# NexusFIX session store and resend proof, 2026-10-01

On HP, a standalone [probe](../../bench/cpp/fixbench/tools/open_source_fix_engines/native/nexusfix_store_recovery_probe.cpp)
built against the pinned clean NexusFIX snapshot
`ffa8b0a014b5cb4020ec8a99fe22fa3a24bfc494` with GCC 11.5. The five
needed GCC 11 compatibility headers were copied outside the upstream checkout;
their [diff](evidence/nexusfix-store-recovery-hp-20261001/gcc11-compat.patch)
and the build [manifest](evidence/nexusfix-store-recovery-hp-20261001/manifest.json)
are retained. The upstream git worktree stayed clean.

The [wire transcript](evidence/nexusfix-store-recovery-hp-20261001/transcript.txt)
shows a first FIX session logging on with sender sequence 1. NexusFIX stored
that outbound Logon and advanced both expected sequence numbers to 2. The
probe destroyed that `SessionManager`, created another one with the same
`MemoryMessageStore`, and logged on with sender sequence 2. It then sent a
counterparty ResendRequest for sequences 1–2. NexusFIX replayed both messages
with original sequence numbers, `43=Y` and `122=OrigSendingTime`; the current
outbound sequence remained 3. The probe exited zero and printed `status=pass`.

This is session recreation and resend evidence within one process. The store
is memory backed; the test does not establish durability across process
termination or prove a production file store. It also measures no latency and
uses no physical link. A corrected physical Stage 5 report and its rate gate
are still required before NexusFIX can become a publishable C++ comparator.