[AGE-4116] fix(frontend): stop bare filename mentions in chat from linking to the wrong file

[bekossy]

Summary

A chat mention like `README.md` was treated as a known, linkable file whenever ANY file with that basename existed anywhere in the session, even if the real file lived in a subfolder (e.g. notes/README.md). Clicking the mention opened the wrong path and showed "Couldn't load this file's content" (#6004).

The root cause is in knownFromRecords (chatFileRefs.tsx): it tail-matched the raw mention text against every file the agent had written, so a bare basename always matched the first written file sharing that name, regardless of where it actually lived. The fix stops bare (no /) mentions from taking that unverified shortcut. They now always go through the existing on-demand path, which reads the real file at that exact location and only renders a link when it actually resolves.

Testing

Verified locally

• Reproduced on localhost:3000: created notes/README.md, got the agent to reference it by bare filename, confirmed the mention now renders as plain text instead of a broken link.
• Confirmed a file created directly at the mount root still links and opens correctly (no regression).

Added or updated tests

• chatFileRefs.test.ts: unit tests on knownFromRecords covering the false-positive case (nested file, bare mention), a still-working qualified mention, a mount-root file correctly deferring to on-demand verification, and an unmatched mention.

QA follow-up

• Markdown-link-style mentions share the same resolver but weren't separately spot-checked.

Demo

Checklist

• I have included a video or screen recording for UI changes, or marked Demo as N/A
• Relevant tests pass locally
• Relevant linting and formatting pass locally
• I have signed the CLA, or I will sign it when the bot prompts me

[linear-code]

AGE-4116

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Project	Deployment	Actions	Updated (UTC)
agenta-documentation	Blocked		Aug 13, 2026 11:06am

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: Repository YAML (base), Organization UI (inherited)

Review profile: CHILL

Plan: Pro Plus

Run ID: f14ec479-438b-454e-b4cc-5761fa574057

📥 Commits

Reviewing files that changed from the base of the PR and between 728f39f and d678972.

📒 Files selected for processing (2)

• web/oss/src/components/Drives/chatFileRefs.test.ts
• web/oss/src/components/Drives/chatFileRefs.tsx

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📝 Walkthrough

Summary by CodeRabbit

• Bug Fixes

  • Improved file-reference detection so bare filenames are verified before being recognized.
  • Prevented unverified mount-root filenames and unwritten file mentions from being treated as known references.

• Tests

  • Added coverage for qualified paths, basename verification, mount-root names, and unwritten mentions.

Walkthrough

The change exports knownFromRecords and rejects bare basenames before recorded-path checks. Tests cover qualified paths, mount-root names, deferred basenames, and unknown references.

Changes

File Reference Verification

Layer / File(s)	Summary
Recorded path verification web/oss/src/components/Drives/chatFileRefs.tsx, web/oss/src/components/Drives/chatFileRefs.test.ts	knownFromRecords is now exported and returns false for candidates without a slash. Tests cover qualified matches, mount-root names, deferred basenames, and unwritten mentions.

Estimated code review effort: 2 (Simple) | ~10 minutes

Mergeability Score: ⚪ Minimal · up to d6789

The change makes bare filename mentions verify the exact path before linking and includes coverage for nested, root-level, and unmatched files; no actionable merge-blocking risk remains beyond normal checks.

Possibly related PRs

• Agenta-AI/agenta#5523: Tests and exports the knownFromRecords file-reference resolver.

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.
Linked Issues check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Out of Scope Changes check	✅ Passed	Check skipped because no linked issues were found for this pull request.
Description check	✅ Passed	The description clearly explains the bare filename linking bug, the fix, and the related tests.
Title check	✅ Passed	The title clearly and concisely identifies the frontend fix for incorrect bare filename links in chat.

✨ Finishing Touches 💡 1

🛠️ Fix failing CI checks 💡

• Create stacked PR
• Commit on current branch

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix/age-4116-chat-file-link-wrong-file

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[chatgpt-codex-connector]

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[github-actions]

Railway Preview Environment

Status	Destroyed (PR closed)

Updated at 2026-08-13T11:38:52.769Z