# License Compatibility Analysis

**Document Version:** 1.1.0
**Last Updated:** 2026-01-20
**StellaOps License:** BUSL-1.1

This document analyzes the compatibility of third-party licenses with StellaOps' BUSL-1.1 license and Additional Use Grant.

---

## 1. BUSL-1.1 Overview

The Business Source License 1.1 (BUSL-1.1) is a source-available license that:

1. **Allows** non-production use, modification, and redistribution of the Licensed Work
2. **Allows** limited production use only as granted in the Additional Use Grant
3. **Requires** preservation of the license text and attribution notices
4. **Provides** a Change License (Apache-2.0) that becomes effective on the Change Date
5. **Restricts** SaaS/hosted service use beyond the Additional Use Grant

### Key Compatibility Principle

> Permissive-licensed code (MIT, BSD, Apache) can be incorporated into BUSL-1.1 projects without changing the overall license. Strong copyleft or service-restriction licenses (GPL/AGPL/SSPL) impose obligations that conflict with BUSL-1.1 distribution terms or Additional Use Grant restrictions.

---

## 2. License Compatibility Matrix

### 2.1 Fully Compatible (Inbound)

These licenses are fully compatible with BUSL-1.1. Code under these licenses can be incorporated into StellaOps.

| License | SPDX | Compatibility | Rationale |
|---------|------|---------------|-----------|
| MIT | MIT | **Yes** | Permissive, no copyleft restrictions |
| Apache-2.0 | Apache-2.0 | **Yes** | Same license, patent grant included |
| BSD-2-Clause | BSD-2-Clause | **Yes** | Permissive, minimal restrictions |
| BSD-3-Clause | BSD-3-Clause | **Yes** | Permissive, no-endorsement clause only |
| ISC | ISC | **Yes** | Functionally equivalent to MIT |
| 0BSD | 0BSD | **Yes** | Public domain equivalent |
| CC0-1.0 | CC0-1.0 | **Yes** | Public domain dedication |
| Unlicense | Unlicense | **Yes** | Public domain dedication |
| PostgreSQL | PostgreSQL | **Yes** | Permissive, similar to MIT/BSD |
| Zlib | Zlib | **Yes** | Permissive |
| BlueOak-1.0.0 | BlueOak-1.0.0 | **Yes** | Permissive |
| Python-2.0 | Python-2.0 | **Yes** | Permissive |

### 2.2 Compatible with Conditions

| License | SPDX | Compatibility | Conditions |
|---------|------|---------------|------------|
| LGPL-2.1-or-later | LGPL-2.1-or-later | **Yes** | Must allow relinking; library boundary required |
| LGPL-3.0-or-later | LGPL-3.0-or-later | **Yes** | Must allow relinking; library boundary required |
| MPL-2.0 | MPL-2.0 | **Yes** | File-level copyleft; MPL files remain isolated |

### 2.3 Incompatible

These licenses are **NOT** compatible with keeping StellaOps under BUSL-1.1:

| License | SPDX | Issue |
|---------|------|-------|
| GPL-2.0-only | GPL-2.0-only | Requires GPL relicensing; incompatible with BUSL distribution |
| GPL-2.0-or-later | GPL-2.0-or-later | Requires GPL relicensing; incompatible with BUSL distribution |
| GPL-3.0-only | GPL-3.0-only | Requires GPL distribution for combined work |
| GPL-3.0-or-later | GPL-3.0-or-later | Requires GPL distribution for combined work |
| AGPL-3.0-only | AGPL-3.0-only | Network copyleft conflicts with BUSL restrictions |
| AGPL-3.0-or-later | AGPL-3.0-or-later | Network copyleft conflicts with BUSL restrictions |
| SSPL-1.0 | SSPL-1.0 | Service source disclosure conflicts with BUSL restrictions |
| Commons Clause | LicenseRef-Commons-Clause | Commercial use restrictions conflict with BUSL grant |
| Proprietary | LicenseRef-Proprietary | No redistribution rights |

---

## 3. Distribution Models

### 3.1 Source Distribution (BUSL-1.1 Compliant)

When distributing StellaOps source code:

```
StellaOps (BUSL-1.1)
+-- StellaOps code (BUSL-1.1)
+-- MIT/BSD deps (retain notices)
+-- Apache-2.0 deps (retain NOTICE files)
+-- MPL/LGPL deps (retain file/library boundaries)
```

**Requirements:**
- Include full BUSL-1.1 license text with Additional Use Grant
- Preserve all third-party copyright and attribution notices
- Preserve NOTICE files from Apache-2.0 dependencies
- Mark modified files with prominent change notices

