slack-toolkit

Slack Toolkit

Direct Slack Web API access via Python CLI. Fills gaps in the official Slack MCP plugin (no Canvas read/update, no reactions) and provides a full fallback when MCP is unavailable.

Rule: Check if the Slack MCP server is connected first. Use this skill only when MCP is unavailable or for operations MCP cannot perform (Canvas read/update, reactions).

Configuration

Variable	Source	Required
$SLACK_USER_TOKEN	Env var or keychainctl get SLACK_USER_TOKEN	Yes (Canvas, reactions, threads)
$SLACK_BOT_TOKEN	Env var or keychainctl get SLACK_BOT_TOKEN	Optional (channel reads, bot actions)

Token resolution: env var first, keychainctl fallback (macOS-only). Validates prefix (xoxp-/xoxb-).

Enterprise Grid

All Slack conversation endpoints require POST with form-encoded body. GET returns not_authed on enterprise grids. The CLI handles this transparently.

Canvas Types

Slack has two incompatible canvas backends. The type is determined at the workspace level — some workspaces (particularly Enterprise Grid) route all canvas creation through the legacy Quip backend, even when using the canvases.create API.

• Quip-type (filetype: "quip"): Legacy format. Read works (auto HTML→markdown). canvases.edit (append/replace) does not work. Content limited to ~4KB per create call. Inline comments not accessible via API.
• New Canvas API (all other filetypes): Full CRUD via canvases.create/canvases.edit. Auto-chunked for large content.

Run canvas probe to detect your workspace type before creating canvases. On quip workspaces, updating content requires creating a new canvas with the full content.

CLI Reference

All commands: python3 ${CLAUDE_PLUGIN_ROOT}/skills/slack-toolkit/scripts/slacker.py <command> [args]

Canvas Operations (MCP gaps)

# Read canvas (auto-detects quip vs new-type, outputs markdown)
slacker.py canvas read <canvas_id>

# Create standalone canvas (always new-type)
slacker.py canvas create <title> --content "# Markdown content"
slacker.py canvas create <title> --content-file /path/to/file.md

# Update canvas — append from file (recommended for code blocks / large content)
slacker.py canvas update <canvas_id> --append-file /path/to/content.md

# Update canvas — append inline (small additions only)
slacker.py canvas update <canvas_id> --append "## New Section\n\nContent here"

# Update canvas — replace a section (requires section_id from read)
slacker.py canvas update <canvas_id> --replace <section_id> --content-file /path/to/content.md

# Rewrite quip canvas as new-type (creates new canvas, outputs both IDs)
slacker.py canvas rewrite <canvas_id>

# Detect workspace canvas type (quip vs new-type)
slacker.py canvas probe

Canvas content uses markdown. On non-quip workspaces, auto-chunks content >3KB. On quip workspaces, large content is truncated with a warning. See references/canvas-operations.md for details.

Reactions (MCP gap)

slacker.py react <channel> <timestamp> <emoji_name>
slacker.py unreact <channel> <timestamp> <emoji_name>

Emoji name without colons (e.g., thumbsup not :thumbsup:).

Threads & History (MCP fallback)

# Full thread with pagination
slacker.py thread <channel> <thread_ts> [--limit 200]

# Channel history
slacker.py history <channel> [--limit 100]

# Parse Slack URL to channel + timestamp
slacker.py parse-url "https://workspace.slack.com/archives/C0123/p1768255289788089"

Common Flags

Flag	Description
--bot	Use bot token instead of user token
--limit N	Max messages to retrieve (default: 200 threads, 100 history; hard cap: 1000)

Output Contract

• stdout: JSON (compact, parseable) or markdown (canvas read)
• stderr: Human-readable errors
• Exit codes: 0=success, 1=usage, 2=auth, 3=API error, 4=rate limited

Thread URL Parsing

Two formats supported:

• https://<workspace>.slack.com/archives/<CHANNEL>/p<TS> → basic
• ...p<TS>?thread_ts=<PARENT>&cid=<CH> → threaded reply

Timestamp: strip p prefix, insert . before last 6 digits.

Reference Documentation

Reference	Content
references/api-reference.md	Endpoint table with methods, scopes, rate tiers
references/canvas-operations.md	Size limits, quip vs new-type, auto-chunking, update patterns