Attribution & License¶

Docs-site note: This is the canonical reference-credit page — link here from anywhere on the site rather than restating attribution inline. Grounded in Vexor's own NOTICE, README.md, and PROVENANCE.md.

Vexor is an original reimplementation, not a fork. This page states plainly what that means, credits the projects that made byte-for-byte compatibility possible, and states the project's license: Apache-2.0.

What "original reimplementation" means¶

Vexor is written from scratch in Zig. Its Agave-compatible behavior was achieved by using the projects below — all Apache-2.0 licensed — as reference implementations and differential test oracles: reading their source, reimplementing the behavior independently in Zig, and verifying the result bit-for-bit against their output. Vexor links none of their code at runtime — including cryptography, which is now a pure-Zig reimplementation with zero Firedancer FFI.

Reference projects¶

Project	Maintainer	Role
Agave	Anza	Primary behavioral reference: consensus and fork choice, SVM + sBPF execution, compute-budget and cost model, CPI, vote/stake/loader programs, sysvars, account (LtHash) hashing.
Firedancer	Jump Crypto	Reference for leaf cryptography (the "Ballet" ed25519/blake3/bn254/poseidon routines) and select high-performance data structures. Vexor no longer links Firedancer at all — its cryptography is an independent pure-Zig reimplementation.
Sig	Syndica	Reference for Zig-idiomatic Solana structures during early bring-up, and (historically) a differential test oracle for the vote program during its rewrite — since removed. Vexor's implementations are independent of Sig at build and at runtime.

All three are Apache-2.0 licensed. This page, and Vexor's NOTICE file, are the attribution given in that spirit for behavior that was reimplemented with these projects as reference — not for code that was copied.

"Agave", "Firedancer", "Sig", and "Solana" are trademarks of their respective owners.

The vote program¶

Vexor's vote program is Vexor-authored (a from-scratch rewrite derived from Agave's vote-program semantics) and is the sole program that executes votes on the live node. During its development, a Sig-derived component served as the differential test oracle — the reference the new implementation was byte-for-byte checked against over 990k+ live instructions. With the rewrite proven out, that oracle has been fully removed from the source tree (July 2026); its historical role remains recorded in the provenance ledger. Vexor is independent of Sig at build and at runtime.

The provenance ledger¶

Project-level attribution (NOTICE) answers "what did we use as a reference, broadly." A separate, fine-grained provenance ledger (PROVENANCE.md) answers the more specific question a maintainer actually needs: which Vexor file and function reimplements which upstream behavior, and how was it verified?

Each entry is keyed by a stable @prov: ID — not a line number, which drifts on every edit — so the mapping survives refactors. In the code, a one-line anchor comment marks the spot (// @prov:cost-model.data-cost); the ledger holds the full detail for that ID: the upstream file/function it corresponds to, whether the Vexor code is a reimplementation (behavior read and rewritten independently), a port (logic translated near-line-by-line), a byte-exact match (verified bit-identical against upstream output or a known-answer test), or built from a published spec (a SIMD proposal, with upstream used only as a cross-check) — and any notes on how it was verified.

This is both a maintenance tool (find what tracks a given upstream change) and the fine-grained half of Vexor's attribution story: it shows, subsystem by subsystem, exactly how "byte-for-byte compatible, independently implemented" was achieved rather than asserting it as a slogan.

License¶

Vexor is licensed under the Apache License, Version 2.0 — the same license as each of the reference projects above. The project's LICENSE file (standard Apache-2.0 text) and NOTICE file (the copyright and reference-attribution statement that accompanies it) ship with the source. The source repository is not yet public; this page and NOTICE are the attribution given in the meantime.