Legba is a production-grade multi-protocol credential bruteforcer, password sprayer, and enumerator written in Rust. It operates as a CLI tool with a plugin-based architecture supporting 30+ protocols (HTTP, SSH, SMB, LDAP, Kerberos, SQL variants, NoSQL, message queues, SNMP, etc.). The core system uses an async runtime (Tokio) and a global plugin inventory managed via a `register_plugin!` macro and the `Plugin` trait. Credential sources are generated by a flexible expression parser that supports wordlists, globs, permutations, ranges, and combinations. Sessions can be saved and restored in JSON format, and output supports text, CSV, and JSONL. In addition to CLI, Legba exposes a REST API and an MCP (Model Context Protocol) server, enabling AI agents to drive credential testing programmatically. A YAML recipe system allows reusable attack configurations with variable substitution.