🚀 COTI V2 Quickstart

This quick start guide will help developers get started with deploying smart contracts onto the COTI network. If you are already familiar with Ethereum, EVM-related technologies, smart contracts and web3, follow the steps below to get started.

You should already be familiar with concepts such as Ethereum, EVM, and Smart Contracts.

If you are new to Ethereum and smart contracts, the following introductory guides are a great place to get started:

• Introduction to Ethereum
• Introduction to Smart Contracts
• Ethereum Virtual Machine (EVM)

{% hint style="info" %} For questions & support join our Discord! {% endhint %}

Useful links

SDKs	Examples	Network Info
Python SDK	Python SDK Examples	Faucet
Typescript SDK	Typescript SDK Examples	Devnet Explorer Testnet Explorer
Hardhat		Chainlist

If you'd like to learn more about COTI's progression, read COTI's evolution from V1 to V2. To get familiar with some of the core concepts of blockchain privacy, get started with the readme-1 section.

Network Info

You can view COTI network information on the networks.md page. To add it to the networks of your wallet application you can use one the following sites:

• https://chainlist.org
• https://chainlist.wtf
• https://devnet.cotiscan.io
• https://testnet.cotiscan.io

{% hint style="info" %} NOTE:

• EOA Wallets such as MetaMask may display a warning about COTI Testnet being a potential scam. This is due to the COTI token existing as an ERC-20 token on Ethereum and using the same token name on COTI Testnet. We're working with wallet providers to fix this issue.
• The COTI Testnet is currently operating in review mode. As such, it may experience unplanned resets. Remember to back up your work regularly and avoid storing any sensitive or confidential data. {% endhint %}

---

{% tabs %} {% tab title="Python" %}

Native Transfer

The following process will help you deploy the native_transfer.py example from the COTI Python SDK Examples project. This script will transfer native funds from your wallet account to a random wallet. It will also:

• Create a EOA (Externally Owned Account)
• Validate minimum balance

{% hint style="info" %} Ensure your environment meets all the pre-requisites. Visit the pre-requisites section of the readme. Alternatively, use an editor like PyCharm to take care of the pre-requisites for you. {% endhint %}

1. Clone the Python examples repo along with its submodules into your desired location

   git clone --recurse-submodules https://github.com/coti-io/coti-sdk-python-examples.git

2. Change directory to the newly create one

   cd coti-sdk-python-examples

3. Install the project's requirements

   python3 -m pip install -r requirements.txt

4. Set the python path as following

   export PYTHONPATH=$PWD

5. Run the native_transfer.py script

   python3 examples/basics/native_transfer.py

   
   Running the script will automatically create an account and a key/value pair with name: ACCOUNT_PRIVATE_KEY (visible in the .env file). The script will output something like this:

   So you dont have an account yet, dont worry... lets create one right now!
   Creation done!
   provider:  https://devnet.coti.io
   chain-id:  13068200
   latest block:  0xc9ec7259bad015c46a0bef9b0988cac70a62e2abaed7459b5265e425bc5cecb8
   account address: 0x0287a7A5bD5f4802D4A6048730a11B2713A16bd4
   account balance:  0 wei ( 0  ether)
   account nonce:  0
   Traceback (most recent call last):
     File "/Users/user/projects/coti-sdk-python/examples/basics/native_transfer.py", line 24, in <module>
       main()
     File "/Users/user/projects/coti-sdk-python/examples/basics/native_transfer.py", line 12, in main
       validate_minimum_balance(web3)  # validate minimum balance
     File "/Users/user/projects/coti-sdk-python/examples/basics/utils.py", line 69, in validate_minimum_balance
       raise Exception(
   Exception: Not enough balance!, head to discord faucet and getsome...https://discord.com/channels/386571547508473876/1235539223595978752 , ask the BOT:devnet 0x0287a7A5bD5f4802D4A6048730a11B2713A16bd4
   
   Process finished with exit code 1
   

   
   It is normal to receive the exception Not enough balance! on the first run. This will be resolved once the account is funded.\

6. Head to the faucet at https://faucet.coti.io to get devnet funds.
   Send the following message to the BOT using your newly created account address:
   
   devnet <account address>
   
   The bot will reply with the message:
   
   <username> faucet transferred 5 COTIv2 (devnet)
   

