Licensing
The skill and the funnel tooling are MIT. The compression engine and the proxy are BSL 1.1. The split blocks exactly one thing — reselling Caveman-as-a-service — and leaves self-hosting and integration wide open.
The two licenses
MIT covers everything in the funnel — the parts you embed, fork, and build on freely, with no strings:
- the
cavemanskill - the CLI, both SDKs, Cavekit, the evals graders
- the browser extension shell, the shared contracts and provider catalog
- the thin Cavemem clients (
mem/js,mem/py)
BSL 1.1 (Business Source License) covers the compression core and the things linked tightly to it:
- the compression engine
- the proxy
- the MCP server, Caveman Shrink, the Cavemem Go core
- the Go platform libraries under
shared/platform
What BSL lets you do
BSL is source-available with one restriction. Under it you may freely:
- read, modify, and self-host the code
- run it in your own product and your own production, on your own infrastructure
- integrate it into your stack, BYOK, single-tenant
The single thing it does not permit is offering the engine itself as a hosted or managed service to third parties: reselling Caveman-as-a-service. That is the case the license blocks.
It sunsets to Apache 2.0
Every BSL component carries a Change Date. On it (2030), the BSL grant automatically converts to Apache 2.0 — fully permissive, restriction gone. BSL here is a time-boxed protection, not a permanent enclosure.
Why split at all
Relicensing the famous MIT skill would be the one move that breaks faith with the community, so it never happens — the skill stays MIT, untouched. But giving away the entire engine under a permissive license would let a competitor host it verbatim and undercut the work that pays for it. BSL threads that needle: the engine is open to read, fork, and self-host, and closed only to the narrow case of reselling it as a service.
Honesty rule
This is open-core drawn along the honesty line, not a bait-and-switch. The public tools produce inferred results locally, on your keys. Hosted products can sell proof the local tool cannot create by itself: verified rollout results on real traffic.
Trademarks and contributions
The code grant conveys no trademark rights. "Powered by Caveman" as nominative use is fine; naming your own product "Caveman" is not. See TRADEMARKS.md in the repo for the exact wording.
Contributions follow a DCO (Developer Certificate of Origin) — you sign off your commits — plus a grant letting the maintainer relicense contributions commercially, so community work to the BSL engine can flow into OEM licenses. MIT parts are plain inbound-equals-outbound. There is no full CLA. See Contributing.