# DBIS HYBX Sidecar Boundary Matrix

**Last updated:** 2026-03-28  
**Purpose:** Define the current boundary, role, and likely RTGS relevance of the HYBX sidecar repositories currently available in the local workspace. This is a repo-backed companion to the RTGS E2E requirements matrix.

## Interpretation

- `Available locally` means the repository exists in `/home/intlc/projects/HYBX_Sidecars`.
- `RTGS relevance` means whether the sidecar is likely part of the initial production RTGS slice, not whether it is interesting or strategically useful.
- `Boundary frozen` means the sidecar has a sufficiently clear place in the RTGS architecture to be used in implementation planning.

## Matrix

| Sidecar | Local repo state | Core purpose | Key internal modules / evidence | RTGS relevance | Boundary frozen? | Notes |
|---------|------------------|--------------|----------------------------------|----------------|------------------|-------|
| `mifos-fineract-sidecar` | Available locally | Compliance and settlement sidecar for Mifos/Fineract | `scsm-api`, `scsm-gateway`, `scsm-compliance`, `scsm-posting`, `scsm-fineract`, `scsm-settlement`, `scsm-reconciliation`, `scsm-audit`, `scsm-events`, `scsm-observability`, `scsm-app` | **High** | **Partial** | This is the strongest candidate for the canonical OMNL/HYBX RTGS sidecar because it already models compliance, posting, settlement, reconciliation, audit, and Fineract integration. |
| `mt103-hardcopy-sidecar` | Available locally | MT-103 hardcopy ingest and deposit-envelope correlation | Go service with document/deposit/payload/submit flows | **Medium** | Partial | Useful for evidence/audit and documentary payment flows, but not necessarily a mandatory first-slice RTGS core dependency. |
| `off-ledger-2-on-ledger-sidecar` | Available locally | XAU-collateralized off-ledger to on-ledger conversion | Collateral registry, orchestrator, ledger adapter, API plan | **High** | Partial | Strong candidate for the bridge between off-ledger payment events and on-ledger liquidity/settlement on Chain 138. |
| `securitization-engine-sidecar` | Available locally | Regulatory accounting and securitization engine | Asset classification, risk/capital, accounting, securitization, reporting | **Medium** | Partial | Important for structured products, capital treatment, and reporting, but likely adjacent to core RTGS rather than in the narrowest first production slice. |
| `card-networks-sidecar` | Available locally | Card auth, clearing, settlement, disputes | `cardnet-auth`, `cardnet-clearing`, `cardnet-fineract`, `cardnet-settlement`, `cardnet-reconciliation`, `cardnet-posting`, `cardnet-audit` | **Medium** | Partial | Highly relevant if card-network settlement is part of the DBIS/HYBX program; otherwise a later rail-specific extension. |
| `server-funds-sidecar` | Available locally | Multi-rail transfers and settlement events | `funds-api`, `funds-transfers`, `funds-settlement`, `funds-reconciliation`, `funds-posting`, `funds-fineract` | **High** | Partial | Strong candidate for server-to-server treasury/funds movement and may be central if the RTGS program uses server-funds orchestration. |
| `securities-sidecar` | Available locally | Securities instruction, settlement, and reconciliation | `securities-instruments`, `securities-instructions`, `securities-settlement`, `securities-reconciliation`, `securities-posting` | **Low/Medium** | Planned | More naturally a securities-settlement extension than a mandatory first RTGS slice. |
| `flash-loan-xau-sidecar` | Available locally | Atomic XAU / LiXAU flash-loan flows | `xau-atomic`, `xau-settlement`, `xau-reconciliation`, `xau-posting` | **Low/Medium** | Planned | Valuable for specialized liquidity/XAU flows, but not required for the narrowest RTGS baseline. |

## Recommended first production slice

For the narrowest credible RTGS implementation, the strongest initial sidecar candidates are:

1. `mifos-fineract-sidecar`
2. `server-funds-sidecar`
3. `off-ledger-2-on-ledger-sidecar`

Those three cover the most direct path across:

- Fineract integration
- compliance / posting / settlement / reconciliation
- treasury/server-funds orchestration
- off-ledger to on-ledger conversion

## Recommended later-phase sidecars

- `mt103-hardcopy-sidecar`
- `card-networks-sidecar`
- `securitization-engine-sidecar`
- `securities-sidecar`
- `flash-loan-xau-sidecar`

These should be added only when the RTGS program confirms those rails or reporting models are actually in scope.

## Boundary decisions still needed

1. Which sidecar owns the canonical settlement orchestration record?
2. Which sidecar owns final posting responsibility versus suggested-entry generation?
3. Which sidecar emits the canonical event consumed by FireFly or on-chain settlement?
4. Which sidecar is system-of-record versus adapter versus evidence generator?

## Related artifacts

- [DBIS_RTGS_E2E_REQUIREMENTS_MATRIX.md](DBIS_RTGS_E2E_REQUIREMENTS_MATRIX.md)
- [GITEA_HYBX_ORGANIZATION_AND_REPOS.md](../11-references/GITEA_HYBX_ORGANIZATION_AND_REPOS.md)
- [HYBX_BATCH_001_OPERATOR_CHECKLIST.md](../04-configuration/mifos-omnl-central-bank/HYBX_BATCH_001_OPERATOR_CHECKLIST.md)