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name: circuit description: "Guides agents building and editing QuantumCircuit objects, registers, bits, gates, control flow, measurements, resets, and circuit-library compositions." disable-model-invocation: true metadata: disco-role: operating license: Apache 2.0

Qiskit circuit workflows

Use this sub-skill when the task is about constructing or editing quantum circuits with qiskit.circuit: QuantumCircuit, registers, bits, parameters, gate composition, control flow, measurements, resets, and circuit-library building blocks.

Read next

• references/workflows.md for build, compose, control-flow, and circuit-library recipes.
• references/troubleshooting.md for CircuitError, parameter binding, and control-flow mistakes.
• ../../references/module-map.md for the top-level package boundaries.
• ../../scripts/check_qiskit_environment.py --sections core for a source-free circuit sanity check.

Include here

• Circuit construction and mutation with QuantumCircuit.
• Register and bit handling with QuantumRegister, ClassicalRegister, AncillaRegister, Qubit, and Clbit.
• Gate application, inversion, control, append/compose, and circuit-library helpers.
• Classical control-flow builders and conditions on circuit internals.
• Measurement, reset, barrier, and lightweight circuit introspection.

Exclude or route elsewhere

• Backend-targeted compilation, Target, CouplingMap, and pass-manager workflows belong in ../transpiler/SKILL.md.
• Primitive execution, Sampler, Estimator, and result containers belong in ../primitives/SKILL.md.
• OpenQASM/QPY import-export belongs in ../serialization/SKILL.md.
• State/operator mathematics belongs in ../quantum-info/SKILL.md.
• Drawing output formats and plot styling belong in ../visualization/SKILL.md.

Default route

If the user has not yet built a valid abstract circuit, start here before moving to transpilation or execution. A good first answer is usually a minimal QuantumCircuit example and then a circuit-specific recipe from the workflows reference.

What to remember

• Circuit methods often mutate in place unless the API explicitly says otherwise.
• measure_all() creates or reuses a classical register; remove_final_measurements() is useful before operator/state analysis or transpilation experiments.
• Control-flow objects carry their own classical-resource constraints. A condition that fits one circuit may not fit another.
• Circuit composition and library gates are usually more useful than manually editing low-level instruction tuples.