> For the complete documentation index, see [llms.txt](https://docs.bill-z.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.bill-z.com/hybrid-infrastructure-model.md).

# hybrid infrastructure model

Billz Pro operates at the intersection of:

**On-chain capital** (treasury, collateralized positions, liquidity logic)\
↔\
**Regulated fiat systems** (SEPA / ACH, compliance, banking constraints)

We call this a **hybrid execution model**.

```mermaid
flowchart TD
    A[Wallet Interaction Layer] --> B[Treasury & Orchestration Layer]
    B --> C[Compliance & Monitoring Layer]
    C --> D[Fiat Rail Execution Layer]
    D --> E[SEPA EUR / ACH USD]
    B --> F[Proof & Reconciliation Artifacts]
```

> ### Layered architecture (visual, high-level)

## Layered architecture (high-level)

### 1) Wallet Interaction Layer

* user-initiated actions
* authorization boundaries
* no private key storage by Billz

### 2) Treasury & Orchestration Layer

* funding mode selection (direct vs collateralized, when available)
* execution routing and policy application
* proof and reference standardization

### 3) Compliance & Monitoring Layer

* KYC / KYB / EDD workflows (as applicable)
* risk-based monitoring
* exception handling and review

### 4) Fiat Rail Execution Layer

* SEPA / ACH initiation via regulated rails
* cutoff logic, holidays, and rail constraints respected

## Why modularity matters

A treasury execution infrastructure must adapt to:

* rail changes
* regulatory changes
* market volatility
* evolving treasury strategies

Modularity helps Billz Pro evolve without forcing operators to rebuild finance workflows.