slack

holla is a CLI tool that lets you interact with Slack as yourself (using your user token). All commands require --workspace <name> (or -w).

Prerequisites

Authenticate first: holla slack auth login --workspace <name>

Check status: holla slack auth whoami --workspace <name>

Sending messages

# Send to a channel
holla slack chat send --channel "#general" --text "Hello" -w <ws>

# Reply to a thread
holla slack chat reply --channel "#general" --ts 1234567890.123456 --text "Reply" -w <ws>

# Multiline via stdin
cat <<'EOF' | holla slack chat send --channel "#general" -w <ws>
Line one
Line two
EOF

# Edit a message
holla slack chat edit --channel "#general" --ts 1234567890.123456 --text "Updated" -w <ws>

# Delete a message
holla slack chat delete --channel "#general" --ts 1234567890.123456 -w <ws>

--text accepts standard markdown (converted to Slack blocks automatically). Use --json to get { ts, channel, text } back after sending.

Markdown formatting — READ THIS BEFORE SENDING

⚠️ holla expects STANDARD MARKDOWN, not Slack mrkdwn. holla converts to Slack blocks server-side. Do not pre-convert your text to Slack mrkdwn. A common mistake is "fixing" **bold** to *bold* thinking Slack needs that — this DOUBLE-CONVERTS and the bold disappears.

Rule of thumb: write the text exactly the way you'd write it in a normal Markdown document. Pass it as-is to --text. Do not touch the asterisks.

What you want	Write this	NOT this (common mistake)
Bold	**text**	*text* (renders as italic, or disappears)
Italic	*text* or _text_
Strikethrough	~text~
Link	[text](url)	<url|text> (Slack-native — don't use)

Tilde (~) as range separator: Slack interprets two ~ in the same text as strikethrough (e.g. 70~80% ... 20~30% strikes through everything between them). Use fullwidth tilde ～ (U+FF5E) instead — visually identical, no strikethrough trigger.

Bold adjacent to non-Latin text: **text** followed immediately by CJK characters (e.g. **회사**만) may render as _회사_만 with visible underscores. Add a space after the closing **: **회사** 만.

Mentioning users

Slack requires <@USER_ID> format for mentions — plain names like @john won't notify anyone.

When the user asks you to send a message to a specific person (e.g. "send this to John"), you must mention that person using <@USER_ID> format so they receive a notification. Look up the user ID before drafting the message, and include the mention in the draft shown to the user — not just in the final sent message.

Workflow

1. Look up channel members to find the user ID:

   holla slack channels members --channel "#general" -w <ws> --json
   

2. Find the target by display name or real name and get their user ID (e.g. U01234567)
3. If uncertain about the match, confirm with the user before proceeding
4. If the target is not a channel member, invite them first:

   holla slack channels invite --channel "#general" --user @username -w <ws>
   

5. Use <@USER_ID> in the message text:

   holla slack chat send --channel "#general" --text "Hey <@U01234567>, take a look" -w <ws>
   

--user argument rules

The --user flag uses @ prefix to trigger name lookup. Without @, the value is treated as a raw user ID.

Input	Behavior
--user @name	Looks up by Slack username → resolves to ID
--user U01234567	Used as-is (raw ID)
--user name	Treated as raw ID → will fail

Always use @ prefix when passing a username.

Reading messages

# Channel history
holla slack channels history --channel "#general" -w <ws> --json

# Thread replies
holla slack channels history --channel "#general" --thread 1234567890.123456 -w <ws> --json

# Single message
holla slack chat get --channel "#general" --ts 1234567890.123456 -w <ws> --json

Use --all to auto-paginate. Use --limit <n> to control count.

Searching

holla slack search messages --query "keyword" -w <ws> --json

Options: --sort timestamp|score, --sort-dir asc|desc, --limit <n>, --page <n>

Permalink in search results

Since v26.3.10, search messages returns a permalink field in --json output — use it directly instead of constructing URLs manually. The permalink correctly points to the message within its thread.

