Transactions API

What would this transaction do if I sent it?

Runs an unsigned EVM or Solana transaction against the latest state: success or revert and why, gas or compute units, return data, events or program logs — without sending it.

POST/api/external/transaction-analysis/transaction-simulation/{chain}

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What it returns

Runs an unsigned transaction against the chain's latest state without signing or sending it, and answers whether it would succeed, revert, or fail because the sender cannot pay; the revert reason; the gas it would use; what it returns; the events it would emit; and the native coin it would move. Token balance changes are read from the emitted Transfer events. No signature, nonce or fee is checked, and the answer holds only for the state it ran against: the next block can change it. On ARC and STABLE, events and native transfers are not available (null), and on STABLE neither is the gas used. On BASE, when the chain's own simulation is unavailable, a second simulator answers; it reports no return data, revert data, revert message or native transfers (null), and it is not used when gas is set. On SOL the body is { transaction } alone: a legacy or version 0 transaction, serialized and base64-encoded, signed or not — signatures are not checked and the latest blockhash replaces the one it was built with. SOL answers the outcome, the failing instruction and its error as revertReason, compute units as gasUsed, the program's return data and the program log lines (programLogs); it has no revert bytes, events or native transfers (null).

Chains

Solana SOL
BNB Chain BNB
Ethereum ETH
Stable STABLE
Base BASE
Robinhood Chain RHC
Arc ARC

Request

Send your key in the x-dex-data-key header. Replace each <placeholder> with a real value.

curl -X POST -H "x-dex-data-key: $DEXDATA_API_KEY" \
  -H "content-type: application/json" \
  -d '{"from":"<from>","to":"<to>","data":"<data>","value":"<value>","gas":"<gas>","transaction":"<transaction>"}' \
  "https://api.dexdata.io/api/external/transaction-analysis/transaction-simulation/SOL"

Parameters
Parameter	Description
`chain` path · string · required	ETH, BNB, BASE, RHC, ARC, STABLE or SOL. On ARC and STABLE the answer carries no events or native transfers (`null`), and on STABLE no gas figure either. On BASE, when the chain's own simulation is unavailable, a second simulator answers, with no return data, revert data, revert message or native transfers (`null`). SOL takes a different body — `{ transaction }`, the serialized transaction — and answers compute units as `gasUsed` and its program log lines as `programLogs`. CELO, ARB, OP and SCROLL return 400 here.
`from` body · string · optional	EVM chains, required: the sending wallet, 0x followed by 40 hexadecimal characters.
`to` body · string · optional	EVM chains, required: the recipient or contract called, 0x followed by 40 hexadecimal characters.
`data` body · string · optional	The calldata, `0x`-prefixed hex of whole bytes. Optional; defaults to `0x` (a plain transfer).
`value` body · string · optional	Native coin sent, in wei, as a decimal string. Optional; defaults to `"0"`.
`gas` body · integer · optional	The gas limit, 21000 to 30000000. Optional; when absent the chain picks a limit high enough to run the call.
`transaction` body · string · optional	SOL only, and then the only field: the transaction serialized and base64-encoded, at most 1232 bytes, legacy or version 0. Unsigned is fine: signature slots may be zeroes. Any recent blockhash works; the latest one replaces it.

Response fields

A JSON response. Every field is always present; null means the value could not be established, never zero.

Response fields of What would this transaction do if I sent it?
Field	Type	Description
`outcome`	string	`success`: the transaction would run to completion. `reverted`: it would fail and undo every change it made. `insufficient-funds`: the sender does not hold the `value` sent plus gas (on SOL: the fee payer cannot pay the fee), so it could not run at all — every other field is then `null`.
`revertReason`	string \| null	The contract's revert message, decoded from the revert data when it is a standard text error, or `Panic(0x..)` for a failed assertion or arithmetic error. `null` when the transaction does not revert, or reverts with a custom error or with no data — read `revertData` for those — and on BASE when the second simulator answered, which reports that a call reverts but not why. On SOL: the failing instruction and its error, e.g. `Instruction 0: custom program error: 0x1`, or the transaction-level error when it could not run, e.g. `AddressLookupTableNotFound`.
`revertData`	string \| null	The raw revert data, lowercase hex, for decoding a custom error. `null` when the transaction does not revert or the chain reported no revert data, on BASE when the second simulator answered, and always on SOL.
`gasUsed`	integer \| null	The gas the run used, reverted runs included; on SOL, the compute units it consumed. `null` for `insufficient-funds`, on STABLE, where the chain does not report it, and on SOL when the transaction could not run at all — never `0`.
`returnData`	string \| null	What the call returned, lowercase hex; `0x` when it returned nothing. `null` unless the outcome is `success`, and on BASE when the second simulator answered. On SOL, the return data a program set, if any.
`logs`	object[] \| null	The events the transaction would emit, in order, native transfers excluded (they are in `nativeTransfers`). `[]` when it emits none or reverts. `null` on ARC and STABLE, where events are not available, on SOL, which has no events (read `programLogs`), and for `insufficient-funds`.
`logs[].address`	string	The contract that emitted the event, lowercase.
`logs[].topics`	string[]	The indexed topics, lowercase; the first is the event signature hash.
`logs[].data`	string	The non-indexed event data, lowercase hex.
`nativeTransfers`	object[] \| null	Every movement of the native coin as the chain traces it — the top-level `value`, and value moved by contracts during the run — in order. `[]` when none or when it reverts. `null` on ARC, STABLE and SOL, where they are not available, on BASE when the second simulator answered, and for `insufficient-funds`.
`nativeTransfers[].from`	string	The sender of the native coin, lowercase.
`nativeTransfers[].to`	string	The recipient of the native coin, lowercase.
`nativeTransfers[].valueWei`	string	The amount in wei, as a decimal string.
`programLogs`	string[] \| null	SOL only: the log lines the programs printed during the run, in order — invocations, messages, compute units consumed, success or failure. `null` on every EVM chain and for `insufficient-funds`.

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