Item 3: the gRPC read-back against the live 2023 R2 server proves the SDK-sent
event PERSISTS (independently read back from event history), resolving the older
WCF/M2 caveat ("server accepts AddS2 but the local dev box does not persist to
v_AlarmEventHistory2") as an environment artifact, not an SDK gap. Also retire the
stale "fresh native capture (SendEvent gRPC framing)" next-step note — SendEvent
over gRPC is now shipped + live-validated.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01B6mcaT2PjRFKcogzp9UkfC
Tested the binary-dive "use deleteFromServer=true" hypothesis directly against
the native client (local 2020 WCF box, Capture-DeleteTagExtendedProperties.ps1
cross-session sync trick). Result: the native DeleteTagExtendedPropertiesByName
with deleteFromServer=true returns Success=true, but the property is re-fetchable
and re-deletable across repeated fresh sessions — it is NEVER durably removed.
So the native client itself only performs an optimistic client-side cache delete
the server does not durably honor (the HCAL cache-sync model the decompile shows).
This supersedes the earlier "code=1, prop survives" note (that was the same-session
sync-gate failure; with proper cross-session sync it returns Success yet still does
not durably delete). A managed DeleteTagExtendedPropertiesAsync would return a
misleading success, so it correctly stays unshipped. Handoff item 7 updated.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01B6mcaT2PjRFKcogzp9UkfC
Captured the native 2023 R2 client's gRPC event send (new capture-send-event
harness scenario): it rides HistoryService.AddStreamValues with the SAME "OS"
(0x534F) storage-sample buffer the WCF path already uses (HistorianEventWrite-
Protocol) — confirming "no distinct RPC", and that it is NOT the historical
write's "ON" buffer. Diffed the write-enabled vs read-only v8 Event open: byte-
identical apart from per-session crypto, so the existing OpenSession event path
is reused unchanged.
So SendEvent-over-gRPC was pure assembly of proven parts:
- HistorianGrpcEventWriteOrchestrator = v8 Event open + CM_EVENT registration
(UpdC3/RegisterTags/EnsureTags) + AddStreamValues(OS buffer).
- HistorianClient.SendEventAsync now routes to it for RemoteGrpc (WCF otherwise).
Live-validated end-to-end against the 2023 R2 server: pure-managed SDK send →
AddStreamValues BSuccess=true → the event reads back from the server (markers
confirmed in returned event rows). The native gRPC RegisterTags(24B) +
EnsureTags(86B) byte-match our serializers (new GrpcEventSendProtocolTests
golden, closing the 83-vs-86 EnsureTags question). Gated live test
SendEventAsync_OverGrpc_AcceptsEvent (opt-in HISTORIAN_GRPC_EVENT_SEND=1).
331 offline tests pass.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01B6mcaT2PjRFKcogzp9UkfC
Mined the full decompiled stock 2023 R2 managed client as the oracle for every
still-pending gRPC item. Governing fact: ArchestrA.HistorianAccess is a C++/CLI
shim into native HistorianClient; the managed Grpc*Client wrappers have zero
call sites, so buffer-building/dispatch for the pending items is native (absent
from the binaries). Sharpened verdicts into handoff.md:
- Items 4/5/6 + OpenStorageConnection: hard-confirmed walled, with real reasons
(SQL gated out client-side via IsManagedHistorian; no Revision RPC in the gRPC
contract; LoadBlocks response is a native blob behind the storage console handle).
- Items 3 (SendEvent) and 7 (DeleteTEP): moved from vague to precise, LOCAL-box
capturable targets (PackToVtq btValues / DeleteTagExtendedPropertiesByName
BtInput with deleteFromServer=true).
