--- /dev/null
+# Investigation Report: Hammersmith One
+
+## Summary
+
+Hammersmith One is a low-contrast sans-serif display family designed by Nicole Fally, with spacing and mastering by Eben Sorkin (Sorkin Type Co.). It was added to Google Fonts in the initial commit (2015-03-07, but date_added is 2011-06-29). The upstream repository at `librefonts/hammersmithone` is an archive-style repo containing SFD (FontForge) and VFB (FontLab) source files, plus TTX decomposed tables. There is no gftools-builder compatible source, no config.yaml, and no designspace. The repo has only a single commit and the sources are in legacy formats only.
+
+## Key Findings
+
+| Field | Value |
+|--------------------|--------------------------------------------------------------|
+| Family Name | Hammersmith One |
+| Designer | Nicole Fally |
+| License | OFL |
+| Date Added | 2011-06-29 |
+| Repository URL | https://github.com/librefonts/hammersmithone |
+| Commit Hash | a5fae41a3eabe8ec4e1d8ff7b3fa6dfde5c4fa87 |
+| Branch | master |
+| Config YAML | None |
+| Source Types | SFD (FontForge), VFB (FontLab), TTX |
+| Weights | Regular only |
+| Google Fonts Ver. | 1.003 |
+| Upstream Repo Ver. | 1.003 (per VERSIONS.txt) |
+| Status | **no_config_possible** |
+| Confidence | HIGH |
+
+## Investigation Details
+
+### METADATA.pb Review
+
+The current METADATA.pb on the main branch of google/fonts has no source block. A source block was added on the `sources_info_2026-02-25` branch (commit 9a14639f3) but has not yet been merged.
+
+### Git History in google/fonts
+
+The font was included in the initial commit `90abd17b4f` (2015-03-07) by Dave Crossland. Key subsequent changes:
+
+1. **ff6fd2655** (2020-10-14) - "hammersmithone: name table updated to match API (#2351)" -- Co-authored by Micah Stupak. Updated the TTF with corrected name table entries.
+2. No other TTF-modifying commits beyond the initial and the name table fix.
+
+### Upstream Repository Analysis
+
+The repository `librefonts/hammersmithone` is cached at `upstream_repos/fontc_crater_cache/librefonts/hammersmithone/`. It contains:
+
+- **Single commit**: `a5fae41a3e` (2014-10-17): "update .travis.yml"
+- **Source files in `src/`**:
+ - `HammersmithOne-Regular.vfb` -- Original FontLab source with contour overlaps
+ - `HammersmithOne-Regular-OTF.sfd` -- FontForge SFD for OTF output
+ - `HammersmithOne-Regular-TTF.sfd` -- FontForge SFD for TTF output with hinting
+ - Various TTX table decompositions
+- **No UFO, Glyphs, or designspace files**
+- **No config.yaml**
+- **Travis CI config**: Uses `fontbakery-build.py` for build/test, not gftools-builder
+
+The repo is a `librefonts` archive -- these were created as mirrors of Google Fonts families with their sources decomposed to TTX. The original source is the VFB file.
+
+### Source Format Assessment
+
+The only editable sources are:
+- VFB (FontLab proprietary binary format) -- not supported by gftools-builder
+- SFD (FontForge format) -- not supported by gftools-builder
+
+The TTX files are decomposed table dumps, not a primary source format for font compilation.
+
+### Version Match
+
+The VERSIONS.txt in the repo states `HammersmithOne-Regular.ttf: Version 1.003`, matching the version string in the google/fonts binary. The google/fonts copy was later updated with a name table fix in PR #2351, but the version number remained 1.003.
+
+## Conclusion
+
+The upstream repository is correctly identified. The commit hash `a5fae41a3eabe8ec4e1d8ff7b3fa6dfde5c4fa87` is the only commit in the repo. The sources are exclusively in SFD/VFB formats, which are not compatible with gftools-builder. No config.yaml is possible without converting the sources to a supported format (UFO or Glyphs).
+
+### Recommended METADATA.pb Source Block
+
+```
+source {
+ repository_url: "https://github.com/librefonts/hammersmithone"
+ commit: "a5fae41a3eabe8ec4e1d8ff7b3fa6dfde5c4fa87"
+}
+```
+
+### Status: no_config_possible
+
+SFD/VFB-only sources. These legacy formats are not compatible with gftools-builder, and creating a config.yaml is not possible without first converting the sources to UFO or Glyphs format.