PsiQuantum Makes Construct FTQC Software Available to All Developers
In September 2025, PsiQuantum launched Construct, our software suite for developing fault-tolerant quantum algorithms. Construct's goal is simple: accelerate progress in the research community by making fault-tolerant algorithm development easier. In the months since launch, researchers from academia, industry, and governments used Construct to train students, develop new algorithms, and conduct original research. The engagement and feedback have made it clear that we need to get these powerful tools into as many hands as possible to accelerate discovery of useful quantum algorithms.
Today, we are launching Construct to the world as a free and open access platform. Now, our research tools are available for the entire community to design quantum circuits, write and simulate quantum algorithms, and optimize resources – all in one platform. And with open access, you can easily share those findings with the broader community.
What is Construct?
Construct is our software suite for developing fault-tolerant algorithms for future utility-scale quantum computers. Unlike NISQ-era algorithms that run on present-day quantum hardware, fault-tolerant algorithms are many orders of magnitude larger and designed for real-world applications. Construct takes several unique approaches:
Designed for fault tolerance from the start: Since PsiQuantum was founded, we have been solely focused on fault tolerant computing. Our tools avoid some of the NISQ capabilities that were helpful for small scale algorithms, but which hinder development of commercially useful quantum algorithms.
Large, validated library of fault tolerant algorithms: Build complex applications from over 100 validated, interoperable, FTQC-focused sub-routines, including alias sampling, quantum phase estimation, and more.
Designed for both research and development: Generate circuits with billions of operations, compile them to any gate set, and conduct accurate quantum resource estimations.
Hardware agnostic: Our software tools are designed for any error corrected utility scale quantum computer. With Construct, you can design and develop algorithms that you bring to any future hardware modality.
Construct contains three primary components:
PsiQuantum Development Kit: Our collection of Python packages for developing and analyzing quantum algorithms in code. Among our packages, Workbench provides useful programming abstractions with a large library of quantum algorithms to quickly compose powerful quantum algorithms. Useful fault tolerant programming techniques like mid-circuit-measurement, uncomputation, and multi-controlled gates are never more than a few characters away.
Circuit Designer: Our visual tool for creating interactive illustrations of fault tolerant quantum algorithms through hierarchical use of sub-routines.
Resource Analyzer: Our visual tool for exploring quantum resource estimates to uncover algorithmic hotspots and guide iterative development and optimization.
Rapid progress on fault tolerant quantum computing depends on more researchers experimenting with new ideas and buildings on each other’s contributions. We’re excited to see what people will build with Construct, discovering quantum utility in new and surprising directions.