How do I use Claude Code Channels (Claude Tag) to search what Claude can find?

Q: Can Claude read a public channel it isn’t in?

Keyword search yes (unless an admin limited search, or the ask comes from a guest-bearing channel where workspace search is unavailable). Full history no until /invite @Claude.

Q: What does “Channels Claude can search” change?

It limits Slack search to public channels Claude has been added to (CHANGELOG 2.1.283; org / workspace / channel scope).

Q: Is this the same as claude --channels?

No. MCP Channels push events into a local Claude Code session. This Spec is Claude Tag Slack search.

Claude Tag can keyword-search public Slack channels; admins can limit search to channels Claude has joined via “Channels Claude can search” (CHANGELOG 2.1.283). Search vs membership, access checks, and fences vs MCP --channels and Desktop.

In Claude Tag (Slack), Claude can keyword-search public channels the way a Slack member searches — finding messages without full channel membership. Full history needs /invite @Claude into that channel. Admins can enable “Channels Claude can search” (CHANGELOG 2.1.283) to limit search to public channels Claude has been added to (org / workspace / channel). Ask @Claude what can you access from this channel?. This is not Claude Code’s research-preview MCP Channels (claude --channels), and not Claude Desktop.

TL;DR: Search ≠ full history. Keyword find on public channels is broader than membership; invite Claude to participate. Admin setting “Channels Claude can search” (2.1.283+) can tighten search to channels Claude joined. Fence: MCP --channels push plugins and Desktop (claude --desktop, Labs desktop 8100) are different products. Labs seed: claude code channels (1600 / KD 18). Checked 2026-09-30.

Search vs membership — what Claude can find

From How Claude Tag works and Get started:

Context	What Claude can do
Thread / channel where Claude is present	Read that conversation’s history (session context)
Other public channels Claude is not in	Keyword search only (same search a Slack user has) — not a full channel dump
Public channel Claude has been added to	Work there; full history where added
Private channels / DMs	Only from inside them
Channel that includes guests	Workspace search is unavailable from those channels

Finding ≠ acting. To participate in a channel, invite with /invite @Claude. Claude Tag is Team/Enterprise Slack path; Pro/Max still use the earlier Claude in Slack path per Code Slack docs — [GAP] confirm plan floor in your org’s Tag admin before assuming Tag features apply.

Admin setting — “Channels Claude can search” (2.1.283)

CHANGELOG 2.1.283 (anthropics/claude-code):

[Claude Tag] Added a "Channels Claude can search" admin setting that limits Claude's Slack search to public channels it has been added to, set per organization, workspace or channel

Effect: when enabled, Slack keyword search is limited to public channels Claude has been added to. Scope: organization, workspace, or channel. Official docs match: “an admin can limit search to channels Claude is in.”

[GAP]: no dedicated admin screenshot / click-path page confirmed same-day — configure in Claude Tag admin settings; do not invent UI steps. CHANGELOG HEAD on check day is 2.1.285 (unrelated additive CLI / Desktop / plugin-configure items) — this Spec owns the 2.1.283 Tag search setting only; no CASCADE invent.

How to check and use search today

Invite for full history: in the channel message box, /invite @Claude (Slack rejects /invite from inside a thread).
Check reach: @Claude what can you access from this channel?
Search: ask Claude to find a known keyword or message across public channels it can search.
Soft: channel replies may show a Configure link (getting-started) — do not invent extra admin UI here.

Not these “Channels”

Thing	What it is	This page?
Claude Tag “Channels Claude can search”	Admin limit on Slack workspace keyword search	Yes — this Spec
Claude Code MCP Channels	Research-preview plugins that push Telegram/Discord/iMessage events into a local session via `claude --channels` (docs)	No — fence only
Claude Desktop / `claude --desktop`	Desktop product / CLI flag (Labs `claude code desktop` 8100 / KD 50 skipped Intake)	No — fence one line
`/doctor prompt-audit`	Audit CLAUDE.md/skills for stale prompts	doctor Spec
`/skill-doctor`	Skills context-cost prune	skill-doctor Spec
Permissions / auto mode	Permission modes	permissions Spec
Memory	CLAUDE.md / memory	memory Spec

Legacy Claude Code in Slack routing modes are retiring in favor of Claude Tag for Team/Enterprise — soft fence only; this page is Tag search, not the legacy setup guide.

Pitfalls

Assuming keyword search = full channel history dump
Expecting private-channel search from another channel
Confusing Tag with MCP --channels install steps under this H1
Writing Desktop / --desktop how-to here
Inventing admin click-paths not in official docs

FAQ

Can Claude read a public channel it isn’t in?

Keyword search yes (unless an admin limited search, or the ask comes from a guest-bearing channel where workspace search is unavailable). Full history no until /invite @Claude.

What does “Channels Claude can search” change?

It limits Slack search to public channels Claude has been added to (CHANGELOG 2.1.283; org / workspace / channel scope).

Is this the same as `claude --channels`?

No. MCP Channels push events into a local Claude Code session. This Spec is Claude Tag Slack search.

Does this work on Pro/Max Claude Tag?

Claude Tag is the Team/Enterprise Slack path; Pro/Max stay on the earlier Claude in Slack path per Slack/Tag docs. Confirm with your admin.

How is this different from `/doctor` or permissions?

Different tools: prompt-audit, skill-doctor, permissions, memory.

Sources (checked 2026-09-30)

CHANGELOG 2.1.283 — “Channels Claude can search” bullet
How Claude Tag works — search vs membership, guests, admin limit
Get started — /invite @Claude, access check prompt
MCP Channels — fence only
Labs: claude code channels 1600 / KD 18 · desktop 8100 fence (labs-kw-2026-09-30)