hermes-agent/website/docs/developer-guide/adding-platform-adapters.md

---
sidebar_position: 9
---

# Adding a Platform Adapter

This guide covers adding a new messaging platform to the Hermes gateway. A platform adapter connects Hermes to an external messaging service (Telegram, Discord, WeCom, etc.) so users can interact with the agent through that service.

:::tip
There are two ways to add a platform:
- **Plugin** (recommended for community/third-party): Drop a plugin directory into `~/.hermes/plugins/` — zero core code changes needed. See [Plugin Path](#plugin-path-recommended) below.
- **Built-in**: Modify 20+ files across code, config, and docs. Use the [Built-in Checklist](#step-by-step-checklist) below.
:::

## Architecture Overview

```
User ↔ Messaging Platform ↔ Platform Adapter ↔ Gateway Runner ↔ AIAgent
```

Every adapter extends `BasePlatformAdapter` from `gateway/platforms/base.py` and implements:

- **`connect()`** — Establish connection (WebSocket, long-poll, HTTP server, etc.) *(abstract)*
- **`disconnect()`** — Clean shutdown *(abstract)*
- **`send()`** — Send a text message to a chat *(abstract)*
- **`send_typing()`** — Show typing indicator (optional override)
- **`get_chat_info()`** — Return chat metadata (optional override)

Inbound messages are received by the adapter and forwarded via `self.handle_message(event)`, which the base class routes to the gateway runner.

## Plugin Path (Recommended)

The plugin system lets you add a platform adapter without modifying any core Hermes code. Your plugin is a directory with two files:

```
~/.hermes/plugins/my-platform/
  PLUGIN.yaml      # Plugin metadata
  adapter.py       # Adapter class + register() entry point
```

### PLUGIN.yaml

Plugin metadata. The `requires_env` and `optional_env` blocks auto-populate `hermes config` UI entries (see [Surfacing Env Vars](#surfacing-env-vars-in-hermes-config) below).

```yaml
name: my-platform
label: My Platform
kind: platform
version: 1.0.0
description: My custom messaging platform adapter
author: Your Name
requires_env:
  - MY_PLATFORM_TOKEN          # bare string works
  - name: MY_PLATFORM_CHANNEL  # or rich dict for better UX
    description: "Channel to join"
    prompt: "Channel"
    password: false
optional_env:
  - name: MY_PLATFORM_HOME_CHANNEL
    description: "Default channel for cron delivery"
    password: false
```

### adapter.py

```python
import os
from gateway.platforms.base import (
    BasePlatformAdapter, SendResult, MessageEvent, MessageType,
)
from gateway.config import Platform, PlatformConfig


class MyPlatformAdapter(BasePlatformAdapter):
    def __init__(self, config: PlatformConfig):
        super().__init__(config, Platform("my_platform"))
        extra = config.extra or {}
        self.token = os.getenv("MY_PLATFORM_TOKEN") or extra.get("token", "")

    async def connect(self) -> bool:
        # Connect to the platform API, start listeners
        self._mark_connected()
        return True

    async def disconnect(self) -> None:
        self._mark_disconnected()

    async def send(self, chat_id, content, reply_to=None, metadata=None):
        # Send message via platform API
        return SendResult(success=True, message_id="...")

    async def get_chat_info(self, chat_id):
        return {"name": chat_id, "type": "dm"}


def check_requirements() -> bool:
    return bool(os.getenv("MY_PLATFORM_TOKEN"))


def validate_config(config) -> bool:
    extra = getattr(config, "extra", {}) or {}
    return bool(os.getenv("MY_PLATFORM_TOKEN") or extra.get("token"))


def _env_enablement() -> dict | None:
    token = os.getenv("MY_PLATFORM_TOKEN", "").strip()
    channel = os.getenv("MY_PLATFORM_CHANNEL", "").strip()
    if not (token and channel):
        return None
    seed = {"token": token, "channel": channel}
    home = os.getenv("MY_PLATFORM_HOME_CHANNEL")
    if home:
        seed["home_channel"] = {"chat_id": home, "name": "Home"}
    return seed


def register(ctx):
    """Plugin entry point — called by the Hermes plugin system."""
    ctx.register_platform(
        name="my_platform",
        label="My Platform",
        adapter_factory=lambda cfg: MyPlatformAdapter(cfg),
        check_fn=check_requirements,
        validate_config=validate_config,
        required_env=["MY_PLATFORM_TOKEN"],
        install_hint="pip install my-platform-sdk",
        # Env-driven auto-configuration — seeds PlatformConfig.extra from
        # env vars before adapter construction. See "Env-Driven Auto-
        # Configuration" section below.
        env_enablement_fn=_env_enablement,
        # Cron home-channel delivery support. Lets deliver=my_platform cron
        # jobs route without editing cron/scheduler.py. See "Cron Delivery"
        # section below.
        cron_deliver_env_var="MY_PLATFORM_HOME_CHANNEL",
        # Per-platform user authorization env vars
        allowed_users_env="MY_PLATFORM_ALLOWED_USERS",
        allow_all_env="MY_PLATFORM_ALLOW_ALL_USERS",
        # Message length limit for smart chunking (0 = no limit)
        max_message_length=4000,
        # LLM guidance injected into system prompt
        platform_hint=(
            "You are chatting via My Platform. "
            "It supports markdown formatting."
        ),
        # Display
        emoji="💬",
    )

    # Optional: register platform-specific tools
    ctx.register_tool(
        name="my_platform_search",
        toolset="my_platform",
        schema={...},
        handler=my_search_handler,
    )
```

