Deterministic projection
Same canonical inputs, configuration, build and time basis produce the same state.
DSE · BFIE
Financial state without duplicate math.
The Bank / Forensic Integrity Engine (BFIE) is the financial and evidentiary lane of the Deterministic State Engines (DSE) family, alongside the Activation Integrity Engine (AIE). It keeps transaction, account, obligation and evidentiary projections inside one deterministic engine boundary.
One calculation authority.
Consumers render BFIE output. They do not reimplement financial truth independently inside dashboards, CRMs or downstream products.
Evidence continuity
Observed bank records and business events remain distinguishable until reconciled.
Integer money math
Hardened calculations use integer minor units and explicit currency rules.
Consumer boundary
Downstream products consume projected state without becoming the source of truth.
Software History
How the engine evolved.
Architecture changed as the operating boundary became clearer. Earlier generations remain part of the evidence trail rather than being rewritten as if the current implementation appeared fully formed.
BFIE began as an AIE-derived deterministic financial evidence scaffold.
The first preserved scaffold identified itself as BFIE v0.1.0 and explicitly derived its operating pattern from AIE. It discovered statements, built a statement registry, normalized transactions, applied strict rule-based classification, generated evidentiary CSV indexes and emitted a run receipt.
The scaffold became a mapping-governed computation rail.
The SQL/ETL and design body added immutable configuration, source and row hashes, run manifests, append-only raw extraction, normalized fact tables, structured data-quality issues and a sequential hash-chain ledger. The accompanying design work formalized declared mapping profiles, temporal ambiguity, conflict-aware transaction identity, replay receipts and receiving-side verification.
A modern Rust projection kernel became the calculation authority.
BFIE was separated as its own DSE field engine and hardened around a Rust projection kernel. The modern boundary uses integer minor-unit money math, explicit time inputs, deterministic duplicate/conflict handling and manifest/run/snapshot hashes so downstream products consume state instead of recreating financial calculations.
The ancestral evidence rail and modern kernel were joined instead of choosing one generation.
Forensic reconciliation established BFIE as one system with two preserved generations: the source/mapping/evidence rail and the modern projection kernel. The service architecture separates ingest and evidence adaptation, the pure project() calculation boundary, and persistence/delivery so provenance can deepen without duplicating projection math.
BFIE now extends deterministic financial geometry without surrendering its evidence boundary.
Later work added a bounded service interface, deterministic trading projection and an explicit forward-allocation contract. Receipts remain evidence produced by the calculation path, not the purpose of the engine; unsupported inputs, missing financial truth and contradictory state still resolve to HOLD rather than invented numbers.
Current Evidence
Hardened Rust runtime uses minor-unit integers; no floating-point financial arithmetic.
Explicit as_of UTC input keeps time-dependent state reproducible.
Duplicate IDs with conflicting payloads produce HOLD and exclusion rather than arbitrary winner selection.
Separate adapter preserves deterministic finance while receipting probabilistic external QPU observations.