapter: telegramAdapter, concurrency: 'concurrent', extractReplyContext });
   },
 });
diff --git a/src/container-runner.ts b/src/container-runner.ts
index bc54632..743b7ce 100644
--- a/src/container-runner.ts
+++ b/src/container-runner.ts
@@ -3,7 +3,7 @@
  * Spawns agent containers with session folder + agent group folder mounts.
  * The container runs the v2 agent-runner which polls the session DB.
  */
-import { ChildProcess, spawn } from 'child_process';
+import { ChildProcess, execSync, spawn } from 'child_process';
 import fs from 'fs';
 import path from 'path';
 
@@ -274,9 +274,19 @@ async function buildContainerArgs(
     }
   }
 
+  // Pass additional MCP servers from container config
+  const containerConfig = agentGroup.container_config ? JSON.parse(agentGroup.container_config) : {};
+  if (containerConfig.mcpServers && Object.keys(containerConfig.mcpServers).length > 0) {
+    args.push('-e', `NANOCLAW_MCP_SERVERS=${JSON.stringify(containerConfig.mcpServers)}`);
+  }
+
   // Override entrypoint: compile agent-runner source, run v2 entry point (no stdin)
   args.push('--entrypoint', 'bash');
-  args.push(CONTAINER_IMAGE);
+
+  // Use per-agent-group image if one has been built, otherwise base image
+  const imageTag = containerConfig.imageTag || CONTAINER_IMAGE;
+  args.push(imageTag);
+
   args.push(
     '-c',
     'cd /app && npx tsc --outDir /tmp/dist 2>&1 >&2 && ln -sf /app/node_modules /tmp/dist/node_modules && node /tmp/dist/index.js',
@@ -284,3 +294,51 @@ async function buildContainerArgs(
 
   return args;
 }
+
+/** Build a per-agent-group Docker image with custom packages. */
+export async function buildAgentGroupImage(agentGroupId: string): Promise<void> {
+  const agentGroup = getAgentGroup(agentGroupId);
+  if (!agentGroup) throw new Error('Agent group not found');
+
+  const containerConfig = agentGroup.container_config ? JSON.parse(agentGroup.container_config) : {};
+  const packages = containerConfig.packages || { apt: [], npm: [] };
+  const aptPackages = (packages.apt || []) as string[];
+  const npmPackages = (packages.npm || []) as string[];
+
+  if (aptPackages.length === 0 && npmPackages.length === 0) {
+    throw new Error('No packages to install. Use install_packages first.');
+  }
+
+  let dockerfile = `FROM ${CONTAINER_IMAGE}\nUSER root\n`;
+  if (aptPackages.length > 0) {
+    dockerfile += `RUN apt-get update && apt-get install -y ${aptPackages.join(' ')} && rm -rf /var/lib/apt/lists/*\n`;
+  }
+  if (npmPackages.length > 0) {
+    dockerfile += `RUN npm install -g ${npmPackages.join(' ')}\n`;
+  }
+  dockerfile += 'USER node\n';
+
+  const imageTag = `nanoclaw-agent:${agentGroupId}`;
+
+  log.info('Building per-agent-group image', { agentGroupId, imageTag, apt: aptPackages, npm: npmPackages });
+
+  // Write Dockerfile to temp file and build
+  const tmpDockerfile = path.join(DATA_DIR, `Dockerfile.${agentGroupId}`);
+  fs.writeFileSync(tmpDockerfile, dockerfile);
+  try {
+    execSync(`${CONTAINER_RUNTIME_BIN} build -t ${imageTag} -f ${tmpDockerfile} .`, {
+      cwd: DATA_DIR,
+      stdio: 'pipe',
+      timeout: 300_000,
+    });
+  } finally {
+    fs.unlinkSync(tmpDockerfile);
+  }
+
+  // Store the image tag in container_config
+  containerConfig.imageTag = imageTag;
+  const { updateAgentGroup } = await import('./db/agent-groups.js');
+  updateAgentGroup(agentGroupId, { container_config: JSON.stringify(containerConfig) });
+
+  log.info('Per-agent-group image built', { agentGroupId, imageTag });
+}
diff --git a/src/db/db-v2.test.ts b/src/db/db-v2.test.ts
index bea9334..81cd68e 100644
--- a/src/db/db-v2.test.ts
+++ b/src/db/db-v2.test.ts
@@ -62,7 +62,7 @@ describe('migrations', () => {
     const db = initTestDb();
     runMigrations(db);
     const row = db.prepare('SELECT MAX(version) as v FROM schema_version').get() as { v: number };
-    expect(row.v).toBe(2);
+    expect(row.v).toBe(3);
   });
 });
 
