* Create cicuit module and circuit/library submodule

* Add MidCircuitMeasure(Instruction) to new circuit library

* Add unit tests

Author: ElePT

qiskit_ibm_runtime/circuit/__init__.py

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+# This code is part of Qiskit.
+#
+# (C) Copyright IBM 2025.
+#
+# This code is licensed under the Apache License, Version 2.0. You may
+# obtain a copy of this license in the LICENSE.txt file in the root directory
+# of this source tree or at http://www.apache.org/licenses/LICENSE-2.0.
+#
+# Any modifications or derivative works of this code must retain this
+# copyright notice, and modified files need to carry a notice indicating
+# that they have been altered from the originals.
+
+"""Module for vendor-specific circuit objects."""
+
+from .library import *

qiskit_ibm_runtime/circuit/library/__init__.py

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+# This code is part of Qiskit.
+#
+# (C) Copyright IBM 2025.
+#
+# This code is licensed under the Apache License, Version 2.0. You may
+# obtain a copy of this license in the LICENSE.txt file in the root directory
+# of this source tree or at http://www.apache.org/licenses/LICENSE-2.0.
+#
+# Any modifications or derivative works of this code must retain this
+# copyright notice, and modified files need to carry a notice indicating
+# that they have been altered from the originals.
+
+"""Module for vendor-specific instructions."""
+
+
+from .mid_circuit_measure import MidCircuitMeasure

qiskit_ibm_runtime/circuit/library/mid_circuit_measure.py

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+# This code is part of Qiskit.
+#
+# (C) Copyright IBM 2025.
+#
+# This code is licensed under the Apache License, Version 2.0. You may
+# obtain a copy of this license in the LICENSE.txt file in the root directory
+# of this source tree or at http://www.apache.org/licenses/LICENSE-2.0.
+#
+# Any modifications or derivative works of this code must retain this
+# copyright notice, and modified files need to carry a notice indicating
+# that they have been altered from the originals.
+
+from qiskit.circuit import Instruction
+
+
+class MidCircuitMeasure(Instruction):
+    def __init__(self, name="measure_2", label=None):
+        if not name.startswith("measure_"):
+            raise ValueError(
+                "Invalid name for mid-circuit measure instruction."
+                "The provided name must start with `measure_`"
+            )
+
+        super().__init__(name, 1, 1, [], label=label)

test/unit/circuit/__init__.py

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+# This code is part of Qiskit.
+#
+# (C) Copyright IBM 2025.
+#
+# This code is licensed under the Apache License, Version 2.0. You may
+# obtain a copy of this license in the LICENSE.txt file in the root directory
+# of this source tree or at http://www.apache.org/licenses/LICENSE-2.0.
+#
+# Any modifications or derivative works of this code must retain this
+# copyright notice, and modified files need to carry a notice indicating
+# that they have been altered from the originals.

test/unit/circuit/test_mid_circ_meas.py

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+# This code is part of Qiskit.
+#
+# (C) Copyright IBM 2025.
+#
+# This code is licensed under the Apache License, Version 2.0. You may
+# obtain a copy of this license in the LICENSE.txt file in the root directory
+# of this source tree or at http://www.apache.org/licenses/LICENSE-2.0.
+#
+# Any modifications or derivative works of this code must retain this
+# copyright notice, and modified files need to carry a notice indicating
+# that they have been altered from the originals.
+
+"""Tests for MidCircuitMeasure instruction."""
+
+from qiskit import QuantumCircuit, generate_preset_pass_manager
+from qiskit.circuit import Instruction
+from qiskit.providers.fake_provider import GenericBackendV2
+from qiskit.transpiler.exceptions import TranspilerError
+
+from qiskit_ibm_runtime.circuit import MidCircuitMeasure
+from qiskit_ibm_runtime.fake_provider import FakeVigoV2
+
+from ...ibm_test_case import IBMTestCase
+
+
+class TestMidCircuitMeasure(IBMTestCase):
+    """Test MidCircuitMeasure instruction."""
+
+    def test_instantiation(self):
+        """Test default instantiation."""
+        mcm = MidCircuitMeasure()
+        self.assertIs(mcm.base_class, MidCircuitMeasure)
+        self.assertIsInstance(mcm, Instruction)
+        self.assertEqual(mcm.name, "measure_2")
+        self.assertEqual(mcm.num_qubits, 1)
+        self.assertEqual(mcm.num_clbits, 1)
+
+    def test_instantiation_name(self):
+        """Test instantiation with custom name."""
+        with self.subTest("measure_3"):
+            mcm = MidCircuitMeasure("measure_3")
+            self.assertIs(mcm.base_class, MidCircuitMeasure)
+            self.assertIsInstance(mcm, Instruction)
+            self.assertEqual(mcm.name, "measure_3")
+            self.assertEqual(mcm.num_qubits, 1)
+            self.assertEqual(mcm.num_clbits, 1)
+
+        with self.subTest("measure_reset"):
+            mcm = MidCircuitMeasure("measure_reset")
+            self.assertIs(mcm.base_class, MidCircuitMeasure)
+            self.assertIsInstance(mcm, Instruction)
+            self.assertEqual(mcm.name, "measure_reset")
+            self.assertEqual(mcm.num_qubits, 1)
+            self.assertEqual(mcm.num_clbits, 1)
+
+        with self.subTest("invalid_name"):
+            with self.assertRaises(ValueError):
+                mcm = MidCircuitMeasure("invalid_name")
+
+    def test_circuit_integration(self):
+        """Test appending to circuit."""
+        mcm = MidCircuitMeasure()
+        qc = QuantumCircuit(1, 2)
+        qc.append(mcm, [0], [0])
+        qc.append(mcm, [0], [1])
+        qc.reset(0)
+        self.assertIs(qc.data[0].operation, mcm)
+        self.assertIs(qc.data[1].operation, mcm)
+
+    def test_transpiler_compat_without(self):
+        """Test that default pass manager FAILS if measure_2 not in Target."""
+        mcm = MidCircuitMeasure()
+        backend = FakeVigoV2()
+        pm = generate_preset_pass_manager(backend=backend, seed_transpiler=0)
+        qc = QuantumCircuit(1, 2)
+        qc.append(mcm, [0], [0])
+        with self.assertRaises(TranspilerError):
+            _ = pm.run(qc)
+
+    def test_transpiler_compat_with(self):
+        """Test that default pass manager PASSES if measure_2 is in Target
+        and doesn't modify the instruction."""
+        mcm = MidCircuitMeasure()
+        backend = GenericBackendV2(num_qubits=5, seed=0)
+        backend.target.add_instruction(mcm, {(i,): None for i in range(5)})
+        pm = generate_preset_pass_manager(backend=backend, seed_transpiler=0)
+        qc = QuantumCircuit(1, 2)
+        qc.append(mcm, [0], [0])
+        transpiled = pm.run(qc)
+        self.assertEqual(transpiled.data[0].operation.name, "measure_2")