Slack Thread Reader

Read and summarize Slack channel history and thread conversations. Use when receiving Slack links (https://...slack.com/archives/...) or requests to view channel/thread/reply conversations, summarize discussions, or check recent messages in a channel.

Script to fetch Slack channel history, threads, and individual replies. Output is LLM-friendly format: one message per line, ascending order (oldest→newest), minimal whitespace.

Script Location

scripts/slack-thread.sh (entry point) → scripts/slack-thread.py (main logic)

Slack Link Structure

text

https://abstract-im.slack.com/archives/C0AE4MGLNUU
                                        ^^^^^^^^^^^
                                        Channel ID

https://abstract-im.slack.com/archives/C0AE4MGLNUU/p1770775935866499
                                        ^^^^^^^^^^^  ^^^^^^^^^^^^^^^^
                                        Channel ID    Message ts (parent)

https://abstract-im.slack.com/archives/C0AE4MGLNUU/p1770776063826049?thread_ts=1770775935.866499&cid=C0AE4MGLNUU
                                        ^^^^^^^^^^^  ^^^^^^^^^^^^^^^^            ^^^^^^^^^^^^^^^^     ^^^^^^^^^^^
                                        Channel ID    Reply ts (child)           Parent ts            Channel ID (duplicate)

• pTS: Timestamp in URL path. p + 10 digits (seconds) + 6 digits (microseconds). API uses seconds.microseconds format (e.g., p1770775935866499 → 1770775935.866499)
• thread_ts: Parent message ts of the thread. If present, it's a reply link
• cid: Duplicate channel ID info (for app deep links, ignored by script)
• ts: Unique ID and timestamp of a Slack message. Unique within a channel

Usage

3 Modes

Link Format	Mode	Behavior
/archives/CHANNEL	Channel	Fetch channel history
/archives/CHANNEL/pTS	Thread	Fetch full thread with ts as parent
/archives/CHANNEL/pTS?thread_ts=...	Reply	Fetch single reply only

Read Thread

bash

scripts/slack-thread.sh https://abstract-im.slack.com/archives/CHANNEL/pTIMESTAMP
scripts/slack-thread.sh <channel-id> <thread-ts>

Read Channel History

bash

scripts/slack-thread.sh https://abstract-im.slack.com/archives/CHANNEL
scripts/slack-thread.sh <channel-id>
scripts/slack-thread.sh <channel-id> --limit 100

Channel History + Thread Replies (Full)

bash

scripts/slack-thread.sh <channel-id> --with-threads
scripts/slack-thread.sh <channel-id> --with-threads --thread-limit 5

Read Single Reply

bash

scripts/slack-thread.sh https://abstract-im.slack.com/archives/CHANNEL/pREPLY_TS?thread_ts=PARENT_TS&cid=CHANNEL

Workflow

1. When given a Slack link or channel ID, use this script to fetch conversation history.
2. ⚠️ If the link type and request content don't match, always ask a clarifying question.
   • Link formats: /archives/CHANNEL = channel, /archives/CHANNEL/pTS = thread, /archives/CHANNEL/pTS?thread_ts=... = reply
   • Example: If given a thread link but asked to "fetch channel history", ask for clarification
3. When asked to summarize channel history: Confirm "Should thread replies be included?" before deciding on --with-threads.
4. Summarize the fetched content or deliver it as-is.

Options

Option	Description	Default
--limit N	Number of channel history messages (0=all)	0 (all)
--from YYYY-MM-DD	Messages after this date only (channel mode)	none
--to YYYY-MM-DD	Messages up to this date only (channel mode)	none
--with-threads	Include thread replies inline	off
--thread-limit N	Max replies per thread (0=all)	0
--desc	Descending order (newest→oldest)	off (default ascending)

Output Format

Sort Order: Ascending (oldest → newest, conversation flow)

Use --desc to switch to descending order.

Reply Mode

text

[reply] ch:C0AE4MGLNUU(#dev-backend) thread:1770775935.866499
[2026-03-04T14:32:28|1770776063.826049] user1: Confirmed, will apply the fix

Thread Mode

text

[thread] ch:C0AE4MGLNUU(#dev-backend) parent:1770775935.866499 replies:144 range:2026-02-25~2026-03-04
[participants] user1, user2, user3, absbot (4)
[2026-02-25T22:57:27|1770775935.866499] user1: Parent message (oldest)
[2026-03-04T14:31:05|1770776005.123456] user1: Second message
[2026-03-04T14:32:28|1770776063.826049] absbot: Latest message text 📎file.png [:thumbsup:user2,user3]

Channel Mode

text

[channel] ch:C0AE4MGLNUU(#dev-backend) msgs:200 threads:3
[participants] user1, user2, user3, absbot (4)
[2026-03-04T14:29:00|1770775740.111111] user1: Message text
[2026-03-04T14:32:28|1770775948.222222] absbot: Message text [thread replies:13 latest:2026-03-04T16:00:00]
 [2026-03-04T14:30:00|1770775800.333333] user3: Thread reply (older)
 [2026-03-04T14:31:00|1770775860.444444] user2: Thread reply (newer)

Output Elements

Element	Format	Example
Timestamp+ID	ISO 8601 + ts	[2026-02-11T17:45:56|1770775935.866499]
Sender	Real name (including bots)	user1:, absbot:
Mention	@name	@user3
Reaction	[:emoji:names]	[:thumbsup:user2,user3]
Attachment	📎filename userID/fileID	📎image.png U0ADM19GY6N/F0ADRC9PEHL
Thread info	[thread replies:N latest:time]	[thread replies:13 latest:2026-03-04T16:00:00]
Inline reply	1-space indentation	[ts] user: text
Participants	[participants] names (N)	[participants] user1, user2 (2)
Channel name	ch:ID(#name)	ch:C0AE4MGLNUU(#dev-backend)

LLM Optimization

• Default ascending: LLM naturally follows conversation flow in chronological order
• Newlines/consecutive spaces within messages → collapsed to single space
• No decorative characters (📌, ---, ├ └ etc. removed)
• No blank lines (messages separated by single newline)
• Thread mode: fetches all messages without omission (automatic pagination)
• Each message includes ts (unique ID): enables referencing specific messages
• Attachment permalink shortened: shows only userID/fileID (removes URL-encoded filename duplication)
  • Output: 📎filename U0ADM19GY6N/F0ADRC9PEHL
  • Full URL reconstruction: https://abstract-im.slack.com/files/{userID}/{fileID}

Technical Details

Pagination & Deduplication

• conversations.replies API duplicates parent message at [0] on every page
• Automatic deduplication via seen_ts set
• Cursor-based pagination collects all replies without omission
• --limit applies only in channel mode (thread mode always fetches all)

Parallel Processing

• Channel name lookup and data fetch run concurrently (saves 1 round-trip)
• --with-threads fetches thread replies in parallel with up to 8 workers
• User name lookups also run in parallel with up to 5 workers

User Cache

• User ID → real name cache at ~/.cache/slack-reader/users.json (TTL 24 hours)
• Cached users are resolved instantly without API calls

Rate Limit

• On 429 response, waits for Retry-After header duration then retries (max 3 attempts)
• Rate limit wait timestamp shared across parallel workers (prevents thundering herd)

Error Handling

• In --with-threads, if an individual thread fetch fails, only that thread is skipped; the rest outputs normally
• Summary of failed thread count and ts printed to stderr

Notes

• Bot must be a member of the channel. On channel_not_found, suggest /invite @absbot.
• Fetching only channel history without --with-threads may miss conversations inside threads.