# Direct Slack Bot Development for Devs

Design doc for the "direct to Slack" dev path, bypassing Matrix/maubot.

## Overview

Devs write Python bots using `slack-bolt` that connect directly to Slack via Socket Mode. No Matrix, no bridge, no maubot.

```
┌─────────────────────────────────────────┐
│ VPS (ops-jrz1)                          │
│                                         │
│  alice's bot.py ──┐                     │
│  bob's bot.py ────┼── Socket Mode ─────────► Slack API
│  carol's bot.py ──┘    (WebSocket)      │
│                                         │
└─────────────────────────────────────────┘
```

## Current Setup

### Credentials

Shared Slack App tokens stored in `/etc/slack-dev.env`:

| Variable | Purpose |
|----------|---------|
| `SLACK_BOT_TOKEN` | Bot identity (xoxb-...) |
| `SLACK_APP_TOKEN` | Socket Mode connection (xapp-...) |

These come from the existing mautrix-slack bridge login (Chochacho workspace, vlad's account).

### Access Control

- File owned by `root:devs`, mode `640`
- Dev users added to `devs` group on creation
- `.bashrc` sources the env file on login

### Scripts

```
/usr/local/bin/dev-add.sh <username> '<ssh-pubkey>'
/usr/local/bin/dev-remove.sh <username> [--archive]
```

## Dev Workflow

### 1. Get Access

Send SSH pubkey to admin. Admin runs:
```bash
ssh root@ops-jrz1 'dev-add.sh alice "ssh-ed25519 AAAA..."'
```

### 2. Connect

```bash
ssh alice@<server-ip>
```

Tokens are available immediately:
```bash
echo $SLACK_BOT_TOKEN  # xoxb-...
echo $SLACK_APP_TOKEN  # xapp-...
```

### 3. Write a Bot

```python
# ~/bot.py
from slack_bolt import App
from slack_bolt.adapter.socket_mode import SocketModeHandler
import os

app = App(token=os.environ["SLACK_BOT_TOKEN"])

@app.message("hello")
def hello(message, say):
    say(f"Hey <@{message['user']}>!")

@app.message("dice")
def dice(message, say):
    import random
    say(f"🎲 You rolled a {random.randint(1, 6)}!")

if __name__ == "__main__":
    print("Bot starting...")
    SocketModeHandler(app, os.environ["SLACK_APP_TOKEN"]).start()
```

### 4. Run It

```bash
pip install slack-bolt
python bot.py
```

Bot responds to "hello" and "dice" in Slack.

## slack-bolt Basics

### Event Handlers

```python
# Match exact text
@app.message("hello")
def handle_hello(message, say):
    say("Hello!")

# Match regex
@app.message(re.compile(r"^roll (\d+)d(\d+)"))
def handle_roll(message, say, context):
    # context["matches"] contains regex groups
    pass

# Match any message
@app.event("message")
def handle_all(event, say):
    pass

# React to app mentions (@bot)
@app.event("app_mention")
def handle_mention(event, say):
    say("You mentioned me!")
```

### Slash Commands

Requires additional Slack App config (not set up yet):
```python
@app.command("/mycommand")
def handle_command(ack, respond, command):
    ack()  # Must acknowledge within 3 seconds
    respond(f"You said: {command['text']}")
```

### Sending Messages

```python
# Reply in thread
say("Reply!", thread_ts=message["ts"])

# Send to specific channel
app.client.chat_postMessage(channel="C1234567", text="Hello")

# Rich formatting (blocks)
say(blocks=[
    {"type": "section", "text": {"type": "mrkdwn", "text": "*Bold* and _italic_"}}
])
```

## Tradeoffs

### vs Maubot/Matrix Path

| Aspect | Direct Slack | Maubot/Matrix |
|--------|--------------|---------------|
| **Setup complexity** | Lower - just Python | Higher - Matrix + bridge + maubot |
| **Feedback loop** | Fast - direct to Slack | Slower - goes through bridge |
| **Mental model** | Simple - just Slack | Complex - Matrix concepts |
| **Documentation** | Excellent (Bolt is popular) | Sparse (maubot is niche) |
| **Process management** | Manual (you run it) | Managed (maubot lifecycle) |
| **Bot identity** | Shared (all bots = same user) | Per-instance configurable |
| **Crash recovery** | Manual restart | Auto-managed |
| **Production path** | Direct - same code works | Need to rewrite for Slack-only |

### Risks

1. **Shared tokens** - All devs use same bot identity
2. **Token exposure** - If leaked, affects everyone
3. **Rate limits** - Shared across all bots
4. **Process sprawl** - N devs = N processes to manage
5. **No guardrails** - Bad code can spam/crash easily

### Mitigations

- Dedicated test channel in Slack
- Supervisor/systemd for process management (not yet set up)
- Tokens in env vars, not code
- Can rotate tokens if leaked (re-login bridge)

## Future Improvements

### Process Management

Options:
1. **systemd user services** - Each dev manages their own
2. **supervisor** - Central process manager
3. **tmux/screen** - Manual but simple
4. **Container per dev** - Isolation but complex

### Starter Template

Create `~/slack-bot-template/` with:
- `bot.py` - Hello world
- `requirements.txt` - slack-bolt pinned
- `Makefile` - run, install targets
- `README.md` - Quick start

### Per-Dev Bot Identity

Create separate Slack App per dev:
- More setup friction
- Full isolation
- Each bot has own name/avatar

### Test Channel

Create `#dev-sandbox` in Slack:
- All dev bots invited
- Safe place to spam
- Doesn't pollute real channels

## References

- [Bolt for Python - Getting Started](https://slack.dev/bolt-python/tutorial/getting-started)
- [Slack API - Socket Mode](https://api.slack.com/apis/connections/socket)
- [Slack API - Events](https://api.slack.com/events)
- [slack-bolt GitHub](https://github.com/slackapi/bolt-python)