feat: support inbound files across all channels

src/channels/shared/file-download.mjs

@@ -0,0 +1,64 @@
+async function cancelResponseBody(response) {
+  try {
+    await response?.body?.cancel?.();
+  } catch {
+    // Preserve the original download failure.
+  }
+}
+
+function hostedByMessagingPlatform(target, allowedHosts) {
+  return !Array.isArray(allowedHosts) || allowedHosts.some((rule) => (
+    typeof rule === 'string'
+    && (target.hostname === rule
+      || (rule.startsWith('.')
+        && (target.hostname === rule.slice(1) || target.hostname.endsWith(rule))))
+  ));
+}
+
+/**
+ * Open a channel-hosted ordinary file as a stream.
+ *
+ * This deliberately has no plugin-defined size, type, count, or download-time
+ * limit. The caller owns cancellation through its AbortSignal and the channel
+ * remains the authority for its own file limits.
+ */
+export async function fetchFileStream(url, {
+  fetchImpl = fetch,
+  headers,
+  signal,
+  allowedHosts,
+} = {}) {
+  const target = new URL(url);
+  if (target.protocol !== 'https:') throw new Error('File download URL must use HTTPS');
+  if (!hostedByMessagingPlatform(target, allowedHosts)) {
+    throw new Error('File download URL is not hosted by the messaging platform');
+  }
+
+  const response = await fetchImpl(target, {
+    method: 'GET',
+    headers,
+    signal,
+    redirect: 'manual',
+  });
+  if (Number.isInteger(response?.status) && response.status >= 300 && response.status < 400) {
+    await cancelResponseBody(response);
+    const error = new Error(`File download redirect was blocked (HTTP ${response.status})`);
+    error.code = 'file-redirect-blocked';
+    throw error;
+  }
+  if (!response?.ok) {
+    await cancelResponseBody(response);
+    const error = new Error(`File download failed with HTTP ${response?.status ?? 'unknown'}`);
+    error.code = 'file-http-error';
+    error.status = response?.status;
+    throw error;
+  }
+  if (response.body?.[Symbol.asyncIterator]) return { stream: response.body };
+  if (typeof response.arrayBuffer === 'function') {
+    const data = Buffer.from(await response.arrayBuffer());
+    return {
+      stream: (async function* fileBody() { yield data; }()),
+    };
+  }
+  throw new Error('File download returned no readable body');
+}

src/channels/shared/harness-client.mjs

@@ -3,6 +3,10 @@ import { randomUUID } from 'node:crypto';
 import { isAbsolute } from 'node:path';
 
 import { adoptRegisteredWorkspaceSession } from './harness-session-binding.mjs';
+import {
+  appendInboundFilesToPrompt,
+  InboundFileError,
+} from './inbound-file.mjs';
 import { outboundArtifactRegistry } from './semantic/artifact.mjs';
 
 // Every channel plugin runs in the same Host process. Sharing ownership by
@@ -466,6 +470,7 @@ export class HarnessClient {
   #commandExecutor;
   #controlExecutor;
   #sessionMaintenanceExecutor;
+  #fileIngressExecutor;
   #managedProcess = null;
   #interactionRegistry;
   #interactionOwnerships;
@@ -486,6 +491,7 @@ export class HarnessClient {
     commandExecutor,
     controlExecutor,
     sessionMaintenanceExecutor,
+    fileIngressExecutor,
   }) {
     if (typeof createWebSocket !== 'function') {
       throw new TypeError('createWebSocket must be a function');
@@ -509,6 +515,9 @@ export class HarnessClient {
       && typeof sessionMaintenanceExecutor !== 'function') {
       throw new TypeError('sessionMaintenanceExecutor must be a function');
     }
+    if (fileIngressExecutor !== undefined && typeof fileIngressExecutor !== 'function') {
+      throw new TypeError('fileIngressExecutor must be a function');
+    }
     this.#baseUrl = new URL(baseUrl);
     this.#workspace = workspace;
     // Keep an omitted preset absent so session.create resolves the Host's current default.
@@ -523,6 +532,7 @@ export class HarnessClient {
     this.#commandExecutor = commandExecutor;
     this.#controlExecutor = controlExecutor;
     this.#sessionMaintenanceExecutor = sessionMaintenanceExecutor;
+    this.#fileIngressExecutor = fileIngressExecutor;
     this.#interactionRegistry = interactionRegistry(this.#baseUrl.origin);
     this.#interactionOwnerships = this.#interactionRegistry.ownerships;
     this.#interactionClaims = this.#interactionRegistry.claims;
@@ -1034,6 +1044,7 @@ export class HarnessClient {
       ? options.onInteractionResolved
       : undefined;
     const control = normalizeControl(options.control);
+    const inboundFiles = Array.isArray(options.files) ? options.files.filter(Boolean) : [];
     await this.ensureRunning({ signal });
     const before = await this.rpc(
       'session.history',
@@ -1075,6 +1086,9 @@ export class HarnessClient {
     let interactionTask = null;
     let artifactsDelivered = false;
     let deliveredArtifactCount = 0;
+    let stagedInboundFiles = null;
+    let promptAccepted = false;
+    let turnFinished = false;
 
