Thanks for the context here. I swept through the related work, and this is now duplicate or superseded.

This PR is now superseded: current main already has the same compatibility-preserving cwd-aware session resume/list fix from the merged canonical branch, and this branch only reworks the same two files with alternate helper shape and duplicate coverage.

Canonical path: Keep the current-main implementation from #97785 and close this duplicate branch; any further session-collision work should be a narrow follow-up against current main.

So I’m closing this here and keeping the remaining discussion on #97785.

I think the cwd-less fallback in this PR needs either a cited shipped-state reason or removal.

Two-lens read:

• Runtime/correctness: sessionFileMatchesCwd() returns true when header.cwd is missing/empty, and SessionManager.list() keeps !session.cwd. In the exact shared-directory collision this PR is fixing, a cwd-less JSONL file remains eligible for both projects; if it is newest, continueRecent(cwdA) can still adopt a transcript that is not proven to belong to cwdA.
• Contract/compat: I checked the first shipped tag that contains this session manager (v2026.5.28) and the latest stable tag I found in this lane (v2026.6.10); both define SessionHeader.cwd: string and write cwd: this.cwd for new session headers. I do not see a tagged upgrade contract for cwd-less session headers.

If there is a real legacy state this preserves, please cite the version/path and add a regression test showing why those files should match every cwd. Otherwise, I think the cwd-scoped paths should require a string header cwd matching the requested cwd, leaving cwd-less/malformed files discoverable only through explicit open/list-all style flows rather than project-scoped resume/list.

@harjothkhara Good catch. I removed the cwd-less fallback entirely.

• sessionFileMatchesCwd() now requires header.cwd === cwd when a cwd is requested; missing/empty cwd no longer matches.
• SessionManager.list() now filters with session.cwd === cwd only.
• Added a regression test that writes a newer cwd-less session file alongside a matching-cwd file and verifies the cwd-less file is ignored by both continueRecent and list.

You are right that shipped headers (v2026.5.28, v2026.6.10) always record cwd, so there is no cited upgrade contract that warranted the fallback.

Real behavior proof for the cwd-collision fix.

I verified the regression tests reproduce the bug on main and pass with this fix.

Repro steps

1. Checked out a temporary branch from main.
2. Applied only the new tests from this PR (src/agents/sessions/session-manager.test.ts) without the source changes.
3. Ran the regression tests.

Before the fix (on main, tests only)

git checkout -b temp-repro main
git checkout fix/96542-session-cwd-collision -- src/agents/sessions/session-manager.test.ts
pnpm test src/agents/sessions/session-manager.test.ts -- --run

Result: 3 failed, 47 passed

• does not resume a session from a different cwd that shares the encoded session dir
  • Expected session-A.jsonl for /home/alice/dev/client/app, but got session-B.jsonl (the newer file belonging to /home/alice/dev/client-app).
• lists only sessions that belong to the requested cwd when dirs collide
  • SessionManager.list(cwdB) returned both session-A.jsonl and session-B.jsonl instead of only session-B.jsonl.
• ignores cwd-less sessions when resuming or listing for a specific cwd
  • Expected matching.jsonl, but got cwdless.jsonl because the cwd-less file was newer.

This confirms the bug: when two project paths collapse to the same encoded session directory, a pure mtime-based pick loads the wrong project's session.

After the fix (on fix/96542-session-cwd-collision)

git checkout fix/96542-session-cwd-collision
pnpm test src/agents/sessions/session-manager.test.ts -- --run

Result: 50 passed, 0 failed

I also ran the broader session test suite:

pnpm test src/agents/sessions/ -- --run

Result: 16 test files passed, 120 tests passed, 0 failed.

Static checks

npx oxfmt --check src/agents/sessions/session-manager.ts src/agents/sessions/session-manager.test.ts
npx oxlint --tsconfig config/tsconfig/oxlint.json src/agents/sessions/session-manager.ts src/agents/sessions/session-manager.test.ts

Both pass with 0 warnings and 0 errors.

@clawsweeper re-review

🦞🧹
ClawSweeper re-review requested.

I asked ClawSweeper to review this item again.
Action: item re-review queued (workflow sweep.yml, event repository_dispatch).
Result: the existing ClawSweeper review comment will be edited in place when the review finishes.

ClawSweeper applied the proposed close for this PR.

• Action: closed this PR.
• Close reason: duplicate or superseded.
• Evidence: durable ClawSweeper review.
• Coverage proof: PR B clearly implements and merged the same concrete session cwd-collision fix that PR A was trying to land, including the relevant continueRecent/list behavior and proof surface. Any differences in helper shape or extra tests are incidental and can be handled on the canonical merged PR/main follow-up path. Covering PR: fix(sessions): avoid cross-cwd recent resumes #97785.