Slack Extended

Extends the core slack skill with file uploads and canvas management. Uses Python scripts that call the Slack API directly with the bot token from ~/.openclaw/openclaw.json.

Requires OAuth scopes: files:write, canvases:write (add at api.slack.com if missing).

File Upload

Upload a local file to a Slack channel:

python3 /mnt/openclaw/skills/slack-extended/scripts/slack_file_upload.py \
  --channel C123ABC \
  --file /path/to/file.png \
  --title "Q4 Report" \
  --message "Here's the latest report"

Arguments:

• --channel (required): Channel ID to share the file in
• --file (required): Path to the local file
• --title: Display title (defaults to filename)
• --message: Comment posted with the file

Returns JSON with file_id, permalink, and channel.

Common patterns:

• Share a generated chart: --file /tmp/chart.png --title "Performance Chart"
• Share a text file: --file ./notes.txt --title "Meeting Notes"
• Share with context: --message "Backtest results for GEM v2" --file results.csv

Canvas Operations

Manage Slack canvases (collaborative documents):

Create a canvas

python3 /mnt/openclaw/skills/slack-extended/scripts/slack_canvas.py create \
  --title "Sprint Notes" \
  --markdown "## Goals\n- Ship feature X\n- Fix bug Y"

Edit a canvas

Append content:

python3 /mnt/openclaw/skills/slack-extended/scripts/slack_canvas.py edit \
  --canvas-id F07ABCD1234 \
  --operation insert_at_end \
  --markdown "## Update\nNew section added"

Replace a section:

python3 /mnt/openclaw/skills/slack-extended/scripts/slack_canvas.py edit \
  --canvas-id F07ABCD1234 \
  --section-id temp:C:abc123 \
  --operation replace \
  --markdown "## Revised Section\nUpdated content"

Operations: insert_at_start, insert_at_end, insert_after, replace, delete

Look up sections

python3 /mnt/openclaw/skills/slack-extended/scripts/slack_canvas.py sections \
  --canvas-id F07ABCD1234

Delete a canvas

python3 /mnt/openclaw/skills/slack-extended/scripts/slack_canvas.py delete \
  --canvas-id F07ABCD1234

Set access

python3 /mnt/openclaw/skills/slack-extended/scripts/slack_canvas.py access \
  --canvas-id F07ABCD1234 \
  --channel C123ABC \
  --level edit

Canvas Markdown

Canvases support: bold, italic, strikethrough, headings (h1-h3), bulleted/ordered lists, checklists, code blocks, code spans, links, tables (max 300 cells), blockquotes, dividers, emojis.

Mentions: ![](@USER_ID) for users, ![](#CHANNEL_ID) for channels.

Bookmarks

Manage link bookmarks in the bookmark bar at the top of Slack channels.

Limitation: Slack API only supports link bookmarks. Folders are a UI-only feature and cannot be created via the API.

Requires OAuth scopes: bookmarks:write, bookmarks:read

List bookmarks

python3 /mnt/openclaw/skills/slack-extended/scripts/slack_bookmark.py list \
  --channel C123ABC

Add a link bookmark

python3 /mnt/openclaw/skills/slack-extended/scripts/slack_bookmark.py add \
  --channel C123ABC \
  --title "Design Docs" \
  --link "https://example.com" \
  --emoji ":link:"

Edit a bookmark

python3 /mnt/openclaw/skills/slack-extended/scripts/slack_bookmark.py edit \
  --channel C123ABC \
  --bookmark-id Bk123 \
  --title "New Title"

Remove a bookmark

python3 /mnt/openclaw/skills/slack-extended/scripts/slack_bookmark.py remove \
  --channel C123ABC \
  --bookmark-id Bk123

Troubleshooting

• missing_scope error: Add the required scope (files:write or canvases:write) at api.slack.com, then reinstall the app to the workspace.
• channel_not_found: Use the channel ID (e.g. C07ABC123), not the channel name.
• not_authed: Bot token may have changed. Check ~/.openclaw/openclaw.json.
• Canvas edit fails: Look up sections first to get valid section_id values.
• missing_scope for bookmarks: Add bookmarks:write and bookmarks:read at api.slack.com, then reinstall.
• Folders not supported: Slack API does not support creating folders — only link bookmarks. Folders can only be created manually in the Slack UI.