/mcp
A Claude Code slash command, read out of the shipped bundle. No mined inventory carries it: everything below comes from what this site has written about it.
Manage MCP server connections and OAuth authentication. Run with no argument to open the interactive list, pass reconnect <server> to reconnect one disconnected server, or pass enable/disable with a server name or all to change connection state without opening the dialog. Also available in non-interactive mode (-p), where running it with no argument prints a text summary of server status instead of opening the list; requires Claude Code v2.1.205 or later
Anthropic's own wording. Read off Commands, captured 2026-09-28.
In the changelogs
86Releases whose published page names /mcp.
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v2.1.307
Option in /mcp to connect a server on claude.ai when sign-in fails
After an MCP server's sign-in fails, the /mcp dialog can offer "Connect on claude.ai", which opens your browser and checks whether the server is connected there
named in this entry, found in this entry's text
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v2.1.302
MCP credential rejection messages come from a shared message set
Messages shown when an MCP server rejects a
headersHelpercredential or an Authorization header now come from one shared set of messagesfound in this entry's text
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v2.1.302
MCP error messages can suggest a new task instead of /mcp, plus rejected-header messages
In some sessions, MCP errors now say to start a new task or chat instead of running /mcp, and rejected credentials get their own messages
found in this entry's text, named in this entry
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v2.1.302
Messages for rejected MCP server credentials are now built in one place
Errors for an MCP server rejecting your
headersHelpercredential or Authorization header now come from shared codefound in this entry's text
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v2.1.300
MCP wait summary leaves some servers out and says so
The summary Claude gets while waiting for MCP servers now filters its failed and needs-sign-in lists and notes when some were left out
found in this entry's text, named in this entry
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v2.1.300
When an app's own tool server fails, Claude no longer asks you to fix it
If an app's own MCP server fails or needs sign-in, Claude now says something went wrong on the app's side instead of naming it
found in this entry's text
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v2.1.299
MCP servers can provide skills, checked before they are loaded
Claude Code can load skills listed by MCP servers, checking each one's size and fingerprint against the server's list first
found in this entry's text
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v2.1.299
Clearer message when an MCP server's tools cannot be listed
A failed MCP reconnect now says the server's tools could not be listed, when that is the actual cause
found in this entry's text
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v2.1.299
Subagents can only use MCP servers approved for the project
MCP servers a subagent asks for are skipped unless approved for the project, with a note to approve them through
/mcpfound in this entry's text, named in this entry
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v2.1.299
MCP folder registration is capped, and some servers are skipped when set from the SDK
Registering MCP folders past a limit is refused,
mcp_set_serversskips filtered servers with errors, and/mcpreports blocked serversfound in this entry's text
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v2.1.296
Remote sessions give accurate sign-in advice for MCP servers
In remote sessions, Claude now explains that claude.ai connectors are authorised in connector settings and other servers can't be signed into there
found in this entry's text
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v2.1.295
MCP servers that failed to connect can be retried at the start of the next turn
MCP servers that failed with a retryable error can be retried automatically at the start of each turn, for a limited number of turns
found in this entry's text
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v2.1.292
MCP sign-in errors now say where to reconnect for the kind of session you are in
MCP not-connected, sign-in and permission errors point either to claude.ai connector settings or to
/mcp, depending on the sessionfound in this entry's text
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v2.1.292
MCP sign-in and permission error messages come from one place
Errors for an MCP server that is not connected, needs more permissions, or needs you to sign in again now share one source, and their wording may differ
found in this entry's text
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v2.1.290
The /chrome menu shows the real connection state, and Reconnect works
The /chrome dialog shows whether Claude in Chrome is connected, connecting, failed or off, and Reconnect now actually tries to reconnect
found in this entry's text
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v2.1.290
Claude stops trying Chrome tools when the browser connection has failed
When Claude in Chrome is on but its connection failed, Claude is told to skip the browser tools and use WebFetch and WebSearch
found in this entry's text
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v2.1.289
Clearer errors when a plugin launches an agent that cannot start
Plugin agent launches now say when required MCP servers have no tools yet, and list the available agents when the named one does not exist
found in this entry's text
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v2.1.286
