ADR 0006: AGPL-3.0-or-later License

  • Status: Accepted

  • Date: 2025-01-10

  • Track: Process

Context

KoproGo’s mission emphasizes:

  1. Transparency: Public code, auditable by users

  2. Collective power: Prevent proprietary forks by large players

  3. Sustainability: Ensure improvements benefit community, not only shareholders

  4. Openness: Encourage contributions while protecting commons

We need a license that:

  • Allows commercial use (ASBL can sell services)

  • Requires derivative works to remain open-source

  • Prevents “SaaS loophole” (hosting modified code without sharing changes)

Decision

We chose AGPL-3.0-or-later (GNU Affero General Public License version 3 or later).

Why AGPL over GPL:

  • AGPL closes the SaaS loophole: Modified code hosted as a service MUST be shared

  • Example: If a competitor hosts modified KoproGo without releasing changes, they violate license

  • GPL would allow this (only binary distribution requires source sharing)

Compatibility:

  • ✅ Compatible with MIT/Apache crates (can use as dependencies)

  • ✅ Allows commercial use (ASBL can charge for hosting/support)

  • ✅ Users can run modified versions privately without sharing

  • ❌ Incompatible with proprietary software (by design - this is a feature)

Consequences

Positive:

  • ✅ Prevents capture: Large players cannot fork without open-sourcing improvements

  • ✅ Ensures transparency: Users can audit financial calculations, security

  • ✅ Encourages contributions: Improvements must be shared back

  • ✅ Mission-aligned: Supports collective ownership, not private extraction

  • ✅ Long-term sustainability: Community benefits from all improvements

Negative:

  • ⚠️ Limits partnerships: Some companies avoid AGPL due to legal concerns

  • ⚠️ Smaller contributor pool: Some developers prefer permissive licenses (MIT/Apache)

  • ⚠️ Compliance burden: Must track dependencies, ensure compatibility

Risk mitigation:

  • Target contributors aligned with mission (cooperatives, civic tech, open-source advocates)

  • Provide clear CONTRIBUTING.md and LICENSE guidance

  • Offer dual licensing for partners if needed (future consideration)

Alternatives Considered

  1. MIT/Apache-2.0 (permissive):

    • ✅ Maximum adoption, no restrictions

    • ❌ Allows proprietary forks without contribution

    • ❌ Misaligned with mission (collective power)

    • Verdict: Rejected as incompatible with values

  2. GPL-3.0 (copyleft):

    • ✅ Requires sharing binary distributions

    • ❌ Allows SaaS loophole (host modified code without sharing)

    • Verdict: Close, but AGPL preferred for SaaS nature of KoproGo

  3. Business Source License (BSL):

    • ✅ Becomes open-source after time delay

    • ❌ Not open-source initially (violates OSD)

    • ❌ Complex, less understood

    • Verdict: Rejected as not truly open-source

  4. European Union Public License (EUPL):

    • ✅ EU-specific, copyleft

    • ❌ Less well-known, weaker network effects

    • Verdict: Good option, AGPL preferred for global recognition

Copyleft in Practice

What requires sharing changes:

  • ✅ Hosting modified KoproGo as a service

  • ✅ Distributing modified binaries

  • ❌ Using KoproGo internally without distribution

  • ❌ Calling KoproGo API from proprietary client (API boundary exception)

Example scenarios:

Scenario 1: Syndic self-hosting

  • Syndic downloads KoproGo, modifies for their needs, hosts for their clients

  • Required: Share modifications (AGPL triggered by network use)

Scenario 2: SaaS competitor

  • Competitor forks KoproGo, adds proprietary features, sells as service

  • Required: Share all modifications including proprietary features (AGPL)

Scenario 3: Mobile app

  • Developer builds proprietary mobile app calling KoproGo API

  • NOT required: API boundary exception (app is separate work)

Communication Strategy

Messaging:

  • “Open-source for transparency and collective power”

  • “We believe property management software should be a commons, not a commodity”

  • “Your contributions improve the platform for everyone”

FAQ:

  • Q: Can I use KoproGo commercially?

  • A: Yes! AGPL allows commercial use. You can charge for hosting, support, customization.

  • Q: Can I modify KoproGo for my own use?

  • A: Yes! If you don’t distribute or host it publicly, no obligation to share.

  • Q: Why not MIT/Apache?

  • A: Mission alignment. We want improvements to benefit the community, not private shareholders.

Next Steps

  • ✅ Add LICENSE file to root (Done)

  • ✅ Add license headers to all source files (Done)

  • ✅ Document in CONTRIBUTING.md (Done)

  • ⏳ Add dependency license checker to CI (cargo deny)

  • ⏳ Publish license FAQ on website

References

  • AGPL-3.0 full text: https://www.gnu.org/licenses/agpl-3.0.html

  • FSF AGPL FAQ: https://www.gnu.org/licenses/agpl-3.0-standalone.html

  • TL;DR Legal: https://tldrlegal.com/license/gnu-affero-general-public-license-v3-(agpl-3.0)