---
sidebar_position: 14
title: "WeCom (Enterprise WeChat)"
description: "Connect Hermes Agent to WeCom via the AI Bot WebSocket gateway"
---

# WeCom (Enterprise WeChat)

Connect Hermes to [WeCom](https://work.weixin.qq.com/) (企业微信), Tencent's enterprise messaging platform. The adapter uses WeCom's AI Bot WebSocket gateway for real-time bidirectional communication — no public endpoint or webhook needed.

See also: [WeCom Callback](./wecom-callback.md) for inbound webhook setup.

## Prerequisites

- A WeCom organization account
- An AI Bot created in the WeCom Admin Console
- The Bot ID and Secret from the bot's credentials page
- Python packages: `aiohttp` and `httpx`

## Setup

### Step 1: Create an AI Bot

#### Recommended: Scan-to-Create (one command)

```bash
hermes gateway setup
```

Select **WeCom** and scan the QR code with your WeCom mobile app. Hermes will automatically create a bot application with the correct permissions and save the credentials.

The setup wizard will:
1. Display a QR code in your terminal
2. Wait for you to scan it with the WeCom mobile app
3. Automatically retrieve the Bot ID and Secret
4. Guide you through access control configuration

#### Alternative: Manual Setup

If scan-to-create is not available, the wizard falls back to manual input:

1. Log in to the [WeCom Admin Console](https://work.weixin.qq.com/wework_admin/frame)
2. Navigate to **Applications** → **Create Application** → **AI Bot**
3. Configure the bot name and description
4. Copy the **Bot ID** and **Secret** from the credentials page
5. Run `hermes gateway setup`, select **WeCom**, and enter the credentials when prompted

:::warning
Keep the Bot Secret private. Anyone with it can impersonate your bot.
:::

### Step 2: Configure Hermes

#### Option A: Interactive Setup (Recommended)

```bash
hermes gateway setup
```

Select **WeCom** and follow the prompts. The wizard will guide you through:
- Bot credentials (via QR scan or manual entry)
- Access control settings (allowlist, pairing mode, or open access)
- Home channel for notifications

#### Option B: Manual Configuration

Add the following to `~/.hermes/.env`:

```bash
WECOM_BOT_ID=your-bot-id
WECOM_SECRET=your-secret

# Optional: restrict access
WECOM_ALLOWED_USERS=user_id_1,user_id_2

# Optional: home channel for cron/notifications
WECOM_HOME_CHANNEL=chat_id
```

### Step 3: Start the gateway

```bash
hermes gateway
```

## Features

- **WebSocket transport** — persistent connection, no public endpoint needed
- **DM and group messaging** — configurable access policies
- **Per-group sender allowlists** — fine-grained control over who can interact in each group
- **Media support** — images, files, voice, video upload and download
- **AES-encrypted media** — automatic decryption for inbound attachments
- **Quote context** — preserves reply threading
- **Markdown rendering** — rich text responses
- **Reply correlation** — responses are correlated to the inbound message context
- **Auto-reconnect** — exponential backoff on connection drops

:::note Streaming and typing indicators
The WeCom adapter delivers each response as a single complete message — it does
**not** stream responses token-by-token, and it does **not** show a typing
indicator. "Reply correlation" (below) only threads a response to its inbound
request; it is not live streaming.
:::

## Configuration Options

Set these in `config.yaml` under `platforms.wecom.extra`:

| Key | Default | Description |
|-----|---------|-------------|
| `bot_id` | — | WeCom AI Bot ID (required) |
| `secret` | — | WeCom AI Bot Secret (required) |
| `websocket_url` | `wss://openws.work.weixin.qq.com` | WebSocket gateway URL |
| `dm_policy` | `open` | DM access: `open`, `allowlist`, `disabled`, `pairing` |
| `group_policy` | `open` | Group access: `open`, `allowlist`, `disabled` |
| `allow_from` | `[]` | User IDs allowed for DMs (when dm_policy=allowlist) |
| `group_allow_from` | `[]` | Group IDs allowed (when group_policy=allowlist) |
| `groups` | `{}` | Per-group configuration (see below) |