     const deliverArtifacts = async () => {
       if (!onArtifact || artifactsDelivered || tracker.turn === null) {
@@ -1103,6 +1117,30 @@ export class HarnessClient {
     const closeArtifactConsumer = outboundArtifactRegistry.openConsumer(sessionId, promptRpcId);
 
     try {
+      if (inboundFiles.length > 0) {
+        if (!this.#fileIngressExecutor) {
+          throw new InboundFileError(
+            'inbound-file-ingress-unavailable',
+            'Harness file ingress is unavailable in this Host process.',
+          );
+        }
+        const sessionList = await this.rpc(
+          'session.list',
+          {},
+          30_000,
+          { signal },
+        );
+        const sessionWorkspace = sessionList?.items?.find(
+          (item) => item?.sessionId === sessionId,
+        )?.cwd;
+        stagedInboundFiles = await this.#fileIngressExecutor({
+          sessionId,
+          workspace: sessionWorkspace,
+          files: inboundFiles,
+          signal,
+        });
+        prompt = appendInboundFilesToPrompt(prompt, stagedInboundFiles);
+      }
       if (interactionSignal) {
         let markOpen;
         const opened = new Promise((resolve) => { markOpen = resolve; });
@@ -1134,6 +1172,7 @@ export class HarnessClient {
         content,
         clientTimeZone: Intl.DateTimeFormat().resolvedOptions().timeZone,
       }, 30_000, { rpcId: promptRpcId, signal });
+      promptAccepted = true;
 
       try {
         const deadline = Date.now() + timeoutMs;
@@ -1159,6 +1198,7 @@ export class HarnessClient {
             }
           }
           if (!tracker.finished) continue;
+          turnFinished = true;
           // An accepted /stop revokes attachment delivery even when Harness
           // preserved a useful partial text answer for the existing UX.
           const artifactCount = ownership?.stopRequested
@@ -1185,6 +1225,11 @@ export class HarnessClient {
         throw turnStoppedError();
       }
     } finally {
+      if (stagedInboundFiles && (!promptAccepted || turnFinished)) {
+        await stagedInboundFiles.cleanup().catch((error) => {
+          console.warn(`[${this.#logPrefix}] unable to clean inbound files:`, error.message);
+        });
+      }
       closeArtifactConsumer();
       if (ownership) {
         this.#unregisterControlOwnership(ownership);