7. Run the native_transfer.py script once more

   python3 examples/basics/native_transfer.py

   
   The script will output as following:

   provider:  https://devnet.coti.io
   chain-id:  13068200
   latest block:  0x4f5b68d9ef7debc0f86b4fc4c50a81020c8de315d65b4ce12b4372ebedef4f95
   account address: 0x0287a7A5bD5f4802D4A6048730a11B2713A16bd4
   account balance:  10000000000000000000 wei ( 10  ether)
   account nonce:  0
   AttributeDict({'blockHash': HexBytes('0x3e0534655361da10c9ee6454d622609c900e3f552435acc9cc963e370ca1d36b'), 'blockNumber': 3395902, 'contractAddress': None, 'cumulativeGasUsed': 21000, 'effectiveGasPrice': 1000000000, 'from': '0x0287a7A5bD5f4802D4A6048730a11B2713A16bd4', 'gasUsed': 21000, 'logs': [], 'logsBloom': HexBytes('0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000'), 'status': 1, 'to': '0x4A68774D7679e63Ea42599Fe076a899036B3642B', 'transactionHash': HexBytes('0x99ad02f33a146945ac3a671857ab5134965b1f3e78fd53a97710bcdcb99dfee7'), 'transactionIndex': 0, 'type': 0})

   
   Now that your account is created and funded, you can now onboard the account to get your new network key.

On-board Account

The following process will help you deploy the onboard_account.py example from the COTI Python SDK Examples repo. This script onboards an EOA into the network. It will also:

• Trigger the network to create a unique AES key for the user
• Encrypt the unique user-specific AES key using the Public key so that its value can be viewed only by the EOA owner.

This is a mandatory script for any operation executed in any contract requiring encrypt/decrypt operations which are part of the new EVM precompiles actions.

1. Run the onboard_account.py script

   python3 examples/onboard/onboard_account.py
   

   
   Running the script will automatically create an account and an ACCOUNT_ENCRYPTION_KEY (visible in the .env file as well as the output). The script output will look something like this:\

   provider:  https://devnet.coti.io
   chain-id:  13068200
   latest block:  0x31f5e889a74777e514abcf83ece21839d96c465419b66b6b977f65d052062c2a
   account address: 0x0287a7A5bD5f4802D4A6048730a11B2713A16bd4
   account balance:  9999936985000000000 wei ( 9.999936985  ether)
   account nonce:  3
   tx receipt:  AttributeDict({'blockHash': HexBytes('0x94dac5f2cf57639fe934457cb33354399567cfad233c2fb3d6a271ecd47830a3'), 'blockNumber': 3399673, 'contractAddress': None, 'cumulativeGasUsed': 225968, 'effectiveGasPrice': 30000000000, 'from': '0x0287a7A5bD5f4802D4A6048730a11B2713A16bd4', 'gasUsed': 225968, 'logs': [AttributeDict({'address': '0xbFC922C10B03EA5dbC90b98dfc8fb334849ccB78', 'topics': [HexBytes('0xb67504ecfeef0230a06f661ea388c2947b4125a35e918ebff5889e3553c29c04'), HexBytes('0x0000000000000000000000000287a7a5bd5f4802d4a6048730a11b2713a16bd4')], 'data': HexBytes('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'), 'blockNumber': 3399673, 'transactionHash': HexBytes('0x69af701a8f65ebf6c007e512ce6bc5e801884c3ae49ad744f47069053e2ed81e'), 'transactionIndex': 0, 'blockHash': HexBytes('0x94dac5f2cf57639fe934457cb33354399567cfad233c2fb3d6a271ecd47830a3'), 'logIndex': 0, 'removed': False})], 'logsBloom': HexBytes('0x00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000100000000000000000000000000000000000400000000000000000000001000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000100000000000000000008000000000000000000000000000000000440000000000000000000000000000000000000000000000000000000000000000000000000000000000000020000000000000000000000000000000000000000000000000000040000000000000000000000000000000'), 'status': 1, 'to': '0xbFC922C10B03EA5dbC90b98dfc8fb334849ccB78', 'transactionHash': HexBytes('0x69af701a8f65ebf6c007e512ce6bc5e801884c3ae49ad744f47069053e2ed81e'), 'transactionIndex': 0, 'type': 0})
   (True, 'ACCOUNT_ENCRYPTION_KEY', 'fd3d781ddcbd1e1cedd2d75460f30636')

   {% hint style="info" %} This encryption key is sensitive. Ensure it is not uploaded to public places and keep it safe. This key is produced per EOA wallet, meaning a unique wallet/EOA combination will have a unique encryption key. {% endhint %}

   
   The .env file will also have other useful information, such as the node address, websocket address, and the contract directories.
   
