Use Qiskit Code Assistant in Visual Studio Code

Learn how to install, use, configure and uninstall the official Qiskit Code Assistant extension in Visual Studio Code (VS Code).

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Install the VS Code extension

To install the VS Code extension, follow these steps:

Install directly from VS Code:

1. Launch VS Code.
2. Click the Extensions icon in the left toolbar.
3. Search for qiskit
4. Find "Qiskit Code Assistant (Beta)" and click Install.

Alternatively, the extension is also available through the VS Code Marketplace.

The extension loads automatically and is listed on the bottom of the VS Code window, as shown. If it is not listed, reload the extension or application.

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Configure extension settings

The following settings can be configured:

• To change keyboard shortcuts, open the Keyboard Shortcuts settings (Cmd/Ctrl+Shift+P -> Preferences: Open Keyboard Shortcuts (JSON)) and search for qiskit-vscode.

• You can change the IBM Quantum API token to use in the VS Code command palette. To do that, type Cmd/Ctrl+Shift+P, search for qiskit, select the Qiskit Code Assistant: Set IBM Quantum API token command, and paste your IBM Quantum API token.

• [Advanced] To change the instance of the Qiskit Code Assistant Service that the extension should use, go to File -> Preferences -> Settings. On the User tab, search for Qiskit, and edit the Qiskit Code Assistant: Url.

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Get started using the Qiskit Code Assistant extension for VS Code

Authentication and setup

After installing the extension, it tries to authenticate you. By default, the package tries to authenticate to IBM Quantum services with the defined Qiskit API token, and uses your token from the QISKIT_IBM_TOKEN environment variable or from the file ~/.qiskit/qiskit-ibm.json (under the section default-ibm-quantum). If you need help configuring your account, follow the instructions in Set up to use IBM Quantum Platform.

By default, the extension uses the granite-8b-qiskit model, which is listed in the Model Picker in the bottom status bar.

The first time you use the granite-8b-qiskit model, a modal opens listing some major restrictions that you should be aware of when using the model. Clicking Accept will accept the disclaimer and enable the model for code generation.

Generate code

While you develop your code using Qiskit, you can ask Qiskit Code Assistant to help you. In general, the Assistant suggests better code in response to Python comments or docstrings, but you can use the Assistant anywhere in your file.

To get a code suggestion, type a prompt, then Ctrl+.. There are two types of prompts you can use:

• Enter partial code and get a suggestion to finish the code. Example:
  from qiskit.circuit import QuantumCircuit
  from qiskit.transpiler.preset_passmanagers import generate_preset_pass_manager
  from qiskit_ibm_runtime import SamplerV2 as Sampler
  from qiskit_ibm_runtime.fake_provider import FakeManilaV2
   
  # Bell Circuit
  qc = QuantumCircuit(2)
  qc.h(0)
  qc.cx(0, 1)
   
  qc.mea # Type Ctrl + . for a code suggestion.

• Type a pound (#) sign, then type your prompt. Example: # Give me a random circuit of 5 qubits and a depth of 4.

Work with code suggestions

Use the following to accept, reject, and cycle through suggestions:

• Press Tab to accept the suggestion or press ESC to reject it.
• After getting a suggestion, type Ctrl + . again to generate additional suggestions.
• When a suggestion is shown, use Option/Alt + ] and Option/Alt + [ to cycle forward and backward, respectively, through the suggestions (if available).
• Hover the cursor over the suggestion to use the pop-up toolbar to cycle through the suggestions, as shown:

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Uninstall the VS Code extension

To remove Qiskit Code Assistant from VS Code, follow these steps:

1. Launch Visual Studio Code.
2. Click the Extensions icon.
3. Search for qiskit and open Qiskit Code Assistant.
4. Click Uninstall.

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Troubleshooting

If you don't see the extension status bar in VS Code, check that the extension is installed and enabled under the extensions tab.

If the extension is installed and enabled, but it cannot select a model, verify that your current API token has been added and the Qiskit Code Assistant: Url is properly set.

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Contribute to the VS Code extension

The code for this official extension is publicly available and open source. Check it out in GitHub.

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Next steps