Channel Adapters - OpenFang

OpenFang connects to messaging platforms through 40 channel adapters, allowing users to interact with their agents across every major communication platform. Adapters span consumer messaging, enterprise collaboration, social media, community platforms, privacy-focused protocols, and generic webhooks.

Common Features

All adapters share a common foundation:

Graceful Shutdown

Coordinated shutdown via watch channel

Resilient Connections

Exponential backoff on connection failures

Secret Management

Zeroizing strings for secure token handling

Message Splitting

Automatic splitting for platform limits

Flexible Overrides

Per-channel model and prompt customization

Policy Enforcement

DM/group policy control per channel

Rate Limiting

Per-user rate limiting protection

Format Support

Markdown, Telegram HTML, Slack Mrkdwn, plain text

All 40 Channels

Core Platforms (7)

Channel	Protocol	Environment Variables	Type
Telegram	Bot API long-polling	`TELEGRAM_BOT_TOKEN`	`Telegram`
Discord	Gateway WebSocket v10	`DISCORD_BOT_TOKEN`	`Discord`
Slack	Socket Mode WebSocket	`SLACK_BOT_TOKEN`, `SLACK_APP_TOKEN`	`Slack`
WhatsApp	Cloud API webhook	`WA_ACCESS_TOKEN`, `WA_PHONE_ID`, `WA_VERIFY_TOKEN`	`WhatsApp`
Signal	signal-cli REST/JSON-RPC	(system service)	`Signal`
Matrix	Client-Server API /sync	`MATRIX_TOKEN`	`Matrix`
Email	IMAP + SMTP	`EMAIL_PASSWORD`	`Email`

Enterprise (8)

Channel	Protocol	Environment Variables	Type
Microsoft Teams	Bot Framework v3 webhook + OAuth2	`TEAMS_APP_ID`, `TEAMS_APP_SECRET`	`Teams`
Mattermost	WebSocket + REST v4	`MATTERMOST_TOKEN`, `MATTERMOST_URL`	`Mattermost`
Google Chat	Service account webhook	`GOOGLE_CHAT_SA_KEY`, `GOOGLE_CHAT_SPACE`	`Custom("google_chat")`
Webex	Bot SDK WebSocket	`WEBEX_BOT_TOKEN`	`Custom("webex")`
Feishu / Lark	Open Platform webhook	`FEISHU_APP_ID`, `FEISHU_APP_SECRET`	`Custom("feishu")`
Rocket.Chat	REST polling	`ROCKETCHAT_TOKEN`, `ROCKETCHAT_URL`	`Custom("rocketchat")`
Zulip	Event queue long-polling	`ZULIP_EMAIL`, `ZULIP_API_KEY`, `ZULIP_URL`	`Custom("zulip")`
XMPP	XMPP protocol	`XMPP_JID`, `XMPP_PASSWORD`, `XMPP_SERVER`	`Custom("xmpp")`

Channel	Protocol	Environment Variables	Type
LINE	Messaging API webhook	`LINE_CHANNEL_SECRET`, `LINE_CHANNEL_TOKEN`	`Custom("line")`
Viber	Bot API webhook	`VIBER_AUTH_TOKEN`	`Custom("viber")`
Facebook Messenger	Platform API webhook	`MESSENGER_PAGE_TOKEN`, `MESSENGER_VERIFY_TOKEN`	`Custom("messenger")`
Mastodon	Streaming API WebSocket	`MASTODON_TOKEN`, `MASTODON_INSTANCE`	`Custom("mastodon")`
Bluesky	AT Protocol WebSocket	`BLUESKY_HANDLE`, `BLUESKY_APP_PASSWORD`	`Custom("bluesky")`
Reddit	OAuth2 polling	`REDDIT_CLIENT_ID`, `REDDIT_CLIENT_SECRET`, `REDDIT_USERNAME`, `REDDIT_PASSWORD`	`Custom("reddit")`
LinkedIn	Messaging API polling	`LINKEDIN_ACCESS_TOKEN`	`Custom("linkedin")`
Twitch	IRC gateway	`TWITCH_TOKEN`, `TWITCH_CHANNEL`	`Custom("twitch")`

Community Platforms (6)

Channel	Protocol	Environment Variables	Type
IRC	Raw TCP PRIVMSG	`IRC_SERVER`, `IRC_NICK`, `IRC_PASSWORD`	`Custom("irc")`
Guilded	WebSocket	`GUILDED_BOT_TOKEN`	`Custom("guilded")`
Revolt	WebSocket	`REVOLT_BOT_TOKEN`	`Custom("revolt")`
Keybase	Bot API polling	`KEYBASE_USERNAME`, `KEYBASE_PAPERKEY`	`Custom("keybase")`
Discourse	REST polling	`DISCOURSE_API_KEY`, `DISCOURSE_URL`	`Custom("discourse")`
Gitter	Streaming API	`GITTER_TOKEN`	`Custom("gitter")`