   Now that the account is onboarded, let's deploy a contract on-chain.

Deploy Data On-Chain

The following process will help you deploy the data_on_chain.py example from the COTI Python SDK Examples repo. As its name suggests, the contract will compile and deploy the corresponding DataOnChain.sol contract, located in the confidentiality-contracts directory.

This contract can be used in order to browse and get a feel of the COTI network. The contract allows for the secure handling of encrypted data, enabling storage, transformation, and arithmetic operations on encrypted values using the MpcCore library. It supports operations where values are encrypted using both network and user keys, ensuring data privacy and security on-chain.

1. Navigate to the examples directory in the confidentiality-contracts directory inside the coti-sdk-python-examples project.

   cd confidentiality-contracts/contracts/examples

2. Run the data_on_chain.py script

   python3 ../../examples/data_onchain/data_on_chain.py

   
   Running the script will deploy the contract and output the address where the contract was deployed. The script output will look something like this (with some omitted block hashes at the end of ther response):\

   provider:  https://devnet.coti.io/rpc
   chain-id:  13068200
   latest block:  0x75a2f9d10db48fdc53f14d9ce565420e680b06231cd34e3c194f14fbd0c5f999
   account address: 0xB101fbd6938AaE2e472E247e36555528d7ff4A89
   account balance:  4993201875000000000 wei ( 4.993201875  ether)
   account nonce:  2
   Compiling DataOnChain...
   Deploying DataOnChain...
   Contract deployed at address: 0x91Af1CD8Bbc3b7dCcd5fF19f522cd9A49067F928
   contract address:  0x91Af1CD8Bbc3b7dCcd5fF19f522cd9A49067F928

   
   The deployment will include the transaction data as well as the address the contract was deployed to:

   Contract deployed at address: 0x91Af1CD8Bbc3b7dCcd5fF19f522cd9A49067F928

   
   You can now view the contract on devnet explorer using the following convention:
   https://explorer-devnet.coti.io/address/<contract deployment address>
   
   In our case:
   https://explorer-devnet.coti.io/contract/0x91af1cd8bbc3b7dccd5ff19f522cd9a49067f928

Let's note the following facts about the contract and the script:

• When the contract was deployed, the uint64 private clearValue variable was assigned a value of 5 as evidenced by lines 15-17 of the contract:

   constructor () {
          clearValue = 5;
      }

• The function getSomeValue of the contract will then return the value of clearValue

• The function basic_get_value of the python script is making sure the value was set as expected.

Now let's take a look on at the basic flow that sends a clear value, encrypts it, and decrypts it.

• The python function basic_clear_encrypt_decrypt initiates the process, calling other functions as necessary.
• The python function save_clear_value_network_encrypted_in_contract is used to pass a clear value from the user.
• Once the value is populated, the script will call the Solidity contract and use its setSomeEncryptedValue function. This function in turn calls setPublic64 from the MpcCore library, which turns the value into GarbledText and then into CipherText using the network key. This value is now encrypted in a network block.
• In order to validate the block had a ClearText input, the block details from the transaction are extracted using the validate_block_has_tx_input_encrypted_value function.
• The value is then encrypted using the function save_network_encrypted_to_user_encrypted_input_in_contract , this function saves the network-encrypted value to the user-encrypted input in the contract.
• The encrypted value is retrieved from the contract using the function get_user_encrypted_from_contract to ensure the encrypted value can be successfully retrieved with the user's AES key. {% endtab %}

{% tab title="Typescript" %}

ERC20

The following process will help you run the erc20.ts example from the COTI Typescript SDK Examples project. The script includes functions for transferring tokens, approving allowances, and handling confidential transactions. The script uses various utilities from the SDK to manage confidential accounts, decrypt values, and ensure correct balances and allowances during transactions. It will also:

• Create a EOA (Externally Owned Account)
• Validate minimum balance

{% hint style="info" %} Ensure your environment meets all the pre-requisites. Visit the pre-requisites section of the readme. {% endhint %}

1. Clone the Typescript examples repo along with its submodules into your desired location

   git clone --recurse-submodules https://github.com/coti-io/coti-sdk-typescript-examples.git

2. Change directory to the newly create one

   cd coti-sdk-typescript-examples

3. Install dependencies

   yarn

4. Run erc20.ts script

   yarn erc20

   
   Running this test will automatically create an account and a key/value pair with name: SIGNING_KEY (visible in the .env file). The script will output something like this:\

   yarn run v1.22.22
   $ ts-node src/main.ts erc20
   ************* Created new account  0x87c13D0f5903a68bE8288E52b23A220CeC6b1aB6  and saved into .env file *************
   /Users/user/projects/coti-sdk-typescript-examples/src/util/onboard.ts:13
         throw new Error(`Please use faucet to fund account ${wallet.address}`)
               ^
   Error: Please use faucet to fund account 0x87c13D0f5903a68bE8288E52b23A220CeC6b1aB6

