ndr: add inbound media support via htree

- Add media.ts helper module to detect and download nhash URLs
- Auto-download nhash1.../filename.ext URLs in incoming messages
- Pass MediaPath/MediaType/MediaUrl to inbound context
- Enable media capability flag

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude <noreply@anthropic.com>

extensions/ndr/src/channel.ts

@@ -34,7 +34,7 @@ export const ndrPlugin: ChannelPlugin<ResolvedNdrAccount> = {
   },
   capabilities: {
     chatTypes: ["direct"], // DMs only
-    media: false, // No media support yet
+    media: true, // Supports nhash media via htree
   },
   reload: { configPrefixes: ["channels.ndr"] },
   configSchema: buildChannelConfigSchema(NdrConfigSchema),
@@ -192,8 +192,8 @@ export const ndrPlugin: ChannelPlugin<ResolvedNdrAccount> = {
         relays: account.relays,
         ndrPath: account.ndrPath,
         dataDir: account.dataDir,
-        onMessage: async (chatId, messageId, senderPubkey, text, replyFn) => {
-          ctx.log?.debug(`[${account.accountId}] Message from ${senderPubkey} in chat ${chatId}: ${text.slice(0, 50)}...`);
+        onMessage: async (chatId, messageId, senderPubkey, text, replyFn, media) => {
+          ctx.log?.debug(`[${account.accountId}] Message from ${senderPubkey} in chat ${chatId}: ${text.slice(0, 50)}...${media ? ` [media: ${media.path}]` : ""}`);
 
           // React with "eyes" emoji to indicate we're processing (like WhatsApp "typing" indicator)
           if (messageId) {
@@ -268,6 +268,10 @@ export const ndrPlugin: ChannelPlugin<ResolvedNdrAccount> = {
             CommandAuthorized: true, // Owner is always authorized
             OriginatingChannel: "ndr" as const,
             OriginatingTo: ndrTo,
+            // Media fields (if nhash URL was downloaded)
+            MediaPath: media?.path,
+            MediaType: media?.mimeType ?? undefined,
+            MediaUrl: media?.url,
           });
 
           // Record the session

extensions/ndr/src/media.ts

@@ -0,0 +1,134 @@
+import { execSync } from "child_process";
+import { mkdirSync, existsSync } from "fs";
+import { join, extname } from "path";
+import { tmpdir } from "os";
+
+/**
+ * Regex to detect nhash URLs in message content.
+ * Matches: nhash1<base32>/filename.ext or just nhash1<base32>
+ */
+const NHASH_REGEX = /\b(nhash1[a-z0-9]+(?:\/[^\s]+)?)\b/i;
+
+/**
+ * Common image/video/audio extensions for MIME type detection
+ */
+const MIME_MAP: Record<string, string> = {
+  ".jpg": "image/jpeg",
+  ".jpeg": "image/jpeg",
+  ".png": "image/png",
+  ".gif": "image/gif",
+  ".webp": "image/webp",
+  ".svg": "image/svg+xml",
+  ".mp4": "video/mp4",
+  ".webm": "video/webm",
+  ".mov": "video/quicktime",
+  ".mp3": "audio/mpeg",
+  ".wav": "audio/wav",
+  ".ogg": "audio/ogg",
+  ".pdf": "application/pdf",
+};
+
+export interface ParsedNhashUrl {
+  full: string;
+  cid: string;
+  filename: string | null;
+}
+
+export interface DownloadedMedia {
+  path: string;
+  mimeType: string | null;
+  url: string;
+}
+
+/**
+ * Parse an nhash URL from message content.
+ * Returns the full match, CID, and optional filename.
+ */
+export function parseNhashUrl(content: string): ParsedNhashUrl | null {
+  const match = content.match(NHASH_REGEX);
+  if (!match) return null;
+
+  const full = match[1];
+  const parts = full.split("/");
+  const cid = parts[0];
+  const filename = parts.length > 1 ? parts.slice(1).join("/") : null;
+
+  return { full, cid, filename };
+}
+
+/**
+ * Detect MIME type from filename extension
+ */
+function mimeFromFilename(filename: string | null): string | null {
+  if (!filename) return null;
+  const ext = extname(filename).toLowerCase();
+  return MIME_MAP[ext] ?? null;
+}
+
+/**
+ * Download media from an nhash URL using htree CLI.
+ * Returns the local file path and detected MIME type.
+ */
+export async function downloadNhashMedia(
+  nhash: ParsedNhashUrl,
+  opts?: { tempDir?: string; timeout?: number }
+): Promise<DownloadedMedia | null> {
+  const tempDir = opts?.tempDir ?? join(tmpdir(), "ndr-media");
+  const timeout = opts?.timeout ?? 30000;
+
+  // Ensure temp directory exists
+  if (!existsSync(tempDir)) {
+    mkdirSync(tempDir, { recursive: true });
+  }
+
+  // Determine output filename
+  const outputFilename = nhash.filename ?? nhash.cid;
+  const outputPath = join(tempDir, outputFilename);
+
+  try {
+    // Run htree get to download the file
+    execSync(`htree get "${nhash.cid}" -o "${outputPath}"`, {
+      encoding: "utf-8",
+      timeout,
+      stdio: ["ignore", "pipe", "pipe"],
+    });
+
+    // Verify file exists
+    if (!existsSync(outputPath)) {
+      return null;
+    }
+
+    return {
+      path: outputPath,
+      mimeType: mimeFromFilename(nhash.filename),
+      url: nhash.full,
+    };
+  } catch {
+    // htree not available or download failed
+    return null;
+  }
+}
+
+/**
+ * Extract and download media from message content.
+ * Returns the downloaded media info and the text with the nhash URL removed.
+ */
+export async function extractAndDownloadMedia(
+  content: string,
+  opts?: { tempDir?: string; timeout?: number }
+): Promise<{
+  media: DownloadedMedia | null;
+  textContent: string;
+}> {
+  const parsed = parseNhashUrl(content);
+  if (!parsed) {
+    return { media: null, textContent: content };
+  }
+
+  const media = await downloadNhashMedia(parsed, opts);
+
+  // Remove the nhash URL from the text content
+  const textContent = content.replace(NHASH_REGEX, "").trim();
+
+  return { media, textContent };
+}

