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Sweep 01 Oct 2026 · 17:27Z Build v2.1.287 508 read Stable v2.1.285 Latest v2.1.287 Next v2.1.287 Feeds RSS JSON llms.txt llms-full.txt Unofficial
Home / Reference / Settings keys

prompt.compose

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.

Claude Code can now compare two versions of a changing schema and label the difference, such as text only or new live additions

Not Anthropic's. This is the line from the earliest changelog entry here that named it, v2.1.286.

First seen — never in a mined build
Last seen — never in a mined build
Builds0 / 130on this box, as of v2.1.287
Written about v2.1.286 first named in a changelog, 30 Sep 2026

In the changelogs

6

Releases whose published page names prompt.compose.

  1. v2.1.286
    New comparison sorts how a tool description has changed

    Claude Code can now compare two versions of a changing schema and label the difference, such as text only or new live additions

    found in this entry's text

  2. v2.1.286
    Plugins can now take over how the system prompt is put together

    A new prompt.compose hook point lets a plugin module build the system prompt from its sections, and Claude Code falls back to its own if that fails

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

  3. v2.1.286
    Plugin hooks gain a prompt.compose method and an asUser option on submit

    Plugin hooks can now call a new prompt.compose method, and prompt.submit now accepts an asUser option that must be true or false

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

  4. v2.1.286
    Early groundwork for prompt composition and cache keep-alive

    Claude Code now contains a new prompt composition hook point and a cache keep-alive beta setting, with no sign they are in use

    found in this entry's text

  5. v2.1.286
    Several new internal log and event names

    Claude Code gained a few new internal names for logging and events, tied to model lists, prompts, MCP images and Chrome tab groups

    found in this entry's text

  6. v2.1.286
    A new prompt.compose event joins the other prompt events

    Claude Code now registers a prompt.compose event alongside prompt.submit, prompt.fill and prompt.suggest

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

First cited

3

The earliest release whose published evidence quoted prompt.compose was v2.1.286, 30 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
v2.1.28630 Sep 2026"prompt.compose": "prompt.compose"
v2.1.28630 Sep 2026prompt.compose
v2.1.28630 Sep 2026prompt.compose: the dispatch failed, the engine composes the prompt itself

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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