flux Docs

flux now has three coordinated documentation surfaces:

• Narrative docs for DEC, FEEC, and the framework language.
• The existing Zig autodoc surface at /api/ for symbol lookup.
• A guided playground for tiny educational kernels compiled to WebAssembly from Zig.

The target reader is the same one implied by the repo vision: someone who wants to learn the numerical language and then trust the implementation details.

Documentation Model

• Use the Foundations section when you want the mathematical story first.
• Use Flux by Concept when you want the framework nouns and ownership boundaries.
• Use Tutorials when you want a deal.II-style sequence of concrete capabilities.
• Use Examples when you want to connect the teaching material back to the shipped Maxwell, Euler, and diffusion surfaces.

First Playground

This is intentionally narrow. The v1 goal is not “browser IDE for all of Zig”; it is “small kernels that teach the structure honestly.”

This guided playground keeps the kernel intentionally tiny: a single oriented triangle, a scalar 0-form on vertices, and the discrete exterior derivative applied twice. The kernel itself runs in WebAssembly compiled from Zig.

Vertex 0 scalar Vertex 1 scalar Vertex 2 scalar Run Snippet

Playground status

Loading the Zig WebAssembly kernel…

dφ on oriented edges

loading…

d(dφ) on the face

loading…

Current Guarantees

• Embedded Zig snippets come from real files in examples/doc_snippets/ or existing example sources.
• The snippet corpus is compiled and tested in CI.
• The docs build copies the Zig API docs into /api/ so narrative pages can deep-link into them without inventing a second reference system.