src/channels/shared/inbound-file.mjs

@@ -0,0 +1,206 @@
+import { createWriteStream } from 'node:fs';
+import { mkdir, mkdtemp, rm, writeFile } from 'node:fs/promises';
+import { isAbsolute, join, relative, resolve } from 'node:path';
+import { pipeline } from 'node:stream/promises';
+
+const FILES_DIRECTORY = join('.dsh-im', 'inbound');
+
+export class InboundFileError extends Error {
+  constructor(code, message, userMessage = '文件接收失败，请重新发送后再试。', options = {}) {
+    super(message, options);
+    this.name = 'InboundFileError';
+    this.code = code;
+    this.userMessage = userMessage;
+  }
+}
+
+function fileSources(message) {
+  return Array.isArray(message?.files) ? message.files.filter(Boolean) : [];
+}
+
+function displayName(value, fallback) {
+  if (typeof value !== 'string') return fallback;
+  const cleaned = value
+    .replaceAll('\\', '/')
+    .split('/')
+    .at(-1)
+    ?.replace(/[\u0000-\u001f\u007f]/g, '')
+    .trim();
+  return cleaned || fallback;
+}
+
+function storageName(value, index) {
+  const cleaned = displayName(value, 'file')
+    .replace(/[^\p{L}\p{N}._ -]/gu, '_')
+    .replace(/^\.+/, '')
+    .slice(0, 160) || 'file';
+  return `${String(index + 1).padStart(2, '0')}-${cleaned}`;
+}
+
+function loadedFile(value) {
+  if (Buffer.isBuffer(value) || value instanceof Uint8Array) {
+    return { data: Buffer.from(value) };
+  }
+  const raw = value?.data ?? value?.buffer;
+  if (Buffer.isBuffer(raw) || raw instanceof Uint8Array) {
+    return {
+      data: Buffer.from(raw),
+      name: value?.name ?? value?.filename,
+      mediaType: value?.mediaType ?? value?.mimetype,
+    };
+  }
+  const stream = value?.stream ?? value;
+  if (stream && typeof stream[Symbol.asyncIterator] === 'function') {
+    return {
+      stream,
+      name: value?.name ?? value?.filename,
+      mediaType: value?.mediaType ?? value?.mimetype,
+    };
+  }
+  return null;
+}
+
+export function hasInboundFiles(message) {
+  return fileSources(message).length > 0;
+}
+
+/** Start provider downloads immediately while preserving the lazy file-source contract. */
+export function prefetchInboundFiles(message, { signal } = {}) {
+  const sources = fileSources(message);
+  if (sources.length === 0) return message;
+  return {
+    ...message,
+    files: sources.map((source) => {
+      if (source?.data !== undefined || typeof source?.load !== 'function') return source;
+      let download;
+      try {
+        download = Promise.resolve(source.load({ signal }));
+      } catch (error) {
+        download = Promise.reject(error);
+      }
+      download.catch(() => undefined);
+      return {
+        ...source,
+        async load({ signal: loadSignal } = {}) {
+          loadSignal?.throwIfAborted();
+          const result = await download;
+          loadSignal?.throwIfAborted();
+          return result;
+        },
+      };
+    }),
+  };
+}
+
+export async function stageInboundFiles(message, {
+  workspace,
+  signal,
+} = {}) {
+  const sources = fileSources(message);
+  if (sources.length === 0) return null;
+  if (typeof workspace !== 'string' || !isAbsolute(workspace)) {
+    throw new InboundFileError(
+      'inbound-file-workspace-unavailable',
+      'The Harness Session workspace is unavailable for inbound files.',
+    );
+  }
+
+  signal?.throwIfAborted();
+  const root = resolve(workspace, FILES_DIRECTORY);
