> For the complete documentation index, see [llms.txt](https://venzofinance.gitbook.io/venzofinance-docs/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://venzofinance.gitbook.io/venzofinance-docs/venzo-app/architecture.md).

# Architecture

How Venzo is built, from the app to the two product architectures underneath it.

Venzo is the application layer of a stack built by City Protocol. Users reach every product through Venzo, the Issuance & Operation Layer launches and runs those products, and two architectures underneath hold the assets: one for Curated Vaults and one for OTPs.

<figure><img src="https://534920511-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FUOkB6OkoR713tjtlF6Z6%2Fuploads%2FnAxIQGegGdNu1Asrj12b%2Ffig-architecture-stack.png?alt=media" alt="Venzo sits above the Issuance and Operation Layer, which sits above the Curated Vault architecture and the OTP architecture"><figcaption><p>Venzo, the Issuance &#x26; Operation Layer, and the two architectures underneath.</p></figcaption></figure>

| Layer                      | What it does                                                                                                                                                |
| -------------------------- | ----------------------------------------------------------------------------------------------------------------------------------------------------------- |
| Venzo                      | The app: Explore, product pages, Portfolio, Campaign and Proof of Reserves. Every subscription is signed from the participant's own wallet.                 |
| Issuance & Operation Layer | The product layer: registry, validation, issuance, reporting, subscriptions, rebalancing, eligibility, disclosure and lifecycle.                            |
| Curated Vault architecture | Pooled vault contracts with a report oracle, epoch settlement and bounded strategy execution, supplied by Vault as a Service and Tokenization as a Service. |
| OTP architecture           | A smart account for each participant that holds every constituent, with scoped permissions for trades.                                                      |

The Curated Vault architecture separates product governance from execution. The curator defines the mandate, the strategy manager executes only inside it, and automated circuit breakers pause the affected functions when a vault breaches a predefined boundary. The OTP architecture keeps every constituent in the participant's own account, so exit stays available even while a product is paused.

## In this section

* [Issuance & Operation Layer](/venzofinance-docs/venzo-app/architecture/issuance-and-operation-layer.md): the product lifecycle shared by both architectures.
* [Capital Flow](/venzofinance-docs/venzo-app/architecture/capital-flow.md), [Deposit Flow](/venzofinance-docs/venzo-app/architecture/deposit-flow.md), [Accounting and Controls](/venzofinance-docs/venzo-app/architecture/accounting-and-controls.md) and [Redemption](/venzofinance-docs/venzo-app/architecture/redemption.md): how a Curated Vault takes, values and returns capital.
* [OTP Account Model](/venzofinance-docs/venzo-app/architecture/otp-account-model.md): how an OTP holds its constituents and carries out trades.