Retrying an MCP sign-in reuses the link that is already open
If an MCP server sign-in is still in progress, Claude Code now reuses its link instead of starting a new sign-in that would break the first
found in this entry's text
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v2.1.285
Plugin hooks can wait for an MCP server to connect, with clearer errors
Plugin hooks now wait for an MCP server to finish connecting and report why it failed, such as needing sign-in
found in this entry's text
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v2.1.284
/mcp reconnect allreconnects every MCP server from the interactive view/mcp reconnect allnow reconnects every MCP server in the interactive terminal and reports how many came backfound in this entry's text, named in this entry
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v2.1.284
/mcp reconnect allnow reconnects every server that needs itRunning /mcp reconnect all now reconnects every disconnected MCP server and reports how many came back
found in this entry's text, named in this entry
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v2.1.284
Claude Code tells you when an MCP server opens your browser to sign in again
When an MCP server asks you to sign in again for more access, a message now says the browser is opening and how to get the link
found in this entry's text, named in this entry
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v2.1.283
Tools your organization blocks in
/mcpnow say why when you select themIn the
/mcptool list, organization-blocked tools can be highlighted and selected, and then show that your organization disabled themfound in this entry's text, named in this entry
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v2.1.283
/mcpno longer claims no servers are configured when some were refused for a reserved nameMCP servers refused because their name is reserved no longer leave
/mcpshowing "No MCP servers configured"found in this entry's text, named in this entry
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v2.1.283
Synced plugins can leave out MCP servers that a terminal cannot sign in to
Behind a server setting that defaults off, synced plugins drop web MCP servers whose last sign-in check found no way to register
found in this entry's text
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v2.1.283
Your own MCP server named "memory" is set aside when Claude Code provides account memory
When Claude Code brings its own "memory" MCP server, any other server with that name is removed and the refusal is shown in /mcp
found in this entry's text
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v2.1.282
claude.ai connector error no longer suggests
/mcpin some sessionsThe error for a claude.ai connector that needs connecting now leaves out the
/mcphint in some kinds of sessionfound in this entry's text, named in this entry
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v2.1.282
Reconnecting a disabled MCP server now says it is disabled
Trying to reconnect a disabled MCP server now explains that it is disabled, with project-specific advice in some remote sessions
found in this entry's text
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v2.1.282
Claude's advice on signing in to MCP servers now has a second version
What Claude is told about MCP servers that need sign-in now comes in two versions, one of which points you to
/mcpto sign infound in this entry's text
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v2.1.282
Claude explains disabled MCP servers differently in some sessions
In some sessions Claude now says disabled MCP servers are off for this project and are re-enabled with
/mcpin a terminalfound in this entry's text, named in this entry
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v2.1.281
/mcp server auth screens: Esc now needs a second press to go back
On the /mcp sign-in and clear-sign-in screens, Esc now has to be pressed twice to go back
found in this entry's text, named in this entry
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v2.1.281
MCP insufficient_scope error now carries the required scope
When an MCP server rejects a tool call for missing permissions, the error now also records which scope was needed
found in this entry's text
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v2.1.281
/mcp "Manage MCP servers" dialog rebuilt on a shared scrolling list component
The /mcp server list now scrolls with a scroll bar and shows each server's status as short labels
found in this entry's text, named in this entry
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v2.1.277
MCP server management messages now branch on a command-menu surface
MCP server management messages can now point to a command-menu UI instead of the terminal
found in this entry's text, named in this entry
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v2.1.274
MCP tool call reauth: new step-up scope handling for insufficient_scope 403s
MCP tool calls now show a specific re-authenticate message when a server needs extra permissions
named in this entry, found in this entry's text
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v2.1.273
MCP OAuth/auth failure messages split into four specific cases
MCP authentication failure messages now split into four specific cases instead of two generic ones
found in this entry's text
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v2.1.273
New toast when MCP server reconnection is exhausted
Claude Code now shows a persistent notification when an MCP server's automatic reconnection attempts run out
found in this entry's text, named in this entry
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v2.1.261
Cloud sessions can now list remote MCP servers attached to the local machine
Running /mcp in a cloud session now also lists MCP servers attached to your local machine.
