xahau-mcp

A Model Context Protocol server for the Xahau network with two firsts: it runs a Hook’s real WebAssembly bytecode in a local VM (no xahaud node required), and it runs a Hooks-specific static-analysis / security rule engine over it — both fully offline. Around that core it adds read-only ledger access, a Xahau-aware binary codec, an instruction-count fee estimate, network-reward math, governance helpers, and unsigned-transaction builders.

Xahau is the XRPL fork whose flagship feature is Hooks — small on-ledger WebAssembly smart contracts. There was no MCP for Xahau and no static analyzer for Hooks; this is both.

The trifecta — safe Hooks, end to end

Three open-source tools, one workflow: write → simulate one tx → prove all inputs. xahau-mcp is the simulate stage.

Why it’s useful

Point any MCP-capable agent (Claude, etc.) at this server and it can:

• See the future before signing — simulate_transaction is a pre-sign flight simulator: every hook an unsigned transaction would trigger runs as real bytecode against live ledger state, with per-hook accept/rollback, decoded emitted transactions, simulated state writes and labeled static engine preflights. Its sibling what_if is a time machine: replay any real historical transaction — with your modifications — at its original ledger. Verified to reproduce a real claim’s emitted GenesisMint payout to the drop (72,251,963 drops), test-locked.

• Run a Hook without deploying it — execute_hook instantiates the real CreateCode WASM in a local VM, supplies the Hook API over a simulated transaction + ledger state, and reports the actual accept/rollback decision, return code/string, state writes, emitted transactions and a call trace. No xahaud node needed.

• Audit a Hook before it’s installed — paste the CreateCode WASM (or an on-ledger hook hash) and get SARIF-lite findings: missing accept/rollback exit, unguarded loops (_g), unknown env imports, dangerous HookGrants, over-broad HookOn, and more.

• Decode the cryptic HookOn bitmap in both directions — the 256-bit, inverted, active-low mask (with the active-high SetHook bit) is easy to get wrong; here it’s verified and round-trip-tested.