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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
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updatedToolOutput

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.

A hook using only the older MCP output field no longer silently rewrites tool results.

Not Anthropic's. This is the line from the earliest changelog entry here that named it, v2.1.236.

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 v2.1.121 first named in a changelog, 27 Apr 2026

In the changelogs

6

Releases whose published page names updatedToolOutput.

  1. v2.1.296
    PostToolUse hooks can rewrite MCP tool results with updatedMCPToolOutput

    A PostToolUse hook can now replace an MCP tool's result using updatedMCPToolOutput when it does not set updatedToolOutput

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

  2. v2.1.293
    Hooks running away from the tool can no longer rewrite its input or result

    Hooks that ran somewhere other than the tool can no longer change its input or result: input changes become a denial, result changes are dropped

    found in this entry's text

  3. v2.1.277
    Tool dispatch gains a 'detached' result path, and hook-output-mismatch errors now carry reason codes

    Tool results get a new 'detached' stop path, and hook output errors now carry machine-readable reason codes

    found in this entry's text

  4. v2.1.236
    Old-style MCP tool-output rewrites from hooks are no longer applied silently

    A hook using only the older MCP output field no longer silently rewrites tool results.

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

  5. v2.1.121

    found in this entry's text

  6. v2.1.121
    updatedToolOutput Hook Property

    found in this entry's text

First cited

1

The earliest release whose published evidence quoted updatedToolOutput was v2.1.121, 27 Apr 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
v2.1.12127 Apr 2026updatedToolOutput

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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