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

# Cross-chain architecture

The networks City Protocol runs on, how $CIT is bridged, and the risks of operating across chains.

## Networks and their roles

City Protocol runs across several EVM networks. The token has one canonical home, each product sits on the network where its strategy or constituents operate, and Venzo presents products from every supported network in one interface.

<figure><img src="https://3297077862-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2FJxNp2waFk6hg1G4lEQZu%2Fuploads%2FQSoHnvCYORBxuiGK5qKa%2Ffig-networks-v21.png?alt=media" alt="Ethereum mainnet holds the canonical $CIT contract, bridged to Arbitrum One, BNB Smart Chain and Base, and each network carries its own products"><figcaption><p>Networks and products as of September 2026. $CIT has one canonical home on Ethereum mainnet and will be bridged to Arbitrum, Base and BNB Smart Chain ahead of listing, and each product sits on the network where its strategy or constituents operate.</p></figcaption></figure>

As of September 2026, the networks carry the following.

| Network          | $CIT                                            | Products                                                                                                             |
| ---------------- | ----------------------------------------------- | -------------------------------------------------------------------------------------------------------------------- |
| Ethereum mainnet | Canonical contract, with the full supply minted | Curated Vault deployments                                                                                            |
| Arbitrum One     | Bridged ahead of listing                        | Curated Vault deployments                                                                                            |
| BNB Smart Chain  | Bridged ahead of listing                        | Index OTPs powered by bStocks, such as the Magnificent Seven Index OTP; planned vault integration                    |
| Base             | Bridged ahead of listing                        | Index OTPs powered by Coinbase Tokenized Stocks, such as the Fantastic Four Index OTP and the Tesla–SpaceX Index OTP |

## Token bridging

$CIT follows a canonical-supply model. The full supply of 10,000,000,000 $CIT was minted once on Ethereum mainnet, and the $CIT tokens on Arbitrum, Base and BNB Smart Chain will be bridged representations, created ahead of listing: a transfer takes tokens out of circulation on the source network, by locking or burning them, before the bridge releases the same amount on the destination network. Let $$S\_k$$ denote the circulating supply of $CIT on network $$k$$, outside the bridge's escrow. Then

$$
S\_{\mathrm{Ethereum}} + S\_{\mathrm{Arbitrum}} + S\_{\mathrm{BNB}} + S\_{\mathrm{Base}} ;\le; 10^{10}
$$

{% hint style="success" %}
**Supply conservation:** The combined circulating supply of $CIT on Ethereum mainnet, Arbitrum One, Base and BNB Smart Chain never exceeds 10,000,000,000, provided the bridge releases tokens on a destination network only against an equal amount locked or burned on the source network.

**Why it holds:** The full supply was minted once on Ethereum mainnet, and the bridged contracts issue tokens only through the bridge. Each transfer removes an amount from circulation on the source network before releasing the same amount on the destination network, so every transfer preserves the combined total, which starts at 10,000,000,000.
{% endhint %}

The bridged and bridge contract addresses are published through City Protocol's official channels before listing, and only those published addresses are official.

## Products across networks

Curated Vaults are deployed across several networks and apply chain abstraction: a participant deposits from a supported EVM network and receives vault shares, while strategy execution and NAV settlement stay on the vault's execution network. OTP constituents are held on the network where they are issued, in the participant's own smart account. Full chain abstraction across supported networks is planned for 2027.

## Cross-chain risks

Operating across several networks adds bridge, messaging, liquidity and network risks.

| Risk                      | Effect                                                                          | Controls                                                                                                              |
| ------------------------- | ------------------------------------------------------------------------------- | --------------------------------------------------------------------------------------------------------------------- |
| Bridge failure or exploit | Bridged $CIT can lose its backing, and tokens in transit can be lost or delayed | Canonical supply on Ethereum mainnet; addresses published before listing; supply on each network reconcilable onchain |
| Message relay failure     | A cross-chain deposit or withdrawal is delayed or fails to complete             | A cross-chain request settles only once its message is delivered, with request status visible per deployment          |
| Network outage            | Downtime, congestion or a reorganization delays settlement                      | Layered pause controls per deployment; settlement at the next valuation point                                         |
| Address spoofing          | Users interact with counterfeit contracts or phishing interfaces                | Official addresses and domains published through official channels                                                    |