Sweep 19 Sep 2026 · 02:36Z Build v2.1.278 500 read Stable v2.1.267 Latest v2.1.278 Next v2.1.278 Feeds RSS JSON llms.txt Unofficial
Claude Code v2.1.274 ·

System-prompt/tool-schema info is now cached and hashed

System prompt and tool schema extraction is now cached and hashed instead of reparsed each time

TierUnder the hoodhow much it should matter to you
Useful2my rating, 1 to 5
Signal1worth watching, 1 to 5
AreaSystem Promptwhat it touches
KindImprovementsin v2.1.274,
Under the hood

System prompt and tool schema extraction is now cached and hashed instead of reparsed each time

What

The internal function that extracts the active system prompt, tools, and tool schemas now caches its parsed result instead of redoing the work on every call, and adds a systemPromptHash field computed by a new hashing function.

Why

Caching avoids repeatedly re-parsing the same system prompt and tool information, and the new hash gives a quick way to check whether the system prompt has changed.

See this entry in the whole of v2.1.274 →