Slack bot API: your agent reads your channels and posts in them, on your own workspace

What’s the best way to ask ChatGPT?

set up treg — https://treg.to/llms.txt

Using treg, read the last two days of #support, summarise the open questions with who asked each one, and post the summary to #support-digest as a single message.

works in

Why this prompt works

Why go through treg.to

One provider, on the account you already own

▚Slack answers this job. You connect it once, treg.to keeps the token server side, and the call is never metered.

treg call slack.slack.messages.history

Every endpoint on this connection is listed on the Slack shelf.

What people actually struggle with

Slack posts in August 2026 were four-fifths agent launches and MCP listicles; about twenty tools were pitched across ~170 posts, one with zero-width characters in the text. These four are people trying to read their own workspace.

Slack cut history reads to one a minute, and it applies to internal apps

“For accessing messages, you can now only make 1 request per minute, with a maximum of 15 messages” @grinich on X, 1,951 likes

What this page can do about it: Still the rule for any unlisted app, and this connection is one. The page says so rather than implying a way round it: a summary of a channel's last day fits the allowance, and that is the job most people are actually asking for.

All anyone wants is the morning summary, and the easy path got switched off

“All I want is to get a summary of my Slack messages and with a list of action items every morning.” r/AI_Agents

What this page can do about it: The same poster found the Claude Slack connector disabled by IT and was unsure they could create an app at all. A manifest install is still an app install, so an admin may have to say yes; after that the digest is one read and one post a day.

The bot has to be in the room

“Turns out the bot needs to be a member of the channel first.” r/indiehackers, 18 points

What this page can do about it: True here too, and the manifest keeps it that way on purpose: read what you invited it to, post where you point it. The same thread had DM scopes rejected in review as too much access, which is why this connection does not ask for them.

Pasting bot tokens into code is where the audit trail goes

“pasting bot tokens into your code... less great when you need to know exactly what your agent can touch” @Mai_Builds on X

What this page can do about it: The token sits with treg.to, the agent holds one team token that works for every tool, and what it can touch is the manifest's scope list, which is fixed and readable. Revoke the bot and the agent's access is gone with it.

What actually differs

Reading history on a new, unlisted app is rationed.

Apps created after May 2025 that are not listed in the Slack Marketplace get one history request a minute and fifteen messages a call, and the bot you install from treg.to's manifest is one of those apps. Nothing here lifts that; treg.to relays the call and the 429 as they are. A daily digest of a busy channel is fine; a backfill of a year is not this tool.

Membership is the read permission.

The bot reads only channels it has been invited to, and direct messages need their own scopes, which the manifest does not request. Posting is broader: the write scope lets it post into any public channel without joining. Slack answers a dead channel or a missing scope with HTTP 200 and ok: false, so read the body, not the status.

History returns top-level messages with authors as user ids, so a readable digest needs the users call to resolve names, and thread replies live behind a separate replies call.

Ask the agent for a summary with names and it will make those calls; ask for the raw rows and it will hand you ids.

What is the Slack bot API?

The Slack Web API is how an app reads and writes a workspace as data: list channels, read a channel's message history, post a message or a threaded reply. A bot token is the credential an installed app holds, scoped to that one workspace and to the permissions its manifest asked for, and everything it does shows up as the bot, not as you. That is the token this connection uses, so the agent reads what the bot can see and posts under the bot's name, never under yours.

Before you start

Does this cost anything?

No. Slack runs on your own workspace, so treg.to relays the call and meters nothing. Only calls on treg.to's own provider keys are billed.

Does my agent post as me or as a bot?

As the bot, always. The connection holds a bot token, which is what makes it auditable: every message it writes carries the bot's name, and it cannot read your DMs or anything a channel you did not invite it to.

Why is reading history slow?

Slack rate-tiers history reads on unlisted apps: one request a minute, fifteen messages each. That is Slack's rule for every app created outside the Marketplace since 2025, and treg.to does not get around it. Ask for windows and let the agent page.

What if my workspace restricts app installs?

Then an admin has to approve the install, the same as any app. treg.to gives you the manifest to submit; it cannot approve it for you.

Other jobs your agent can do