Fathom MCP Server

fathom

Current release: 1.0.0 (2026-10-29). Deferred items are listed in COMPLIANCE.md; release history in CHANGELOG.md.

Clean-room reverse-engineering MCP, written in Rust: one provider-neutral MCP server for reverse engineering — native binaries, JavaScript/Electron applications, .NET assemblies, web captures, EVM bytecode, and process behavior — where every result is an evidence envelope that states what was observed, what was derived, what was not examined, and what the provider cannot establish.

The design is specified in SPEC.md: capability inventory mapped from upstream's public contracts, per-capability Rust strategy, evidence and error models, a deterministic fail-closed policy engine, and the staging plan. Design source: morluto/rea (MIT), credited in NOTICE; no upstream code is used.

Why clean-room Rust

Upstream REA is TypeScript/Node distributed through npm. Fathom exists to keep the capability on a Rust-first, pinned, auditable supply chain — the estate's standing direction (SPEC §1).

Shape

• fathom-core — config, error contracts, evidence model, policy, tool registry, confinement, bounded processes.
• fathom-mcp-server — MCP stdio + streamable HTTP transports.
• fathom-a2a — signed A2A agent card (JCS + Ed25519).
• fathom-native — Ghidra headless provider + binary layout (goblin).
• fathom-js — JavaScript/Electron static analysis (oxc) + ASAR.
• fathom-managed — .NET PE/CLI metadata (manual ECMA-335).
• fathom-observe — process capture, HAR reading, EVM selectors.
• fathom-cli — the fathom binary (serve, card, doctor, one-shot analysis).

Build

nix build          # or: nix develop, then cargo build --workspace
cargo test --workspace

License

This project is licensed under the Apache License, Version 2.0.