diff --git a/src/db/messaging-groups.ts b/src/db/messaging-groups.ts
index 6c792d8..1acf16f 100644
--- a/src/db/messaging-groups.ts
+++ b/src/db/messaging-groups.ts
@@ -109,3 +109,14 @@ export function updateMessagingGroupAgent(
 export function deleteMessagingGroupAgent(id: string): void {
   getDb().prepare('DELETE FROM messaging_group_agents WHERE id = ?').run(id);
 }
+
+/** Get all messaging groups wired to an agent group (reverse lookup). */
+export function getMessagingGroupsByAgentGroup(agentGroupId: string): MessagingGroup[] {
+  return getDb()
+    .prepare(
+      `SELECT mg.* FROM messaging_groups mg
+       JOIN messaging_group_agents mga ON mga.messaging_group_id = mg.id
+       WHERE mga.agent_group_id = ?`,
+    )
+    .all(agentGroupId) as MessagingGroup[];
+}
diff --git a/src/db/migrations/003-pending-approvals.ts b/src/db/migrations/003-pending-approvals.ts
new file mode 100644
index 0000000..9fc2704
--- /dev/null
+++ b/src/db/migrations/003-pending-approvals.ts
@@ -0,0 +1,18 @@
+import type { Migration } from './index.js';
+
+export const migration003: Migration = {
+  version: 3,
+  name: 'pending-approvals',
+  up(db) {
+    db.exec(`
+      CREATE TABLE pending_approvals (
+        approval_id  TEXT PRIMARY KEY,
+        session_id   TEXT NOT NULL REFERENCES sessions(id),
+        request_id   TEXT NOT NULL,
+        action       TEXT NOT NULL,
+        payload      TEXT NOT NULL,
+        created_at   TEXT NOT NULL
+      );
+    `);
+  },
+};
diff --git a/src/db/migrations/index.ts b/src/db/migrations/index.ts
index 114a521..3a51c5f 100644
--- a/src/db/migrations/index.ts
+++ b/src/db/migrations/index.ts
@@ -3,6 +3,7 @@ import type Database from 'better-sqlite3';
 import { log } from '../../log.js';
 import { migration001 } from './001-initial.js';
 import { migration002 } from './002-chat-sdk-state.js';
+import { migration003 } from './003-pending-approvals.js';
 
 export interface Migration {
   version: number;
@@ -10,7 +11,7 @@ export interface Migration {
   up: (db: Database.Database) => void;
 }
 
-const migrations: Migration[] = [migration001, migration002];
+const migrations: Migration[] = [migration001, migration002, migration003];
 
 export function runMigrations(db: Database.Database): void {
   db.exec(`
diff --git a/src/db/schema.ts b/src/db/schema.ts
index b54210d..d2ed36a 100644
--- a/src/db/schema.ts
+++ b/src/db/schema.ts
@@ -93,11 +93,13 @@ CREATE TABLE messages_in (
   content        TEXT NOT NULL
 );
 
--- Host tracks which messages_out IDs have been delivered.
+-- Host tracks delivery outcomes for messages_out IDs.
 -- Avoids writing to outbound.db (container-owned).
 CREATE TABLE delivered (
-  message_out_id TEXT PRIMARY KEY,
-  delivered_at   TEXT NOT NULL
+  message_out_id      TEXT PRIMARY KEY,
+  platform_message_id TEXT,
+  status              TEXT NOT NULL DEFAULT 'delivered',
+  delivered_at        TEXT NOT NULL
 );
 `;
 
diff --git a/src/db/sessions.ts b/src/db/sessions.ts
index c2373f3..45e911f 100644
--- a/src/db/sessions.ts
+++ b/src/db/sessions.ts
@@ -1,4 +1,4 @@
-import type { PendingQuestion, Session } from '../types.js';
+import type { PendingApproval, PendingQuestion, Session } from '../types.js';
 import { getDb } from './connection.js';
 
