D1 holds the record
The reusable contracts assume append-only observations and explicit effective views, not in-place correction of provider facts.
Architecture
How evidence becomes an answer
The design separates facts, operational choices, deterministic read models, and agent explanations so one failure does not quietly become financial truth.
Provider feedClosed statementsOwner corrections
↓01 · evidenceImmutable observations
↓Keep what each source actually said.
02 · operationsEffective ledger
↓Resolve supersession, lifecycle, exclusions, and repairs reversibly.
03 · meaningDeterministic finance views
↓Cashflow, debt, net worth, merchants, transfers, and recurring commitments.
Agent investigationQualified answersBounded repair work
MCP carries the evidence
Tool results state freshness, coverage, status, provenance, and limitations beside the requested data.
Agents stay outside the math
A steward can retry derived work or investigate a case. It cannot make an unsupported row real.