Also correct the HistorianGrpcRevisionProbe doc comment: it probes the
non-streamed ORIGINAL-insert path (AddNonStreamValues), a distinct capability
from revision EDITS (native AddRevisionValues trio, no gRPC RPC) — the prior
comment conflated them.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01B6mcaT2PjRFKcogzp9UkfC
Bring the doc header current with the merged event-row parser fix: bump
"Last updated" to 2026-06-23 and correct the Build And Test known-good
result from 321/321 to the actual 328/328 (build clean 0/0), noting the
+7 are the HistorianEventRowProtocolTests golden + gated-capture coverage.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01B6mcaT2PjRFKcogzp9UkfC
Updated the live-blocker item (1) to reflect that all four next-session angles for the
gRPC event zero-rows are now tested and ruled out (transport, metadata/cert, topology,
data store) and that the parse path is verified against the provided client with a latent
multi-row bug fixed. Corrected the two historical event-row-layout skeletons that wrongly
described 0x1E as a per-row marker: it is a one-time buffer header field and rows are
markerless (which is why the old parser returned only the first row of any multi-row
buffer, on WCF too).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01B6mcaT2PjRFKcogzp9UkfC
Records the row-retrieval pickup now that the v8 ExchangeKey auth is solved and the
gap is proven connection-level (not client payload):
- grpc-event-query-capture.md: a "NEXT SESSION — the server-side / connection angle"
section — what's already proven (don't redo), the in-place tooling, and ordered,
testable hypotheses (HTTP/2 vs gRPC-Web transport [leading], TLS client cert,
HTTP/2 frame capture, SQL event-store scoping).
- handoff.md item 1: updated to "v8 auth solved; row retrieval connection-gated",
pointing at the NEXT SESSION section; the "to move any item" summary updated.
Doc-only; sanitization scan clean.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01B6mcaT2PjRFKcogzp9UkfC
Item 1 is no longer capture-gated (the capture is done, merged 8ad160b). Update it
to: the capture-event run read 50 events from the stock client; the v6 request is
shipped; the remaining gate is the native v8 Event-type OpenConnection (a
ConnectionType field the SDK's v6 Open2 format lacks), a scoped RE+impl follow-on.
Points at docs/reverse-engineering/grpc-event-query-capture.md. Also corrected the
"to move any item" summary so item 1 no longer reads as needing a fresh capture.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01B6mcaT2PjRFKcogzp9UkfC
Live SQL ground truth (user-authorized one-time read via SOCKS->SQL relay)
disproves the gate on the open gRPC event-row item. The live 2023 R2 server
IS event-bearing — Runtime.dbo.Events holds 19,356 rows in the last 30 days
(90,944 in 365) — yet the empty-filter gRPC event query still returns zero rows
and long-polls to the deadline over that same window.
So GetNextEventQueryResultBuffer returning nothing is NOT "no events on the
server"; the empty-filter request shape (filter / namespace / event-tag
registration) doesn't match existing rows. The remaining work is a fresh native
gRPC event-query capture of the stock client, not access to a different server.
- handoff.md: rewrite open-item #1 with the SQL numbers + capture-gated framing;
update the "to move any item" summary to match.
- HistorianGrpcIntegrationTests: correct the event-read test comment (drop the
false "idle dev box holds no events" rationale; document 19k-events-yet-zero-rows).
No behavior change (test edit is comment-only). Sanitization scan clean.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01B6mcaT2PjRFKcogzp9UkfC
The handoff doc was anchored at 2026-05-04 (read-path blocker era). Add a
"Current Status (2026-06-22)" section at the top summarizing the full shipped
read/write/config/client-side surface across WCF + gRPC, the 8 remaining gated
items (event-row retrieval, active-SF magnitude, SendEvent capture, SQL wall,
R4.2 edits, ReadBlocks, the disproven DelTep gRPC probe, deferred-by-design),
and what would unblock each. Reframe the old "Active Blocker" as a historical
read-path record; fix the stale 55/55 test count to 321/321 offline.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01B6mcaT2PjRFKcogzp9UkfC
HistorianSspiClient rewritten on top of System.Net.Security.NegotiateAuthentication
in place of P/Invoke into secur32.dll's InitializeSecurityContextW. The class
keeps the same Next() / Dispose() / two-constructor surface so callers don't
change. RequiredProtectionLevel=EncryptAndSign + AllowedImpersonationLevel=
Identification produces a request-flag set equivalent to the captured native
0x2081C / 0x81C bitmasks (still preserved as constants for the existing unit
tests). Removes the only Windows P/Invoke in the production SDK; the
[SupportedOSPlatform("windows")] gating elsewhere stays in place pending a
separate sweep.