Self-Hosted (1)

Channel	Protocol	Environment Variables	Type
Nextcloud Talk	REST polling	`NEXTCLOUD_TOKEN`, `NEXTCLOUD_URL`	`Custom("nextcloud")`

Privacy-Focused (3)

Channel	Protocol	Environment Variables	Type
Threema	Gateway API webhook	`THREEMA_ID`, `THREEMA_SECRET`	`Custom("threema")`
Nostr	NIP-01 relay WebSocket	`NOSTR_PRIVATE_KEY`, `NOSTR_RELAY`	`Custom("nostr")`
Mumble	TCP text protocol	`MUMBLE_SERVER`, `MUMBLE_USERNAME`, `MUMBLE_PASSWORD`	`Custom("mumble")`

Workplace (4)

Channel	Protocol	Environment Variables	Type
Pumble	Webhook	`PUMBLE_WEBHOOK_URL`, `PUMBLE_TOKEN`	`Custom("pumble")`
Flock	Webhook	`FLOCK_TOKEN`	`Custom("flock")`
Twist	API v3 polling	`TWIST_TOKEN`	`Custom("twist")`
DingTalk	Robot API webhook	`DINGTALK_TOKEN`, `DINGTALK_SECRET`	`Custom("dingtalk")`

Notification Services (2)

Channel	Protocol	Environment Variables	Type
ntfy	SSE pub/sub	`NTFY_TOPIC`, `NTFY_SERVER`	`Custom("ntfy")`
Gotify	WebSocket	`GOTIFY_TOKEN`, `GOTIFY_URL`	`Custom("gotify")`

Integration (1)

Channel	Protocol	Environment Variables	Type
Webhook	Generic HTTP with HMAC-SHA256	`WEBHOOK_URL`, `WEBHOOK_SECRET`	`Custom("webhook")`

Channel Configuration

All channel configurations live in ~/.openfang/config.toml under the [channels] section.

[channels.telegram]
bot_token_env = "TELEGRAM_BOT_TOKEN"
default_agent = "assistant"
allowed_users = ["123456789"]

[channels.discord]
bot_token_env = "DISCORD_BOT_TOKEN"
default_agent = "coder"

[channels.slack]
bot_token_env = "SLACK_BOT_TOKEN"
app_token_env = "SLACK_APP_TOKEN"
default_agent = "ops"

Common Configuration Fields

bot_token_env / token_env

The environment variable holding the bot/access token. OpenFang reads the token from this env var at startup. All secrets are stored as Zeroizing<String> and wiped from memory on drop.

default_agent

The agent name (or ID) that receives messages when no specific routing applies.

allowed_users

Optional list of platform user IDs allowed to interact. Empty means allow all.

overrides

Optional per-channel behavior overrides. See Channel Overrides section below.

Channel Overrides

Every channel adapter supports ChannelOverrides, which let you customize behavior per channel without modifying the agent manifest.

[channels.telegram.overrides]
model = "gemini-2.5-flash"
system_prompt = "You are a concise Telegram assistant. Keep replies under 200 words."
dm_policy = "respond"
group_policy = "mention_only"
rate_limit_per_user = 10
threading = true
output_format = "telegram_html"
usage_footer = "compact"

Override Fields

Field	Type	Default	Description
`model`	`Option<String>`	Agent default	Override the LLM model for this channel
`system_prompt`	`Option<String>`	Agent default	Override the system prompt
`dm_policy`	`DmPolicy`	`Respond`	How to handle direct messages
`group_policy`	`GroupPolicy`	`MentionOnly`	How to handle group/channel messages
`rate_limit_per_user`	`u32`	`0` (unlimited)	Max messages per minute per user
`threading`	`bool`	`false`	Send replies as thread responses
`output_format`	`Option<OutputFormat>`	`Markdown`	Output format for this channel
`usage_footer`	`Option<UsageFooterMode>`	None	Append token usage to responses

Output Formats and Policies

Output Formatter

The formatter module converts Markdown output from the LLM into platform-native formats:

Format	Target	Notes
`Markdown`	Standard Markdown	Default; passed through as-is
`TelegramHtml`	Telegram HTML subset	Converts `bold` to `<b>`, `code` to `<code>`
`SlackMrkdwn`	Slack mrkdwn	Converts `bold` to `bold`, links to `<url\|text>`
`PlainText`	Plain text	Strips all formatting

DM Policy

Controls how the adapter handles direct messages:

Policy	Behavior
`Respond`	Respond to all DMs (default)
`AllowedOnly`	Only respond to DMs from users in `allowed_users`
`Ignore`	Silently drop all DMs

Group Policy

Controls how the adapter handles messages in group chats, channels, and rooms:

Policy	Behavior
`All`	Respond to every message in the group
`MentionOnly`	Only respond when the bot is @mentioned (default)
`CommandsOnly`	Only respond to `/command` messages
`Ignore`	Silently ignore all group messages

Policy enforcement happens in dispatch_message() before the message reaches the agent loop. This means ignored messages consume zero LLM tokens.

