Announcements and credits
Osprey's libraries and applications reimplement the APIs, formats and ideas of
remarkable open-source projects, and the language leans on several more as
development oracles. We are grateful to the authors named below: their work made
these ports possible, they retain ownership of it, and none of this is an
endorsement by them. The package audit that pins every fact is
src/osprey/packages/license-audit.json.
Announcements
The latest posts from the blog, newest first:
- Osprey Agent: a Coding Agent on the pydantic-ai Port —
- An Accessibility Tree AI Agents Can Drive: Automated UI Testing by Label —
- How to Chromecast From a Mac to a TV: A Native Player Written in Osprey —
- A Rust UI Framework Without Writing Rust: GPUI Apps as State Machines —
- Static Typing for Python-Style Code, Without Writing Type Hints —
- Desktop Apps on GPUI, Written in Osprey —
- Python Packages in Osprey: NumPy, PyTorch-Style Code, and uv —
- Automated Testing with Osprey Hunt: Find the Input That Crashes —
Earlier posts are on the blog index.
Libraries
Ported and derived libraries. The licence column shows the terms of the Osprey package, with a link where upstream licence text is retained or pointed to. Each upstream project's own licence lives with the project linked in the first column.
| Project | Authors | Osprey licence | Osprey package | Relationship |
|---|---|---|---|---|
| CPython CAST v2 sender (project-owned) | NIMBLESITE PTY LTD, Australia | MIT | @osprey/chromecast | port |
| einops | Alex Rogozhnikov and the einops contributors | MIT | @osprey/einops | port |
| Faiss | Meta Platforms, Inc. and the Faiss contributors | MIT | @osprey/faiss | port |
| FastAPI | Sebastián Ramírez and the FastAPI contributors | MIT AND BSD-3-Clause | @osprey/fastapi | port |
| FlashAttention | contributors of flash-attention (Dao-AILab) | MIT | @osprey/flash-attn | port |
| GGUF | Georgi Gerganov and the ggml contributors | MIT | @osprey/gguf | port |
| Jinja | the Pallets team and the Jinja contributors | MIT AND Apache-2.0 | @osprey/jinja2 | port |
| micrograd | Andrej Karpathy | MIT | @osprey/micrograd | port |
| NumPy | contributors of NumPy | MIT | @osprey/numpy | port |
| pydantic-ai | Pydantic Services Inc. and the pydantic-ai contributors (Douwe Maan, David Sanchez, Aditya Vardhan, David Montague, Marcelo Trylesinski, Alex Hall, Samuel Colvin, and others) | MIT | @osprey/pydantic-ai | port |
| CPython re | contributors of CPython, and the Unicode Consortium (derived tables) | MIT AND Unicode-DFS-2016 | @osprey/re | port |
| rouge-score | The Google Research Authors, and the NLTK contributors | MIT | @osprey/rouge-score | port |
| SacreBLEU | contributors of SacreBLEU | MIT | @osprey/sacrebleu | port |
| safetensors | contributors of safetensors (Hugging Face) | MIT | @osprey/safetensors | port |
| SciPy (special functions) | the SciPy developers; retained numerical kernels by Stephen L. Moshier (Cephes) and John Maddock (Boost) | MIT AND BSD-3-Clause AND BSL-1.0 | @osprey/scipy | port |
| scikit-learn | contributors of scikit-learn | MIT | @osprey/sklearn | port |
| NumPy (closeness comparison) | contributors of NumPy | MIT | @osprey/testing | inspired by |
| tiktoken | OpenAI and the tiktoken contributors, and the Unicode Consortium (derived tables) | MIT AND Unicode-3.0 | @osprey/tiktoken | port |
| tokenizers | contributors of Hugging Face tokenizers, and the Unicode Consortium (derived tables) | MIT AND Unicode-DFS-2016 AND Unicode-3.0 | @osprey/tokenizers | port |
| PyTorch | contributors of PyTorch | MIT | @osprey/torch | port |
| Transformers | contributors of Hugging Face Transformers | MIT | @osprey/transformers | port |
Original Osprey libraries, credited to the project itself:
| Project | Authors | Osprey licence | Osprey package | Relationship |
|---|---|---|---|---|
| Osprey (native UI framework) | NIMBLESITE PTY LTD, Australia | MIT | @osprey/native | original |
| Osprey (typed scene library) | NIMBLESITE PTY LTD, Australia | MIT | @osprey/graphics | original |
| Osprey (JSON codec) | NIMBLESITE PTY LTD, Australia | MIT | @osprey/json | original |
| Osprey (signal-flow editor) | NIMBLESITE PTY LTD, Australia | MIT | @osprey/signal-flow | original |
| Osprey (UI test library) | NIMBLESITE PTY LTD, Australia | MIT | @osprey/uitest | original |
| Osprey (VS Code editor SDK) | NIMBLESITE PTY LTD, Australia | MIT | @osprey/vscode | original |
Applications and examples
Applications and examples that derive from outside work and have no package audit entry.
| Project | Authors | Upstream licence | Osprey app or example | Relationship |
|---|---|---|---|---|
| micrograd demo notebook | Andrej Karpathy | MIT | Classifier | port |
| FAISS flat-index tutorial | Meta Platforms, Inc. and affiliates | MIT | Vector search | port |
| Google Research ROUGE application | The Google Research Authors | Apache-2.0 | Text evaluation | port |
| GPUI painting example | contributors of GPUI (Zed Industries) | Apache-2.0 | Painting | port |
| GPUI (gpui.rs) | contributors of GPUI (Zed Industries) | Apache-2.0 | GPUI host | binding |
| pydantic-ai (Agent.run_sync) | Pydantic Services Inc. and the pydantic-ai contributors | MIT | Osprey Agent | port |
| GPT-2 (124M) | OpenAI | MIT | GPT-2 | port |
| Lean 4 and Mathlib | the Lean and Mathlib developers | Apache-2.0 | Mathlib port and Proof Workbench | port |
| Qwen/Qwen3.8-27B | contributors of Qwen3.8-27B | Apache-2.0 | Local coding model | port (planned) |