proxmox/docs/03-deployment/DBIS_RTGS_FIRST_SLICE_ARCHITECTURE.md

DBIS RTGS First Slice Architecture

Last updated: 2026-03-28
Purpose: Freeze the narrowest credible first production slice for the DBIS RTGS program using the assets currently available in the repository and local environment.

Design principle

The first production slice should avoid expanding the critical path with systems that are not yet deployed or not yet evidenced in the workspace. The goal is to get to a real end-to-end settlement slice with the minimum number of moving parts.

Included in first slice

Core runtime

• Chain 138 / Hyperledger Besu
• Explorer / Blockscout
• FireFly primary (6200)
• Mifos / Fineract / OMNL rail

Selected HYBX sidecars

• mifos-fineract-sidecar
• server-funds-sidecar
• off-ledger-2-on-ledger-sidecar

Deferred from first slice

• FireFly secondary (6201)
• Fabric runtime
• Indy runtime
• Mojaloop integration
• Aries / AnonCreds / Ursa runtime
• Cacti runtime
• card-network, securities, and flash-loan specialized sidecars

Why these sidecars

mifos-fineract-sidecar

This is the strongest general-purpose banking sidecar for the first slice because it already models:

• compliance
• posting
• settlement
• reconciliation
• audit
• Fineract integration
• events
• observability

server-funds-sidecar

This is the best fit for treasury/funds movement orchestration because it already exposes:

• transfer initiation
• approvals
• settlement events
• reconciliation
• Fineract integration

off-ledger-2-on-ledger-sidecar

This is the best fit for the off-ledger to on-ledger bridge because it already frames:

• collateral or source-of-value lock
• conversion initiation
• settlement
• extinguish/release flow

First-slice interaction flow

1. Participant/office exists in OMNL / Fineract.
2. A transfer or settlement intent enters through the canonical banking rail.
3. mifos-fineract-sidecar validates, screens, posts, and settles the banking-side event.
4. server-funds-sidecar coordinates treasury/server-funds transfer semantics where needed.
5. off-ledger-2-on-ledger-sidecar maps qualifying off-ledger value into the Chain 138 settlement path.
6. Chain 138 settlement contracts record or confirm the on-ledger leg.
7. Reconciliation and audit artifacts are produced.
8. The regulatory package path is generated from the resulting evidence set.

Immediate implementation sequence

Sequence A — Banking rail

1. Freeze the OMNL / Fineract tenant and operator path.
2. Freeze the participant / treasury / GL model.
3. Validate the HYBX-BATCH-001 operator flow end to end.

Sequence B — Sidecar baseline

1. Build and validate mifos-fineract-sidecar.
2. Build and validate server-funds-sidecar.
3. Build and validate off-ledger-2-on-ledger-sidecar.
4. Record runtime dependencies, health endpoints, and deployment units.

Sequence C — Settlement mapping

1. Freeze the canonical Chain 138 settlement contracts used by RTGS.
2. Define the exact event handoff from sidecars to on-chain settlement.
3. Define reconciliation outputs and operator evidence.

Exclusion rule

Anything not listed in “Included in first slice” must not be treated as a blocker for initial RTGS activation unless governance explicitly changes scope.

Related artifacts

• DBIS_RTGS_E2E_REQUIREMENTS_MATRIX.md
• DBIS_HYBX_SIDECAR_BOUNDARY_MATRIX.md
• DBIS_MOJALOOP_INTEGRATION_STATUS.md
• DBIS_HYPERLEDGER_IDENTITY_STACK_DECISION.md