open-standards/wai/wai-quantum-cli/README.md

wai-quantum

The command line of the WAI quantum stack. It runs OpenQASM programs on this machine, planned and run by the same engine as the quantum job service (wai_quantum::engine), so a job gives the same result here as there. It also sends programs to the service, checks and draws them, verifies receipts, and serves its tools to agents over MCP.

Installing it

Where	How
Any platform with Rust	cargo install wai-quantum-cli (installs the wai-quantum binary)
macOS or Linux, with Homebrew	brew tap transaction-science/tap https://git.transaction.science/Transaction-Science/homebrew-tap then brew install wai-quantum
Windows, with Scoop	scoop bucket add transaction-science https://git.transaction.science/Transaction-Science/scoop-bucket then scoop install wai-quantum
Anywhere	a prebuilt archive from the releases tagged wai-quantum-cli-v…

The prebuilt archives are:

• macOS for Apple silicon and for Intel, with the GPU state vector;
• Linux for x86_64 and arm64, linked statically, so any distribution runs them;
• Windows for x86_64.

Each archive has a .sha256 file beside it (shasum -a 256 -c). A tag wai-quantum-cli-v<version> builds them on the project's own runners (release/, .github/workflows/wai-quantum-cli-release.yml), and writes the Homebrew formula and the Scoop manifest for them.

Running a program

wai-quantum run bell.qasm --shots 1000
wai-quantum run prog.qasm -o "Z0 Z1" -o "0.5 X2" -a 000 -a 111
wai-quantum run prog.qasm --noise depolarizing_2q=0.01 --noise readout=0.02
wai-quantum run prog.qasm --method mps --option max_bond=128
cat prog.qasm | wai-quantum run --json > job.json

A program is OpenQASM 3, or the OpenQASM 2 forms in common use. The reader accepts:

• registers, and a gate applied to a whole register;
• the standard gates;
• ctrl and negctrl modifiers;
• gate definitions;
• measurement and reset anywhere, and if on measured bits;
• generators: integer inputs, consts and for loops, so one program describes a family of circuits.

It refuses while, inv and pow, giving the line of each.

A generator takes its inputs with --input, which every command accepts, and instance writes the circuit out:

cat > ghz.qasm <<'QASM'
OPENQASM 3.0;
input uint n;
qubit[n] q;
h q[0];
for uint i in [0:n-2] { cx q[i], q[i + 1]; }
QASM
wai-quantum run ghz.qasm --input n=40 --shots 100
wai-quantum instance ghz.qasm --input n=3

--method auto (the default) picks the strongest method the program admits:

Method	Takes
exact	dyadic angles; the state vector, the same bits on every machine
statevector	any angle
stabilizer	Clifford circuits, to tens of thousands of qubits
mps	matrix product states
pauli	Pauli dynamics, for expectation values
tensor_network	amplitudes
cutrank	a Clifford circuit with a layer of rotations
density_matrix, trajectories	noise

wai-quantum methods lists each method's reach in a job's memory here (--memory-gb, default 16).

Each result names:

• its method, and why that method was chosen;
• its accuracy class;
• the counts, expectation values or amplitudes asked for;
• its receipt.

Receipts

Every result is signed over the request and the result in their canonical JSON. The service signs with its key; this tool signs with this user's key:

• --key FILE, or $WAI_QUANTUM_KEY, names a file holding the key;
• otherwise the key is $XDG_CONFIG_HOME/wai/quantum-key, or ~/.config/wai/quantum-key. It is made from the system's random source on first use and is readable by its owner only.

wai-quantum key prints the key's did:key. --demo-key signs with the published demo key. Its receipts show only that a result is unaltered, not who signed it.

wai-quantum run prog.qasm --json > job.json
wai-quantum verify job.json              # VALID, and the signer's did:key
wai-quantum submit prog.qasm --json > svc.json
wai-quantum verify svc.json              # the same check on the service's receipt

A receipt shows that this key signed this request and this result, and anyone can rerun the request to compare. It does not say who holds the key.

Checking and drawing

wai-quantum lint prog.qasm               # ok, with its shape, or the line of the first problem
wai-quantum plan prog.qasm               # the method and why, the memory and work, without running
wai-quantum draw prog.qasm --width 80

q0: ─────H─────●──M0──────
               │
q1: ───────────⊕──●───M1──
                  │
q2: ──Rz(π/4)─────⊕───M2──

Critique, equivalence and improvement

wai-quantum critique prog.qasm               # its measures, a modelled fidelity, and its smells with their lines
wai-quantum equivalent a.qasm b.qasm         # the same circuit? exit 0 the same, 1 different, 2 unchecked
wai-quantum improve prog.qasm > better.qasm  # its smells fixed; what changed, and the check, on standard error
wai-quantum shortcuts prog.qasm              # each exact classical route to simulating it, and its cost here

The critique's figures are computed, not estimated: gates by kind, two-qubit gates, depth and two-qubit depth, the T count, and whether the program is a Clifford circuit. Its fidelity is a model at reference error rates, and says so. Its smells are gates that cancel, rotations that merge or do nothing, idle qubits, and qubits acted on but never measured.

equivalent compares two programs up to a global phase. Clifford circuits are compared by their tableaus at any size, and others on every basis state up to 8 qubits. Between 8 and 22 qubits it compares them on random product states, which is evidence, not proof. Beyond that it answers unchecked, with the reason. improve rewrites only statements alone on their lines, and prints a rewrite only when the check does not find it different.

shortcuts lists every exact classical route the engine knows for simulating the program, each with its memory and operations, and names the cheapest. The routes:

• the stabilizer tableau, for Clifford circuits;
• the cut-rank sum, for a Clifford circuit followed by one layer of one-qubit gates;
• an exact matrix product state, at a bond bounded across each cut by the operator Schmidt ranks of the gates that cross it;
• the light cone of a one-qubit expectation value;
• a tensor-network contraction, with --thorough, which also searches longer for a cut-rank order;
• the state vector.

A cheap route proves a design classically easy. None being cheap proves nothing about hardness: other methods, approximate ones above all, may cost far less.

The service

wai-quantum submit sends a job to https://wai.transaction.science/quantum-jobs, or to --service URL (also read from $WAI_QUANTUM_SERVICE). It waits for a long job to finish, then prints the result just as run does.

For agents

wai-quantum mcp is a Model Context Protocol server on standard input and output. Its tools are:

• run_quantum_circuit
• plan_quantum_circuit
• lint_qasm
• critique_qasm
• check_equivalent
• improve_qasm
• classical_shortcuts
• draw_circuit
• verify_quantum_result
• list_methods

Runs happen on this machine and are signed with this user's key; nothing is sent anywhere. In an MCP client's configuration:

{ "mcpServers": { "wai-quantum": { "command": "wai-quantum", "args": ["mcp"] } } }

The research tools

wai-quantum lab … holds the research tools:

• algorithms from the catalogue, OpenQASM and QIR export, and receipts over them;
• error correction at circuit level;
• qLDPC memory;
• fault-tolerant resource estimates and architectures;
• DMRG, TDVP and molecules;
• neural quantum states;
• Gaussian boson sampling;
• optimisation;
• the compute fabric;
• information and transport.

wai-quantum lab help lists them. wai-quantum verify also checks the receipts they sign.

Builds

• Default: submit, over HTTPS.
• --features metal: the single-precision state vector on the GPU (--method statevector_single), on macOS.
• --no-default-features --target wasm32-wasip2: a WASI component without submit. It gives the same output under any WASI runtime.

wai-quantum completions zsh (or bash, fish, elvish, PowerShell) prints shell completion.