extensions/ndr/src/ndr-bus.ts

@@ -1,4 +1,11 @@
 import { spawn, type ChildProcess } from "child_process";
+import { extractAndDownloadMedia, type DownloadedMedia } from "./media.js";
+
+export interface NdrMessageMedia {
+  path: string;
+  mimeType: string | null;
+  url: string;
+}
 
 export interface NdrBusOptions {
   accountId: string;
@@ -6,7 +13,7 @@ export interface NdrBusOptions {
   relays: string[];
   ndrPath: string;
   dataDir: string | null;
-  onMessage: (chatId: string, messageId: string, senderPubkey: string, text: string, reply: (text: string) => Promise<void>) => Promise<void>;
+  onMessage: (chatId: string, messageId: string, senderPubkey: string, text: string, reply: (text: string) => Promise<void>, media?: NdrMessageMedia) => Promise<void>;
   onNewSession?: (chatId: string, theirPubkey: string) => Promise<void>;
   onError?: (error: Error, context: string) => void;
   onConnect?: () => void;
@@ -94,15 +101,30 @@ export async function startNdrBus(options: NdrBusOptions): Promise<NdrBusHandle>
             const chatId = json.chat_id;
             const messageId = json.message_id ?? "";
             const senderPubkey = json.from_pubkey;
-            const content = json.content;
+            const rawContent = json.content;
 
             // Create reply function
             const reply = async (text: string) => {
               await runNdrCommand(ndrPath, [...baseArgs, "send", chatId, text]);
             };
 
-            onMessage(chatId, messageId, senderPubkey, content, reply).catch((err) => {
-              onError?.(err, "message_handler");
+            // Extract and download any nhash media URLs
+            extractAndDownloadMedia(rawContent).then(({ media, textContent }) => {
+              const messageMedia = media ? {
+                path: media.path,
+                mimeType: media.mimeType,
+                url: media.url,
+              } : undefined;
+              // Use textContent (with nhash removed) if media was found, otherwise use raw content
+              const content = media ? textContent : rawContent;
+              onMessage(chatId, messageId, senderPubkey, content, reply, messageMedia).catch((err) => {
+                onError?.(err, "message_handler");
+              });
+            }).catch((err) => {
+              // If media extraction fails, still process the message with raw content
+              onMessage(chatId, messageId, senderPubkey, rawContent, reply).catch((handlerErr) => {
+                onError?.(handlerErr, "message_handler");
+              });
             });
           }