Business model
souxmar is open-core, not closed-source-with-an-open-shell. The desktop app, CLI, Python library, plugin SDK, and every reference plugin are all Apache 2.0. Premium services attached to them are optional.
This page lives at /business/ on the public site so it's easy to link to from sales conversations + investor decks. The same content lives in docs/BUSINESS_MODEL.md in the repo; the two stay in sync via a CI cross-check.
Tiers at a glance
| Tier | Price (placeholder, v0.9 alpha) | What you get |
|---|---|---|
| Free | $0 | Full desktop app + CLI + Python lib + plugin SDK + BYOK AI + local compute. Apache 2.0. |
| Pro | $20 / month / user | Managed AI proxy (no key management) + cloud sync + priority support. |
| Team | $35 / month / user, billed yearly | Pro + SSO (SAML / OIDC) + shared project library + per-team audit log. |
| Enterprise | Custom | Team + on-prem AI proxy + dedicated support + SLA. |
See the tiers page for the full feature matrix.
What's open and what's hosted
The line is clear:
- Open source: anything that runs on the user's machine. The desktop app, CLI, libraries, plugin SDK, ALL example plugins
- reference adapters (OpenCASCADE, Gmsh, OpenFOAM, FEniCSx wrappers). Apache 2.0.
- Hosted (Pro+): services that require infrastructure we operate. Managed AI proxy (handles your prompts without you shipping a key), cloud sync (encrypted-at-rest project storage), hosted compute offload (submit a CFD solve to managed HPC). Each is opt-in per project; the free tier never silently calls out.
Why we won't relicense
The desktop app being open source is a load-bearing trust commitment to engineers in regulated industries (aerospace, defence, medical devices). They can audit every line. We've documented the no-relicensing decision in docs/BUSINESS_MODEL.md
- in our governance docs; it's not something a future investor can unilaterally change.
The hosted services are where commercial revenue comes from. The ratio scales properly because the open-core surface is the entire product; the Pro tier is convenience layered on top.
Plugin marketplace
Sprint 16 launches the paid plugin marketplace. Authors set the price; we take 10 % + payment-processor fees. The marketplace itself is open-core — the listing format is part of the public docs/plugin-index.toml surface; the paid distribution channel adds Stripe integration + ed25519-signing for the per-author trust chain.
90 / 10 split was chosen deliberately:
- It's the same split Apple's App Store starts at (15 % after year 1, but we don't have year-1 marketing budgets).
- Microsoft Store is 12 % for apps, 0 % for games. We're closer to Apple's apps story.
- Steam is 30 %. That's too aggressive for a niche professional market.
Foundation handoff
Sometime around v1.5 (post-marketplace launch, post-Pro-revenue- profitable) we plan to transfer governance to a software foundation (Apache Software Foundation, Linux Foundation, or similar). The hosted services + the for-profit entity that operates them stay commercial; the open-core trademark + the governance of the codebase move out.
This is years away. It's documented here because regulated-industry buyers ask, and the answer affects their decisions.
How to support souxmar without paying
- File bugs. Especially from public-alpha real-world use.
- Author plugins. Even free plugins enrich the ecosystem.
- Cite us. If you ship a paper or a product on top of souxmar, please credit the project + link to celikgo.github.io/souxmar.
- Spread the word. Talk at your local FEM/CFD meetup; post your studies; share with engineers who'd benefit.