### Configuration

Users configure the platform in `config.yaml`:

```yaml
gateway:
  platforms:
    my_platform:
      enabled: true
      extra:
        token: "..."
        channel: "#general"
```

Or via environment variables (which the adapter reads in `__init__`).

### What the Plugin System Handles Automatically

When you call `ctx.register_platform()`, the following integration points are handled for you — no core code changes needed:

| Integration point | How it works |
|---|---|
| Gateway adapter creation | Registry checked before built-in if/elif chain |
| Config parsing | `Platform._missing_()` accepts any platform name |
| Connected platform validation | Registry `validate_config()` called |
| User authorization | `allowed_users_env` / `allow_all_env` checked |
| Env-only auto-enable | `env_enablement_fn` seeds `PlatformConfig.extra` + `home_channel` |
| Cron delivery | `cron_deliver_env_var` makes `deliver=<name>` work |
| `hermes config` UI entries | `requires_env` / `optional_env` in `plugin.yaml` auto-populate |
| send_message tool | Routes through live gateway adapter |
| Webhook cross-platform delivery | Registry checked for known platforms |
| `/update` command access | `allow_update_command` flag |
| Channel directory | Plugin platforms included in enumeration |
| System prompt hints | `platform_hint` injected into LLM context |
| Message chunking | `max_message_length` for smart splitting |
| PII redaction | `pii_safe` flag |
| `hermes status` | Shows plugin platforms with `(plugin)` tag |
| `hermes gateway setup` | Plugin platforms appear in setup menu |
| `hermes tools` / `hermes skills` | Plugin platforms in per-platform config |
| Token lock (multi-profile) | Use `acquire_scoped_lock()` in your `connect()` |
| Orphaned config warning | Descriptive log when plugin is missing |

## Env-Driven Auto-Configuration

Most users set up a platform by dropping env vars into `~/.hermes/.env` rather than editing `config.yaml`. The `env_enablement_fn` hook lets your plugin pick those env vars up **before** the adapter is constructed, so `hermes gateway status`, `get_connected_platforms()`, and cron delivery see the correct state without instantiating the platform SDK.

```python
def _env_enablement() -> dict | None:
    """Seed PlatformConfig.extra from env vars.

    Called by the platform registry during load_gateway_config().
    Return None when the platform isn't minimally configured — the
    caller then skips auto-enabling. Return a dict to seed extras.

    The special 'home_channel' key is extracted and becomes a proper
    HomeChannel dataclass on the PlatformConfig; every other key is
    merged into PlatformConfig.extra.
    """
    token = os.getenv("MY_PLATFORM_TOKEN", "").strip()
    channel = os.getenv("MY_PLATFORM_CHANNEL", "").strip()
    if not (token and channel):
        return None
    seed = {"token": token, "channel": channel}
    home = os.getenv("MY_PLATFORM_HOME_CHANNEL")
    if home:
        seed["home_channel"] = {
            "chat_id": home,
            "name": os.getenv("MY_PLATFORM_HOME_CHANNEL_NAME", "Home"),
        }
    return seed


def register(ctx):
    ctx.register_platform(
        name="my_platform",
        label="My Platform",
        adapter_factory=lambda cfg: MyPlatformAdapter(cfg),
        check_fn=check_requirements,
        validate_config=validate_config,
        env_enablement_fn=_env_enablement,
        # ... other fields
    )
```

