# Introduction to block and transaction structure

# 1. Block structure of GXChain

  • A block contains some transactions, a transaction contains the some operations, and a opreation contains the functions such as calling contract, voting, transfering, etc.

  • We can get the most intuitive understanding of GXChain through GXChain's block structure. A complete block contains the following information:

  "previous": "0092ab99afb1a7bc9107d85796ce7219214c5700",                   //ID of the previous block
  "timestamp": "2018-12-12T07:44:18",                                       //Generate timestamp of the block
  "witness": "1.6.30",                                                      //object ID
  "transaction_merkle_root": "b0e3fc1caf19cb57530f5b14ad903779221f487c",    //Trading Merkelgen
  "extensions": [],
  "witness_signature": "1f6335138fa77a52986ed0e0980ece86b919f84cf06647c2fdea3382578287c2e5403088d960cd75d5d5f134647bae80d1189e0a417f0d5bc127b294949864d662",    //signature
  "transactions": [
      "ref_block_num": 43928,               // The block information referenced by the transaction (ref_block_num, ref_block_prefix are from the previous block ID, which can be specified by itself)
      "ref_block_prefix": 3666011859,
      "expiration": "2018-12-12T07:45:12",  // Transaction expiration time
      "operations": [                       // transactions contains operations
          75,       //Operation opcode, the number 75 indicates the call contract
            "fee": {                    // Provided fee
              "amount": 13097,          // The amount of the fee, which contains accuracy information. For example, if the accuracy is 5, the fee should be divide by 100000.
              "asset_id": "1.3.1"       // Fee asset ID
            "account": "1.2.882",       // Caller account ID
            "contract_id": "1.2.881",   // Contract account ID
            "amount": {                 // Assets attached to the transaction
              "amount": 135000,
              "asset_id": "1.3.1"
            "method_name": "roll",      // action name
            "data": "1e6632693277676439536b6c717065594a7a54736c6a3658316e4873797941008813",     //action params
            "extensions": []
      "extensions": [],
      "signatures": [       // transaction signatures
      "operation_results": [        //The execution result of the operation which includes the cost of handing、cpu and ram
            "billed_cpu_time_us": 505,
            "ram_usage_bs": 430,
            "fee": {
              "amount": 13097,
              "asset_id": "1.3.1"
  "block_id": "0092ab9a9e7e11137fa487176f7e10992fef1c47",       //block id
  "signing_key": "GXC6xSvFR3hohUGut8tsARuJPMPvkdmc3KnVg2KvrKw9cvLTbTP3u",   //Public key of the TrustNode
  "transaction_ids": [
    "ba2bdb39acda14e11bc645a41e6d0e0cba14921d"      //transaction ids

# 2. Operation

The GXChain block contains multiple operations, and each operation corresponds to a Code number. According to the Code numbers, We can judge which operations are included in the block according to Code numbers. For example, the block 1769028 (opens new window) contains a transfer transaction, and Code 0 corresponds to the transfer operation. The correspondence between Code and operation which are often used :

Code Operation Type
0 transfer
5 create account
6 update account
73 proxy transfer
74 deploy contract
75 call contract
76 update contract

# 3. Object on GXChain

The data structure of the related type on GXChain is saved by the object, the object ID is its identifier (format: x.x.x), and the instance id of the object is the last digit of the object ID. Example: The nathan account ID is 1.2.17, the instance id is 17; the GXC asset ID is 1.3.1, the instance id is 1, and the common object types are as follows:

ID Object Type
1.2.x Account object
1.3.x Asset object
1.5.x Committee object
1.6.x Witness object
1.10.x Proposal object
1.11.x Operation history object
1.13.x To unfreeze balance object
1.14.x Budget item object
1.25.x Loyalty program freezes balance object
2.0.0 System global parameter object
2.1.x Dynamic parameter object
2.3.x Asset dynamic parameter object
2.5.x Account balance object
2.6.x Account statistics object
2.7.x Transaction object
2.8.x Block abstract object
2.9.x Account transaction history object
2.12.x Witness schedule object