[FEATURE] Cache CLAUDE.md between sessions — skip reload when file unchanged

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Problem Statement

Problem

Per the official documentation:

Each Claude Code session begins with a fresh context window. Two mechanisms carry knowledge across sessions: - CLAUDE.md files - Auto memory Both are loaded at the start of every conversation.

This means the full contents of all discovered CLAUDE.md files are injected into context on every session start, regardless of whether the files have changed. For users who restart sessions frequently (context limits, breaks, task switching), identical tokens are consumed repeatedly with zero informational value.

The cost scales with:

• Number of CLAUDE.md files in the hierarchy (ancestor directory walking)
• Files imported via @ syntax (up to 5 hops)
• .claude/rules/*.md files
• Frequency of session restarts

Context

• The memory documentation recommends keeping files under 200 lines but provides no mechanism to avoid redundant loading
• MEMORY.md already has a 200-line / 25KB truncation limit, showing context budget is a recognized concern
• claudeMdExcludes exists for monorepos, showing precedent for controlling what gets loaded
• /compact re-reads CLAUDE.md from disk, confirming the system already has a reload path

Impact

Low-effort optimization (hash comparison is trivial) that saves tokens proportional to CLAUDE.md size x session restart frequency. Most beneficial for power users with structured project instructions who restart sessions often.

Proposed Solution

Option A — Full cache (best for unchanged files):

Cache a hash or mtime of each loaded CLAUDE.md file between sessions. On session start:

1. Discover files as usual (directory walk, imports, rules)
2. Compare hash/mtime against cached values
3. If unchanged, reuse cached content without re-consuming tokens
4. If changed, reload and update cache

Option B — Diff injection (best for small edits):

When a file has changed since last session, inject only the diff rather than the full file. For a one-line edit in a 200-line CLAUDE.md, this saves ~99% of the tokens that would otherwise be re-loaded. Full reload only when the diff exceeds a threshold (e.g. >50% of the file changed).

Both options are compatible and could be combined.

Written by Claude

Alternative Solutions

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Priority

Medium - Would be very helpful

Feature Category

Interactive mode (TUI)

Use Case Example

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Additional Context

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