Provenance and Licensing

gridoxide's own code is licensed under Apache-2.0 (LICENSE). Several pieces of third-party code are vendored, translated, or linked, and each carries its own terms. This page is the summary; the authoritative per-file detail lives in the PROVENANCE.md files kept alongside the code they describe.

The crate-wide license field

Cargo.toml's license field is:

Apache-2.0 AND BSD-3-Clause AND LGPL-2.1-or-later

That is accurate for every default cargo build, not just an opt-in one — because src/klu_native/ is always built, with no feature gate.

Always built: `src/klu_native/`

src/klu_native/ is a from-scratch Rust translation of vendored SuiteSparse AMD, BTF, and KLU C source. A close translation of licensed source is reasonably a derivative work regardless of implementation language, so it carries forward its upstream license — and that is not one license here:

Upstream package	License	Translated into
`AMD`	BSD-3-Clause	`amd/aat.rs`, `amd/core.rs`, `amd/postorder.rs`, `amd/mod.rs`
`BTF`	LGPL-2.1-or-later	`btf/maxtrans.rs`, `btf/strongcomp.rs`, `btf/mod.rs`
`KLU`	LGPL-2.1-or-later	`analyze.rs`, `kernel.rs`, `factor.rs`, `scale.rs`, `refactor.rs`, `solve.rs`

src/klu_native/PROVENANCE.md has the exact file-by-file mapping back to the upstream C, including which specific functions each Rust file was ported from and how shared header material was classified. See Inside KLU for what the ported algorithm actually does.

Opt-in: `--features klu`

Building with cargo build --features klu additionally compiles the vendored SuiteSparse C itself into the binary via FFI. vendor/suitesparse/ is a partial vendoring of SuiteSparse at tag v7.12.2 (commit 42151688813c45846a597edcb601435a0e38f3dd, 2026-02-10) — only the Source/ and Include/ subdirectories of five packages (SuiteSparse_config, AMD, COLAMD, BTF, KLU), each keeping its own Doc/License.txt:

Package	License
`AMD`	BSD-3-Clause
`COLAMD`	BSD-3-Clause
`BTF`	LGPL-2.1-or-later
`KLU`	LGPL-2.1-or-later
`SuiteSparse_config`	BSD-3-Clause

This adds no license beyond what is already listed above, but it does add LGPL's relinking obligations for anyone distributing a binary built with that feature. The klu-dynamic sub-feature exists for that case: it links a system-installed libklu.so instead of statically linking the vendored copy. See vendor/suitesparse/PROVENANCE.md for exactly what was and was not vendored, and how to update to a newer SuiteSparse release.

Opt-in: `--features pardiso`

A separate case from all of the above. It dynamically links a locally-installed Intel oneMKL (libmkl_rt.so) at build and run time, under Intel's own Simplified Software License — not LGPL, not OSS, and not vendored or redistributed by this repo in any form. No MKL header or source is copied in; bindgen only reads the local install's own mkl_pardiso.h at build time to generate FFI bindings.

Because nothing MKL-derived is ever copied into or shipped by this crate, Cargo.toml's license field does not change for this feature. Anyone who builds with --features pardiso and distributes the resulting binary is responsible for their own compliance with Intel's oneMKL redistribution terms — this project doesn't audit that on their behalf.

Opt-in: `--features cgmes` — the cimoxide dependency

The optional cgmes feature (src/cgmes.rs) depends on cimoxide's decoder and generated-structs crates, a separate Rust project by the same author providing CGMES RDF/XML decoding into typed CIM structs.

Upstream: https://github.com/m-mirz/cimoxide
Crates: cimoxide-decoder and cimoxide-structs, both 0.3.0

cimoxide is Apache-2.0, matching gridoxide's own license — no licensing mismatch from this dependency.

The `package =` rename

Cargo.toml pulls both in under their old, shorter names:

cimdecoder = { package = "cimoxide-decoder", version = "0.3.0", optional = true }
cimstructs = { package = "cimoxide-structs", version = "0.3.0", optional = true }

The crates.io names are cimoxide--prefixed, but src/cgmes.rs and the CGMES tests were written against cimdecoder/cimstructs, so package = keeps every existing use path valid rather than renaming 33 references for no behavioural gain.

Formerly a git dependency

Until cimoxide's crates.io release, these were a git dependency pinned to a vendor/gridoxide branch — main plus one commit force-adding the code generator's normally-gitignored output, since cimstructs's source is produced by cargo run -p cimgen from ENTSO-E's RDF/SHACL schemas and so does not exist on a fresh main clone.

Updating

To pick up a newer cimoxide schema or generator change:

Release the new version from the cimoxide repo (make generate, then make build && make test before publishing — cimstructs's generated source is what a schema change moves).
Bump the version = value in this repo's Cargo.toml for the cimdecoder and cimstructs dependencies, and update the version noted above.
Run cargo build --features cgmes and cargo test --features cgmes to confirm the converter still matches tests/cgmes_microgrid_be_test.rs's expectations — CGMES field names or shapes could in principle change between schema versions. The fixture-backed CGMES tests silently skip when tests/data/CGMES-Test-Configurations isn't checked out, so git submodule update --init tests/data/CGMES-Test-Configurations first, or the run proves nothing beyond "it compiles".

Test fixtures

The CGMES conformance fixtures under tests/data/cgmes/ are referenced via a git submodule rather than committed, because of their own licensing — see tests/data/cgmes/README.md.

Power Grid Book