Load nested CLAUDE.md files in place for Claude runs

[ppXD]

Summary

• Nested memory loads in place. Under the settings pin, Claude 2.1.263 no longer attaches a subdirectory's CLAUDE.md, .claude/CLAUDE.md or unscoped rule when the run reads below it. An --add-dir naming that subdirectory does load all of it before the first request:

  • labelled as project instructions;
  • with what its rules import, a scoped rule's imports included;
  • with none of its settings.

  Each build walks below the cwd: breadth first, never through a link, never into .git, node_modules or a dot-directory. It adds every such directory after the workspace and its repositories, shallowest first, when all of them fit 16 directories and 32 KiB, imported bytes included. Past that none is added and the launch says so. A directory whose only memory is a scoped rule that imports a file counts too.

• Containment and cost. Each directory the walk would add passes the same outside-link guard as a root (ClaudeWorkspaceMemory.Guard), as it is found.

  • One budget per build (ClaudeWorkspaceMemory.Budget.cs) covers the walk and every check: 65536 distinct lookups, 1048576 path components walked and 64 MiB read, with every path resolved once. PhysicalPath.File spends components from an Allowance.
  • Before the budget, a link target that repeats d/../ made one lookup cost about 15 ms, and a crafted tree held the synchronous build for minutes.
  • Roots are checked first. Past the budget, the walk stops, unchecked directories are left out, and one notice says so.

• Which rules count. ClaudeRuleScope.Read mirrors the CLI's frontmatter parse.

  • A rule is classified from its first 4 KiB. When that head opens a fence it does not close, the rule is read on to the close, up to 4 MiB, so a long frontmatter no longer reads as unconditional. Past 4 MiB the rule is unclassified and the launch says so.
  • A rules entry that links outside the cwd counts for nothing, as the CLI skips it.
  • A tree with no nested memory builds the argv it built before.

Test plan

• Unit: the full suite passes (11945 passed, 1 skipped). New cases:
  • imported bytes counted against the byte budget (32768/32769);
  • a scoped rule alone, with and without an import;
  • a frontmatter closing past 4 KiB, scoped and unscoped;
  • a frontmatter that never closes within 4 MiB;
  • a rule linked into a primary-repository sibling;
  • a 1000-directory and a 16-directory chain-of-links tree, each finishing under 30 s with the budget notice;
  • shared imports resolved once;
  • the budget pinned (Rule 8).
• Unit, mutations (each restored by copy): each of these turns at least one new case red:
  • budget off;
  • imports uncounted;
  • scoped imports ignored;
  • classification from the head only;
  • a linked-outside rule counted;
  • roots checked after the walk;
  • memo off.
• Integration (Postgres): RealHarnessWorkspaceMemoryTests 6/6.
• E2E on macOS, real Claude 2.1.263 and Codex 0.142.2: RepositoryConfigE2ETests 9/9.
  • The nested-in-place arms now also require imp/ on the --add-dir. Its only memory is a scoped rule that imports imp/guide.md.
  • The import must be in the first request, and the rule's own text in no request.
  • Ignoring scoped-rule imports turns both rows red.
• Review bench at the stack tip:
  • a 19990-directory linked tree: 294.5 s → 1.4 s;
  • 16 in-place directories importing 100 chain links: 23.1 s → 1.5 s.
• CI root sandbox lane: floor 102, markers nested-in-place claude-code single-repo/multi-repo Confined and nested-over-budget claude-code single-repo Confined
• CI non-root lane: 18 arms, marker [repo-config-e2e] ran non-root nested-in-place claude-code single-repo Standard uid=1654