Probed R1.4 GetHistorianInfo (GETHI) live against the local 2020 server.
GETHI returns native error type 4 / code 1 for the exact native request shape
across 5 handle formats (storage GUID, context GUID, uint decimal/X8/0x-hex)
even with Stat.GetV ×2 priming. Its result is discarded (TryRun) in the only
place it's used, so it was never actually verified to return data managed-side.
This confirms a structural boundary on the 2020 WCF surface: ops taking a uint
client handle work (the proven read/browse/metadata/status/event surface);
ops taking a string GUID handle (ExeC, QTB, QTG, GETHI, GetTepByNm, ...) are
blocked behind an unmapped native session/filter registration. Every remaining
M1 *read* item (R1.1/R1.4/R1.5/R1.6) is string-handle -> all gated on that one
RE target. Reachable uint-handle items: R1.7 event filters, R1.8/R1.9 summary
modes.
New: docs/reverse-engineering/wcf-string-handle-wall.md (full dichotomy + table).
Roadmap R1.4/R1.5/R1.6 struck through; reachable items re-pointed.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Joseph Doherty
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