### 3.2 Binary Distribution (BUSL-1.1 Compliant)

When distributing StellaOps binaries (containers, packages):

```
StellaOps Binary
+-- LICENSE (BUSL-1.1)
+-- NOTICE.md (all attributions)
+-- third-party-licenses/ (full license texts)
+-- Source link (optional, transparency only)
```

**Requirements:**
- Include BUSL-1.1 license with Additional Use Grant
- Include NOTICE file with all attributions
- Include license texts for vendored code

### 3.3 Network Service (No Copyleft Clause)

BUSL-1.1 restricts SaaS/hosted service use beyond the Additional Use Grant. Operating StellaOps as a service is permitted only within the grant limits or under a commercial license; see `LICENSE` for details.

### 3.4 Aggregation (Not Derivation)

The following are considered **aggregation**, not derivation:

| Scenario | Classification | BUSL-1.1 Impact |
|----------|---------------|-------------------|
| PostgreSQL database | Aggregation | PostgreSQL stays PostgreSQL-licensed |
| RabbitMQ message broker | Aggregation | RabbitMQ stays MPL-2.0 |
| Docker containers | Aggregation | Base image licenses unaffected |
| Kubernetes orchestration | Aggregation | K8s stays Apache-2.0 |
| Hardware (HSM) | Interface only | HSM license unaffected |

**Rationale:** These components communicate via network protocols, APIs, or standard interfaces and are not linked into StellaOps binaries.

### 3.5 Plugin Distribution (Community Plugin Grant)

The Community Plugin Grant Addendum (`LICENSE-ADDENDUM-COMMUNITY-PLUGIN-GRANT.md`)
provides additional terms for plugin development and distribution.

**When distributing StellaOps Plugins:**

```
Plugin Distribution
+-- Plugin code (your license)
+-- Attribution to StellaOps
+-- If derivative work:
    +-- LICENSE (BUSL-1.1)
    +-- LICENSE-ADDENDUM-COMMUNITY-PLUGIN-GRANT.md
    +-- NOTICE.md
```

**Requirements by Plugin Type:**

| Plugin Type | License | Attribution | Include LICENSE | Include Addendum |
|-------------|---------|-------------|-----------------|------------------|
| API-only (no StellaOps code) | Your choice | Recommended | No | No |
| Includes StellaOps code | BUSL-1.1 | Required | Yes | Yes |
| Bundled with StellaOps | BUSL-1.1 | Required | Yes | Yes |
| Competing managed service | Commercial | N/A | N/A | N/A |

**Not Allowed Without Commercial License:**
- Redistributing plugins as part of a competing managed service offering
- White-labeling StellaOps functionality through plugins
- Embedding plugins in multi-tenant SaaS offerings to third parties

**See Also:**
- `docs/legal/PLUGIN_DEVELOPER_FAQ.md` - Detailed plugin licensing FAQ
- `docs/legal/SAAS_MSP_GUIDANCE.md` - SaaS and MSP hosting scenarios

---

## 4. Specific Dependency Analysis

### 4.1 BouncyCastle Cryptography (MIT)

| Aspect | Status |
|--------|--------|
| License | MIT |
| Compatibility | Full |
| Usage | Linked into binaries |
| Requirement | Include copyright notice in NOTICE.md |

### 4.2 Npgsql/PostgreSQL (PostgreSQL License)

| Aspect | Status |
|--------|--------|
| License | PostgreSQL (permissive) |
| Compatibility | Full |
| Usage | NuGet package (linked) |
| Requirement | Include copyright notice in NOTICE.md |

### 4.3 Polly (BSD-3-Clause)

| Aspect | Status |
|--------|--------|
| License | BSD-3-Clause |
| Compatibility | Full |
| Usage | NuGet package (linked) |
| Requirement | Include copyright notice; no endorsement claims |

### 4.4 RxJS (Apache-2.0)

| Aspect | Status |
|--------|--------|
| License | Apache-2.0 |
| Compatibility | Full |
| Usage | npm package (bundled in frontend) |
| Requirement | Preserve NOTICE file |

### 4.5 CryptoPro CSP (Commercial)

| Aspect | Status |
|--------|--------|
| License | Commercial (LicenseRef-CryptoPro) |
| Compatibility | N/A - Not distributed |
| Usage | PKCS#11 interface only |
| Requirement | Customer obtains own license |

**Analysis:** StellaOps provides only the integration code (BUSL-1.1). CryptoPro CSP binaries are never distributed by StellaOps.

```
StellaOps Ships:
+-- PKCS#11 interface code (BUSL-1.1)
+-- Configuration documentation
+-- Integration tests (mock only)

Customer Provides:
+-- CryptoPro CSP license
+-- CryptoPro CSP binaries
+-- Hardware tokens (optional)
```

### 4.6 AlexMAS.GostCryptography (MIT)

| Aspect | Status |
|--------|--------|
| License | MIT |
| Compatibility | Full |
| Usage | Source vendored |
| Requirement | Include copyright notice; license file preserved |

**Analysis:** The fork is MIT-licensed and compatible with BUSL-1.1. The combined work remains BUSL-1.1 with MIT attribution preserved.

