Building your first Qollab project·Lesson 2 of 5

Use the Code Playground

Work with a project file tree, select a backend and read or download the result from the Code tab.

QollabProduct docs
·4 min read
The Code tab in file tree view with project files beside the editor and Run Project in the header.

The Code Playground is the Code tab where you edit project files, choose a backend and inspect each run.

A Python / Qiskit project and a JS / Qiskit wrapper project use the same file tree and runner. The JavaScript project also renders an interactive page above the console. Run a circuit in JavaScript covers that project shape.

To edit code, open your project in edit mode or fork someone else's public project. You can run a public project without editing it.

Open the project files

Select Code. The tab labels its editable state Edit Code and its read-only state View Code. Use file tree view to open, create, rename, remove or upload files. The editor applies syntax highlighting. After a failed run, it can highlight a reported source line.

Open the runner

The runner has two entry points:

  • From the Code tab, select Run Project, then select Run.
  • From the project header, select Run on Qollab.

Both paths open the Select QPU dialog before the run starts.

The Code tab in Run Project mode, with the Run button above an empty console.
Run Project mode. The orange box marks the Run button that opens Select QPU.

A Python main() with supported, type-annotated parameters adds fields under Run settings at the top of the dialog. The current Python starter adds Shots, Exclude Low Probability Values and Low Probability Threshold. A JS project does not get this form, so its shot count stays in the code.

Choose a backend

The Select QPU dialog groups the available backends by where they run:

  • Locally Run Simulators contains the built-in ideal simulator, the AWS Braket ideal simulator and one folded IBM row for eight noise-model simulators. The built-in simulator starts immediately. AWS and IBM load their libraries the first time you select them.
  • Remotely Run Simulators contains four IonQ noise-model simulators.
  • Quantum Computer contains available hardware backends. Hardware uses credits and may be offline or queued.

Simulators cost nothing on qollab.xyz.

The Select QPU dialog with a Shots field under Run settings above a list of free simulators.
Run settings and local simulators appear first; remote simulators and quantum computers continue below.

Run and read the output

Select a backend, then select Run in the dialog. The built-in simulator starts immediately. A first AWS or IBM run waits while the browser loads its Python packages. Remote simulators and hardware can also wait for a remote queue.

The run view can show:

  • Console output from Python print() or JavaScript console.log(), together with runtime errors.
  • Probabilities for the built-in simulator and IonQ simulator or hardware runs. AWS and IBM runs do not show this panel.
  • Circuit for IonQ simulator or hardware runs.
The console after a built-in simulator run, showing the circuit and each outcome's share beside the Probabilities panel.
A finished built-in simulator run. The orange box marks the Probabilities panel.

Copy or download the output

The console toolbar has buttons to copy its text or download the full output as HTML. A completed download uses this filename pattern:

<username>-<project-name>-output-completed-<ISO-timestamp>.html

Browser compatibility

The Code Playground supports Chrome, Edge, Opera and Firefox 153 or later. Safari is not supported.

Next up4 · Fork and continue a projectFork any public project into your own editable copy, then keep building on it.Continue →

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