slack-send-message

What this skill does

# Slack Send Message Skill

Send Slack messages and DMs as yourself using your authenticated browser session credentials. The target (channel or user) is inferred directly from your prompt — no pre-configuration required.

**Features:**
- ✅ Send messages to channels using `#channel-name`
- ✅ Send DMs to users using `@username`
- ✅ Automatic status verification before sending
- ✅ Integrates with `slack-search-user` for user lookups
- ✅ Supports matching by username, real name, or display name (case-insensitive)

## Usage

When the user asks to send a Slack message, follow these steps:

### Step 0: Verify Slack is configured

ALWAYS check status first. The PLUGIN_ROOT is determined dynamically:

```bash
# Determine plugin root (adjust path based on where you're running from)
PLUGIN_ROOT="$HOME/.claude/plugins/marketplaces/djalmaaraujo-claude-code-plugins/plugins/slack"

STATUS_OUTPUT=$("$PLUGIN_ROOT/skills/slack-status/check.sh")
STATUS_CODE=$(echo "$STATUS_OUTPUT" | cut -d'|' -f1)

if [ "$STATUS_CODE" != "OK" ]; then
  echo "⚠️ Slack is not properly configured"
  echo "Please run: /slack:slack-setup"
  exit 1
fi
```

### Step 1: Extract target and message from prompt

Parse the user's prompt to identify:

- **Target**: Look for channel references like `#channel-name` or user references like `@username`
- **Message**: The content the user wants to send

Examples of target extraction:

- "Send 'hello' to #general" → target: `#general`, message: `hello`
- "Post in slack-ai-testing: build complete" → target: `#slack-ai-testing`, message: `build complete`
- "Message @fulano saying good morning" → target: `@fulano`, message: `good morning`
- "DM @john: are you ready?" → target: `@john`, message: `are you ready?`

### Step 2: Determine if target is a channel or user

Check if the target starts with `@` (user DM) or `#` (channel):

- **If target starts with `@`**: This is a DM, proceed to Step 2a
- **If target starts with `#` or is a plain channel name**: This is a channel, proceed to Step 2b

### Step 2a: For DMs - Find user and send message

When the target is a user (starts with `@`), you need to:

1. **Use the slack-search-user skill** to find the user ID
2. **Open a DM channel** using `conversations.open` API
3. **Send the message** to that channel

Here's the complete flow:

```bash
#!/bin/bash

PLUGIN_ROOT="$HOME/.claude/plugins/marketplaces/djalmaaraujo-claude-code-plugins/plugins/slack"
source "$PLUGIN_ROOT/lib/config.sh"
source "$PLUGIN_ROOT/lib/slack-api.sh"

TARGET_USER="fulano"  # extracted from @fulano
MESSAGE="Your message here"

# Load config
load_config

# Step 1: Use slack-search-user to find the user
# The script outputs debug info to stderr and user ID to stdout
USER_ID=$("$PLUGIN_ROOT/skills/slack-search-user/search-user.sh" "$TARGET_USER")
SEARCH_EXIT_CODE=$?

if [ $SEARCH_EXIT_CODE -ne 0 ] || [ -z "$USER_ID" ]; then
  echo "✗ User not found: $TARGET_USER"
  exit 1
fi

echo "✓ Found user ID: $USER_ID"

# Step 2: Open DM channel
echo "Opening DM channel..."
DM_RESPONSE=$(slack_conversations_open "$USER_ID")

CHANNEL_ID=$(echo "$DM_RESPONSE" | jq -r '.channel.id')

if [ "$CHANNEL_ID" = "null" ] || [ -z "$CHANNEL_ID" ]; then
  echo "✗ Failed to open DM channel"
  exit 1
fi

# Step 3: Send message
echo "Sending message..."
SEND_RESPONSE=$(slack_chat_post_message "$CHANNEL_ID" "$MESSAGE")

if slack_check_response "$SEND_RESPONSE"; then
  echo "✓ Message sent successfully!"
else
  ERROR=$(slack_get_error "$SEND_RESPONSE")
  echo "✗ Error sending message: $ERROR"
  exit 1
fi
```

