# laszlopere/mcp-bytesmith [Health: Active]

**Category:** 🔑 Cryptography  
**Repository:** https://github.com/laszlopere/mcp-bytesmith  
**GitHub Stars:** 2  
**Views:** 3  
**Installs:** 0  
**Upvotes:** 0  
**Directory Page:** https://allmcps.com/mcp/laszlopere-mcp-bytesmith

## Description
Local byte-wrangling toolbox: encoding (hex/Base64/Base32/Base58/Base45…), cryptographic + CRC hashing, base conversion, and CSPRNG tokens/passphrases, plus an opt-in Ethereum/EVM toolset (keccak, ABI/RLP codecs, EIP-191/712 hashing, function/event selectors, EIP-55). No network calls. uvx mcp-bytesmith.

## Claude Desktop Quick Installation
Install path detected from listing signals. Uses `uvx` (confidence: high):

```json
"mcpServers": {
  "mcp-bytesmith": {
    "command": "uvx",
    "args": ["mcp-bytesmith"]
  }
}
```

## Documentation

## What laszlopere/mcp-bytesmith MCP server does

laszlopere/mcp-bytesmith MCP server exposes a broad collection of local data and cryptography primitives through FastMCP, the official Python MCP SDK. The core package handles byte encoding and decoding, hashing, keyed authentication, integer base conversion, byte manipulation, URI processing, text normalization, character-set conversion, string escaping, Unicode inspection, random value generation, identifier creation, password hashing, and key derivation.

The core tools are built on the Python standard library and do not require network access. An `info` tool reports active toolsets and version information. This makes the server suitable for agents that need to inspect or transform supplied data without sending it to a remote service.

## How it works

The server communicates over MCP and can be started locally over stdio. Tool calls perform calculations in the local Python process. The `encode` and `decode` tools cover formats such as hexadecimal, Base64 variants, Base32 variants, Base58 and Base58check, and Base45. Hashing includes cryptographic, CRC, and fast non-cryptographic digests; `hash_file` reads a local file and can compare its digest with an expected value.

Optional toolsets add domain-specific functions. The Ethereum extra covers Keccak-256, EIP-191 and EIP-712 hashing, ABI and RLP codecs, selectors, calldata, event logs, revert data, bytecode, transactions, storage slots, checksummed addresses, ENS hashes, mnemonic and HD derivation, and contract addresses. The serialization extra adds CBOR, MessagePack, bencode, ASN.1 DER/BER, SSZ, and raw protobuf-wire decoding. Some of these capabilities require the relevant optional dependencies.

## Setup and configuration

Install and run the distribution with `uvx mcp-bytesmith`, or use a development checkout with `uv sync` followed by `uv run mcp-bytesmith`. The package requires Python 3.10 or newer. Core functionality is available without extra dependencies.

Install the `ethereum` extra to activate the Ethereum/EVM tools. Install the `serialize` extra for the serialization toolset. The README also refers to a `crypto` extra for bcrypt, Argon2 variants, and ASN.1 support. No environment variables or remote service credentials are documented as required.

## Tools and capabilities

Core capabilities include:

- Encode and decode common binary and textual representations.
- Calculate hashes, CRC values, HMACs, and file checksums.
- Convert integers between bases and edit byte sequences by padding, trimming, slicing, or concatenating.
- Build and parse `data:` and `otpauth://` URIs.
- Normalize Unicode, transcode character sets, escape strings, and inspect code points.
- Generate CSPRNG-backed bytes, tokens, passphrases, UUIDs, ULIDs, and nanoids.
- Create and verify password storage strings, or derive raw key material with PBKDF2, scrypt, or HKDF.

With the optional Ethereum toolset, laszlopere/mcp-bytesmith MCP server can encode and decode ABI and RLP data, inspect contract ABIs, calculate selectors, decode logs and revert payloads, disassemble deployed bytecode, calculate storage slots, and derive several Ethereum-related values. The serialization toolset uses a format selector and, where needed, an explicit schema.

## Limitations and notes

The server performs local computations and makes no network calls, so it does not query blockchains, resolve names online, or retrieve external files. File hashing operates on files available to the local process. Protobuf support is decode-only and, without a `.proto` schema, reports wire-level information rather than field names. SSZ encoding and decoding depend on a supplied schema. The project notes that additional cryptography, identifier, and validation toolsets remain on the roadmap.

The project is licensed under GPLv3. The bundled EFF passphrase list and BIP-39 English wordlist have separate licenses described in the repository.

_Full upstream README: https://allmcps.com/mcp/laszlopere-mcp-bytesmith/readme_