Canvases

# Read a canvas (outputs markdown)
holla slack canvases read --canvas <id> -w <ws>
holla slack canvases read --canvas <id> -w <ws> --json  # includes id, title, markdown, timestamps

# Create (with optional auto-share)
holla slack canvases create --title "Title" --markdown "content" --channel "#general" -w <ws>

# Create from file via stdin (--stdio required)
cat document.md | holla slack canvases create --title "Title" --stdio -w <ws>

# Look up section IDs (required for targeted edits)
holla slack canvases sections --canvas <id> --contains "search text" -w <ws> --json

# Edit a specific section (replace, insert_before, insert_after, delete)
holla slack canvases edit --canvas <id> --operation replace --section-id <section-id> --markdown "new content" -w <ws>

# Edit via stdin (--stdio required)
cat content.md | holla slack canvases edit --canvas <id> --operation insert_at_end --stdio -w <ws>

# Append to end (no section-id needed)
holla slack canvases edit --canvas <id> --operation insert_at_end --markdown "more" -w <ws>

# Share
holla slack canvases access-set --canvas <id> --level read --channels "#general" -w <ws>

# Delete
holla slack canvases delete --canvas <id> -w <ws>

Operations: insert_at_start, insert_at_end, insert_before, insert_after, replace, delete

Important: Section IDs change after each edit. Always look up fresh IDs with sections before editing. The --contains filter requires at least one search term.

Canvas markdown limitations: The Slack Canvas API does not support bullet sub-items under numbered lists (e.g. 1. item → - sub). This causes canvas_creation_failed. The CLI auto-converts these to numbered sub-items (with a warning), but when writing markdown for canvases, prefer consistent nesting: bullets under bullets, or numbers under numbers.

Channels

holla slack channels list -w <ws> --json          # List channels
holla slack channels info --channel "#general" -w <ws>  # Channel info
holla slack channels members --channel "#general" -w <ws> --json  # Members
holla slack channels topic --channel "#general" --topic "New topic" -w <ws>

Other commands

holla slack reactions add --channel <ch> --ts <ts> --name thumbsup -w <ws>
holla slack pins add --channel <ch> --ts <ts> -w <ws>
holla slack stars add --channel <ch> --ts <ts> -w <ws>
holla slack bookmarks add --channel <ch> --title "Link" --link "https://..." -w <ws>
holla slack reminders add --text "Do thing" --time "in 1 hour" -w <ws>
holla slack files upload --channels "#general" --file ./doc.pdf -w <ws>
holla slack files download --file <file-id> -o ./output.pdf -w <ws>
holla slack users info --user @username -w <ws> --json
holla slack api <method> --body '{"key":"value"}' -w <ws>  # Raw API passthrough

Note: holla slack api is a raw passthrough — messages sent via api chat.postMessage appear as bot, not as the user. Always use holla slack chat send / reply / edit for messaging.

Output formats

All read commands support: --json (structured), --plain (tab-separated), or table (default).

Name resolution

Channels accept #name or ID. Users accept @name or ID. Fuzzy matching suggests corrections on typos.

Post-action verification (REQUIRED)

After any write action (send, reply, edit, delete, reactions add/remove, mentions, etc.), always re-fetch the result to verify it worked correctly:

# After sending/editing a message — verify content and formatting
holla slack chat get --channel <ch> --ts <ts> -w <ws> --json

# After adding a reaction — verify it appears
holla slack channels history --channel <ch> --limit 1 -w <ws> --json

What to check:

• Message content: Does the rendered text match the intended format? (markdown, line breaks, etc.)
• Mentions: Did <@USER_ID> resolve to the correct person? Is the mention actually visible?
• Mention removal: If a message was edited to remove a mention, verify the mention is actually gone in the fetched result
• Reactions: Confirm the reaction emoji name resolved correctly and appears on the right message
• Deletions: Confirm the message/reaction is actually gone

Never assume a write action succeeded — always verify.

After verification, always provide the permalink so the user can check the result themselves:

holla slack chat permalink --channel <ch> --ts <ts> -w <ws>

Report the permalink URL back to the user along with the verification result.