The simple rule: If Exqub is a component in your product — a wallet, a verifier, an agent framework — Apache 2.0 applies. If Exqub is your product — you forked it, rebranded it, and are selling credential infrastructure — the commercial licence applies.
Licensing layers
LAYER 1
Protocol Specification
Freely implementable by anyone. Read it, implement it, redistribute it — with attribution.
▼ Show components · Licence: CC BY 4.0
LAYER 2
Core Cryptographic Engine
Apache 2.0 for integrators. Commercial licence only if you're building competing credential infrastructure.
▼ Show components · Licence: Apache 2.0 / ECL
LAYER 3
Application Crates & SDKs
Use freely. No restrictions. Build wallets, verifiers, agent frameworks, whatever you need.
▼ Show components · Licence: Apache 2.0
LAYER 4
Operational Tooling
All Apache 2.0 except the Reference Issuer Service, which is dual-licensed to prevent rebranded hosting.
▼ Show components · Licence: Apache 2.0 *
Which licence applies to me?
Common scenarios. If yours isn't listed, the answer is almost certainly Apache 2.0.
Building a mobile wallet that verifies Exqub credentials
Your wallet uses Exqub as a library. No commercial licence needed.
Building a SaaS platform with credential verification
Verification is a feature of your platform, not the platform itself.
Government agency building a national credential system
You're using Exqub as infrastructure, not repackaging it as a competing product.
Integrating verification into an agent framework
LangChain, AutoGPT, CrewAI — Exqub is a component in your product.
Security research and auditing
Always free. We want you to audit the code.
Offering 'Exqub Verification as a Service' as primary product
Contact us. Under $1M revenue: Apache 2.0 terms apply.
Cloud provider offering managed Exqub Issuer service
For the Reference Issuer. Or implement from the spec (CC BY 4.0) with no licence needed.
Forking exqub-core to build a competing protocol
Or implement from the spec without using our codebase.
Commercial licence details
The Exqub Commercial Licence (ECL) applies only to organisations building competing credential infrastructure products using the core engine. Key terms:
Revenue threshold
Under $1M attributable revenue: Apache 2.0 terms apply regardless of use case
No enterprise edition
Same source code for all users. No proprietary features behind a paywall
Contribution credit
Upstream contributions reduce licence fees proportionally
Dissolution clause
If Exqub ceases maintenance for 24 months, all code converts to Apache 2.0 automatically
The specification is always free.
Anyone can implement the Exqub Protocol from the specification (CC BY 4.0) without using our codebase or paying a licence fee. This is by design — open protocols become standards; proprietary protocols become products. If you prefer to build from scratch rather than use the reference implementation, nothing stops you.