> ## 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.

# Bytecode.hash

> Compute keccak256 hash of bytecode

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

<Tabs>
  <Tab title="Namespace API">
    ## `Bytecode.hash(code): Hash`

    Compute keccak256 hash of bytecode (with auto-injected crypto).

    **Parameters:**

    * `code: BrandedBytecode` - Bytecode to hash

    **Returns:** `HashType` - Bytecode hash (32 bytes)

    **Example:**

    ```typescript theme={null}
    import * as Bytecode from 'tevm/Bytecode'

    const code = Bytecode('0x6001')
    const hash = Bytecode.hash(code)
    // Uint8Array(32) [...]
    ```
  </Tab>

  <Tab title="Factory API">
    ## `Hash({ keccak256 })(code): Hash`

    Tree-shakeable factory pattern with explicit crypto dependencies.

    **Dependencies:**

    * `keccak256: (data: Uint8Array) => Uint8Array` - Keccak256 hash function

    **Parameters:**

    * `code: BrandedBytecode` - Bytecode to hash

    **Returns:** `HashType` - Bytecode hash (32 bytes)

    **Example:**

    ```typescript theme={null}
    import { Hash } from 'tevm/Bytecode'
    import { hash as keccak256 } from 'tevm/crypto/Keccak256'

    const hashFn = Hash({ keccak256 })
    const code = new Uint8Array([0x60, 0x01])
    const hash = hashFn(code)
    // Uint8Array(32) [...]
    ```

    **Bundle size:** Crypto only included if you import it.
  </Tab>

  <Tab title="C">
    ## `hash_t bytecode_hash(bytecode_t bytecode)`

    Compute keccak256 hash of bytecode.

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

    uint8_t code[] = {0x60, 0x01};
    bytecode_t bc = bytecode_init(code, 2);

    hash_t hash_result = bytecode_hash(bc);
    printf("Hash: ");
    for (size_t i = 0; i < 32; i++) {
        printf("%02x", hash_result.bytes[i]);
    }
    printf("\n");

    bytecode_free(bc);
    hash_free(hash_result);
    ```

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

## Performance

Hash computation depends on imported keccak256 implementation. Factory API enables explicit control over crypto bundling.