**Key points:**
- Uses `slack-search-user` script - no inline user search code
- Uses shared API functions from `lib/slack-api.sh`
- Clean and maintainable
- Easy to debug

### Step 2b: For channels - Send directly

When the target is a channel (starts with `#` or is a plain channel name):

```bash
#!/bin/bash

PLUGIN_ROOT="$HOME/.claude/plugins/marketplaces/djalmaaraujo-claude-code-plugins/plugins/slack"
source "$PLUGIN_ROOT/lib/config.sh"
source "$PLUGIN_ROOT/lib/slack-api.sh"

# Remove # prefix if present
CHANNEL_NAME="slack-ai-testing"  # extracted from #slack-ai-testing
MESSAGE="Your message here"

# Load config
load_config

# Send message directly (Slack resolves channel names automatically)
echo "Sending message to #$CHANNEL_NAME..."
SEND_RESPONSE=$(slack_chat_post_message "$CHANNEL_NAME" "$MESSAGE")

if slack_check_response "$SEND_RESPONSE"; then
  echo "✓ Message sent successfully to #$CHANNEL_NAME!"
else
  ERROR=$(slack_get_error "$SEND_RESPONSE")
  echo "✗ Error sending message: $ERROR"
  exit 1
fi
```

**Important**: Pass the channel name directly (e.g., `general`, `slack-ai-testing`). The Slack API accepts both channel names and channel IDs.

### Step 3: Verify the response

The response will be JSON. Check for `"ok": true` to confirm the message was sent successfully.

A successful response looks like:

```json
{
  "ok": true,
  "channel": "C0A7V415BKQ",
  "ts": "1234567890.123456",
  "message": { ... }
}
```

An error response looks like:

```json
{
  "ok": false,
  "error": "channel_not_found"
}
```

## Examples

### Example 1: Channel message

**User prompt:** "Send a message to #slack-ai-testing saying hello from Claude Code"

1. Check Slack status
2. Extract target: `#slack-ai-testing`, message: `hello from Claude Code`
3. Detect it's a channel (starts with `#`)
4. Send message using `slack_chat_post_message`

### Example 2: DM to a user

**User prompt:** "Send a DM to @djalma saying: can you review my PR?"

1. Check Slack status
2. Extract target: `@djalma`, message: `can you review my PR?`
3. Detect it's a user DM (starts with `@`)
4. Search for user "djalma" using `slack-search-user`
5. Get the user ID (e.g., `U01ULLNEM3Q`)
6. Open DM channel using `conversations.open`
7. Get the channel ID (e.g., `D98765XYZ`)
8. Send the message to that channel

## Configuration

This skill uses the centralized Slack plugin configuration at:
```
~/.claude/plugins/marketplaces/djalmaaraujo-claude-code-plugins/plugins/slack/config.json
```

## Integration

This skill integrates with:
- **slack-status** - Validates configuration before sending
- **slack-search-user** - Finds users for DMs
- **lib/config.sh** - Loads shared configuration
- **lib/slack-api.sh** - Uses shared API functions

## Important Notes

- **Automatic validation**: Checks Slack status before every message
- **Channels vs DMs**:
  - **Channels** (starting with `#` or plain names): No channel ID lookup needed
  - **DMs** (starting with `@`): Uses `slack-search-user` to find user, then opens DM channel
- **User search integration**: Delegates all user lookups to `slack-search-user` skill
- **Messages appear as you**: These messages are sent as your authenticated user, not as a bot
- **Requirements**:
  - `jq` is required
  - Python 3.6+ is required
  - Slack plugin must be configured (run `/slack:slack-setup` if needed)

## Troubleshooting

| Error                        | Solution                                                                                                          |
| ---------------------------- | ----------------------------------------------------------------------------------------------------------------- |
| `Slack is not properly configured` | Run `/slack:slack-setup` to configure credentials |
| `invalid_auth`               | Token or cookie expired. Re-run `/slack:slack-setup` |
| `channel_not_found`          | Check the channel name spelling or verify you have access |
| `not_in_channel`             | You need to join the channel first |
| `User 'X' not found`         | The username doesn't exist or doesn't match any name fields |
| DM channel ID is null/empty  | The `conversations.open` response failed. Check user ID validity |