### 4.7 axe-core/Playwright (@axe-core/playwright - MPL-2.0)

| Aspect | Status |
|--------|--------|
| License | MPL-2.0 |
| Compatibility | Yes (with conditions) |
| Usage | Dev dependency only |
| Requirement | MPL files remain in separate files |

**Analysis:** MPL-2.0 is file-level copyleft. Since this is a dev dependency used only for accessibility testing (not distributed in production), there are no special requirements for end-user distribution.

---

## 5. Outbound Licensing

### 5.1 StellaOps Core

All StellaOps-authored code is licensed under BUSL-1.1:

```
SPDX-License-Identifier: BUSL-1.1
Copyright (C) 2026 stella-ops.org
```

### 5.2 Documentation

Documentation is licensed under:
- Code examples: BUSL-1.1 (same as source)
- Prose content: CC-BY-4.0 (where specified)
- API specifications: BUSL-1.1

### 5.3 Configuration Samples

Sample configuration files (`etc/*.yaml.sample`) are:
- Licensed under: BUSL-1.1
- Derived configurations by users: User's choice (no copyleft propagation)

---

## 6. Compliance Checklist

### 6.1 For StellaOps Maintainers

- [ ] All new dependencies checked against allowlist
- [ ] NOTICE.md updated for new MIT/Apache-2.0/BSD dependencies
- [ ] third-party-licenses/ includes texts for vendored code
- [ ] No GPL/AGPL or incompatible licenses introduced
- [ ] LICENSE and NOTICE shipped with source and binary distributions

### 6.2 For StellaOps Operators (Self-Hosted)

- [ ] LICENSE and NOTICE preserved in deployment
- [ ] Commercial components (CryptoPro, HSM) separately licensed
- [ ] Attribution notices accessible to end users (docs or packaged file)

### 6.3 For Contributors

- [ ] New code contributed under BUSL-1.1
- [ ] No proprietary code introduced
- [ ] Third-party code properly attributed
- [ ] License headers in new files

---

## 7. FAQ

### Q: Can I use StellaOps commercially?
**A:** Yes, within the Additional Use Grant limits or under a commercial license. SaaS/hosted third-party use requires a commercial license.

### Q: Can I modify StellaOps for internal use?
**A:** Yes. Non-production use is permitted, and production use is allowed within the Additional Use Grant or with a commercial license.

### Q: Does using StellaOps make my data BUSL-licensed?
**A:** No. BUSL-1.1 applies to software, not data processed by the software. Your SBOMs, vulnerability data, and configurations remain yours.

### Q: Can I integrate StellaOps with proprietary systems?
**A:** Yes, via API/network interfaces. This is aggregation, not derivation. Your proprietary systems retain their licenses.

### Q: Do I need to disclose my CryptoPro CSP license?
**A:** CryptoPro CSP is customer-provided. StellaOps only ships integration code. Your CSP license is between you and CryptoPro.

---

## 8. References

- [Apache License 2.0](https://www.apache.org/licenses/LICENSE-2.0)
- [Apache 2.0 FAQ](https://www.apache.org/foundation/license-faq.html)
- [SPDX License List](https://spdx.org/licenses/)
- [REUSE Best Practices](https://reuse.software/tutorial/)
- [BUSL-1.1 License Text](https://spdx.org/licenses/BUSL-1.1.html)

---

## 9. Related Documents

- `LICENSE-ADDENDUM-COMMUNITY-PLUGIN-GRANT.md` - Community Plugin Grant Addendum
- `docs/legal/PLUGIN_DEVELOPER_FAQ.md` - Plugin developer FAQ
- `docs/legal/SAAS_MSP_GUIDANCE.md` - SaaS and MSP guidance
- `docs/legal/ENFORCEMENT_TELEMETRY_POLICY.md` - Audit and compliance policy

---

*Document maintained by: Legal + Security Guild*
*Last review: 2026-01-25*