found in this entry's text, named in this entry
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v2.1.257
New MCP connection error messages
MCP connection failures now say when a server is not approved for the project, pointing you at /mcp, or when the account changed.
found in this entry's text, named in this entry
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v2.1.257
MCP control-channel operations gate on control-channel-safe checks before enable/auth
Enabling or authenticating an MCP server now says whether it is managed, disabled or unapproved, with the step to take.
found in this entry's text, named in this entry
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v2.1.257
MCP project-approval message added for control-channel auth/enable
SDK and control-channel callers are now told an MCP server must be approved in /mcp before it can be enabled.
found in this entry's text, named in this entry
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v2.1.248
/mcp warns when a tool description is too long for the model
/mcp now flags tools whose description is too long for the model to fully receive.
named in this entry, found in this entry's text
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v2.1.248
MCP and OAuth errors are redacted when the session persists off your machine
MCP and OAuth error text is redacted when your session runs off your machine.
named in this entry, found in this entry's text
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v2.1.248
/mcp groups claude.ai connectors by a check rather than one exact type name
/mcp now groups claude.ai connectors correctly even when configured in different shapes.
named in this entry, found in this entry's text
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v2.1.248
MCP reconnect errors are hidden on remote sessions
On remote sessions, MCP reconnect errors show a generic note and log the detail locally.
found in this entry's text
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v2.1.248
Caller-supplied names are sanitised before being echoed in error messages
Names you or a caller supply are sanitised before appearing in error messages.
named in this entry, found in this entry's text
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v2.1.248
Untrusted names escaped across MCP and config messages
MCP and config error messages now escape server names and inputs before printing them.
found in this entry's text
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v2.1.247
/mcpserver dialog no longer acts on the wrong rowPressing Enter in the /mcp server list no longer opens the wrong server.
named in this entry, found in this entry's text
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v2.1.247
Cloud bridge MCP server URLs are checked against this session's own route
MCP URLs from the cloud bridge must match your own session route or they're dropped.
found in this entry's text
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v2.1.242
Slash commands load on demand instead of at startup
Built-in slash commands load when you invoke them, so startup does less work.
found in this entry's text
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v2.1.238
Calling a tool on a disabled MCP server errors instead of quietly reconnecting
Calling a tool on a disabled MCP server would tell you to re-enable it, but that path is off.
named in this entry, found in this entry's text
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v2.1.238
MCP servers can be turned off per project, with clearer failure reasons
You can disable an MCP server per project, and failures now name the actual reason.
named in this entry, found in this entry's text
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v2.1.238
Reconnecting an MCP server can discard its cached discovery
Reconnecting an MCP server can now throw away its cached tool list and rediscover everything.
named in this entry
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v2.1.238
MCP servers can connect lazily from a cached entry
Tool calls to a remembered MCP server could dial it on demand, but the cache behind it is off.
named in this entry, found in this entry's text
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v2.1.227
/mcp reconnect reports every reason at once
/mcp reconnect allnow lists every reason servers failed in one message instead of stopping early.named in this entry, found in this entry's text
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v2.1.227
/mcpexplains servers changed in another session/mcpnow explains servers that another session enabled or disabled behind your back.named in this entry, found in this entry's text
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v2.1.227
Bulk MCP reconnect and enable/disable report changes made in other sessions
Bulk MCP reconnect and enable now summarise when another session changed servers behind you.
named in this entry, found in this entry's text
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v2.1.223
/mcp is dispatchable from thin clients
You can now run /mcp from thin clients where it was previously hidden.
named in this entry, found in this entry's text
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v2.1.223
MCP status reply trims terminal-only advice in non-interactive and remote sessions
The /mcp status reply stops telling you to type commands you cannot type in that session.
named in this entry, found in this entry's text
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v2.1.223
/mcp summary drops the "use the terminal" hint in remote workspaces
The /mcp status line stops telling you to use a terminal you don't have in remote workspaces.
