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Sweep 10 Nov 2026 · 02:18Z Build v2.1.322 539 read Stable v2.1.311 Latest v2.1.322 Next v2.1.322 Feeds RSS JSON llms.txt llms-full.txt Unofficial
Home / Reference / Settings keys

startupFailureReason

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.

Headless mode's startup-failure errors now include a structured reason code

Not Anthropic's. This is the line from the earliest changelog entry here that named it, v2.1.274.

First seen — never in a mined build
Last seen — never in a mined build
Builds0 / 161on this box, as of v2.1.322
Written about v2.1.274 first named in a changelog, 16 Sep 2026

In the changelogs

2

Releases whose published page names startupFailureReason.

  1. v2.1.274
    Headless/stream-json errors gain a structured startupFailureReason field

    Headless mode's startup-failure errors now include a structured reason code

    found in this entry's text

  2. v2.1.274
    CLI startup errors now carry a machine-readable startupFailureReason

    Headless Claude Code errors now include a machine-readable startupFailureReason field like session_held_by_background

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

First cited

2

The earliest release whose published evidence quoted startupFailureReason was v2.1.274, 16 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
v2.1.27416 Sep 2026startupFailureReason: "session_held_by_background"
v2.1.31227 Oct 2026startupFailureReason: this.lastStartupFailureReason

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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