   
   It is normal to receive the exception Error: Please use faucet to fund account on the first run. This will be resolved once the account is funded. \

5. Head to the faucet at https://faucet.coti.io to get devnet funds.
   Send the following message to the BOT using your newly created account, visible in the fourth line of the response Created new account 0x87c13D0f5903a68bE8288E52b23A220CeC6b1aB6 [...]

devnet <account address>
   
   The bot will reply with the message:
   
   <username> faucet transferred 5 COTIv2 (devnet)
   

6. Run erc20.ts script once more

   yarn erc20

{% endtab %}

{% tab title="Hardhat" %}

ERC20Example

The following process will help you run the ERC20Example.sol example from the COTI confidentiality-contracts project. The contract defines a custom ERC20 token called ERC20Example that extends the functionality of the ConfidentialERC20 token. Additionally it will:

• Create a EOA (Externally Owned Account)
• Validate minimum balance

The contract is compiled and deployed with Hardhat using the confidential-erc20.test.ts test suite contained in the test-hardhat directory of the project.

{% hint style="info" %} Ensure your environment meets all the pre-requisites. Visit the pre-requisites section of the readme. {% endhint %}

1. Clone the confidentiality-contracts repo

   git clone https://github.com/coti-io/confidentiality-contracts.git

2. Change directory to the newly create one

   cd confidentiality-contracts

3. Install dependencies

   yarn

4. Build and compile contracts

   yarn build

5. Run the test-erc20 test suite

   yarn test-erc20

   
   Running this test will automatically create an account and a key/value pair with name: SIGNING_KEYS (visible in the .env file). The script will output something like this:\

   yarn run v1.22.22
   
     Confidential ERC20
       1) "before all" hook in "Confidential ERC20"
   
     0 passing (39ms)
     1 failing
   
     1) Confidential ERC20
          "before all" hook in "Confidential ERC20":
        Error: Created new random account 0x17EDB982c3569D29EbaF407F72aDD05722d5f179.
        Please use faucet to fund it.

   
   It is normal to receive the exception Error: Created new random account [...] Please use faucet to fund it. on the first run. This will be resolved once the account is funded. \

6. Head to the faucet at https://faucet.coti.io to get devnet funds.
   Send the following message to the BOT using your newly created account, visible in the last part of the response.
   
   devnet <account address>
   
   The bot will reply with the message:
   
   <username> faucet transferred 5 COTIv2 (devnet)
   

7. Run the test-erc20 test suite once more.

   yarn test-erc20

   
   The script output will look like this:\

   Confidential ERC20
   ************* Onboarding user  0x17EDB982c3569D29EbaF407F72aDD05722d5f179  *************
   ************* Onboarding user  0xe1E7315F6970F353661fc84FFd9238133cED3677  *************
   ************* Onboarded! created user key and saved into .env file *************
   ************* Onboarded! created user key and saved into .env file *************
       Deployment
         ✔ Deployed address should not be undefined
         ✔ Owner initial balance (123ms)
         ✔ Function 'name' should be correct (130ms)
         ✔ Function 'symbol' should be correct (123ms)
         ✔ Function 'decimals' should be correct (119ms)
         ✔ Function 'totalSupply' should be correct (117ms)
       Transfer 5
         ✔ Transfer - clear (9469ms)
         ✔ Transfer - Confidential (5260ms)
         ✔ TransferFrom - clear without giving allowance should fail (9905ms)
         ✔ TransferFrom - clear (9770ms)
         ✔ TransferFrom - Confidential (10265ms)
         ✔ Approve/Allowance - Confidential (10255ms)
   
     12 passing (1m)
   
   ✨  Done in 69.69s.

Running the test suite does the following:

• Deploys the ERC20Example contract: Sets up the token with specific details (name, symbol, initial supply).
• Tests the deployment: Verifies the contract address, initial balance, and token details (name, symbol, decimals, total supply).
• Tests transfers: Both clear and confidential transfers, including transferFrom functionality with and without prior allowance.
• Tests approvals and allowances: Ensures that the contract correctly handles approvals and allowances, both clear and confidential. {% endtab %} {% endtabs %}