## Access Policies

### DM Policy

Controls who can send direct messages to the bot:

| Value | Behavior |
|-------|----------|
| `open` | Anyone can DM the bot (default) |
| `allowlist` | Only user IDs in `allow_from` can DM |
| `disabled` | All DMs are ignored |
| `pairing` | Pairing mode (for initial setup) |

```bash
WECOM_DM_POLICY=allowlist
```

### Group Policy

Controls which groups the bot responds in:

| Value | Behavior |
|-------|----------|
| `open` | Bot responds in all groups (default) |
| `allowlist` | Bot only responds in group IDs listed in `group_allow_from` |
| `disabled` | All group messages are ignored |

```bash
WECOM_GROUP_POLICY=allowlist
```

### Per-Group Sender Allowlists

For fine-grained control, you can restrict which users are allowed to interact with the bot within specific groups. This is configured in `config.yaml`:

```yaml
platforms:
  wecom:
    enabled: true
    extra:
      bot_id: "your-bot-id"
      secret: "your-secret"
      group_policy: "allowlist"
      group_allow_from:
        - "group_id_1"
        - "group_id_2"
      groups:
        group_id_1:
          allow_from:
            - "user_alice"
            - "user_bob"
        group_id_2:
          allow_from:
            - "user_charlie"
        "*":
          allow_from:
            - "user_admin"
```

**How it works:**

1. The `group_policy` and `group_allow_from` controls determine whether a group is allowed at all.
2. If a group passes the top-level check, the `groups.<group_id>.allow_from` list (if present) further restricts which senders within that group can interact with the bot.
3. A wildcard `"*"` group entry serves as a default for groups not explicitly listed.
4. Allowlist entries support the `*` wildcard to allow all users, and entries are case-insensitive.
5. Entries can optionally use the `wecom:user:` or `wecom:group:` prefix format — the prefix is stripped automatically.

If no `allow_from` is configured for a group, all users in that group are allowed (assuming the group itself passes the top-level policy check).

## Media Support

### Inbound (receiving)

The adapter receives media attachments from users and caches them locally for agent processing:

| Type | How it's handled |
|------|-----------------|
| **Images** | Downloaded and cached locally. Supports both URL-based and base64-encoded images. |
| **Files** | Downloaded and cached. Filename is preserved from the original message. |
| **Voice** | Voice message text transcription is extracted if available. |
| **Mixed messages** | WeCom mixed-type messages (text + images) are parsed and all components extracted. |

**Quoted messages:** Media from quoted (replied-to) messages is also extracted, so the agent has context about what the user is replying to.

### AES-Encrypted Media Decryption

WeCom encrypts some inbound media attachments with AES-256-CBC. The adapter handles this automatically:

- When an inbound media item includes an `aeskey` field, the adapter downloads the encrypted bytes and decrypts them using AES-256-CBC with PKCS#7 padding.
- The AES key is the base64-decoded value of the `aeskey` field (must be exactly 32 bytes).
- The IV is derived from the first 16 bytes of the key.
- This requires the `cryptography` Python package (`pip install cryptography`).

No configuration is needed — decryption happens transparently when encrypted media is received.

### Outbound (sending)

| Method | What it sends | Size limit |
|--------|--------------|------------|
| `send` | Markdown text messages | 4000 chars |
| `send_image` / `send_image_file` | Native image messages | 10 MB |
| `send_document` | File attachments | 20 MB |
| `send_voice` | Voice messages (AMR format only for native voice) | 2 MB |
| `send_video` | Video messages | 10 MB |

**Chunked upload:** Files are uploaded in 512 KB chunks through a three-step protocol (init → chunks → finish). The adapter handles this automatically.

**Automatic downgrade:** When media exceeds the native type's size limit but is under the absolute 20 MB file limit, it is automatically sent as a generic file attachment instead:

- Images > 10 MB → sent as file
- Videos > 10 MB → sent as file
- Voice > 2 MB → sent as file
- Non-AMR audio → sent as file (WeCom only supports AMR for native voice)

Files exceeding the absolute 20 MB limit are rejected with an informational message sent to the chat.

