Licensing Structure
ACP uses a multi-layered licensing scheme. Each project layer has its own license, chosen to fit its purpose. Version 1.0, effective April 9, 2026.
Layer 1: Protocol Specification
What: ACP Protocol v4.0, protocol documentation, API specifications, mathematical formulas (phi-convergence, D-score, H-total), description of 7 axiom levels.
Files: ACP_COMPLETE_PROTOCOL_v4.md, ACP_ECOSYSTEM.md, AI.md, docs/, README.md
License: CC-BY-4.0
A protocol is a standard. Standards must be maximally accessible. CC-BY-4.0 allows any use with attribution. Similarly: W3C specs, RFC documents.
What you can do: use, cite, implement, translate.
What you cannot do: remove attribution.
Layer 2: Reference Implementation (Source Code)
What: Python backend (FastAPI), consensus engine, LLM adapters, oracles, metrics, API routes.
Files: src/, tests/, examples/, main.py
License: BSL 1.1 (Apache 2.0 after April 9, 2030)
The Business Source License 1.1 allows non-production use. On April 9, 2030, it automatically transitions to Apache 2.0, which provides patent protection (patent grant), is the standard for protocols and infrastructure (Kubernetes, gRPC, TensorFlow), requires attribution (NOTICE file) but not copyleft, and is compatible with GPL.
What you can do: use, modify, sell, close-source the code (after the change date).
What you cannot do: use the ACP brand (see Trademark Policy), remove the NOTICE.
Layer 3: Frontend
What: Next.js web application, UI components, playground.
Files: frontend/
License: BSL 1.1 (Apache 2.0 after April 9, 2030)
Consistency with the backend. The frontend is part of the reference implementation.
Layer 4: Verified Datasets
What: Verified axioms across 7 levels.
Repository: ACP-DATASETS
License: ACP-VERIFIED-1.0 (custom)
Datasets are curated content, not code. Standard software licenses do not fit. A custom license allows free non-commercial use, mandatory attribution, prohibition of commercial use without permission, and prohibition of labeling modified data as "ACP-VERIFIED".
Layer 5: System Prompts
What: 15 system prompts for AI agents.
Repository: ACP-PROMPTS
License: MIT
Prompts are instructions for AI. Maximum freedom of use stimulates adoption. Prompts without the engine are useless.
Layer 6: Enterprise / Premium (future)
What: Hosted API, custom datasets, SLA, priority support, advanced analytics, Conclave Mode enterprise features.
License: Commercial (TBD)
Enterprise licensing (ELv2 or PolyForm Shield) will be determined upon launch of the enterprise product.
Summary Table
| Layer | License | Copyleft | Commercial OK | Patent Grant |
|---|---|---|---|---|
| Protocol spec | CC-BY-4.0 | No | Yes (with attribution) | N/A |
| Source code | BSL 1.1 (Apache 2.0 after 2030) | No | License required | Yes (after change date) |
| Frontend | BSL 1.1 (Apache 2.0 after 2030) | No | License required | Yes (after change date) |
| Datasets | ACP-VERIFIED-1.0 | No | Permission required | N/A |
| Prompts | MIT | No | Yes | No |
| Enterprise | Commercial | N/A | License required | N/A |
Protective Mechanisms
The licensing structure is reinforced by five protective mechanisms:
- Trademark -- the "ACP" brand is protected independently of the code license (see Trademark Policy).
- CLA -- contributors grant sublicensing rights (see Contributor License Agreement).
- Patent Grant -- Apache 2.0 includes an automatic patent grant.
- NOTICE file -- mandatory attribution upon distribution.
- Dataset license -- custom license for verified data.
Frequently Asked Questions
Can I fork ACP and make my own product?
Yes, the code under Apache 2.0 (after the change date) allows it. But you cannot call it "ACP" or use the logo (see Trademark Policy).
Can I use ACP in a commercial project?
After the BSL 1.1 change date, yes, for free. You need to keep the NOTICE file and copyright.
Can I take the datasets and sell them?
Not without permission. ACP-VERIFIED-1.0 prohibits commercial use without a license. Write to enterprise@axiomprotocol.org.
If I contribute code, do I give up all rights?
You grant a license for use (CLA). Authorship (copyright) remains yours. We cannot remove your name from git history.
Can ACP change the license in the future?
The CLA gives the project the right to sublicense, which theoretically allows changing the license for new code. Already released versions remain under the original license forever.