Two languages: OpenQASM 3 and Qiskit

from qiskit import QuantumCircuit
from numpy import pi

qc = QuantumCircuit(2, 2)
qc.h(0)
qc.cx(0, 1)
qc.rz(pi/4, 1)
qc.measure([0, 1], [0, 1])

OPENQASM 3.0;
include "stdgates.inc";
qubit[2] q;
bit[2] c;
h q[0];
cx q[0], q[1];
rz(pi/4) q[1];
c[0] = measure q[0];
c[1] = measure q[1];

QubitLab treats OpenQASM 3 as the single source of truth: the composer, the simulators and the hardware jobs all read QASM. Python is read by a translator that walks the abstract syntax tree and recognises QuantumCircuit calls, gate methods, measure, barrier, for-range loops, constant arithmetic with pi, and the control-flow builders (if_test, while_loop, for_loop, switch). Nothing is executed, so a script can never read your files or call the network.

• Accepted: qc.h(0), qc.cx(0, 1), qc.rx(pi/2, 0), qc.measure(0, 0), qc.measure_all(), qc.barrier(), for i in range(n): …, with qc.if_test((c[0], 1)): …
• Ignored with a warning: transpile(), AerSimulator(), draw(), print()
• Rejected with a line number: anything whose value is not a literal, such as random numbers or file reads.

OPENQASM 3.0;
include "stdgates.inc";
qubit[2] q;
bit[2] c;
h q[0];
cx q[0], q[1];
c = measure q;