named in this entry, found in this entry's text
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v2.1.222
claude importis stubbed out in this buildThe import command exists but just prints a message instead of starting a session here.
found in this entry's text
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v2.1.222
MCP: rejected claude.ai session token is now visible
Your MCP server list now flags a rejected login token, and clears the warning once it recovers.
named in this entry
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v2.1.221
Inline /mcp enable/disable detects changes made in another session
When /mcp enable or disable does nothing, it now tells you if another session already changed it.
named in this entry, found in this entry's text
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v2.1.221
/mcp status surfaces cached servers
The /mcp view now counts cached servers separately so you can tell them from live connections.
named in this entry, found in this entry's text
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v2.1.221
Reconnecting a disabled MCP server tells you to enable it
Reconnecting a disabled MCP server now just tells you to enable it first.
named in this entry, found in this entry's text
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v2.1.221
MCP servers can start in a new "cached" state instead of blocking on connect
MCP servers with a saved cache now show tools instantly and only connect when you first use them.
named in this entry, found in this entry's text
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v2.1.221
MCP reconnect and enable refuse to run against a disabled server
Reconnecting or enabling a disabled MCP server now fails with a message telling you to enable it in /mcp.
named in this entry, found in this entry's text
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v2.1.221
MCP enable/disable failures report the underlying error
Turning an MCP server on or off now shows the real error instead of a vague message.
named in this entry, found in this entry's text
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v2.1.221
/mcp enable and disable report per-server failures
Enabling or disabling MCP servers now tells you when some didn't actually change.
named in this entry, found in this entry's text
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v2.1.221
MCP server details show the negotiated protocol version
MCP server details now show the protocol version negotiated with each connected server.
named in this entry
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v2.1.221
MCP server menu hides Authenticate for disabled or blocked servers
In /mcp, Authenticate is hidden for disabled or policy-blocked servers, with an explanation if you try.
named in this entry, found in this entry's text
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v2.1.221
Rewritten inline /mcp replies for cross-session enable/disable
/mcp now tells you when another session already enabled or disabled a server, and how to make your change stick.
named in this entry, found in this entry's text
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v2.1.221
/mcp explains cross-session enable/disable drift
/mcp gains clearer messages for cross-session enable/disable conflicts and servers blocked by managed policy.
named in this entry, found in this entry's text
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v2.1.219
MCP reconnect failure text is sanitized and length-capped
MCP reconnect errors now show cleaned-up, shortened text instead of raw messy error output.
named in this entry, found in this entry's text
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v2.1.219
Unused MCP skills are now called out separately
Unused MCP skills get their own line in the skill report with server-specific advice.
named in this entry, found in this entry's text
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v2.1.213
Background Sessions: Clearer "No Terminal" Error Messages
found in this entry's text
- v2.1.205
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v2.1.205
Improved MCP and enterprise-policy error messages
found in this entry's text
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v2.1.198
MCP Tip Improved
found in this entry's text
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v2.1.166
/mcpinline control in headless and agent contextsfound in this entry's text
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v2.1.163
MCP Server Failure Notification
found in this entry's text
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v2.1.122
Improved MCP Authentication Error Messages
found in this entry's text
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v2.0.77
Enterprise MCP Exclusive Mode
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v1.0.63
MCP Server Status Indicators
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v1.0.11
Enhanced MCP OAuth Authentication
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v0.2.41
New Features
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First cited
26The earliest release whose published evidence quoted /mcp was v2.1.163, 4 Jun 2026. That is the oldest release this project wrote about it, so it is a floor on the name's age and not the release that introduced it. It is not a presence reading: which builds carried the name is the table below.
20 further spans in the ledger name it. The list above is the earliest first and stops at 6.
Presence across releases
0The miner has never read a build containing this name. It is here because a changelog entry of ours names it, which is evidence that it existed and not evidence of which releases carried it. The inventory starts at v2.1.138 and everything older than that was never mined.
Read out of the published npm bundle release by release, and out of Anthropic's own documentation as this site captured it. Nothing on this page is a description anybody here wrote about what the slash command does. All slash commands.