Relevant field for JSON RPC getTransaction method

Question

I'm parsing some information regarding transactions from JSON RPC API. However, I'm confused concerning innerInstructions and instructions (in transactions) fields.

Basically, I just want to know the type of transfer, the amount and from/to.

For example, if you look at this transaction signature in solscan.io in Transaction Actions field:

5Duc8t3dVWKBz48TwdSyJXaUSpeLQQPeDorEsxqokSAbvb3tdyoDPL8fp81udu8DgDMJSjvFPgUvwigbkYaxnuwk

From JSON RPC API, all information required are inside innerInstructions field. But in transactions field which contain instructions field I'm getting only the following:

instructions: [
  {
    accounts: [],
    data: LLMtf9,
    programId: ComputeBudget111111111111111111111111111111,
    stackHeight: None
  }, 
  {
    accounts: [...],
    data: 88nNHV4ezjuwf94ruuMVS,
    programId: GaaxVrdMh69Dhce9u4uSpdXD8L9J51SZ4x8vQywR6d7s,
    stackHeight:
    None
   }
], 
recentBlockhash: 5teZ8Af9VfDakJh8aQMzL7axv799ThAnRa38JnvAR2RF},
[...]

• So does all transactions request provide the relevant information in innerTransactions only and instructions field from transactions can be ignored ? Is there any specific case ?

Answer 1

You need to consider both fields.

A transaction has a sequence of instructions, where each instruction has a program ID, accounts and data. That program freely determines how it interprets the data and how it uses the accounts.

One thing that program can do is call out to other programs, this is called Cross-Program invocation (CPI). When it does this, it will do the same thing - it'll pass data + accounts to a different program ID. These calls show as the innerInstructions of the transaction.

So a transaction could call directly to eg. the Orca program (which is used for a swap in your example transaction), and that would show as an instruction in the transaction. Or, as in your example transaction, it might call to a different program which then makes a CPI call to Orca, and that would show the Orca call as an inner instruction.

You need to consider the data in both to understand what has happened in the transaction.