Microsoft and GitHub Showcase Early Preview of Pylance-Pyrefly Integration at PyCon US 2026

Breaking: Microsoft and GitHub to Debut Pylance-Pyrefly Integration at PyCon US 2026

Long Beach, CA – Microsoft and GitHub today confirmed an early preview of Pylance’s integration with Meta’s new Pyrefly type checker, set to debut at PyCon US 2026. The integration will be demonstrated at the Meta booth on Saturday, May 16, at 1:00 p.m.

“This integration represents a significant step forward in Python type checking for the community,” said Dr. Sarah Kaiser, Principal Developer Advocate at Microsoft. “We’re excited to gather feedback from early adopters before the full release later this year.” The feature is currently available only in the Insiders build of Pylance.

Hands-On Labs and Booth Activities

Attendees are invited to the Microsoft and GitHub booth for 10-minute interactive labs covering GitHub Copilot, Azure DocumentDB, Microsoft Foundry, Microsoft Agent Framework, Azure PostgreSQL, and Azure AI Search. Labs run throughout the conference days.

“Our goal is to demonstrate real-world productivity gains in under 10 minutes,” added Pamela Fox, Cloud Developer Advocate. “From AI-powered coding with Copilot to scalable data solutions, these hands-on sessions offer something for every Python developer.”

Technical Sessions and Talks

Microsoft experts will deliver eight sessions across the conference, starting Wednesday, May 13, with a workshop on building your first MCP server in Python. Key sessions include:

• “Dungeons and Databases: Build NPC agents to work with data in DocumentDB and Postgres” – Wednesday, 1:30 p.m., Room 201B
• “Education Summit: Big Lessons from Small Models, Teaching Python AI with SLMs” – Thursday, 2:40 p.m., Room 104C
• “Your Slides, But Faster: Building an AI-powered presentation workflow” – Thursday, 3:40 p.m., Room 104C
• “PyCharlas: Cómo pasé de perdida a enseñar Python + IA a miles, en un año” – Friday, 3:30 p.m., Room 104C
• “Maintainer Summit Tools Track: Dev Containers” – Saturday, 2:30 p.m., Room 201A
• “A bridge over (not) troubled waters: Collecting marine data from your couch” – Sunday, 1:00 p.m., Grand Ballroom A

All sessions are open to registered PyCon attendees. Additional details are available on the conference schedule.

Background

PyCon US is the largest annual gathering for the Python programming community, bringing together thousands of developers, educators, and industry leaders. Microsoft and GitHub have been active participants for many years, showcasing their latest tools and services for Python development.

The new Pylance-Pyrefly integration builds on Microsoft’s investment in Python tooling. Pylance, Microsoft’s language server for Python, already provides fast type checking and IntelliSense. Pyrefly is Meta’s upcoming type checker, designed to improve performance and accuracy.

What This Means

For Python developers, the integration promises faster, more reliable type checking without switching editors. Early access through the Insiders build allows the community to influence the final product.

“By combining Pylance’s rich features with Pyrefly’s novel approach, we’re making type checking simpler and more efficient,” said Marko Hotti, Senior Program Manager at Microsoft. “We expect this to benefit everyone from beginners to maintainers of large codebases.” As PyCon approaches, developers should watch for more announcements and consider attending the hands-on labs to get early hands‑on experience.