HistorianStorageType (Cyclic = 1, Delta = 2):
Captured 2026-05-04 via --write-storage-type on the harness. Delta differs
from Cyclic in three places — header byte 10 (0x02 -> 0x06), flag-block
byte 1 (0x01 -> 0x02), and 4 zero bytes inserted after StorageRate before
the FILETIME. Server persists Tag.StorageType=1/2 accordingly. Plumbed
through HistorianTagDefinition.StorageType + serializer + orchestrator + 2
new tests (golden bytes + live SQL persistence verification).
Docs polish:
CLAUDE.md no longer claims "no P/Invoke" (HistorianSspiClient is the one
allowed P/Invoke surface); updated test count to 169+; AGENTS.md Required
SDK Surface and Repository Layout brought up to date with the live state
including the write surface; handoff.md "not a git working tree" obsolete
note removed.
171/171 tests pass with the NegotiateAuthentication replacement (was 169;
+2 new tests for StorageType).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
ApplyScaling (HistorianTagDefinition.ApplyScaling):
The EnsT2 trailer's second byte controls server-side scaling — `FE 00`
mirrors MinRaw to MinEU and sets AnalogTag.Scaling=0; `FE 01` persists
distinct MinRaw/MaxRaw and sets Scaling=1. Decoded by toggling
set_ApplyScaling on the native harness and capturing the wire bytes for
both values with identical inputs. The earlier docs claimed
EnsureTagAsync needed a follow-up "UpdateTags" call; the WCF surface has
no such operation — toggling that one byte is the whole fix.
StorageRate (HistorianTagDefinition.StorageRateMs):
Serializer accepts a non-default rate, validated empirically against
the live server which only accepts quantized values
(1000/5000/10000/60000/300000 ms).
EnsureTagAsync upsert semantics:
Second call on the same tag name with different fields succeeds and
updates Description, MinEU, MaxEU, MinRaw, MaxRaw, Scaling in place
(verified by direct SQL inspection in a live test).
Plan + doc closeout:
write-commands-reverse-engineering.md rewritten as a current-state
plan with three workstreams (A doc closeout / B idempotency / C1
StorageRate) and a parallelism table; prior phase notes preserved as
appendix. handoff.md, implementation-status.md, wcf-contract-evidence.md,
README.md updated to remove "writes are out of scope" / non-existent
UpdateTags references and document the actual EnsT2 wire format
including the `FE xx` trailer.
Reverse-engineering harness gains --write-apply-scaling and a SQL
post-check that prints the persisted AnalogTag bounds so future RE
sessions can verify wire→DB causality without leaving the harness.
169/169 tests pass (was 165; +4 new tests covering ApplyScaling,
StorageRate golden bytes, StorageRate live persistence, and
EnsureTagAsync upsert semantics).
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Full read-only SDK (src/AVEVA.Historian.Client) implementing the CLAUDE.md required
surface against AVEVA Historian's binary WCF protocol — no native AVEVA runtime
dependency. All operations live-verified against a local Historian:
- ProbeAsync, ReadRawAsync, ReadAggregateAsync, ReadAtTimeAsync, ReadEventsAsync
- BrowseTagNamesAsync, GetTagMetadataAsync (17 native data-type codes mapped)
- GetConnectionStatusAsync, GetStoreForwardStatusAsync, GetSystemParameterAsync
- 108/108 unit + integration tests pass
Includes the reverse-engineering toolkit (tools/AVEVA.Historian.ReverseEngineering)
used to decode the protocol: WCF probes, IL inspection via dnlib, and IL-rewrite
instrumentation (instrument-wcf-{write,read}message etc.) plus the .NET Framework
trace harness (tools/AVEVA.Historian.NativeTraceHarness) for parity testing.
Sanitized handoff evidence under docs/reverse-engineering/. Native AVEVA binaries
(current/, aveva-install-x64/, aveva-install-x86/) are gitignored — fetch separately
from the AVEVA installer.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
Joseph Doherty