besu/docs/Privacy/Creating-Sending-Private-Transactions.md

description: Creating and sending private transactions

Creating and Sending Private Transactions

The EEA JavaScript library is provided to create and send signed RLP-encoded private transactions.

!!! note Private transactions either deploy contracts or call contract functions. Ether transfer transactions cannot be private.

Using Multinode Example

To use the examples provided in EEA JS library with your privacy network:

1. Clone the PegaSysEng/eeajs repository:

   git clone https://github.com/PegaSysEng/eeajs.git
   

2. In the eeajs directory:

   npm install
   

3. In the example directory, update the keys.js file to include:

   • Orion node public keys
   • Pantheon node RPC URLs
   • Pantheon node private keys

4. If the chainID specified in the genesis file for your network is not 2018, update deployContract.js, storeValueFromNode1.js, and storeValueFromNode2.js to specify your chain ID instead of 2018.

5. In the example/multiNodeExample directory, deploy the contract:

   node deployContract.js
   

   A private transaction receipt is returned.

   Transaction Hash  0x23b57ddc3ecf9c9a548e4401a411420ffc0002fd259a86d5656add7c6108beeb
   Waiting for transaction to be mined ...
   Private Transaction Receipt
    { contractAddress: '0xfee84481da8f4b9a998dfacb38091b3145bb01ab',
     from: '0x9811ebc35d7b06b3fa8dc5809a1f9c52751e1deb',
     to: null,
     output:
      '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',
     logs: [] } 
   

6. Copy the contract address from the private transaction receipt and set the CONTRACT_ADDRESS environment variable:

   export CONTRACT_ADDRESS=<Contract Address from Private Transaction Receipt>
   

   !!! example bash export CONTRACT_ADDRESS=0xfee84481da8f4b9a998dfacb38091b3145bb01ab

7. Store a value in the contract from Node 1:

   node storeValueFromNode1.js
   

   The value of 1000 (3e8 in hex) is stored by Node 1 and is visible to Node 1 and Node 2.

   Transaction Hash: 0xd9d71cc6f64675e1a48183ded8f08930af317eb883ebae4c4eec66ae68618d85
   Waiting for transaction to be mined ...
   Event Emited: 0x0000000000000000000000009811ebc35d7b06b3fa8dc5809a1f9c52751e1deb00000000000000000000000000000000000000000000000000000000000003e8
   Waiting for transaction to be mined ...
   Get Value from http://localhost:8545: 0x00000000000000000000000000000000000000000000000000000000000003e8
   Waiting for transaction to be mined ...
   Get Value from http://localhost:8546: 0x00000000000000000000000000000000000000000000000000000000000003e8
   Waiting for transaction to be mined ...
   Get Value from http://localhost:8547: 0x
   

8. Store a value in the contract from Node 2:

   node storeValueFromNode2.js
   

   The value of 42 (2a in hex) is stored by Node 1 and is visible to Node 1 and Node 2.

   Transaction Hash: 0xa025433aec47a71b0230f12f43708812fd38ff7b7c1dc89a715f71dcbd5fbdbf
   Waiting for transaction to be mined ...
   Event Emited: 0x000000000000000000000000372a70ace72b02cc7f1757183f98c620254f9c8d000000000000000000000000000000000000000000000000000000000000002a
   Waiting for transaction to be mined ...
   Get Value from http://localhost:8545: 0x000000000000000000000000000000000000000000000000000000000000002a
   Waiting for transaction to be mined ...
   Get Value from http://localhost:8546: 0x000000000000000000000000000000000000000000000000000000000000002a
   Waiting for transaction to be mined ...
   Get Value from http://localhost:8547: 0x
   

   !!! note The Node 3 Orion log messages indicate payloads cannot be found. This is expected behaviour because Node 3 does not have access to the private transactions between Node 1 and Node 2.