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Sweep 22 Oct 2026 · 21:04Z Build v2.1.309 528 read Stable v2.1.308 Latest v2.1.309 Next v2.1.309 Feeds RSS JSON llms.txt llms-full.txt Unofficial
Home / Reference / Settings keys

mcpServers

setting never mined JSON

A Claude Code settings key, read out of the shipped bundle. No mined inventory carries it: everything below comes from what this site has written about it.

An MCP server literally named __proto__ now warns you instead of silently loading nothing.

Not Anthropic's. This is the line from the earliest changelog entry here that named it, v2.1.219.

First seen — never in a mined build
Last seen — never in a mined build
Builds0 / 150on this box, as of v2.1.309
Written about v2.1.172 first named in a changelog, 10 Jun 2026

In the changelogs

17

Releases whose published page names mcpServers.

  1. v2.1.296
    Plugin agents now warn about misspelled and unsupported settings

    Plugin agent files now log a warning for settings Claude Code does not recognize, suggest the likely intended name, and flag more ignored ones

    found in this entry's text

  2. v2.1.290
    disableClaudeAiMcp now also blocks claude.ai servers you add yourself

    With disableClaudeAiMcp set, a claude.ai proxy server passed by --mcp-config or the SDK mcpServers option no longer connects either

    found in this entry's text

  3. v2.1.283
    Plugin validation checks more manifest paths

    claude plugin validate now checks paths for more plugin parts and flags a .json path that is really a folder

    found in this entry's text

  4. v2.1.281
    plugin validate: MCP server paths, inline servers and unquoted hook placeholders

    plugin validate now checks MCP server entries and warns about unquoted placeholders in hook commands

    found in this entry's text

  5. v2.1.281
    Plugin validation now checks a plugin's MCP server files

    Plugin validation now checks a plugin's MCP server files for bad settings, insecure addresses and credentials left in plain text

    found in this entry's text, named in this entry

  6. v2.1.274
    MCP server 'add' now rejects host-only transport types explicitly

    Adding host-only MCP server types (sdk, sse-ide, ws-ide) via config now fails with a clear error

    found in this entry's text

  7. v2.1.271
    Renamed 'servers' key in MCP config now suggested without a trailing period

    The suggestion to rename a 'servers' key to 'mcpServers' in MCP config now ends without a trailing period

    found in this entry's text

  8. v2.1.259
    Managed settings can now supply MCP servers directly ("managed" as a first-class MCP source)

    Organizations can push HTTPS MCP servers straight from managed settings; they can't be removed locally and their URLs are masked.

    found in this entry's text

  9. v2.1.248
    Bad crossSessionInbound values are now named where they surface

    A bad crossSessionInbound value is now named directly instead of a generic settings complaint.

    found in this entry's text

  10. v2.1.248
    MCP server list over the control protocol is trimmed

    SDK and IDE clients now only see MCP server names and status, not full config.

    found in this entry's text

  11. v2.1.246
    Plugin interfaces are checked before they are used

    A plugin publishing an interface for others now fails loudly if it isn't a proper object of functions.

    found in this entry's text

  12. v2.1.238
    Agents in untrusted folders can no longer define inline MCP servers

    Agents in untrusted folders can no longer define inline MCP servers; trust the project to allow it.

    found in this entry's text

  13. v2.1.235
    Remote /plugin reload and remote-session init tolerate partial responses

    Remote /plugin reload and remote-session init now tolerate partial or missing response fields

    found in this entry's text

  14. v2.1.235
    plugin eval warns when the eval directory overlaps the plugin's declared component paths

    plugin eval warns or errors when its eval directory overlaps a plugin's own command, agent, or MCP server paths

    found in this entry's text

  15. v2.1.219
    "__proto__" rejected as an MCP server name

    An MCP server literally named __proto__ now warns you instead of silently loading nothing.

    named in this entry, found in this entry's text

  16. v2.1.182
    disableClaudeAiConnectors Setting

    found in this entry's text

  17. v2.1.172
    --plugin-dir-no-mcp Flag

    found in this entry's text

First cited

2

The earliest release whose published evidence quoted mcpServers was v2.1.271, 14 Sep 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.

ReleaseDateThe span that was quoted
v2.1.27114 Sep 2026Rename the top-level "servers" key to "mcpServers" in
v2.1.2905 Oct 2026a claudeai-proxy server passed explicitly (e.g. via --mcp-config or the SDK mcpServers option) does not connect either

Presence across releases

0

The 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 settings key does. All settings keys.

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