Quint

MCP server for the Quint formal specification language. Wraps the Quint CLI to make formal verification accessible to any LLM-powered workflow.

Quick Start

1. Install Quint CLI

npm i -g @informalsystems/quint

2. Add to Claude Code

claude mcp add quint -- npx @dpdanpittman/mcp-server-quint

That's it. You now have 6 formal verification tools available in Claude Code.

Other MCP Clients

Any MCP-compatible client can use this server over stdio:

npx @dpdanpittman/mcp-server-quint

With Supergateway (HTTP transport)

{ name: 'quint', command: 'node', args: ['/path/to/mcp-server-quint/index.js'] }

Tools

quint_typecheck

Type-check a Quint specification. Provide either source (inline .qnt code) or file_path.

quint_run

Simulate a Quint spec with random execution. Optionally check an invariant. Returns a counterexample trace if violated.

Parameter	Description
source / file_path	Spec to simulate
init	Init action name (default: "init")
step	Step action name (default: "step")
invariant	Invariant to check
max_samples	Number of runs (default: 10000)
max_steps	Steps per run (default: 20)
seed	Random seed for reproducibility

quint_test

Run named test definitions (run statements). Optionally filter by match regex.

quint_verify

Exhaustive model checking via Apalache. Checks ALL reachable states, not just random samples. Requires Java 17+ and Apalache.

quint_parse

Parse a spec and return the intermediate representation (IR) as JSON.

quint_docs

Quick reference for Quint syntax. Topics: sets, maps, lists, actions, temporal, types, modules, testing, or all.

Example

module bank {
  var balances: str -> int
  val ADDRS = Set("alice", "bob")
  action init = balances' = ADDRS.mapBy(_ => 100)
  action transfer(sender: str, receiver: str, amt: int): bool = all {
    balances.get(sender) >= amt,
    balances' = balances.set(sender, balances.get(sender) - amt)
                        .set(receiver, balances.get(receiver) + amt)
  }
  action step = {
    nondet sender = ADDRS.oneOf()
    nondet receiver = ADDRS.oneOf()
    nondet amt = 1.to(balances.get(sender)).oneOf()
    transfer(sender, receiver, amt)
  }
  val no_negatives = ADDRS.forall(a => balances.get(a) >= 0)
}

Environment Variables

Variable	Default	Description
QUINT_CMD	quint	Path to Quint CLI binary
QUINT_TIMEOUT	120000	CLI timeout in ms

License

PolyForm Noncommercial 1.0.0