 // ── Sessions ──
@@ -90,3 +90,24 @@ export function getPendingQuestion(questionId: string): PendingQuestion | undefi
 export function deletePendingQuestion(questionId: string): void {
   getDb().prepare('DELETE FROM pending_questions WHERE question_id = ?').run(questionId);
 }
+
+// ── Pending Approvals ──
+
+export function createPendingApproval(pa: PendingApproval): void {
+  getDb()
+    .prepare(
+      `INSERT INTO pending_approvals (approval_id, session_id, request_id, action, payload, created_at)
+       VALUES (@approval_id, @session_id, @request_id, @action, @payload, @created_at)`,
+    )
+    .run(pa);
+}
+
+export function getPendingApproval(approvalId: string): PendingApproval | undefined {
+  return getDb().prepare('SELECT * FROM pending_approvals WHERE approval_id = ?').get(approvalId) as
+    | PendingApproval
+    | undefined;
+}
+
+export function deletePendingApproval(approvalId: string): void {
+  getDb().prepare('DELETE FROM pending_approvals WHERE approval_id = ?').run(approvalId);
+}
diff --git a/src/delivery.ts b/src/delivery.ts
index 12676f3..74be38d 100644
--- a/src/delivery.ts
+++ b/src/delivery.ts
@@ -11,16 +11,22 @@ import Database from 'better-sqlite3';
 import fs from 'fs';
 import path from 'path';
 
-import { getRunningSessions, getActiveSessions, createPendingQuestion } from './db/sessions.js';
-import { getAgentGroup } from './db/agent-groups.js';
+import { GROUPS_DIR } from './config.js';
+import { getRunningSessions, getActiveSessions, createPendingQuestion, getSession, createPendingApproval } from './db/sessions.js';
+import { getAgentGroup, getAdminAgentGroup, createAgentGroup, updateAgentGroup } from './db/agent-groups.js';
+import { getMessagingGroupsByAgentGroup } from './db/messaging-groups.js';
 import { log } from './log.js';
-import { openInboundDb, openOutboundDb, sessionDir, inboundDbPath } from './session-manager.js';
-import { resetContainerIdleTimer } from './container-runner.js';
+import { openInboundDb, openOutboundDb, sessionDir, inboundDbPath, resolveSession, writeSessionMessage, writeSystemResponse } from './session-manager.js';
+import { resetContainerIdleTimer, wakeContainer } from './container-runner.js';
 import type { OutboundFile } from './channels/adapter.js';
 import type { Session } from './types.js';
 
 const ACTIVE_POLL_MS = 1000;
 const SWEEP_POLL_MS = 60_000;
+const MAX_DELIVERY_ATTEMPTS = 3;
+
+/** Track delivery attempt counts. Resets on process restart (gives failed messages a fresh chance). */
+const deliveryAttempts = new Map<string, number>();
 
 export interface ChannelDeliveryAdapter {
   deliver(
@@ -30,7 +36,7 @@ export interface ChannelDeliveryAdapter {
     kind: string,
     content: string,
     files?: OutboundFile[],
-  ): Promise<void>;
+  ): Promise<string | undefined>;
   setTyping?(channelType: string, platformId: string, threadId: string | null): Promise<void>;
 }
 
@@ -136,16 +142,44 @@ async function deliverSessionMessages(session: Session): Promise<void> {
     const undelivered = allDue.filter((m) => !deliveredIds.has(m.id));
     if (undelivered.length === 0) return;
 
+    // Ensure platform_message_id column exists (migration for existing sessions)
+    migrateDeliveredTable(inDb);
+
     for (const msg of undelivered) {
       try {
-        await deliverMessage(msg, session, inDb);
-        // Track delivery in inbound.db (host-owned) — not outbound.db
+        const platformMsgId = await deliverMessage(msg, session, inDb);
         inDb
-          .prepare("INSERT OR IGNORE INTO delivered (message_out_id, delivered_at) VALUES (?, datetime('now'))")
-          .run(msg.id);
+          .prepare(
+            "INSERT OR IGNORE INTO delivered (message_out_id, platform_message_id, status, delivered_at) VALUES (?, ?, 'delivered', datetime('now'))",
+          )
+          .run(msg.id, platformMsgId ?? null);
+        deliveryAttempts.delete(msg.id);
         resetContainerIdleTimer(session.id);
       } catch (err) {
-        log.error('Failed to deliver message', { messageId: msg.id, sessionId: session.id, err });
+        const attempts = (deliveryAttempts.get(msg.id) ?? 0) + 1;
+        deliveryAttempts.set(msg.id, attempts);
+        if (attempts >= MAX_DELIVERY_ATTEMPTS) {
+          log.error('Message delivery failed permanently, giving up', {
+            messageId: msg.id,
+            sessionId: session.id,
+            attempts,
+            err,
+          });
+          inDb
+            .prepare(
+              "INSERT OR IGNORE INTO delivered (message_out_id, platform_message_id, status, delivered_at) VALUES (?, NULL, 'failed', datetime('now'))",
+            )
+            .run(msg.id);
+          deliveryAttempts.delete(msg.id);
+        } else {
+          log.warn('Message delivery failed, will retry', {
+            messageId: msg.id,
+            sessionId: session.id,
+            attempt: attempts,
+            maxAttempts: MAX_DELIVERY_ATTEMPTS,
+            err,
+          });
+        }
       }
     }
   } finally {
@@ -165,7 +199,7 @@ async function deliverMessage(
   },
   session: Session,
   inDb: Database.Database,
-): Promise<void> {
+): Promise<string | undefined> {
   if (!deliveryAdapter) {
     log.warn('No delivery adapter configured, dropping message', { id: msg.id });
     return;
@@ -181,8 +215,7 @@ async function deliverMessage(
 
