> ## Documentation Index
> Fetch the complete documentation index at: https://cosmos-docs-cosmjs-docs.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# Transaction Execution Errors

> Handling transaction execution failures from DeliverTx responses.

When a transaction is included in a block but execution fails (e.g. out of gas,
insufficient funds, contract panic), `broadcastTx` does **not** throw. Instead
it returns a `DeliverTxResponse` with a non-zero `code`.

## Checking Success or Failure

```typescript theme={"system"}
import {
  isDeliverTxSuccess,
  isDeliverTxFailure,
  assertIsDeliverTxSuccess,
} from "@cosmjs/stargate";

const result = await client.signAndBroadcast(address, messages, fee);

if (isDeliverTxSuccess(result)) {
  console.info("Success:", result.transactionHash);
} else {
  console.error(`Failed with code ${result.code}: ${result.rawLog}`);
}

// Or throw on failure:
assertIsDeliverTxSuccess(result);
// Throws: "Error when broadcasting tx <hash> at height <height>. Code: <code>; Raw log: <rawLog>"
```

## Common Execution Failures

| Failure            | Where it appears                               | Typical cause                                   |
| ------------------ | ---------------------------------------------- | ----------------------------------------------- |
| Out of gas         | `result.rawLog` contains "out of gas"          | Gas limit too low; increase fee or use `"auto"` |
| Insufficient funds | `result.rawLog` contains "insufficient funds"  | Sender balance too low for amount + fee         |
| Invalid message    | `result.rawLog` describes the validation error | Wrong field values or missing required fields   |
| Contract error     | `result.rawLog` contains the contract error    | CosmWasm contract returned an error             |

CosmJS does not define constants for Cosmos SDK error codes. The `code` and
`codespace` fields are passed through from the node. Inspect `rawLog` (SDK \<
0.50) or `events` (SDK 0.50+) for human-readable details.

## CosmWasm Convenience Methods

Methods like `upload`, `instantiate`, `execute`, and `migrate` on
`SigningCosmWasmClient` throw a plain `Error` when `isDeliverTxFailure` is true,
instead of returning the `DeliverTxResponse`:

```typescript theme={"system"}
try {
  const { contractAddress } = await client.instantiate(
    sender, codeId, msg, label, "auto",
  );
} catch (error) {
  // "Error when broadcasting tx <hash> at height <height>. Code: <code>; Raw log: <rawLog>"
}
```