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ZENDEX Testnet Technical & Operational Documentation

Welcome to the official ZENDEX Public Testnet Documentation. This documentation serves as the comprehensive technical and operational reference for traders, liquidity providers, institutional partners, and developers participating in the testnet release at testnet.zendex.fi.

Testnet User Notes​

In the testnet version of ZENDEX, transactions are still sent from your connected wallet, so your actions can be linked to that wallet. Token movements in the pools, such as swap amounts, are visible on-chain like any AMM trade.

Regarding your dust address, your dust address receives withdrawals and any leftover amounts from swaps and liquidity actions. It is a normal EVM address derived from your Zendex Key, so it is not your connected wallet. You can see it in the header and on the Account page.

To use the funds that arrive there:

  1. On the Account page, click Reveal secret key and copy it.
  2. In MetaMask, choose Add account or hardware wallet → Import account and paste the key. The imported account is your dust address.
  3. Send it a little testnet ETH for gas before moving tokens out of it (see Getting Started On Testnet below).

You can also set your own dust address on the Account page, for example a fresh wallet you already control.

Getting Started On Testnet​

  1. Get testnet ETH for gas from the Horizen Testnet Hub.
  2. On the Faucet page, wrap some testnet ETH into WZEN and mint tUSDC, tcbBTC or tZKZ. Use Add to wallet to see them in MetaMask.
  3. Generate a Zendex Key on the Deposit page and back it up.
  4. Deposit tokens, then swap, trade or add liquidity.

Introduction to ZENDEX​

ZENDEX is a privacy-preserving hybrid decentralized exchange deployed on the Horizen EVM execution layer. By unifying a private Automated Market Maker (AMM) based on constant-product pricing with a hidden Limit Order Book under a single Zero-Knowledge (ZK) framework, ZENDEX allows market participants to execute trades, deploy capital, and manage order flow without exposing balances, trade sizes, order intent, or wallet identity on-chain.

Traditional decentralized exchanges publish all state changes directly to a public mempool, exposing user activity to predatory tactics. ZENDEX eliminates state exposure by replacing public balance accounting with cryptographic commitments, zero-knowledge proofs, and zero-knowledge identity compliance layers.

Privacy on the public testnet is distinct from mainnet. The testnet does not yet provide every property described for mainnet, for example your actions can still be linked to your connected wallet. See Testnet User Notes above and Privacy Guarantees.

ZENDEX Testnet​

The ZENDEX Public Testnet (testnet.zendex.fi) is the live, sandbox deployment designed to stress-test protocol performance, validate client-side UltraPlonk proof generation, and benchmark the execution dynamics of shielded DeFi primitives on the Horizen Testnet (Chain ID: 2651420).

Core ZENDEX Testnet Links:

Mint Horizen Testnet ETH here: https://horizen-testnet.hub.caldera.xyz/

Use the ZENDEX Testnet here: https://www.testnet.zendex.fi/

The ZENDEX Testnet phase is not only a technical proving ground, but it is a community ignition phase for professional DeFi executors who believe in decentralized technologies and private on-chain execution. ZENDEX has built and will continue to build on Horizen.

Our goal is to continue to cultivate a core group of early users, operators, developers, and institutional observers who understand the value of shielded DeFi and help shape its evolution. This public testnet phase is launched with Hacken's incentivized Dual Defense programme as we continue to run testnet private swaps, hidden orders, and ZK-based workflows in order to gather real ecosystem feedback, refine the ZENDEX UX, and harden circuits under load if needed. As our tight knit ecosystem grows, usership increases and Dual Defense concludes, this community becomes the foundation upon which we transition with into mainnet. We aim to enter mainnet as an aligned group of decentralized, on-chain, privacy enthusiasts who understand ZENDEX' unique mechanics, and are ready to become or onboard unique partners ready who are ready to integrate these advanced features, and who aim to take this validated and operational pipeline into a future where ZENDEX continues to enhance a DeFi principles and as ZENDEX prepares to launch these first steps towards our Horizen Mainnet we are prepared to innovate this zk-private, decentralized, DeFi protocol smoothly, securely, and with momentum.

The Shielded Testnet Identity Creation Process​

Unlike standard EVM dApps where a wallet connection exposes your address and token balances directly to the protocol state, interaction on ZENDEX requires establishing a ZENDEX Shielded Identity:

  1. Prerequisite (Acquiring Gas): Before initiating any on-chain actions, participants must acquire Horizen Testnet ETH to pay for transaction gas fees on the Horizen EVM execution layer. Users can claim testnet gas directly from the Horizen Testnet Hub.
  2. Key Generation: Generate a Zendex Key in the app, on the Deposit page of testnet.zendex.fi. It is created and stored only in your browser, and holds a dedicated client-side ZK public/private keypair (pkx,pky)(\text{pk}_x, \text{pk}_y) used strictly inside Noir zero-knowledge circuits. It is separate from your wallet's private key, and you should back it up from the Account page.
  3. Vault Deposit & Identity Anchoring: The onboarding process completes when the user executes an initial asset deposit into the non-upgradeable ZendexVault contract. The deposit locks public testnet tokens and generates a initial Poseidon commitment:

C=Poseidon(asset_id,amount,Poseidon(random_blinding,pkx,pky))C = \text{Poseidon}\left(\text{asset\_id}, \text{amount}, \text{Poseidon}\left(\text{random\_blinding}, \text{pk}_x, \text{pk}_y\right)\right)

  1. Merkle Leaf Minting: The output commitment CC is appended to the TreeOperator incremental Merkle tree. This single cryptographic leaf establishes the user's active ZENDEX Testnet Identity, granting them full authority to generate valid inclusion and spend proofs for all subsequent swaps, limit orders, and liquidity operations. On the public testnet, transactions are still sent from your connected wallet, so this leaf does not hide your wallet address; that differs from mainnet (see Privacy Guarantees).
+-----------------------------------------------------------------------------------+
|                        ZENDEX TESTNET ONBOARDING PROCESS                          |
+-----------------------------------------------------------------------------------+
  [Step 1: Horizen Faucet]  ---> Obtain Horizen Testnet ETH at horizen-testnet.hub.caldera.xyz
                                      |
                                      v
  [Step 2: Key Generation]  ---> Generate Zendex Key (local ZK keypair: pk_x, pk_y)
                                      |
                                      v
  [Step 3: Vault Deposit]   ---> Lock public ERC-20 tokens into ZendexVault
                                      |
                                      v
  [Step 4: Leaf Minting]    ---> Poseidon Commitment appended to TreeOperator
                                      |
                                      v
  [Shielded Identity Live]  ---> Perform private AMM swaps, place limit orders, split/join

Your Wallet vs. Your Zendex Key​

ZENDEX uses two different keys:

  • Your wallet (e.g. MetaMask) holds your public tokens, pays gas and signs transactions.
  • Your Zendex Key is created in the app and stored only in your browser. It owns your private deposits. It is not your wallet's private key: never paste your wallet seed phrase or private key into ZENDEX.

Back up your Zendex Key from the Account page (Download backup). If you lose it, you lose access to your private deposits.

What Is Stored in Your Browser​

Your Zendex Key and the secrets of your notes are stored in your browser only, per wallet. Clearing site data or switching browsers or devices hides your deposits from the app. The backup file restores your Zendex Key, but not your deposit history, so don't clear browser data while you have open deposits.