   // Agent-to-agent — route to target session
   if (msg.channel_type === 'agent') {
-    log.info('Agent-to-agent message', { from: session.id, target: msg.platform_id });
-    // TODO: route to target agent's session DB
+    await routeAgentMessage(msg, session);
     return;
   }
 
@@ -222,11 +255,19 @@ async function deliverMessage(
     if (files.length === 0) files = undefined;
   }
 
-  await deliveryAdapter.deliver(msg.channel_type, msg.platform_id, msg.thread_id, msg.kind, msg.content, files);
+  const platformMsgId = await deliveryAdapter.deliver(
+    msg.channel_type,
+    msg.platform_id,
+    msg.thread_id,
+    msg.kind,
+    msg.content,
+    files,
+  );
   log.info('Message delivered', {
     id: msg.id,
     channelType: msg.channel_type,
     platformId: msg.platform_id,
+    platformMsgId,
     fileCount: files?.length,
   });
 
@@ -234,6 +275,71 @@ async function deliverMessage(
   if (fs.existsSync(outboxDir)) {
     fs.rmSync(outboxDir, { recursive: true, force: true });
   }
+
+  return platformMsgId;
+}
+
+/** Route an agent-to-agent message to the target agent's session. */
+async function routeAgentMessage(
+  msg: { id: string; platform_id: string | null; content: string },
+  sourceSession: Session,
+): Promise<void> {
+  const targetAgentGroupId = msg.platform_id;
+  if (!targetAgentGroupId) {
+    log.warn('Agent message missing target agent group ID', { id: msg.id });
+    return;
+  }
+
+  const targetGroup = getAgentGroup(targetAgentGroupId);
+  if (!targetGroup) {
+    log.warn('Target agent group not found', { id: msg.id, targetAgentGroupId });
+    return;
+  }
+
+  const sourceGroup = getAgentGroup(sourceSession.agent_group_id);
+  const sourceAgentName = sourceGroup?.name || sourceSession.agent_group_id;
+
+  // Find or create a session for the target agent
+  const { session: targetSession } = resolveSession(targetAgentGroupId, null, null, 'agent-shared');
+
+  // Enrich content with sender info
+  const content = JSON.parse(msg.content);
+  const enrichedContent = JSON.stringify({
+    text: content.text,
+    sender: sourceAgentName,
+    senderId: sourceSession.agent_group_id,
+  });
+
+  const messageId = `agent-${Date.now()}-${Math.random().toString(36).slice(2, 8)}`;
+  writeSessionMessage(targetAgentGroupId, targetSession.id, {
+    id: messageId,
+    kind: 'chat',
+    timestamp: new Date().toISOString(),
+    platformId: sourceSession.agent_group_id,
+    channelType: 'agent',
+    threadId: null,
+    content: enrichedContent,
+  });
+
+  log.info('Agent message routed', { from: sourceSession.agent_group_id, to: targetAgentGroupId, targetSession: targetSession.id });
+
+  const freshSession = getSession(targetSession.id);
+  if (freshSession) {
+    await wakeContainer(freshSession);
+  }
+}
+
+/** Ensure the delivered table has new columns (migration for existing sessions). */
+function migrateDeliveredTable(db: Database.Database): void {
+  const cols = new Set(
+    (db.prepare("PRAGMA table_info('delivered')").all() as Array<{ name: string }>).map((c) => c.name),
+  );
+  if (!cols.has('platform_message_id')) {
+    db.prepare('ALTER TABLE delivered ADD COLUMN platform_message_id TEXT').run();
+  }
+  if (!cols.has('status')) {
+    db.prepare("ALTER TABLE delivered ADD COLUMN status TEXT NOT NULL DEFAULT 'delivered'").run();
+  }
 }
 
