# Agent Slack

> Slack CLI for agents: read URLs/threads/history/unreads/later/canvases/workflows, create/edit canvases from Markdown, search messages/files, download attachments, lookup users, list/create/invite channels, open DMs, compose messages, manage Slack-native drafts, schedule sends, and explicit sends/edits/deletes/reactions/mark-read/uploads.

- Skill: `stablyai/agent-slack` (Agent Skill, multi-file: 3 files)
- Install (CLI): `npx skillmds add stablyai/agent-slack`
- Raw SKILL.md: https://api.skillmd.com/api/skills/stablyai/agent-slack/raw
- Safety review: pending
- Works with: Claude Code, Claude.ai, OpenAI Codex
- Category: AI & ML
- Author: stablyai (https://skillmd.com/u/stablyai)
- Updated: 2026-09-09
- Page: https://skillmd.com/skills/stablyai/agent-slack

---


# agent-slack

Use `agent-slack` from `$PATH`. If it is missing, install it with:

```bash
curl -fsSL https://raw.githubusercontent.com/stablyai/agent-slack/main/install.sh | sh
```

Fallback: `npm i -g agent-slack` (Node >= 22.5).

Run `agent-slack --help` or the relevant subcommand help before guessing a command or flag.
If a capability named here is absent from installed help, report version skew instead of guessing. Do not self-update the CLI without explicit authorization.

## Safety

- Read and search freely.
- Perform write actions only when explicitly requested: sends, edits, deletes, reactions, invitations, channel or canvas creation/editing, mark-read operations, scheduling or canceling delivery, uploads, Later state/reminder changes, DM/group-DM creation, and `workflow run`. Workflow runs can execute downstream actions.
- For compose- or review-only requests, return proposed text without invoking Slack, or use `message draft create` to add a Slack-native draft the user can review and send (nothing is posted). `message compose` is send-capable; use it only when the user explicitly asks to open the interactive editor. In CI or another noninteractive environment, do not invoke it without separate authorization to send immediately: CI skips the editor and sends supplied text.
- With `AGENT_SLACK_SAFE_MODE=1` (or the global `--safe-mode` flag) set, safe mode is enforced at the tool level: `message send` is redirected to the draft editor and `message edit`/`message delete` are blocked. Use it when nothing should post without human review.

## Workflow

1. Run `agent-slack auth whoami`. If needed, import credentials with `auth import-desktop`, `auth import-brave`, `auth import-chrome`, or `auth import-firefox`, then run `auth test`.
2. Prefer a Slack message URL when one is available. It carries the workspace, channel, and timestamp needed by most message operations.
3. Choose the narrowest read operation: `message get` for one message, `message list` for a full thread or channel history, and `search messages` or `search files` for discovery.
4. Use output limits such as `--limit`, `--max-body-chars`, and `--max-content-chars` to avoid unnecessary context.
5. For a requested write, execute only the requested mutation and verify the resulting JSON metadata.

For scheduled writes, prefer `--schedule` with an ISO 8601 timestamp and explicit offset when timezone matters. Named `--schedule-in` phrases use the executing environment's local timezone; confirm that it matches the user's intent.

Named `later remind --in` values such as `tomorrow` or `monday` also use the executing environment's local timezone at 9:00. Confirm that timezone or pass an explicit Unix timestamp.

Use `--no-unfurl` with `message send` or `message compose` when the user wants Slack link and media previews suppressed. It cannot be combined with `message send --attach`.

Ordinary `message send` and `message edit` calls auto-convert lists. `message send --blocks` and `message edit --blocks` use supplied Block Kit blocks, while `message send --attach` sends its initial comment without automatic list conversion. Inside auto-converted lists, use Slack's `<URL|label>` syntax because CommonMark `[label](URL)` links are not converted into labeled link elements.

Slack-native drafts (`message draft list|create|update|delete`) manage drafts that appear in the user's Slack client; `create` posts nothing. `create` and `update` accept repeatable `--attach <path>`; on `update` the files are added to the draft's existing attachments rather than replacing them. They use undocumented session endpoints and require browser-style auth (xoxc/xoxd).

`canvas edit` uses Slack's public `canvases.edit` API and applies exactly one operation per call. The
default `replace` operation replaces the whole canvas; section-targeted inserts/replacements and
deletes require the section ID returned by Slack's Canvas tooling, while `rename` takes `--title`.
Content operations take exactly one `--file` or `--markdown` source. It requires a standard token
with `canvases:write`; imported browser credentials can create standalone canvases but cannot edit.

## Conditional references

- Read [references/targets.md](references/targets.md) only when choosing between a message URL, channel, or user target, or when resolving multiple workspaces.
- Read [references/output.md](references/output.md) only when handling returned message or canvas metadata, resolved users, or downloaded and failed attachments.