## Reply-Mode Responses

When the bot receives a message via the WeCom callback, the adapter remembers the inbound request ID. If a response is sent while the request context is still active, the adapter uses WeCom's reply-mode (`aibot_respond_msg`) to correlate the response directly to the inbound message. This provides a more natural conversation experience in the WeCom client.

The full response is delivered as a single message — the adapter does not stream tokens incrementally. If the inbound request context has expired or is unavailable, the adapter falls back to proactive message sending via `aibot_send_msg`.

Reply-mode also works for media: uploaded media can be sent as a reply to the originating message.

## Connection and Reconnection

The adapter maintains a persistent WebSocket connection to WeCom's gateway at `wss://openws.work.weixin.qq.com`.

### Connection Lifecycle

1. **Connect:** Opens a WebSocket connection and sends an `aibot_subscribe` authentication frame with the bot_id and secret.
2. **Heartbeat:** Sends application-level ping frames every 30 seconds to keep the connection alive.
3. **Listen:** Continuously reads inbound frames and dispatches message callbacks.

### Reconnection Behavior

On connection loss, the adapter uses exponential backoff to reconnect:

| Attempt | Delay |
|---------|-------|
| 1st retry | 2 seconds |
| 2nd retry | 5 seconds |
| 3rd retry | 10 seconds |
| 4th retry | 30 seconds |
| 5th+ retry | 60 seconds |

After each successful reconnection, the backoff counter resets to zero. All pending request futures are failed on disconnect so callers don't hang indefinitely.

### Deduplication

Inbound messages are deduplicated using message IDs with a 5-minute window and a maximum cache of 1000 entries. This prevents double-processing of messages during reconnection or network hiccups.

## All Environment Variables

| Variable | Required | Default | Description |
|----------|----------|---------|-------------|
| `WECOM_BOT_ID` | ✅ | — | WeCom AI Bot ID |
| `WECOM_SECRET` | ✅ | — | WeCom AI Bot Secret |
| `WECOM_ALLOWED_USERS` | — | _(empty)_ | Comma-separated user IDs for the gateway-level allowlist |
| `WECOM_HOME_CHANNEL` | — | — | Chat ID for cron/notification output |
| `WECOM_WEBSOCKET_URL` | — | `wss://openws.work.weixin.qq.com` | WebSocket gateway URL |
| `WECOM_DM_POLICY` | — | `open` | DM access policy |
| `WECOM_GROUP_POLICY` | — | `open` | Group access policy |

## Troubleshooting

| Problem | Fix |
|---------|-----|
| `WECOM_BOT_ID and WECOM_SECRET are required` | Set both env vars or configure in setup wizard |
| `WeCom startup failed: aiohttp not installed` | Install aiohttp: `pip install aiohttp` |
| `WeCom startup failed: httpx not installed` | Install httpx: `pip install httpx` |
| `invalid secret (errcode=40013)` | Verify the secret matches your bot's credentials |
| `Timed out waiting for subscribe acknowledgement` | Check network connectivity to `openws.work.weixin.qq.com` |
| Bot doesn't respond in groups | Check `group_policy` setting and ensure the group ID is in `group_allow_from` |
| Bot ignores certain users in a group | Check per-group `allow_from` lists in the `groups` config section |
| Media decryption fails | Install `cryptography`: `pip install cryptography` |
| `cryptography is required for WeCom media decryption` | The inbound media is AES-encrypted. Install: `pip install cryptography` |
| Voice messages sent as files | WeCom only supports AMR format for native voice. Other formats are auto-downgraded to file. |
| `File too large` error | WeCom has a 20 MB absolute limit on all file uploads. Compress or split the file. |
| Images sent as files | Images > 10 MB exceed the native image limit and are auto-downgraded to file attachments. |
| `Timeout sending message to WeCom` | The WebSocket may have disconnected. Check logs for reconnection messages. |
| `WeCom websocket closed during authentication` | Network issue or incorrect credentials. Verify bot_id and secret. |
