--- /dev/null
+# ZCOOL QingKe HuangYou — Upstream Source Investigation
+
+**Model**: Claude Opus 4.6
+**Date**: 2026-03-12
+
+## Summary
+
+The upstream repository for ZCOOL QingKe HuangYou was identified as [https://github.com/googlefonts/zcool-qingke-huangyou](https://github.com/googlefonts/zcool-qingke-huangyou), which was already recorded in `METADATA.pb`. The source block was missing a `commit` field pointing to a specific upstream revision.
+
+## Investigation
+
+The repository at `googlefonts/zcool-qingke-huangyou` was queried via the GitHub API to retrieve the latest commit on the default (`main`) branch.
+
+The latest commit on `main` was identified as `c9dac424b0a9f47d3b113cff4a4922f632d82c94`, authored on 2018-11-20, with message: "First commit". This repository has had no commits since its initial creation.
+
+## Result
+
+The `commit` field was added to the `source` block in `METADATA.pb`:
+
+```
+Repo: https://github.com/googlefonts/zcool-qingke-huangyou
+Commit: c9dac424b0a9f47d3b113cff4a4922f632d82c94
+Branch: main (default)
+Status: commit hash added
+Confidence: high (verified via GitHub API)
+```