+  await mkdir(root, { recursive: true, mode: 0o700 });
+  const directory = await mkdtemp(join(root, 'turn-'));
+  const files = [];
+
+  try {
+    for (const [index, source] of sources.entries()) {
+      signal?.throwIfAborted();
+      let value;
+      try {
+        value = source?.data === undefined
+          ? await source?.load?.({ signal })
+          : source.data;
+      } catch (error) {
+        if (signal?.aborted) throw error;
+        throw new InboundFileError(
+          'inbound-file-download-failed',
+          `Unable to download inbound file ${index + 1}: ${error?.message ?? String(error)}`,
+          '文件下载失败，请重新发送后再试。',
+          { cause: error },
+        );
+      }
+
+      const loaded = loadedFile(value);
+      if (!loaded) {
+        throw new InboundFileError(
+          'inbound-file-data-invalid',
+          `Inbound file ${index + 1} returned no readable data.`,
+        );
+      }
+      const name = displayName(loaded.name ?? source?.name, `file-${index + 1}`);
+      const path = join(directory, storageName(name, index));
+      if (loaded.data) {
+        await writeFile(path, loaded.data, { mode: 0o600, signal });
+      } else {
+        try {
+          await pipeline(
+            loaded.stream,
+            createWriteStream(path, { flags: 'wx', mode: 0o600 }),
+            { signal },
+          );
+        } catch (error) {
+          if (signal?.aborted) throw error;
+          throw new InboundFileError(
+            'inbound-file-download-failed',
+            `Unable to stream inbound file ${index + 1}: ${error?.message ?? String(error)}`,
+            '文件下载失败，请重新发送后再试。',
+            { cause: error },
+          );
+        }
+      }
+      const relativePath = relative(resolve(workspace), path);
+      if (!relativePath || relativePath.startsWith('..') || isAbsolute(relativePath)) {
+        throw new InboundFileError(
+          'inbound-file-path-invalid',
+          'The staged inbound file escaped the Harness Session workspace.',
+        );
+      }
+      files.push(Object.freeze({
+        name,
+        path: relativePath,
+        ...(typeof (loaded.mediaType ?? source?.mediaType) === 'string'
+          && (loaded.mediaType ?? source.mediaType).trim()
+          ? { mediaType: (loaded.mediaType ?? source.mediaType).trim() }
+          : {}),
+      }));
+    }
+    return Object.freeze({
+      files: Object.freeze(files),
+      async cleanup() {
+        await rm(directory, { recursive: true, force: true });
+      },
+    });
+  } catch (error) {
+    await rm(directory, { recursive: true, force: true }).catch(() => undefined);
+    throw error;
+  }
+}
+
+export function appendInboundFilesToPrompt(prompt, staged) {
+  if (!staged?.files?.length) return prompt;
+  const manifest = [
+    '<dsh_im_files>',
+    JSON.stringify({
+      description: 'Files uploaded with this user message. Paths are relative to the current Harness workspace.',
+      files: staged.files,
+    }),
+    '</dsh_im_files>',
+  ].join('\n');
+
+  if (Array.isArray(prompt)) return [...prompt, { type: 'text', text: manifest }];
+  const text = typeof prompt === 'string' ? prompt.trim() : '';
+  return text ? `${text}\n\n${manifest}` : manifest;
+}
+
+export function inboundFileUserMessage(error) {
+  return error instanceof InboundFileError ? error.userMessage : null;
+}

