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Sweep 22 Oct 2026 · 04:32Z Build v2.1.308 527 read Stable v2.1.308 Latest v2.1.308 Next v2.1.308 Feeds RSS JSON llms.txt llms-full.txt Unofficial
Home / Reference / Feature flags

tengu_builtin_mcp_toggle

flag never mined JSON

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

MCP server names are now redacted in toggle telemetry events.

Not Anthropic's. This is the line from the earliest changelog entry here that named it, v2.1.261.

First seen — never in a mined build
Last seen — never in a mined build
Builds0 / 149on this box, as of v2.1.308
Written about v2.1.85 first named in a changelog, 26 Mar 2026

In the changelogs

2

Releases whose published page names tengu_builtin_mcp_toggle.

  1. v2.1.261
    MCP server name redaction in toggle telemetry

    MCP server names are now redacted in toggle telemetry events.

    found in this entry's text, named in this entry, gate cited by this entry

  2. v2.1.85
    Built-in MCP Server Toggle [Gradual Rollout]

    gate cited by this entry, found in this entry's text

Gate readings

0

No release here has a gate table behind it for this flag. Most published releases have none at all: the readings exist only for versions the pipeline captured flag state on.

First cited

2

The earliest release whose published evidence quoted tengu_builtin_mcp_toggle was v2.1.85, 26 Mar 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
v2.1.8526 Mar 2026tengu_builtin_mcp_toggle
v2.1.2614 Sep 2026i("tengu_builtin_mcp_toggle", { serverName: Up(e, ALe(e)), enabled: t });

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 feature flag does. All feature flags.

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