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---
name: slack-channel-monitor
description: >
This skill should be used when the user asks to "monitor a Slack channel",
"watch Slack for messages", "create a Slack bot that responds to mentions",
"set up an OpenHands Slack integration", "trigger OpenHands from Slack",
"respond to @openhands in Slack", or "poll Slack channels for a trigger
phrase". Guides the user through creating a cron automation that watches up
to 10 Slack channels and starts an OpenHands conversation whenever a
configurable trigger phrase is detected.
triggers:
- /slack-monitor:poll
---
# Slack Channel Monitor
Create a cron automation that polls up to 10 Slack channels every minute.
Windows PowerShell equivalents for the setup, packaging, upload, and API-check shell snippets are in `references/windows.md`.
When a message containing the **trigger phrase** (default: `@openhands`) is
detected it:
1. Adds a ๐ reaction to the triggering message.
2. Opens an OpenHands conversation with the message and recent channel context.
3. Posts a reply in the Slack thread with a link to the conversation.
On every subsequent run:
- New Slack thread replies are forwarded only when they contain the trigger
phrase, so unrelated conversation in the thread is ignored.
- When the conversation finishes (or errors), the agent's final response is
posted back to the Slack thread.
- Completed conversations stay in a short follow-up watch window, allowing
triggered Slack replies to continue the same OpenHands conversation.
> **Local mode only.** This automation targets the local OpenHands setup
> (`dev:automation` stack). A cloud/webhook-based variant is out of scope here.
---
## Prerequisites
### Required secrets
Verify that at least one of the following secrets is set in
**OpenHands Settings โ Secrets** before proceeding:
| Secret name | Token type | Minimum scopes |
|---|---|---|
| `SLACK_BOT_TOKEN` | Bot (`xoxb-โฆ`) | `channels:history`, `channels:read`, `reactions:write`, `chat:write` |
| `SLACK_USER_TOKEN` | User (`xoxp-โฆ`) | Same as bot, plus `search:read` for multi-channel efficiency |
Check with:
```bash
# For bot token:
curl -s https://slack.com/api/auth.test -H "Authorization: Bearer $SLACK_BOT_TOKEN" \
| python3 -c "import json,sys; d=json.load(sys.stdin); print('ok' if d.get('ok') else d.get('error'))"
# For user token:
curl -s https://slack.com/api/auth.test -H "Authorization: Bearer $SLACK_USER_TOKEN" \
| python3 -c "import json,sys; d=json.load(sys.stdin); print('ok' if d.get('ok') else d.get('error'))"
```
If neither token is present, inform the user and stop - the automation cannot
function without Slack credentials.
### Optional secret
| Secret name | Default | Purpose |
|---|---|---|
| `OPENHANDS_URL` | `http://localhost:8000` | Base URL used to build conversation links posted in Slack |
---
## Setup Workflow
Follow these steps in order.
### Step 1 - Collect channels
Ask the user: *"Which Slack channels should be monitored? You can provide
channel names (e.g. `#general`) or IDs (e.g. `C0123456789`)."*
**If the user provides channel names**, resolve them to IDs:
```bash
SLACK_TOKEN="${SLACK_BOT_TOKEN:-$SLACK_USER_TOKEN}"
curl -s "https://slack.com/api/conversations.list?types=public_channel,private_channel&limit=200&exclude_archived=true" \
-H "Authorization: Bearer $SLACK_TOKEN" \
| python3 -c "
import json, sys
data = json.load(sys.stdin)
if not data.get('ok'):
print('ERROR:', data.get('error'))
exit(1)
names = set(n.lstrip('#') for n in ['CHANNEL_NAMES_HERE'.split(',')])
for ch in data.get('channels', []):
if ch['name'] in names:
print(f\"{ch['name']} โ {ch['id']}\")
"
```
Replace `CHANNEL_NAMES_HERE` with the comma-separated names the user provided.
**If `conversations.list` returns `missing_scope` or `not_authed`:**
Inform the user: *"The token doesn't have permission to list channels. Please
provide the channel IDs directly (right-click a channel in Slack โ Copy link -
the last path segment starting with `C` is the ID)."*
**If the bot token lacks `channels:read`** for private channels, the user can
either invite the bot first (`/invite @botname`) or switch to a user token.
