--mcp-config
A Claude Code CLI flag, read out of the shipped bundle. It has been in the build since v2.1.138, including the newest one read.
What it is
Load MCP servers from JSON files or strings (space-separated). When you pass this flag with -p, Claude Code waits for still-pending servers to connect before running the first turn, up to the [MCP_TIMEOUT](/docs/en/env-vars) startup timeout, 30 seconds by default; a server with a [cached tool list](/docs/en/mcp#managing-your-servers) skips the wait and connects on first use. The wait requires Claude Code v2.1.221 or later
Anthropic's own wording. Read off CLI reference, captured 2026-08-28.
Presence across releases
| Releases | Reading | Declared type | Default |
|---|---|---|---|
| 2.1.245 – 2.1.251 6 releases | never mined | — | — |
| 2.1.138 – 2.1.243 95 releases | in the build | — | — |
A row reading never mined is a release with no archived bundle behind it. Nothing was read out of it, so nothing here says whether the name was in it. A declared type or a default is only ever what that release's own bundle stated.
Changelog entries naming it
-
v2.1.239Command-line flag parsing rewritten around an explicit table of value-taking flags
Flags that take values no longer swallow or drop their arguments, and
--is handled.named in this entry
-
v2.1.239Administrators can forbid server-delivered MCP servers with
disableSideloadFlagsAdmins can set disableSideloadFlags to block --mcp-config and refuse MCP servers pushed in from outside your config.
named in this entry
-
v2.1.239Remote Control bridge sessions reject foreign --mcp-config entries
Remote Control bridge children reject foreign --mcp-config servers and rebuild the meta server themselves.
named in this entry
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v2.1.239Remote sessions drop disallowed --mcp-config servers instead of failing the run
Remote sessions drop disallowed --mcp-config servers and keep running instead of failing.
named in this entry
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v2.1.239More specific explanations when an --mcp-config is ignored
Skipped --mcp-config servers now name managed settings or a Remote Control child as the reason.
named in this entry
-
v2.1.229Enterprise managed-mcp.json takes exclusive control of MCP servers
In remote mode an enterprise MCP config drops all other MCP servers, explaining each one.
named in this entry
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v2.1.229Enterprise MCP config now overrides
--mcp-configwith a named warningWhen enterprise MCP config wins over your
--mcp-config, the log names the file and dropped servers.named in this entry
-
v2.1.219MCP servers skipped by --mcp-config are now reported
MCP servers rejected from --mcp-config are now listed on stderr and in the init message instead of vanishing.
named in this entry
Documentation pages
- CLI reference reference table Claude Code CLI
- Manage multiple agents with agent view mentions it Claude Code CLI
- Claude Code changelog mentions it Claude Code CLI
- Claude Code GitHub Actions mentions it Claude Code CLI
- Run Claude Code programmatically mentions it Claude Code CLI
- Control MCP server access for your organization mentions it Claude Code CLI
- Deploy managed settings mentions it Claude Code CLI
- Connect Claude Code to tools via MCP mentions it Claude Code CLI
- Manage sessions mentions it Claude Code CLI
- Claude Code settings mentions it Claude Code CLI
- Week 20 · May 11–15, 2026 mentions it Claude Code CLI
A reference table page is one whose own table defines this name, and it is where the description above came from. A page that mentions it carries the name somewhere in its text and may say nothing about it at all. Every page carrying it.
Names beside it
Every CLI flag in the inventory starting --mcp, up to twelve of them.
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 CLI flag does. All CLI flags.