Follow Discord
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

appendSubagentSystemPrompt

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 new appendSubagentSystemPrompt option lets a subagent's system-prompt append differ from the main session's.

Not Anthropic's. This is the line from the earliest changelog entry here that named it, v2.1.252.

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 v2.1.111 first named in a changelog, 16 Apr 2026

In the changelogs

4

Releases whose published page names appendSubagentSystemPrompt.

  1. v2.1.260
    get_context_usage no longer factors in appendSubagentSystemPrompt

    Context-usage estimates for embedding hosts no longer count the subagent system-prompt append.

    found in this entry's text

  2. v2.1.252
    New appendSubagentSystemPrompt option threaded through session/agent config

    A new appendSubagentSystemPrompt option lets a subagent's system-prompt append differ from the main session's.

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

  3. v2.1.252
    appendSubagentSystemPrompt threaded into more system-prompt construction call sites

    Internal plumbing now threads a subagent-specific system prompt option through more call sites.

    found in this entry's text

  4. v2.1.111
    SDK: Subagent System Prompt Injection

    found in this entry's text

First cited

4

The earliest release whose published evidence quoted appendSubagentSystemPrompt was v2.1.111, 16 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
v2.1.11116 Apr 2026appendSubagentSystemPrompt
v2.1.25231 Aug 2026appendSubagentSystemPrompt: k
v2.1.25231 Aug 2026appendSubagentSystemPrompt: v.appendSubagentSystemPrompt
v2.1.2603 Sep 2026appendSubagentSystemPrompt: T.appendSubagentSystemPrompt

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.

Feedback