Slack API Skill

Fetch threads and search messages using direct API calls (no MCP server needed).

1. Prerequisites

1.1. Environment Variables

export SLACK_MCP_XOXC_TOKEN="xoxc-..." export SLACK_MCP_XOXD_TOKEN="xoxd-..."

2. URL Formats

2.1. Message URL (archives format)

https://xxx.slack.com/archives/C1234567890/p1234567890123456

• C1234567890 = channel ID

• p1234567890123456 = timestamp (remove p , insert . before last 6 digits)

• p1234567890123456 → 1234567890.123456

2.2. Channel URL (client format)

https://app.slack.com/client/E1234567890/C1234567890 https://app.slack.com/client/E1234567890/D1234567890

• First ID (E...) = Enterprise/Workspace ID

• Second ID = channel ID (C = channel, D = DM)

3. Fetch Channel History

Fetch latest messages from a channel (useful for bot DMs like Google Calendar).

3.1. Extract Channel ID from Client URL

URL="https://app.slack.com/client/E05CUN3JKJN/D07UW8G7C9H" CHANNEL=$(echo "$URL" | sed -n 's|./client/[^/]/([^/]).|\1|p') echo "$CHANNEL" # D07UW8G7C9H

3.2. Fetch Latest Messages

CHANNEL="D07UW8G7C9H" FILE=$(mkoutput --dir tmp --label output) curl -s -X POST "https://slack.com/api/conversations.history"
-H "Authorization: Bearer $SLACK_MCP_XOXC_TOKEN"
-H "Cookie: d=$SLACK_MCP_XOXD_TOKEN"
-d "channel=${CHANNEL}"
-d "limit=20" > "$FILE"

Extract calendar events (for Google Calendar DM)

jq '.messages[] | select(.attachments) | .attachments[] | select(.title) | {pretext, title, text}' "$FILE"

4. Fetch Thread

4.1. Parse URL and Fetch

Example URL: https://xxx.slack.com/archives/C1234567890/p1234567890123456

CHANNEL="C1234567890" TS="1234567890.123456"

curl -s "https://slack.com/api/conversations.replies?channel=${CHANNEL}&ts=${TS}"
-H "Authorization: Bearer ${SLACK_MCP_XOXC_TOKEN}"
-H "Cookie: d=${SLACK_MCP_XOXD_TOKEN}" | jq '.messages[] | {user, text, ts}'

4.2. One-liner with URL Parsing

URL="https://xxx.slack.com/archives/C08V9MYDQ1C/p1736929199388759" CHANNEL=$(echo "$URL" | sed -n 's|./archives/([^/])/.|\1|p') TS_RAW=$(echo "$URL" | sed -n 's|./p([0-9]).|\1|p') TS="${TS_RAW:0:10}.${TS_RAW:10}" curl -s "https://slack.com/api/conversations.replies?channel=${CHANNEL}&ts=${TS}"
-H "Authorization: Bearer ${SLACK_MCP_XOXC_TOKEN}"
-H "Cookie: d=${SLACK_MCP_XOXD_TOKEN}" | jq '.messages[] | {user, text, ts}'

4.3. Fetch Single Message (conversations.history)

CHANNEL="C1234567890" TS="1234567890.123456"

curl -s -X POST "https://slack.com/api/conversations.history"
-H "Authorization: Bearer ${SLACK_MCP_XOXC_TOKEN}"
-H "Cookie: d=${SLACK_MCP_XOXD_TOKEN}"
-d "channel=${CHANNEL}" -d "latest=${TS}" -d "limit=1" -d "inclusive=true" | jq '.messages[0]'

5. Output Format

Show each message with:

• User ID (or resolve to name if needed)

• Message text

• Timestamp

6. Search Messages

NOTE: Enterprise Grid may restrict search.messages API with enterprise_is_restricted error.

6.1. Basic Search

QUERY="keyword" curl -s "https://slack.com/api/search.messages?query=$(echo "$QUERY" | jq -sRr @uri)&count=20"
-H "Authorization: Bearer ${SLACK_MCP_XOXC_TOKEN}"
-H "Cookie: d=${SLACK_MCP_XOXD_TOKEN}" | jq '.messages.matches[] | {channel: .channel.name, user, text, ts, permalink}'

6.2. Search with Filters

Search in specific channel

QUERY="in:#channel-name keyword"

Search from specific user

QUERY="from:@username keyword"

Search with date range

QUERY="after:2026-01-01 before:2026-01-15 keyword"

Combined filters

QUERY="in:#general from:@john after:2026-01-01 terraform"

curl -s "https://slack.com/api/search.messages?query=$(echo "$QUERY" | jq -sRr @uri)&count=20&sort=timestamp&sort_dir=desc"
-H "Authorization: Bearer ${SLACK_MCP_XOXC_TOKEN}"
-H "Cookie: d=${SLACK_MCP_XOXD_TOKEN}" | jq '.messages.matches[] | {channel: .channel.name, user, text, ts, permalink}'

6.3. Search Options

• count : Number of results (default 20, max 100)

• sort : score (relevance) or timestamp

• sort_dir : asc or desc

7. Error Handling

• If ok: false in response, show error message

• Common errors:

• channel_not_found

• invalid channel ID

• thread_not_found

• invalid timestamp

• invalid_auth

• token expired or invalid

• enterprise_is_restricted

• Enterprise Grid API restriction