Collect up to 10 channel IDs. Record them as a Python list literal, e.g.:
```python
["C0123456789", "C9876543210"]
```
### Step 2 - Collect trigger phrase
Ask the user: *"What trigger phrase should OpenHands respond to?
(Press Enter to use the default: `@openhands`)"*
Accepted values: any non-empty string unlikely to appear accidentally, e.g.
`@openhands`, `jazz hands`, `take-me-to-funky-town`.
### Step 3 - Generate the automation script
Read `scripts/main.py` from this skill's directory and **copy it verbatim**.
Apply exactly three constant substitutions near the top of the file:
> **Do not reimplement, simplify, or hand-write a replacement script.**
> The template already contains the correct secret-loading, state-path,
> conversation-creation, and context-forwarding logic. Only the three
> configuration constants below should change unless syntax validation fails.
| Placeholder | Replace with |
|---|---|
| `TRIGGER_PHRASE = "@openhands"` | `TRIGGER_PHRASE = "{user_phrase}"` |
| `CHANNEL_IDS: list[str] = []` | `CHANNEL_IDS: list[str] = {channel_id_list}` |
| `DEFAULT_OPENHANDS_URL = "http://localhost:8000"` | `DEFAULT_OPENHANDS_URL = "{url}"` (keep default if user has no preference) |
Write the customised script to a temporary directory:
```bash
mkdir -p /tmp/slack-monitor-build
# copy scripts/main.py to /tmp/slack-monitor-build/main.py
# then replace only the three constants above
```
Validate syntax before packaging:
```bash
python3 -m py_compile /tmp/slack-monitor-build/main.py && echo "Syntax OK"
```
Then run a quick integrity check to confirm the template structure is still
present and only the configuration block was customised:
```bash
grep -n 'TRIGGER_PHRASE = "' /tmp/slack-monitor-build/main.py
grep -n 'CHANNEL_IDS: list\[str\] =' /tmp/slack-monitor-build/main.py
grep -n 'DEFAULT_OPENHANDS_URL = "' /tmp/slack-monitor-build/main.py
grep -n 'def get_secret' /tmp/slack-monitor-build/main.py
grep -n 'def _state_file_path' /tmp/slack-monitor-build/main.py
grep -n 'def create_conversation' /tmp/slack-monitor-build/main.py
```
If any of those checks fail, stop and re-copy the template instead of trying to
repair a hand-written variant.
### Step 4 - Package and upload
Determine the Automation backend URL and auth from the `<RUNTIME_SERVICES>`
block in your system context:
- Use the **Automation backend** `url_from_agent` as `OPENHANDS_HOST`
- Auth: `X-Session-API-Key: $OPENHANDS_AUTOMATION_API_KEY`
If no Automation backend is listed in `<RUNTIME_SERVICES>`, stop and tell
the user to start the full automation stack.
```bash
tar -czf /tmp/slack-monitor.tar.gz -C /tmp/slack-monitor-build .
# OPENHANDS_HOST: read from <RUNTIME_SERVICES> Automation backend url_from_agent
OPENHANDS_HOST="<automation-url-from-runtime-services>"
TARBALL_PATH=$(curl -s -X POST \
"${OPENHANDS_HOST}/api/automation/v1/uploads?name=slack-channel-monitor" \
-H "X-Session-API-Key: $OPENHANDS_AUTOMATION_API_KEY" \
-H "Content-Type: application/gzip" \
--data-binary @/tmp/slack-monitor.tar.gz \
| python3 -c "import json,sys; print(json.load(sys.stdin)['tarball_path'])")
echo "Uploaded: $TARBALL_PATH"
```
If the upload fails with a size error, the tarball must be under 1 MB.
`main.py` is under 15 KB so this should never trigger.
### Step 5 - Create the automation
```bash
curl -s -X POST "${OPENHANDS_HOST}/api/automation/v1" \
-H "X-Session-API-Key: $OPENHANDS_AUTOMATION_API_KEY" \
-H "Content-Type: application/json" \
-d "{
\"name\": \"Slack Channel Monitor\",
\"trigger\": {\"type\": \"cron\", \"schedule\": \"* * * * *\"},
\"tarball_path\": \"$TARBALL_PATH\",
\"entrypoint\": \"python3 main.py\",
\"timeout\": 55
}" | python3 -m json.tool
```
A 55-second timeout keeps runs well within the 60-second cron window.
Record the returned `id` - share it with the user as confirmation.
