Slack Web API

Slack Web API Skill

Use the bundled Bun+TypeScript CLI wrapper to call Slack Web API methods with a bot token.

Preconditions

• Ensure SLACK_TOKEN is set in the shell environment.
• Run the script from this repo (uses the local @slack/web-api dependency).

CLI Wrapper (Bun + TS)

Script: scripts/slack_web_api.ts

Commands:

• list_channels
• post
• post_table
• delete
• search
• channel_history
• thread
• reactions_add
• reactions_remove

Optional flags:

• --resolve_users true to add user_name fields
• --include_threads true to embed full thread replies in channel_history
• post supports rich message inputs:
  • --text_file for multiline body from file
  • --unescape_text true to convert \n/\t escapes in --text into actual newlines/tabs
  • --blocks_json / --blocks_file for Block Kit
  • --attachments_json / --attachments_file for legacy attachments
  • --thread_ts, --reply_broadcast true, --unfurl_links false, --unfurl_media false, --mrkdwn true
• post_table supports:
  • --headers_json / --headers_file
  • --rows_json / --rows_file
  • --title, --text, --include_index true
  • --max_rows (default 20), --max_col_width (default 32)

All commands return JSON to stdout.

Examples

List channels (all pages):

SLACK_TOKEN=... bun ./ .codex/skills/slack-web-api/scripts/slack_web_api.ts list_channels --all true

Post message:

SLACK_TOKEN=... bun ./ .codex/skills/slack-web-api/scripts/slack_web_api.ts post --channel C123 --text "Hello"

Post message with escaped newlines:

SLACK_TOKEN=... bun ./ .codex/skills/slack-web-api/scripts/slack_web_api.ts post \
  --channel C123 \
  --text "Line 1\\nLine 2\\n- bullet" \
  --unescape_text true

Post rich Block Kit message from JSON string:

SLACK_TOKEN=... bun ./ .codex/skills/slack-web-api/scripts/slack_web_api.ts post \
  --channel C123 \
  --text "Fallback text" \
  --blocks_json '[{"type":"header","text":{"type":"plain_text","text":"Perf Update"}},{"type":"section","text":{"type":"mrkdwn","text":"*All probes:* :white_check_mark: 24/24 exposed"}}]'

Post rich Block Kit message from file:

SLACK_TOKEN=... bun ./ .codex/skills/slack-web-api/scripts/slack_web_api.ts post \
  --channel C123 \
  --text "Fallback text" \
  --blocks_file /tmp/slack-blocks.json

Post an aligned table:

SLACK_TOKEN=... bun ./ .codex/skills/slack-web-api/scripts/slack_web_api.ts post_table \
  --channel C123 \
  --title "Pipeline Performance (user_add)" \
  --headers_json '["kind","exposed","timeout","p50_min","p90_min"]' \
  --rows_json '[["account",12,0,8.79,33.73],["video",12,0,12.01,50.44]]'

Post a larger table from file (array of objects):

SLACK_TOKEN=... bun ./ .codex/skills/slack-web-api/scripts/slack_web_api.ts post_table \
  --channel C123 \
  --headers_json '["kind","platform","status","minutes_to_exposed"]' \
  --rows_file /tmp/perf_rows.json \
  --include_index true \
  --max_rows 40 \
  --max_col_width 40

Search messages:

SLACK_TOKEN=... bun ./ .codex/skills/slack-web-api/scripts/slack_web_api.ts search --query "in:#general budget review" --count 100

Read an entire channel history (paginate):

SLACK_TOKEN=... bun ./ .codex/skills/slack-web-api/scripts/slack_web_api.ts channel_history --channel C123 --all true

Fetch a thread:

SLACK_TOKEN=... bun ./ .codex/skills/slack-web-api/scripts/slack_web_api.ts thread --channel C123 --ts 1712345678.9012 --all true --resolve_users true

Channel history with usernames + embedded threads:

SLACK_TOKEN=... bun ./ .codex/skills/slack-web-api/scripts/slack_web_api.ts channel_history --channel C123 --all true --resolve_users true --include_threads true

Add/remove reactions:

SLACK_TOKEN=... bun ./ .codex/skills/slack-web-api/scripts/slack_web_api.ts reactions_add --channel C123 --ts 1712345678.9012 --name eyes
SLACK_TOKEN=... bun ./ .codex/skills/slack-web-api/scripts/slack_web_api.ts reactions_remove --channel C123 --ts 1712345678.9012 --name eyes

Delete a message:

SLACK_TOKEN=... bun ./ .codex/skills/slack-web-api/scripts/slack_web_api.ts delete --channel C123 --ts 1712345678.9012

Pattern: read + analyze a channel

1. Fetch history to JSON:

   SLACK_TOKEN=... bun ./ .codex/skills/slack-web-api/scripts/slack_web_api.ts channel_history --channel C123 --all true > /tmp/slack.json
   

2. Analyze locally (summaries, keyword extraction, timeline, etc.).

Notes

• Use channel IDs (C.../G...) for reliability.
• search respects Slack’s search index, while channel_history is raw channel data.
• If API permissions block results, update bot scopes in Slack app settings.