---
name: slack
description: Read and find recent messages in joined Slack channels, then send user-confirmed messages as the connected bot.
when_to_use: |
  Use when the user wants to find or summarize Slack content the connected
  app can access, or send a message to a channel or conversation the app
  has joined.
connections: [slack]
allowed_tools: [Bash]
license: Apache-2.0
metadata:
  author: acedatacloud
  version: "1.3"
---

Use the [Slack Web API](https://api.slack.com/methods) with the connected
bot token in `$SLACK_TOKEN`. Send it only to `https://slack.com/api/` over
HTTPS. Check the JSON `ok` field and HTTP status for every response; report
Slack's error value when a call fails. Respect `Retry-After` on HTTP 429.

Messages are sent as the AceDataCloud bot, not as the user's Slack account.
The app cannot upload files, join channels, or read arbitrary conversations
between other users. Channel and conversation history is available only
where the app has been added. The bot token cannot use Slack's legacy
`search.messages` method: it returns `not_allowed_token_type` even though
the app has `search:read.public`. Studio does not receive the Slack event
`action_token` needed for the Real-time Search API. Do not claim
workspace-wide search or call either API with this connection.

## Verify the connected workspace

```sh
curl -sS -H "Authorization: Bearer $SLACK_TOKEN" \
  https://slack.com/api/auth.test
```

Use the returned team and bot user to check that the connection targets the
workspace the user intended.

## List channels visible to the app

```sh
curl -sS -G -H "Authorization: Bearer $SLACK_TOKEN" \
  https://slack.com/api/conversations.list \
  --data-urlencode "types=public_channel,private_channel" \
  --data-urlencode "limit=200"
```

Follow `response_metadata.next_cursor` to paginate. Resolve channel names
to IDs from this response rather than inventing IDs.

## Read channel history or a thread

```sh
curl -sS -G -H "Authorization: Bearer $SLACK_TOKEN" \
  https://slack.com/api/conversations.history \
  --data-urlencode "channel=C0123456789" \
  --data-urlencode "limit=15"

curl -sS -G -H "Authorization: Bearer $SLACK_TOKEN" \
  https://slack.com/api/conversations.replies \
  --data-urlencode "channel=C0123456789" \
  --data-urlencode "ts=1777656720.123456"
```

Read a private channel or direct message only if the app is a member. If
Slack returns `not_in_channel` or `channel_not_found`, ask the user to add
the app to that conversation. Do not try to join it automatically.

## Find a keyword in one joined channel's recent messages

Ask the user for a channel when they request search without one. Fetch only
that channel's recent history, then filter the returned messages locally.
This is a bounded recent-history scan, not Slack's native search. State the
time window and whether older messages remain unread. On new installs of
commercial apps outside the Slack Marketplace, Slack may limit
`conversations.history` to one call per minute with at most 15 messages;
respect `Retry-After` and do not fan out across channels.

```sh
KEYWORD="deploy"
curl -sS -G -H "Authorization: Bearer $SLACK_TOKEN" \
  https://slack.com/api/conversations.history \
  --data-urlencode "channel=C0123456789" \
  --data-urlencode "limit=15" \
  | jq --arg q "$KEYWORD" '{ok, error, has_more, matches: [.messages[]? | select((.text // "") | contains($q)) | {ts, user, text}]}'
```

If Slack returns an error, report it rather than claiming the search
succeeded. An empty match list is only a result for the messages fetched,
not proof that the keyword is absent from the channel's full history.

## Resolve a member

```sh
curl -sS -G -H "Authorization: Bearer $SLACK_TOKEN" \
  https://slack.com/api/users.lookupByEmail \
  --data-urlencode "email=alice@example.com"
```

Use member details only to identify people in retrieved content. Do not send
unsolicited direct messages or enumerate members for outreach.

## Send a message or thread reply

Before each send, resolve the exact workspace, channel or existing
conversation, and final message text. Call `request_action_confirmation`
with `kind: "generic"` and show those three values. Send only if the user
confirms. If the confirmation tool is unavailable, return a draft. If this
is an unattended run, send only when the saved task already authorizes that
exact destination and content; otherwise return a draft.

The bot must already be a member of the target channel or conversation.
If Slack returns `not_in_channel` or `channel_not_found`, ask the user
to add the app there. Do not call `conversations.join`. Do not retry a
`chat.postMessage` request whose outcome is unknown; first check the
channel history to avoid duplicates.

```sh
curl -sS -X POST https://slack.com/api/chat.postMessage \
  -H "Authorization: Bearer $SLACK_TOKEN" \
  -H "Content-Type: application/json; charset=utf-8" \
  -d "$(jq -nc --arg ch "C0123456789" --arg text "Confirmed message" \
    '{channel:$ch, text:$text}')"
```

For a reply in an existing thread, include its exact `thread_ts` in the
payload. Check `ok`, `channel`, and `ts` in the response and report the
sent message link or channel and timestamp.

If `auth.test` returns `not_authed` or `invalid_auth`, ask the user to
reconnect Slack at `https://studio.acedata.cloud/console/connectors`.