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# ExecutionError

## Overview

Decode reverts from the Tempo precompiles in `Abis.core` and format their messages. Unknown errors retain their original message without the `execution reverted:` prefix.

## Recipes

### Decode a Revert

Pass the error from a failed call to `ExecutionError.from`. The decorated copy
retains the original properties and adds decoded fields when revert data is known.

```ts twoslash
import { ExecutionError } from 'viem/tempo'

const error = ExecutionError.from({ // [!code focus]
  data: '0x82b42900',
  message: 'execution reverted',
})

// [!code focus:start]
error.errorName
// @log: 'Unauthorized'
error.message
// @log: 'Unauthorized.'
// [!code focus:end]
```

### Serialize Error Metadata

Use `ExecutionError.serialize` to select JSON-safe execution metadata without
the original stack, cause, custom properties, or decoded arguments.

```ts twoslash
import { ExecutionError } from 'viem/tempo'

const error = ExecutionError.from('0x82b42900')
const metadata = ExecutionError.serialize(error) // [!code focus]

// [!code focus:start]
metadata
// @log: {
// @log:   errorName: 'Unauthorized',
// @log:   abiItem: { type: 'error', name: 'Unauthorized', inputs: [] },
// @log:   message: 'Unauthorized.',
// @log:   data: '0x82b42900',
// @log: }
// [!code focus:end]
```

## `from`

Decorates a copy of an error with decoded execution fields and a readable message. The input remains unchanged.

### Usage

```ts
import { ExecutionError } from 'viem/tempo'

const error = ExecutionError.from({
  data: '0x82b42900',
  message: 'execution reverted',
})
error.errorName // 'Unauthorized'
error.message // 'Unauthorized.'
```

You can also pass a four-byte selector or complete ABI-encoded revert data:

```ts
import { ExecutionError } from 'viem/tempo'

const error = ExecutionError.from('0x82b42900')
error.message // 'Unauthorized.'
```

### Parameters

#### error

* **Type:** `Error | Hex | { data?: Hex; message: string }`

An error instance or a plain object with a message and optional revert data. Error instances can also contain revert data in a nested `cause` or `error`, or a Viem error's `walk` result. When decoding fails, the message comes from `details`, `shortMessage`, or `message`, in that order.

### Return Value

`ExecutionError.from.ReturnType`

Error objects retain their prototype, stack, cause, and custom properties. Known errors contain `errorName`, `abiItem`, `args`, `data`, and `message`. Unknown errors receive `errorName: 'unknown'` and a fallback `message`.

Hex input produces a plain object with `data`. Selector-only input has no decoded arguments; message placeholders such as `{0}` remain uninterpolated when arguments are required.

## `serialize`

Selects execution metadata for JSON serialization. Original error properties, including stack, cause, and custom fields, are omitted along with decoded arguments.

### Usage

```ts
import { ExecutionError } from 'viem/tempo'

const error = ExecutionError.from(new Error('execution reverted: failed'))
const rpc = ExecutionError.serialize(error)
JSON.stringify(rpc)
// '{"errorName":"unknown","message":"failed"}'
```

### Parameters

#### preimage

* **Type:** `ExecutionError.ExecutionError`

An error returned by `ExecutionError.from`.

### Return Value

`ExecutionError.Rpc`

The execution metadata without `args`. Original properties and decoded arguments remain available on the decorated error.

## `messages`

Message templates cover every error signature in `Abis.core`. Placeholders such as `{0}` refer to decoded arguments by position.

```ts
import { ExecutionError } from 'viem/tempo'

ExecutionError.messages['InsufficientBalance()']
// 'Insufficient balance.'
```

For repository maintenance, run `bun scripts/checkTempoErrors.ts` after updating the ABIs or templates. The check reports missing messages, unknown signatures, and placeholders absent from their ABI signature. `pnpm gen:tempo-abis` also runs this check against the checked-in ABIs.