---
title: "simulateTransaction"
method: POST
path: "/"
---

# simulateTransaction

`POST /`

Runs the Solana RPC `simulateTransaction` method.

## Request body

- object
  - `jsonrpc` '2.0', required — The JSON-RPC protocol version.
  - `id` string, required — A unique identifier for the request.
  - `method` 'simulateTransaction', required — The name of the RPC method to invoke.
  - `params` union[], required — Parameters for simulating a transaction.
    - union
      - string — The signed transaction, as an encoded string (base58 or base64).
      - object — Configuration object for the simulation.
        - `encoding` 'base58' | 'base64' — Encoding used for the transaction data.
        - `skipPreflight` boolean — Skip the preflight transaction checks.
        - `preflightCommitment` 'confirmed' | 'finalized' | 'processed' — Commitment level to use for preflight.
        - `sigVerify` boolean — If true, verify the transaction signatures.
        - `replaceRecentBlockhash` boolean — If true, replace the transaction recent blockhash with the most recent one.
        - `minContextSlot` integer — Minimum slot at which to perform preflight transaction checks.
        - `innerInstructions` boolean — If true, include inner instructions in the response.
        - `accounts` object
          - `addresses` string[] — Array of accounts to return, as base-58 encoded strings.
          - `encoding` 'base64' | 'base58' | 'base64+zstd' | 'jsonParsed' — Encoding format for returned account data.

## Response `200`

Successfully simulated the transaction.

- object
  - `jsonrpc` '2.0' — The JSON-RPC protocol version.
  - `id` string — Identifier matching the request.
  - `result` object — Result of the simulated transaction.
    - `context` object — Context of the simulation response.
      - `apiVersion` string — The API version of the RPC node.
      - `slot` integer — Slot in which the data was fetched.
    - `value` object — Details of the simulated transaction result.
      - `accounts` object[], nullable
      - `err` object, nullable — Error if the transaction failed, null if successful.
      - `innerInstructions` unknown
      - `loadedAccountsDataSize` integer, nullable — Total size in bytes of all account data loaded during simulation.
      - `logs` string[], nullable — Program execution logs from the transaction simulation.
      - `replacementBlockhash` object, nullable — Replacement blockhash information when replaceRecentBlockhash is enabled.
        - `blockhash` string — The replacement blockhash.
        - `lastValidBlockHeight` integer — The last valid block height for the replacement blockhash.
      - `returnData` object, nullable — Data returned by the transaction if any.
        - `programId` string
        - `data` string[]
      - `unitsConsumed` integer, nullable — Total compute units consumed during the simulation.

---

[API](https://skmtc.net/solanatracker/apis/solana-tracker-data-api.md) · [All operations](https://skmtc.net/solanatracker/apis/solana-tracker-data-api/llms.txt) · [OpenAPI document](https://skmtc-service-staging.skmtc.workers.dev/v1/apis/solanatracker/solana-tracker-data-api/versions/c07c6f82d0c4/schema)