Building a True Code Diff Panel for Open-Source Agents

Federal-Teaching2800 · reddit · 2026-07-15

A developer created a new code preview interface for the local desktop app of the open-source Python agent Chimera, designed to **honestly show users exactly what files the Agent modified**. **Technical Implementation Details**: - Abandoning broad file-level summaries and Git-restricted `git diff`, the final approach uses `difflib` to generate precise per-file diffs based on pre- and post-run snapshots. - This solution doesn't rely on Git and accurately pinpoints changes made during a single run. **Honest Rollbacks**: When a validation failure triggers a workspace rollback, the UI explicitly marks these changes as "attempted but reverted," rather than faking success or hiding them. The command executor also honestly identifies itself instead of masquerading as a full interactive terminal. The developer finally asked the community: should AI code modifications rolled back due to validation failures be hidden, or explicitly marked as "attempted"?

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