 /**
@@ -309,6 +415,207 @@ async function handleSystemAction(
       break;
     }
 
+    case 'create_agent': {
+      const requestId = content.requestId as string;
+      const name = content.name as string;
+      let folder =
+        (content.folder as string) || name.toLowerCase().replace(/[^a-z0-9_-]/g, '_').replace(/_+/g, '_');
+      const instructions = content.instructions as string | null;
+
+      try {
+        // Avoid duplicate folders
+        const { getAgentGroupByFolder } = await import('./db/agent-groups.js');
+        if (getAgentGroupByFolder(folder)) {
+          folder = `${folder}_${Date.now()}`;
+        }
+
+        const agentGroupId = `ag-${Date.now()}-${Math.random().toString(36).slice(2, 8)}`;
+
+        createAgentGroup({
+          id: agentGroupId,
+          name,
+          folder,
+          is_admin: 0,
+          agent_provider: null,
+          container_config: null,
+          created_at: new Date().toISOString(),
+        });
+
+        const groupPath = path.join(GROUPS_DIR, folder);
+        fs.mkdirSync(groupPath, { recursive: true });
+
+        if (instructions) {
+          fs.writeFileSync(path.join(groupPath, 'CLAUDE.md'), instructions);
+        }
+
+        writeSystemResponse(session.agent_group_id, session.id, requestId, 'success', {
+          agentGroupId,
+          name,
+          folder,
+        });
+
+        log.info('Agent group created via system action', { agentGroupId, name, folder });
+      } catch (e) {
+        writeSystemResponse(session.agent_group_id, session.id, requestId, 'error', {
+          error: e instanceof Error ? e.message : String(e),
+        });
+      }
+      break;
+    }
+
+    case 'add_mcp_server': {
+      const requestId = content.requestId as string;
+      const serverName = content.name as string;
+      const command = content.command as string;
+      const serverArgs = content.args as string[];
+      const serverEnv = content.env as Record<string, string>;
+
+      try {
+        const agentGroup = getAgentGroup(session.agent_group_id);
+        if (!agentGroup) throw new Error('Agent group not found');
+
+        const containerConfig = agentGroup.container_config ? JSON.parse(agentGroup.container_config) : {};
+        if (!containerConfig.mcpServers) containerConfig.mcpServers = {};
+        containerConfig.mcpServers[serverName] = { command, args: serverArgs || [], env: serverEnv || {} };
+
+        updateAgentGroup(session.agent_group_id, { container_config: JSON.stringify(containerConfig) });
+
+        writeSystemResponse(session.agent_group_id, session.id, requestId, 'success', {
+          message: `MCP server "${serverName}" added. Will take effect on next container restart.`,
+        });
+
+        log.info('MCP server added', { agentGroupId: session.agent_group_id, name: serverName });
+      } catch (e) {
+        writeSystemResponse(session.agent_group_id, session.id, requestId, 'error', {
+          error: e instanceof Error ? e.message : String(e),
+        });
+      }
+      break;
+    }
+
+    case 'install_packages': {
+      const requestId = content.requestId as string;
+      const apt = (content.apt as string[]) || [];
+      const npm = (content.npm as string[]) || [];
+      const reason = content.reason as string;
+
+      const agentGroup = getAgentGroup(session.agent_group_id);
+      if (!agentGroup) {
+        writeSystemResponse(session.agent_group_id, session.id, requestId, 'error', { error: 'Agent group not found' });
+        break;
+      }
+
+      // Find admin channel for approval card
+      const adminGroup = getAdminAgentGroup();
+      let approvalChannelType: string | null = null;
+      let approvalPlatformId: string | null = null;
+
+      if (adminGroup) {
+        const adminMGs = getMessagingGroupsByAgentGroup(adminGroup.id);
+        if (adminMGs.length > 0) {
+          approvalChannelType = adminMGs[0].channel_type;
+          approvalPlatformId = adminMGs[0].platform_id;
+        }
+      }
+
+      if (!approvalChannelType || !approvalPlatformId) {
+        writeSystemResponse(session.agent_group_id, session.id, requestId, 'error', {
+          error: 'No admin channel found for approval',
+        });
+        break;
+      }
+