## Cron Delivery

To let `deliver=my_platform` cron jobs route to a configured home channel, set `cron_deliver_env_var` to the env var name that holds the default chat/room/channel ID:

```python
ctx.register_platform(
    name="my_platform",
    ...
    cron_deliver_env_var="MY_PLATFORM_HOME_CHANNEL",
)
```

The scheduler reads this env var when resolving the home target for `deliver=my_platform` jobs, and also treats the platform as a valid cron target in `_KNOWN_DELIVERY_PLATFORMS`-style checks. If your `env_enablement_fn` seeds a `home_channel` dict (see above), that takes precedence — `cron_deliver_env_var` is the fallback for cron jobs that run before env seeding.

### Out-of-process cron delivery

`cron_deliver_env_var` makes your platform a recognized `deliver=` target. To make the actual send succeed when the cron job runs in a separate process from the gateway (i.e., `hermes cron run` separate from `hermes gateway`), register a `standalone_sender_fn`:

```python
async def _standalone_send(
    pconfig,
    chat_id,
    message,
    *,
    thread_id=None,
    media_files=None,
    force_document=False,
):
    """Open an ephemeral connection / acquire a fresh token, send, and close."""
    # ... open connection, send message, return result ...
    return {"success": True, "message_id": "..."}
    # or {"error": "..."}

ctx.register_platform(
    name="my_platform",
    ...
    cron_deliver_env_var="MY_PLATFORM_HOME_CHANNEL",
    standalone_sender_fn=_standalone_send,
)
```

Why this hook is necessary: built-in platforms (Telegram, Discord, Slack, etc.) ship direct REST helpers in `tools/send_message_tool.py` so cron can deliver without holding the gateway in the same process. Plugin platforms historically depended on `_gateway_runner_ref()`, which returns `None` outside the gateway process, so without `standalone_sender_fn` the cron-side send fails with `No live adapter for platform '<name>'`.

The function receives the same `pconfig` and `chat_id` that the live adapter would, plus optional `thread_id`, `media_files`, and `force_document` keyword arguments. Returning `{"success": True, "message_id": ...}` is treated as a successful delivery; returning `{"error": "..."}` surfaces the message in cron's `delivery_errors`. Exceptions raised inside the function are caught by the dispatcher and reported as `Plugin standalone send failed: <reason>`. Reference implementations live in `plugins/platforms/{irc,teams,google_chat}/adapter.py`.

## Surfacing Env Vars in `hermes config`

`hermes_cli/config.py` scans `plugins/platforms/*/plugin.yaml` at import time and auto-populates `OPTIONAL_ENV_VARS` from `requires_env` and (optional) `optional_env` blocks. Use the rich-dict form to contribute proper descriptions, prompts, password flags, and URLs — the CLI setup UI picks them up for free.

```yaml
# plugins/platforms/my_platform/plugin.yaml
name: my_platform-platform
label: My Platform
kind: platform
version: 1.0.0
description: >
  My Platform gateway adapter for Hermes Agent.
author: Your Name
requires_env:
  - name: MY_PLATFORM_TOKEN
    description: "Bot API token from the My Platform console"
    prompt: "My Platform bot token"
    url: "https://my-platform.example.com/bots"
    password: true
  - name: MY_PLATFORM_CHANNEL
    description: "Channel to join (e.g. #hermes)"
    prompt: "Channel"
    password: false
optional_env:
  - name: MY_PLATFORM_HOME_CHANNEL
    description: "Default channel for cron delivery (defaults to MY_PLATFORM_CHANNEL)"
    prompt: "Home channel (or empty)"
    password: false
  - name: MY_PLATFORM_ALLOWED_USERS
    description: "Comma-separated user IDs allowed to talk to the bot"
    prompt: "Allowed users (comma-separated)"
    password: false
```

**Supported dict keys:** `name` (required), `description`, `prompt`, `url`, `password` (bool; auto-detected from `*_TOKEN` / `*_SECRET` / `*_KEY` / `*_PASSWORD` / `*_JSON` suffix when omitted), `category` (defaults to `"messaging"`).

Bare-string entries (`- MY_PLATFORM_TOKEN`) still work — they get a generic description auto-derived from the plugin's `label`. If a hardcoded entry for the same var already exists in `OPTIONAL_ENV_VARS`, it wins (back-compat); the plugin.yaml form acts as the fallback.

### Reference Implementation

See `plugins/platforms/irc/` in the repo for a complete working example — a full async IRC adapter with zero external dependencies.