Setup Guides

Create a bot

Open Telegram and message @BotFather. Send /newbot and follow the prompts.

Set environment variable

export TELEGRAM_BOT_TOKEN=123456789:ABCdefGHIjklMNOpqrsTUVwxyz

Configure in config.toml

[channels.telegram]
bot_token_env = "TELEGRAM_BOT_TOKEN"
default_agent = "assistant"

[channels.telegram.overrides]
output_format = "telegram_html"
group_policy = "mention_only"

Restart the daemon

openfang start

How It Works: Uses long-polling via the getUpdates API with 30-second timeout. Automatically splits responses over 4096 characters. Interactive Setup:

openfang channel setup telegram

Discord

Create a Discord application

Go to Discord Developer Portal and create a new application.

Add a bot

Go to the Bot section, click “Add Bot”, and enable Message Content Intent under Privileged Gateway Intents.

Invite the bot

Go to OAuth2 > URL Generator, select scope bot and permissions Send Messages + Read Message History. Use the generated URL to invite the bot.

Set environment variable

export DISCORD_BOT_TOKEN=MTIzNDU2Nzg5.ABCDEF.ghijklmnop

Configure in config.toml

[channels.discord]
bot_token_env = "DISCORD_BOT_TOKEN"
default_agent = "coder"

How It Works: Connects to Discord Gateway via WebSocket (v10). Handles reconnection, heartbeating, and session resumption automatically.

Slack

Create a Slack app

Go to Slack API, click “Create New App” > “From Scratch”.

Enable Socket Mode

Go to Settings > Socket Mode, enable it, and generate an App-Level Token with scope connections:write.

Add bot scopes

Go to OAuth & Permissions and add: chat:write, app_mentions:read, im:history, im:read, im:write.

Install to workspace

Install the app to your workspace and copy the Bot User OAuth Token.

Set environment variables

export SLACK_APP_TOKEN=xapp-1-...
export SLACK_BOT_TOKEN=xoxb-...

Configure in config.toml

[channels.slack]
bot_token_env = "SLACK_BOT_TOKEN"
app_token_env = "SLACK_APP_TOKEN"
default_agent = "ops"

[channels.slack.overrides]
output_format = "slack_mrkdwn"
threading = true

How It Works: Uses Socket Mode WebSocket connection. When threading = true, replies are sent to the message’s thread via thread_ts.

Set up Meta Business account

Go to Meta for Developers and create a Business App.

Add WhatsApp product

Add the WhatsApp product and set up a test phone number.

Get credentials

Copy the Phone Number ID, Permanent Access Token, and choose a Verify Token.

Set environment variables

export WA_PHONE_ID=123456789012345
export WA_ACCESS_TOKEN=EAABs...
export WA_VERIFY_TOKEN=my-secret-verify-token

Configure in config.toml

[channels.whatsapp]
mode = "cloud_api"
phone_number_id_env = "WA_PHONE_ID"
access_token_env = "WA_ACCESS_TOKEN"
verify_token_env = "WA_VERIFY_TOKEN"
webhook_port = 8443
default_agent = "assistant"

Set up webhook

In the Meta dashboard, configure webhook URL: https://your-domain.com:8443/webhook/whatsapp with your verify token.

How It Works: Runs an HTTP server to receive webhooks from WhatsApp Cloud API. Handles verification (GET) and message reception (POST).

Matrix

Create bot account

Create a bot account on your Matrix homeserver and generate an access token.

Set environment variable

export MATRIX_TOKEN=syt_...

Configure in config.toml

[channels.matrix]
homeserver_url = "https://matrix.org"
access_token_env = "MATRIX_TOKEN"
user_id = "@openfang-bot:matrix.org"
default_agent = "assistant"

Invite the bot

Invite the bot to the rooms you want it to monitor.

How It Works: Uses Matrix Client-Server API with long-polling /sync. Processes new messages from joined rooms.

Email

Create app password

For Gmail, create an App Password.

Set environment variable

export EMAIL_PASSWORD=abcd-efgh-ijkl-mnop

Configure in config.toml

[channels.email]
imap_host = "imap.gmail.com"
imap_port = 993
smtp_host = "smtp.gmail.com"
smtp_port = 587
username = "you@gmail.com"
password_env = "EMAIL_PASSWORD"
poll_interval = 30
default_agent = "email-assistant"

How It Works: Polls IMAP inbox at configured interval. Sends replies via SMTP, preserving subject line threading.