### Step 6 - Confirm
Tell the user:
> โ
**Slack Channel Monitor** is running!
>
> - Automation ID: `{id}`
> - Channels: `{channel list}`
> - Trigger phrase: `{phrase}`
> - Polling every minute via cron `* * * * *`
> - State file: `~/.openhands/workspaces/automation-state/slack_poller_{id}.json`
>
> Send a message containing `{phrase}` in any monitored channel to test it.
> The bot will react with ๐ and reply with a link to the new conversation.
---
## Runtime Behaviour (per poll)
Each cron run executes `main.py`, which runs **10 polling iterations** (every
5 seconds) within the 55-second timeout window. Each iteration:
1. **Loads state** from the JSON file (see `references/state-schema.md`).
2. **Resolves the Slack token** - checks `SLACK_USER_TOKEN` then `SLACK_BOT_TOKEN`.
3. **Fetches new messages:**
- User token + `search:read` + > 1 channel โ single `search.messages` call
(searches for the trigger phrase across all channels).
- Otherwise โ one `conversations.history` call per channel.
4. **Fetches due thread replies** - polls at most one tracked thread per
iteration using per-thread exponential backoff to stay within Slack rate
limits.
5. **Processes messages** in chronological order:
- Skips messages already in `processed_ts` (dedup across the overlap window).
- Skips bot messages and any `ts` in `bot_message_ts`.
- Reply in a tracked thread whose text contains the trigger phrase โ forwards
a follow-up request to the existing conversation and resets the follow-up
watch window. Replies without the trigger phrase are marked processed and
ignored.
- Contains trigger phrase outside a tracked conversation โ ๐ reaction, create
a new conversation, post link.
- Thread replies: agent receives full thread history for context.
- Root messages: agent receives the trigger text only.
6. **Checks conversation statuses** - for each active conversation where
`time.time() - last_activity > 15 s`:
- If status is `idle`, `finished`, `error`, or `stuck` โ fetch the agent's
final response via `/api/conversations/{id}/agent_final_response` and post
it to the Slack thread using Slack's `markdown_text` field so Markdown
formatting renders correctly. Mark the record `watching` for five minutes
so triggered follow-up replies can continue the same conversation.
7. **Advances `last_poll`** to `now - 10 s` (overlap window prevents boundary
races). If a conversation creation failed, pins `last_poll` further back to
retry on the next iteration.
8. **Saves state** (including `processed_ts`) and continues to the next iteration.
9. After all iterations, fires the completion callback.
Debug output is written to both stdout and a persistent log at:
```
{WORKSPACE_BASE_ROOT}/automation-state/slack_poller_debug.log
```
---
## Additional Resources
### Reference Files
- **`references/slack-api.md`** - Slack token types, required scopes, API
endpoint reference, rate limits, and common error codes.
- **`references/state-schema.md`** - State JSON schema, field definitions,
example file, and conversation lifecycle diagram.
### Script Template
- **`scripts/main.py`** - The complete automation script. Customise the three
constants at the top (`TRIGGER_PHRASE`, `CHANNEL_IDS`, `DEFAULT_OPENHANDS_URL`)
before packaging.
---
## Troubleshooting
| Symptom | Likely cause | Fix |
|---|---|---|
| Bot doesn't react to messages | Token missing or bot not in channel | Verify token with `auth.test`; `/invite @botname` |
| `not_in_channel` error in run logs | Bot token used but bot not a member | Invite bot or switch to user token |
| `missing_scope` error | Token lacks required scopes | Re-install Slack app with correct scopes (see `references/slack-api.md`) |
| No messages detected | `last_poll` timestamp is in the future | Delete the state file to reset; it will be recreated on next run |
| Conversation link 404 | `OPENHANDS_URL` points to wrong host | Set the `OPENHANDS_URL` secret to the correct base URL |
| Summary never posted | Conversation stuck in `running` state | Check conversation in the OpenHands UI; the agent may need intervention |
| Duplicate conversations created | `processed_ts` state missing or corrupted | Delete the state file to reset; dedup will rebuild on next run |
| Trigger message processed on each cron run | State file deleted between runs | Ensure `automation-state/` directory is persistent across runs |
| Debug info needed | Need detailed per-message trace | Check `{WORKSPACE_BASE_ROOT}/automation-state/slack_poller_debug.log` |