---

## Step-by-Step Checklist (Built-in Path)

:::note
This checklist is for adding a platform directly to the Hermes core codebase — typically done by core contributors for officially supported platforms. Community/third-party platforms should use the [Plugin Path](#plugin-path-recommended) above.
:::

### 1. Platform Enum

Add your platform to the `Platform` enum in `gateway/config.py`:

```python
class Platform(str, Enum):
    # ... existing platforms ...
    NEWPLAT = "newplat"
```

### 2. Adapter File

Create `gateway/platforms/newplat.py`:

```python
from gateway.config import Platform, PlatformConfig
from gateway.platforms.base import (
    BasePlatformAdapter, MessageEvent, MessageType, SendResult,
)

def check_newplat_requirements() -> bool:
    """Return True if dependencies are available."""
    return SOME_SDK_AVAILABLE

class NewPlatAdapter(BasePlatformAdapter):
    def __init__(self, config: PlatformConfig):
        super().__init__(config, Platform.NEWPLAT)
        # Read config from config.extra dict
        extra = config.extra or {}
        self._api_key = extra.get("api_key") or os.getenv("NEWPLAT_API_KEY", "")

    async def connect(self) -> bool:
        # Set up connection, start polling/webhook
        self._mark_connected()
        return True

    async def disconnect(self) -> None:
        self._running = False
        self._mark_disconnected()

    async def send(self, chat_id, content, reply_to=None, metadata=None):
        # Send message via platform API
        return SendResult(success=True, message_id="...")

    async def get_chat_info(self, chat_id):
        return {"name": chat_id, "type": "dm"}
```

For inbound messages, build a `MessageEvent` and call `self.handle_message(event)`:

```python
source = self.build_source(
    chat_id=chat_id,
    chat_name=name,
    chat_type="dm",  # or "group"
    user_id=user_id,
    user_name=user_name,
)
event = MessageEvent(
    text=content,
    message_type=MessageType.TEXT,
    source=source,
    message_id=msg_id,
)
await self.handle_message(event)
```

### 3. Gateway Config (`gateway/config.py`)

Three touchpoints:

1. **`get_connected_platforms()`** — Add a check for your platform's required credentials
2. **`load_gateway_config()`** — Add token env map entry: `Platform.NEWPLAT: "NEWPLAT_TOKEN"`
3. **`_apply_env_overrides()`** — Map all `NEWPLAT_*` env vars to config

### 4. Gateway Runner (`gateway/run.py`)

Five touchpoints:

1. **`_create_adapter()`** — Add an `elif platform == Platform.NEWPLAT:` branch
2. **`_is_user_authorized()` allowed_users map** — `Platform.NEWPLAT: "NEWPLAT_ALLOWED_USERS"`
3. **`_is_user_authorized()` allow_all map** — `Platform.NEWPLAT: "NEWPLAT_ALLOW_ALL_USERS"`
4. **Early env check `_any_allowlist` tuple** — Add `"NEWPLAT_ALLOWED_USERS"`
5. **Early env check `_allow_all` tuple** — Add `"NEWPLAT_ALLOW_ALL_USERS"`
6. **`_UPDATE_ALLOWED_PLATFORMS` frozenset** — Add `Platform.NEWPLAT`

### 5. Cross-Platform Delivery

1. **`gateway/platforms/webhook.py`** — Add `"newplat"` to the delivery type tuple
2. **`cron/scheduler.py`** — Add to `_KNOWN_DELIVERY_PLATFORMS` frozenset and `_deliver_result()` platform map

### 6. CLI Integration

1. **`hermes_cli/config.py`** — Add all `NEWPLAT_*` vars to `_EXTRA_ENV_KEYS`
2. **`hermes_cli/gateway.py`** — Add entry to `_PLATFORMS` list with key, label, emoji, token_var, setup_instructions, and vars
3. **`hermes_cli/platforms.py`** — Add `PlatformInfo` entry with label and default_toolset (used by `skills_config` and `tools_config` TUIs)
4. **`hermes_cli/setup.py`** — Add `_setup_newplat()` function (can delegate to `gateway.py`) and add tuple to the messaging platforms list
5. **`hermes_cli/status.py`** — Add platform detection entry: `"NewPlat": ("NEWPLAT_TOKEN", "NEWPLAT_HOME_CHANNEL")`
6. **`hermes_cli/dump.py`** — Add `"newplat": "NEWPLAT_TOKEN"` to platform detection dict