src/channels/shared/text-harness-bridge.mjs

@@ -23,6 +23,10 @@ import {
   imagePromptUserMessage,
   promptContentForMessage,
 } from './image-prompt.mjs';
+import {
+  hasInboundFiles,
+  inboundFileUserMessage,
+} from './inbound-file.mjs';
 import {
   harnessAnswerForQuestion,
   harnessQuestionText,
@@ -50,6 +54,7 @@ function canClaimInteractionReply(message, pending, senderId) {
   return pending.actor === senderId
     && (message.kind !== 'group' || message.addressed === true)
     && !hasInboundImages(message)
+    && !hasInboundFiles(message)
     && Boolean(cleanText(message.content));
 }
 
@@ -171,7 +176,7 @@ export class TextHarnessBridge {
     const key = `${kind}:${conversationId}`;
     const pending = this.#pendingInteractions.get(key);
     const text = cleanText(normalized.content);
-    const commandRunner = isControlCommand(text)
+    const commandRunner = hasInboundFiles(normalized) ? null : isControlCommand(text)
       ? runControlCommand
       : (isModelCommand(text)
           ? runModelCommand
@@ -194,7 +199,7 @@ export class TextHarnessBridge {
       key,
       actor: senderId,
       messageId,
-      text: hasInboundImages(normalized) ? '' : normalized.content,
+      text: hasInboundImages(normalized) || hasInboundFiles(normalized) ? '' : normalized.content,
       addressed: normalized.kind !== 'group' || normalized.addressed === true,
       hasPendingQuestion: Boolean(pending),
       questionCompletion: pending?.submitting || pending?.claimedReplyMessageId
@@ -300,6 +305,7 @@ export class TextHarnessBridge {
         {
           signal: this.#signal,
           hasImages: hasInboundImages(message),
+          hasFiles: hasInboundFiles(message),
           pendingInteraction: this.#pendingInteractions.has(key)
             || this.#approvals.hasPending(key),
           control: { owner: this, key },
@@ -423,16 +429,17 @@ export class TextHarnessBridge {
         return;
       }
       const hasImages = hasInboundImages(message);
-      if (!text && !hasImages) {
-        await this.#bot.sendText(target, '目前支持文字和图片消息。');
+      const hasFiles = hasInboundFiles(message);
+      if (!text && !hasImages && !hasFiles) {
+        await this.#bot.sendText(target, '目前支持文字、图片和文件消息。');
         return;
       }
       const command = text.toLowerCase();
-      if (!hasImages && command === '/help') {
+      if (!hasImages && !hasFiles && command === '/help') {
         await this.#bot.sendText(target, [
           `${this.#descriptor.label}机器人已连接 DeepSeek Harness。`,
           '',
-          '直接发送文字或图片即可继续当前会话。',
+          '直接发送文字、图片或文件即可继续当前会话。',
           '/new  开启一个全新会话',
           '/compact  压缩当前会话的较早上下文',
           '/workspace 工作区绝对路径  切换工作区',
@@ -453,12 +460,12 @@ export class TextHarnessBridge {
         ].join('\n'));
         return;
       }
-      if (!hasImages && command === '/status') {
+      if (!hasImages && !hasFiles && command === '/status') {
         await this.#harness.ensureRunning({ signal: this.#signal });
         await this.#bot.sendText(target, `${this.#descriptor.label}机器人与 DeepSeek Harness 连接正常。`);
         return;
       }
-      const workspaceCommand = !hasImages
+      const workspaceCommand = !hasImages && !hasFiles
         ? await runWorkspaceCommand(text, this.#harness, conversationKey)
         : null;
       if (workspaceCommand) {
@@ -467,12 +474,12 @@ export class TextHarnessBridge {
         }
         return;
       }
-      if (!hasImages && command === '/new') {
+      if (!hasImages && !hasFiles && command === '/new') {
         await this.#state.clearSession(conversationKey);
         await this.#bot.sendText(target, '已开启新会话。请发送你的问题。');
         return;
       }
-      const compactCommand = !hasImages
+      const compactCommand = !hasImages && !hasFiles
         ? await runCompactCommand(
             text,
             this.#harness,
@@ -527,6 +534,7 @@ export class TextHarnessBridge {
             requiresMention: message.kind === 'group',
           }),
           onInteractionResolved: (resolution) => this.#handleInteractionResolved(resolution),
+          files: message.files,
         },
       });
       const visibleAnswer = !cleanText(answer) && artifacts.length > 0
@@ -600,6 +608,18 @@ export class TextHarnessBridge {
         }
         return;
       }
+      const fileErrorMessage = inboundFileUserMessage(error);
+      if (fileErrorMessage) {
+        try {
+          await this.#bot.sendText(target, fileErrorMessage);
+        } catch (sendError) {
+          this.#logger.error?.(
+            `[dsh-im:${this.#descriptor.key}] failed to send the file error reply:`,
+            sendError,
+          );
+        }
+        return;
+      }
       this.#logger.error?.(`[dsh-im:${this.#descriptor.key}] failed to process a message:`, error);
       try {
         await this.#bot.sendText(target, '消息处理失败，请稍后重试。');
@@ -642,7 +662,7 @@ export class TextHarnessBridge {
 
     const target = message.replyTarget;
     const text = cleanText(message.content);
-    if (!text || hasInboundImages(message)) {
+    if (!text || hasInboundImages(message) || hasInboundFiles(message)) {
       try {
         await this.#bot.sendText(target, '请用文字回答当前问题。');
       } catch (error) {