NEO3 Development Guide

A development guide for basic tool developers of NEO3 to facilitate the underlying construction

Table

• Wallets
• Transactions
• RPC
• Smart contracts
• NeoVM

Changes in NEO3

Wallet

• UPDATE

  • Address Script: change the way to construct the address script with the public key

    • Ordinary Address

    NEO2: 0x21 + publicKey(compressed 33bytes) + 0xac()
    NEO3: 0x21 + publicKey(compressed 33bytes) + 0x68 + 0x747476aa
    

    • Multi-Signature Address

    NEO2: emitPush(N) + 0x21 + publicKey1(compressed 33bytes) + .... + 0x21 + publicKeym(compressed 33bytes)  + emitPush(M) + 0xae()
    NEO3: emitPush(N) + 0x21 + publicKey1(compressed 33bytes) + .... + 0x21 + publicKeym(compressed 33bytes)  + emitPush(M) + 0x68 + 0xc7c34cba
    

Transactions

• UPDATE

  • System Fee: cancel the free discount of 10 GAS for each transaction and redefine the fee of each OpCode
  • Network Fee: redefine the calculation formula for the network fee

• DELETE

  • Transaction Type: discard the previous 9 types of the transaction in NEO2 and use the unified transaction instead, as well as the redefinition of the transaction structure
  • Assets: discard the UTXO model for the NEO and GAS token, using the account model implemented by the native contract instead

RPC

• UPDATE

  • Invocation Style: getblockheader，getrawmempool
  • Returns: getblock，getblockheader，getrawtransaction，getversion，getcontractstate

• DELETE

  • Discard the following commands: claimgas, dumpprivkey, getaccountstate, getapplicationlog, getassetstate, getbalance, getclaimable, getmetricblocktimestamp, getnep5balances, getnep5transfers, getnewaddress, gettxout, getunclaimed, getunclaimedgas, getunspents, getwalletheight, importprivkey, invoke, listaddress, sendfrom, sendtoaddress, sendmany, etc.

Smart Contracts

• ADD

  • Manifest: used to describe the features of the contract and deployed with AVM files
  • native contracts: running in the native code rather than in the virtual machine, including NeoToken, GasToken and PolicyToken
  • Accessing to network resources: to be added
  • System Trigger: triggered when the node receives a new block and currently only triggers the execution of the native contract
  • Interop Service: System.Blockchain.GetTransactionFromBlock

• UPDATE

  • Reduce the system fee for OpCode and interop services

• DELETE

  • Interop Service:Neo.Header.GetVersion, Neo.Header.GetMerkleRoot, Neo.Header.GetNextConsensus, Neo.Transaction.GetScript, Neo.Transaction.GetWitnesses, Neo.Witness.GetVerificationScript, Neo.Contract.GetScript, Neo.Contract.IsPayable, System.Blockchain.GetHeader, System.Header.GetIndex, System.Header.GetHash, System.Header.GetPrevHash, System.Header.GetTimestamp, System.Block.GetTransactionCount, System.Block.GetTransactions, System.Block.GetTransaction, System.Transaction.GetHash

NeoVM

• ADD

  • OpCode DUPFROMALTSTACKBOTTOM, ISNULL, PUSHNULL

• DELETE

  • Discard the following opcodes: APPCALL, TAILCALL, SHA1, SHA256, HASH160, HASH256, CHECKSIG, VERIFY, CHECKMULTISIG, CALL_I, CALL_E, CALL_ED, CALL_ET, CALL_EDT, etc.

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