### 7. Tools

1. **`tools/send_message_tool.py`** — Add `"newplat": Platform.NEWPLAT` to platform map
2. **`tools/cronjob_tools.py`** — Add `newplat` to the delivery target description string

### 8. Toolsets

1. **`toolsets.py`** — Add `"hermes-newplat"` toolset definition with `_HERMES_CORE_TOOLS`
2. **`toolsets.py`** — Add `"hermes-newplat"` to the `"hermes-gateway"` includes list

### 9. Optional: Platform Hints

**`agent/prompt_builder.py`** — If your platform has specific rendering limitations (no markdown, message length limits, etc.), add an entry to the `_PLATFORM_HINTS` dict. This injects platform-specific guidance into the system prompt:

```python
_PLATFORM_HINTS = {
    # ...
    "newplat": (
        "You are chatting via NewPlat. It supports markdown formatting "
        "but has a 4000-character message limit."
    ),
}
```

Not all platforms need hints — only add one if the agent's behavior should differ.

### 10. Tests

Create `tests/gateway/test_newplat.py` covering:

- Adapter construction from config
- Message event building
- Send method (mock the external API)
- Platform-specific features (encryption, routing, etc.)

### 11. Documentation

| File | What to add |
|------|-------------|
| `website/docs/user-guide/messaging/newplat.md` | Full platform setup page |
| `website/docs/user-guide/messaging/index.md` | Platform comparison table, architecture diagram, toolsets table, security section, next-steps link |
| `website/docs/reference/environment-variables.md` | All NEWPLAT_* env vars |
| `website/docs/reference/toolsets-reference.md` | hermes-newplat toolset |
| `website/docs/integrations/index.md` | Platform link |
| `website/sidebars.ts` | Sidebar entry for the docs page |
| `website/docs/developer-guide/architecture.md` | Adapter count + listing |
| `website/docs/developer-guide/gateway-internals.md` | Adapter file listing |

## Parity Audit

Before marking a new platform PR as complete, run a parity audit against an established platform:

```bash
# Find every .py file mentioning the reference platform
search_files "bluebubbles" output_mode="files_only" file_glob="*.py"

# Find every .py file mentioning the new platform
search_files "newplat" output_mode="files_only" file_glob="*.py"

# Any file in the first set but not the second is a potential gap
```

Repeat for `.md` and `.ts` files. Investigate each gap — is it a platform enumeration (needs updating) or a platform-specific reference (skip)?

## Common Patterns

### Long-Poll Adapters

If your adapter uses long-polling (like Telegram or Weixin), use a polling loop task:

```python
async def connect(self):
    self._poll_task = asyncio.create_task(self._poll_loop())
    self._mark_connected()

async def _poll_loop(self):
    while self._running:
        messages = await self._fetch_updates()
        for msg in messages:
            await self.handle_message(self._build_event(msg))
```

### Callback/Webhook Adapters

If the platform pushes messages to your endpoint (like WeCom Callback), run an HTTP server:

```python
async def connect(self):
    self._app = web.Application()
    self._app.router.add_post("/callback", self._handle_callback)
    # ... start aiohttp server
    self._mark_connected()

async def _handle_callback(self, request):
    event = self._build_event(await request.text())
    await self._message_queue.put(event)
    return web.Response(text="success")  # Acknowledge immediately
```

For platforms with tight response deadlines (e.g., WeCom's 5-second limit), always acknowledge immediately and deliver the agent's reply proactively via API later. Agent sessions run 3–30 minutes — inline replies within a callback response window are not feasible.

### Token Locks

If the adapter holds a persistent connection with a unique credential, add a scoped lock to prevent two profiles from using the same credential:

```python
from gateway.status import acquire_scoped_lock, release_scoped_lock

async def connect(self):
    if not acquire_scoped_lock("newplat", self._token):
        logger.error("Token already in use by another profile")
        return False
    # ... connect

async def disconnect(self):
    release_scoped_lock("newplat", self._token)
```

## Reference Implementations

| Adapter | Pattern | Complexity | Good reference for |
|---------|---------|------------|-------------------|
| `bluebubbles.py` | REST + webhook | Medium | Simple REST API integration |
| `weixin.py` | Long-poll + CDN | High | Media handling, encryption |
| `wecom_callback.py` | Callback/webhook | Medium | HTTP server, AES crypto, multi-app |
| `telegram.py` | Long-poll + Bot API | High | Full-featured adapter with groups, threads |