+      const approvalId = `appr-${Date.now()}-${Math.random().toString(36).slice(2, 8)}`;
+
+      createPendingApproval({
+        approval_id: approvalId,
+        session_id: session.id,
+        request_id: requestId,
+        action: 'install_packages',
+        payload: JSON.stringify({ apt, npm, reason }),
+        created_at: new Date().toISOString(),
+      });
+
+      const packageList = [...apt.map((p: string) => `apt: ${p}`), ...npm.map((p: string) => `npm: ${p}`)].join(', ');
+      if (deliveryAdapter) {
+        await deliveryAdapter.deliver(
+          approvalChannelType,
+          approvalPlatformId,
+          null,
+          'chat-sdk',
+          JSON.stringify({
+            type: 'ask_question',
+            questionId: approvalId,
+            question: `Agent "${agentGroup.name}" requests package installation:\n${packageList}${reason ? `\nReason: ${reason}` : ''}`,
+            options: ['Approve', 'Reject'],
+          }),
+        );
+      }
+
+      log.info('Package install approval requested', { approvalId, agentGroup: agentGroup.name, apt, npm });
+      break;
+    }
+
+    case 'request_rebuild': {
+      const requestId = content.requestId as string;
+      const reason = content.reason as string;
+
+      const agentGroup = getAgentGroup(session.agent_group_id);
+      if (!agentGroup) {
+        writeSystemResponse(session.agent_group_id, session.id, requestId, 'error', { error: 'Agent group not found' });
+        break;
+      }
+
+      // Find admin channel for approval card
+      const adminGroup2 = getAdminAgentGroup();
+      let rebuildChannelType: string | null = null;
+      let rebuildPlatformId: string | null = null;
+
+      if (adminGroup2) {
+        const adminMGs2 = getMessagingGroupsByAgentGroup(adminGroup2.id);
+        if (adminMGs2.length > 0) {
+          rebuildChannelType = adminMGs2[0].channel_type;
+          rebuildPlatformId = adminMGs2[0].platform_id;
+        }
+      }
+
+      if (!rebuildChannelType || !rebuildPlatformId) {
+        writeSystemResponse(session.agent_group_id, session.id, requestId, 'error', {
+          error: 'No admin channel found for approval',
+        });
+        break;
+      }
+
+      const rebuildApprovalId = `appr-${Date.now()}-${Math.random().toString(36).slice(2, 8)}`;
+
+      createPendingApproval({
+        approval_id: rebuildApprovalId,
+        session_id: session.id,
+        request_id: requestId,
+        action: 'request_rebuild',
+        payload: JSON.stringify({ reason }),
+        created_at: new Date().toISOString(),
+      });
+
+      if (deliveryAdapter) {
+        await deliveryAdapter.deliver(
+          rebuildChannelType,
+          rebuildPlatformId,
+          null,
+          'chat-sdk',
+          JSON.stringify({
+            type: 'ask_question',
+            questionId: rebuildApprovalId,
+            question: `Agent "${agentGroup.name}" requests a container rebuild.${reason ? `\nReason: ${reason}` : ''}`,
+            options: ['Approve', 'Reject'],
+          }),
+        );
+      }
+
+      log.info('Container rebuild approval requested', { approvalId: rebuildApprovalId, agentGroup: agentGroup.name });
+      break;
+    }
+
     default:
       log.warn('Unknown system action', { action });
   }
diff --git a/src/index.ts b/src/index.ts
index f24a4cb..0b29e6f 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -14,9 +14,10 @@ import { ensureContainerRuntimeRunning, cleanupOrphans } from './container-runti
 import { startActiveDeliveryPoll, startSweepDeliveryPoll, setDeliveryAdapter, stopDeliveryPolls } from './delivery.js';
 import { startHostSweep, stopHostSweep } from './host-sweep.js';
 import { routeInbound } from './router.js';
-import { getPendingQuestion, deletePendingQuestion, getSession } from './db/sessions.js';
-import { writeSessionMessage } from './session-manager.js';
-import { wakeContainer } from './container-runner.js';
+import { getPendingQuestion, deletePendingQuestion, getPendingApproval, deletePendingApproval, getSession } from './db/sessions.js';
+import { getAgentGroup, updateAgentGroup } from './db/agent-groups.js';
+import { writeSessionMessage, writeSystemResponse } from './session-manager.js';
+import { wakeContainer, buildAgentGroupImage } from './container-runner.js';
 import { log } from './log.js';
 