Agent Routing

The AgentRouter determines which agent receives an incoming message:

Per-channel default

Each channel config has a default_agent field. Messages from that channel go to that agent.

User-agent binding

If a user has been associated with a specific agent, messages from that user route to that agent.

Command prefix

Users can switch agents by sending /agent coder in chat. Subsequent messages route to the “coder” agent.

Fallback

If no routing applies, messages go to the first available agent.

WebChat (Built-in)

The WebChat UI is embedded in the daemon and requires no configuration:

http://127.0.0.1:4200/

Real-time Chat

WebSocket-based communication

Streaming Responses

Text deltas arrive as generated

Agent Selection

Switch between running agents

Token Usage Display

Live token and cost tracking

Writing Custom Adapters

To add support for a new messaging platform, implement the ChannelAdapter trait.

The ChannelAdapter Trait

pub trait ChannelAdapter: Send + Sync {
    fn name(&self) -> &str;
    fn channel_type(&self) -> ChannelType;
    
    async fn start(
        &self,
    ) -> Result<Pin<Box<dyn Stream<Item = ChannelMessage> + Send>>, Box<dyn std::error::Error>>;
    
    async fn send(
        &self,
        user: &ChannelUser,
        content: ChannelContent,
    ) -> Result<(), Box<dyn std::error::Error>>;
    
    async fn send_typing(&self, _user: &ChannelUser) -> Result<(), Box<dyn std::error::Error>> {
        Ok(())
    }
    
    async fn stop(&self) -> Result<(), Box<dyn std::error::Error>>;
    
    fn status(&self) -> ChannelStatus {
        ChannelStatus::default()
    }
    
    async fn send_in_thread(
        &self,
        user: &ChannelUser,
        content: ChannelContent,
        _thread_id: &str,
    ) -> Result<(), Box<dyn std::error::Error>> {
        self.send(user, content).await
    }
}

Implementation Steps

Define your adapter

Create crates/openfang-channels/src/myplatform.rs:

use crate::types::{ChannelAdapter, ChannelType, ...};
use tokio::sync::watch;
use zeroize::Zeroizing;

pub struct MyPlatformAdapter {
    token: Zeroizing<String>,
    client: reqwest::Client,
    shutdown: watch::Receiver<bool>,
}

Implement the trait

Use ChannelType::Custom("myplatform".to_string()) for the channel type. Wrap secrets in Zeroizing<String>. Use exponential backoff for connection failures.

In crates/openfang-channels/src/lib.rs:

pub mod myplatform;

Wire into the bridge

Add initialization logic in crates/openfang-api/src/channel_bridge.rs.

Add config support

Define config struct in openfang-types and add to ChannelsConfig.

Add CLI setup wizard

Add case to cmd_channel_setup in crates/openfang-cli/src/main.rs.

Key points for new adapters:

Only the 9 most common channels have named ChannelType variants. All others use Custom(String).
Wrap secrets in Zeroizing<String> so they are wiped from memory on drop.
Accept a watch::Receiver<bool> for coordinated shutdown with the daemon.
Use the shared split_message(text, max_len) utility for platforms with message length limits.

​Common Features

Graceful Shutdown

Resilient Connections

Secret Management

Message Splitting

Flexible Overrides

Policy Enforcement

Rate Limiting

Format Support

​All 40 Channels

​Core Platforms (7)

​Enterprise (8)

​Social Media (8)

​Community Platforms (6)

​Self-Hosted (1)

​Privacy-Focused (3)

​Workplace (4)

​Notification Services (2)

​Integration (1)

​Channel Configuration

​Common Configuration Fields

​Channel Overrides

​Override Fields

​Output Formats and Policies

​Output Formatter

​DM Policy

​Group Policy

​Setup Guides

​Telegram

​Discord

​Slack

​WhatsApp

​Matrix

​Email

​Agent Routing

​WebChat (Built-in)

Real-time Chat

Streaming Responses

Agent Selection

Token Usage Display

​Writing Custom Adapters

​The ChannelAdapter Trait

​Implementation Steps

Common Features

All 40 Channels

Core Platforms (7)

Enterprise (8)

Social Media (8)

Community Platforms (6)

Self-Hosted (1)

Privacy-Focused (3)

Workplace (4)

Notification Services (2)

Integration (1)

Channel Configuration

Common Configuration Fields

Channel Overrides

Override Fields

Output Formats and Policies

Output Formatter

DM Policy

Group Policy

Setup Guides

Telegram

Discord

Slack

WhatsApp

Matrix

Email

Agent Routing

WebChat (Built-in)

Writing Custom Adapters

The ChannelAdapter Trait

Implementation Steps