> ## Documentation Index
> Fetch the complete documentation index at: https://voltaire.tevm.sh/llms.txt
> Use this file to discover all available pages before exploring further.

# Address.fromHex

> Create address from hex string

<Card title="Try it Live" icon="play" href="https://playground.tevm.sh?example=primitives/address.ts">
  Run Address examples in the interactive playground
</Card>

<Warning>
  **This page is a placeholder.** All examples on this page are currently AI-generated and are not correct. This documentation will be completed in the future with accurate, tested examples.
</Warning>

<Tip>
  View the complete executable example at [`playground/src/examples/primitives/address/from-hex.ts`](https://github.com/evmts/voltaire/blob/main/playground/src/examples/primitives/address/from-hex.ts).
</Tip>

<Tabs>
  <Tab title="C">
    ## `primitives_address_from_hex(const char* hex, PrimitivesAddress* out_address): int`

    Create address from hex string in C. Accepts hex strings with or without `0x` prefix.

    **Parameters:**

    * `hex: const char*` - Hex string (with or without `0x` prefix)
    * `out_address: PrimitivesAddress*` - Pointer to output address struct (20 bytes)

    **Returns:** `int` - `PRIMITIVES_SUCCESS` (0) on success, error code otherwise

    **Example:**

    ```c theme={null}
    #include "primitives.h"

    // From hex string
    PrimitivesAddress addr1;
    int result = primitives_address_from_hex("0x742d35Cc6634C0532925a3b844Bc9e7595f51e3e", &addr1);
    if (result != PRIMITIVES_SUCCESS) {
        // Handle error
    }

    // From hex without prefix
    PrimitivesAddress addr2;
    result = primitives_address_from_hex("742d35Cc6634C0532925a3b844Bc9e7595f51e3e", &addr2);

    // Case insensitive
    PrimitivesAddress addr3;
    result = primitives_address_from_hex("0x742D35CC6634C0532925A3B844BC9E7595F51E3E", &addr3);
    ```

    **Error Handling:**

    * Returns non-zero error code on failure
    * Check result before using `out_address`
    * Common errors: invalid hex format, incorrect length

    **Memory:** No allocation - address is copied to provided struct.

    **Defined in:** [primitives.h:103](https://github.com/evmts/voltaire/blob/main/src/primitives.h#L103)
  </Tab>
</Tabs>

## Format Requirements

**Length (implementation-dependent):**

**TypeScript implementations (Class API):**

* **Requires** `0x` prefix: exactly 42 characters total

**Zig and C implementations:**

* **Accepts** both formats:
  * With `0x` prefix: exactly 42 characters
  * Without `0x` prefix: exactly 40 characters

**Characters:**

* Valid: `0-9`, `a-f`, `A-F`
* Invalid: `g-z`, `G-Z`, whitespace, special characters

**Case sensitivity:**

* Parsing is case-insensitive
* Both lowercase and uppercase hex are accepted
* Mixed-case (EIP-55 checksummed) addresses are valid

## Error Handling

```typescript theme={null}
import { Address } from '@tevm/voltaire'

// Missing 0x prefix
try {
  Address("742d35Cc6634C0532925a3b844Bc9e7595f51e3e")
} catch (e) {
  console.error(e) // InvalidHexFormatError
}

// Wrong length
try {
  Address("0x742d35")
} catch (e) {
  console.error(e) // InvalidHexFormatError
}

// Invalid characters
try {
  Address("0xGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGGG")
} catch (e) {
  console.error(e) // InvalidHexStringError
}
```

## Validation Before Parsing

Use `Address.isValid()` to check before parsing:

```typescript theme={null}
const input = "0x742d35Cc6634C0532925a3b844Bc9e7595f51e3e"

if (Address.isValid(input)) {
  const addr = Address(input)
  console.log(addr.toHex())
} else {
  console.error("Invalid address format")
}
```

## EIP-55 Checksums

`fromHex()` accepts checksummed addresses but does not validate checksums. Use `isValidChecksum()` to validate before parsing:

```typescript theme={null}
const checksummed = "0x5aAeb6053F3E94C9b9A09f33669435E7Ef1BeAed"

if (Address.isValidChecksum(checksummed)) {
  const addr = Address(checksummed)
  console.log("Checksum valid")
} else {
  console.warn("Invalid checksum, but parsing anyway")
  const addr = Address(checksummed)
}
```

## See Also

* [from](/primitives/address/from) - Universal constructor
* [fromBytes](/primitives/address/from-bytes) - Create from Uint8Array
* [toHex](/primitives/address/to-hex) - Convert to hex string
* [toChecksummed](/primitives/address/to-checksummed) - Convert to EIP-55 checksummed hex
* [isValid](/primitives/address/is-valid) - Validate address format
* [isValidChecksum](/primitives/address/is-valid-checksum) - Validate EIP-55 checksum
* [EIP-55: Mixed-case checksum](https://eips.ethereum.org/EIPS/eip-55)