 // Channel barrel — each enabled channel self-registers on import.
@@ -83,7 +84,7 @@ async function main(): Promise<void> {
         log.warn('No adapter for channel type', { channelType });
         return;
       }
-      await adapter.deliver(platformId, threadId, { kind, content: JSON.parse(content), files });
+      return adapter.deliver(platformId, threadId, { kind, content: JSON.parse(content), files });
     },
     async setTyping(channelType, platformId, threadId) {
       const adapter = getChannelAdapter(channelType);
@@ -125,8 +126,15 @@ function buildConversationConfigs(channelType: string): ConversationConfig[] {
   return configs;
 }
 
-/** Handle a user's response to an ask_user_question card. */
+/** Handle a user's response to an ask_user_question card or an approval card. */
 async function handleQuestionResponse(questionId: string, selectedOption: string, userId: string): Promise<void> {
+  // Check if this is a pending approval (install_packages, request_rebuild)
+  const approval = getPendingApproval(questionId);
+  if (approval) {
+    await handleApprovalResponse(approval, selectedOption, userId);
+    return;
+  }
+
   const pq = getPendingQuestion(questionId);
   if (!pq) {
     log.warn('Pending question not found (may have expired)', { questionId });
@@ -163,6 +171,66 @@ async function handleQuestionResponse(questionId: string, selectedOption: string
   await wakeContainer(session);
 }
 
+/** Handle an admin's response to an approval card. */
+async function handleApprovalResponse(
+  approval: import('./types.js').PendingApproval,
+  selectedOption: string,
+  userId: string,
+): Promise<void> {
+  const session = getSession(approval.session_id);
+  if (!session) {
+    deletePendingApproval(approval.approval_id);
+    return;
+  }
+
+  if (selectedOption === 'Approve') {
+    const payload = JSON.parse(approval.payload);
+
+    if (approval.action === 'install_packages') {
+      const agentGroup = getAgentGroup(session.agent_group_id);
+      const containerConfig = agentGroup?.container_config ? JSON.parse(agentGroup.container_config) : {};
+      if (!containerConfig.packages) containerConfig.packages = { apt: [], npm: [] };
+      if (payload.apt) containerConfig.packages.apt.push(...payload.apt);
+      if (payload.npm) containerConfig.packages.npm.push(...payload.npm);
+
+      updateAgentGroup(session.agent_group_id, { container_config: JSON.stringify(containerConfig) });
+
+      writeSystemResponse(session.agent_group_id, session.id, approval.request_id, 'success', {
+        message: 'Packages approved. Run request_rebuild to apply.',
+        approved: { apt: payload.apt, npm: payload.npm },
+      });
+
+      log.info('Package install approved', { approvalId: approval.approval_id, userId });
+    } else if (approval.action === 'request_rebuild') {
+      try {
+        await buildAgentGroupImage(session.agent_group_id);
+        writeSystemResponse(session.agent_group_id, session.id, approval.request_id, 'success', {
+          message: 'Container image rebuilt. Changes will take effect on next container start.',
+        });
+        log.info('Container rebuild approved and completed', { approvalId: approval.approval_id, userId });
+      } catch (e) {
+        writeSystemResponse(session.agent_group_id, session.id, approval.request_id, 'error', {
+          error: `Rebuild failed: ${e instanceof Error ? e.message : String(e)}`,
+        });
+        log.error('Container rebuild failed', { approvalId: approval.approval_id, err: e });
+      }
+    }
+  } else {
+    // Rejected
+    writeSystemResponse(session.agent_group_id, session.id, approval.request_id, 'error', {
+      error: `Request rejected by admin (${userId})`,
+    });
+    log.info('Approval rejected', { approvalId: approval.approval_id, action: approval.action, userId });
+  }
+
+  deletePendingApproval(approval.approval_id);
+
+  // Wake container so the agent's polling MCP tool picks up the response
+  if (session) {
+    await wakeContainer(session);
+  }
+}
+
 /** Graceful shutdown. */
 async function shutdown(signal: string): Promise<void> {
   log.info('Shutdown signal received', { signal });
diff --git a/src/session-manager.ts b/src/session-manager.ts
index 94a1d58..804c38d 100644
--- a/src/session-manager.ts
+++ b/src/session-manager.ts
@@ -64,7 +64,7 @@ function generateId(): string {
  */
 export function resolveSession(
   agentGroupId: string,
-  messagingGroupId: string,
+  messagingGroupId: string | null,
   threadId: string | null,
   sessionMode: 'shared' | 'per-thread' | 'agent-shared',
 ): { session: Session; created: boolean } {
@@ -74,7 +74,7 @@ export function resolveSession(
     if (existing) {
       return { session: existing, created: false };
     }
-  } else {
+  } else if (messagingGroupId) {
     const lookupThreadId = sessionMode === 'shared' ? null : threadId;
     const existing = findSession(messagingGroupId, lookupThreadId);
     if (existing) {
@@ -144,6 +144,9 @@ export function writeSessionMessage(
     recurrence?: string | null;
   },
 ): void {
+  // Extract base64 attachment data, save to inbox, replace with file paths
+  const content = extractAttachmentFiles(agentGroupId, sessionId, message.id, message.content);
+
   const dbPath = inboundDbPath(agentGroupId, sessionId);
   const db = new Database(dbPath);
   db.pragma('journal_mode = DELETE');
@@ -166,7 +169,7 @@ export function writeSessionMessage(
       platformId: message.platformId ?? null,
       channelType: message.channelType ?? null,
       threadId: message.threadId ?? null,
-      content: message.content,
+      content,
       processAfter: message.processAfter ?? null,
       recurrence: message.recurrence ?? null,
     });
@@ -177,6 +180,44 @@ export function writeSessionMessage(
   updateSession(sessionId, { last_active: new Date().toISOString() });
 }
 
