A developer known on GitHub as duriantaco has published Fyn, a Rust-based fork of the uv Python package manager that removes built-in telemetry collection and introduces several workflow features absent from the upstream project. The repository has accumulated 284 stars and 3 forks since its publication. The developer’s legal name was not available at time of publication.
- Fyn is a fork of Astral‘s uv package manager, rebuilt in Rust, with all telemetry collection removed.
- The project adds a built-in task runner, a
fyn shellcommand for virtual environment activation, and afyn upgradecommand for one-step dependency updates. - The repository contains 8,832 commits and includes a MANIFESTO.md document explaining the project’s philosophy and motivations.
- Fyn claims 10–100x faster installation speeds than pip, matching the performance profile of its uv upstream.
What Happened
Developer duriantaco published Fyn, described in the project’s own documentation as “an independent Python package manager built on uv’s foundation, with telemetry removed, new features added, and long-standing bugs fixed.” The tool targets Python developers who want uv’s Rust-powered performance without the data collection that uv enables by default. The repository is publicly available at github.com/duriantaco/fyn.
uv, developed by Astral, collects anonymous usage statistics by default. Users can opt out via the UV_NO_TELEMETRY=1 environment variable, but the setting must be applied manually. Fyn removes the telemetry code entirely rather than relying on opt-out configuration.
Why It Matters
uv has become one of the fastest-growing Python tooling projects, positioning itself as a single replacement for pip, pip-tools, pipx, poetry, pyenv, twine, and virtualenv. Its adoption in production environments has prompted some developers to scrutinize its data practices more closely.
Fyn enters a space where several competing Python package managers — including Poetry and PDM — have long operated without telemetry. The fork does not challenge uv’s technical architecture; it extends and modifies it, retaining the Rust core while removing analytics infrastructure and adding task-runner capabilities the upstream tool lacks.
Technical Details
Fyn retains uv’s Rust-based resolver and installer, which the project claims delivers installation speeds 10–100x faster than pip. This figure is a project claim based on benchmark documentation included in the repository (BENCHMARKS.md); independent third-party benchmarks were not available at time of publication.
The repository contains 8,832 commits, a fyn.lock file format distinct from uv’s lockfile, and a fyn.schema.json for configuration validation. A built-in task runner allows developers to define and execute project tasks directly inside pyproject.toml files — a feature not present in uv. The fyn shell command activates virtual environments interactively, and fyn upgrade handles one-command dependency updates across a project.
Fyn also supports Cargo-style workspaces for monorepo-scale projects and includes script execution with inline dependency metadata, following the PEP 723 format. The project includes a MANIFESTO.md file that documents the philosophical rationale behind the fork, though its full contents were not reproduced in the available source material.
Who’s Affected
The primary audience is Python developers working in environments where outbound telemetry is restricted by policy — including corporate networks, air-gapped infrastructure, and regulated industries such as financial services and healthcare. Teams already using uv in CI/CD pipelines can evaluate Fyn as a drop-in replacement, since the project states it maintains compatibility with pip interfaces.
Developers using Poetry or PDM who have considered migrating to uv for speed gains but were deterred by telemetry concerns now have a documented alternative. Fyn supports macOS, Linux, and Windows, and can be installed via PyPI using pip or pipx, or compiled from source using Cargo.
What’s Next
The project currently lists two open issues and no open pull requests, suggesting it is in an early but active phase of development. duriantaco has not published a formal roadmap, and it is unclear whether the project intends to track uv upstream releases on a fixed schedule or selectively merge changes.
The core technical risk for adopters is maintenance lag: if Astral ships security patches or resolver improvements to uv, Fyn users will depend on the fork maintainer to incorporate those changes promptly. The project includes a SECURITY.md file and a CONTRIBUTING.md, indicating some infrastructure for community involvement, but the contributor base remains small at the time of this report.
