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… caching Replace current time and working directory in the environment section with static OS platform info (os.platform/release/arch). Current time and working directory can be obtained via tool execution, and their presence in the system prompt broke prefix caching across runs. Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
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Summary
Current timeandWorking directoryfrom the system prompt environment section — both can be obtained via tool execution (date,pwd)os.platform(),os.release(),os.arch()) which is actually useful for knowing the execution environmentstartedAtparameter fromcreateInstructionMessageand related functions since it's no longer neededThis makes the system prompt fully static, enabling cross-run prefix caching on providers that support it (Fireworks, Anthropic, etc.).
Test plan
bun run testpassesbun run validate:changesetpassesbun run typecheckpasses (only pre-existing@perstack/logerrors)🤖 Generated with Claude Code