+/**
+ * If message content has attachments with base64 `data`, save them to
+ * the session's inbox directory and replace with `localPath`.
+ */
+function extractAttachmentFiles(
+  agentGroupId: string,
+  sessionId: string,
+  messageId: string,
+  contentStr: string,
+): string {
+  let parsed: Record<string, unknown>;
+  try {
+    parsed = JSON.parse(contentStr);
+  } catch {
+    return contentStr;
+  }
+
+  const attachments = parsed.attachments as Array<Record<string, unknown>> | undefined;
+  if (!Array.isArray(attachments)) return contentStr;
+
+  let changed = false;
+  for (const att of attachments) {
+    if (typeof att.data === 'string') {
+      const inboxDir = path.join(sessionDir(agentGroupId, sessionId), 'inbox', messageId);
+      fs.mkdirSync(inboxDir, { recursive: true });
+      const filename = (att.name as string) || `attachment-${Date.now()}`;
+      const filePath = path.join(inboxDir, filename);
+      fs.writeFileSync(filePath, Buffer.from(att.data as string, 'base64'));
+      att.localPath = `inbox/${messageId}/${filename}`;
+      delete att.data;
+      changed = true;
+      log.debug('Saved attachment to inbox', { messageId, filename, size: att.size });
+    }
+  }
+
+  return changed ? JSON.stringify(parsed) : contentStr;
+}
+
 /** Open the inbound DB for a session (host reads/writes). */
 export function openInboundDb(agentGroupId: string, sessionId: string): Database.Database {
   const dbPath = inboundDbPath(agentGroupId, sessionId);
@@ -201,6 +242,27 @@ export function openSessionDb(agentGroupId: string, sessionId: string): Database
   return openInboundDb(agentGroupId, sessionId);
 }
 
+/** Write a system response to a session's inbound.db so the container's findQuestionResponse() picks it up. */
+export function writeSystemResponse(
+  agentGroupId: string,
+  sessionId: string,
+  requestId: string,
+  status: string,
+  result: Record<string, unknown>,
+): void {
+  writeSessionMessage(agentGroupId, sessionId, {
+    id: `sys-resp-${Date.now()}-${Math.random().toString(36).slice(2, 8)}`,
+    kind: 'system',
+    timestamp: new Date().toISOString(),
+    content: JSON.stringify({
+      type: 'question_response',
+      questionId: requestId,
+      status,
+      result,
+    }),
+  });
+}
+
 /** Mark a container as running for a session. */
 export function markContainerRunning(sessionId: string): void {
   updateSession(sessionId, { container_status: 'running', last_active: new Date().toISOString() });
diff --git a/src/types.ts b/src/types.ts
index 5d473d6..0d6983d 100644
--- a/src/types.ts
+++ b/src/types.ts
@@ -88,3 +88,14 @@ export interface PendingQuestion {
   thread_id: string | null;
   created_at: string;
 }
+
+// ── Pending approvals (central DB) ──
+
+export interface PendingApproval {
+  approval_id: string;
+  session_id: string;
+  request_id: string;
+  action: string;
+  payload: string; // JSON
+  created_at: string;
+}