# Implementation Questions

**Purpose**: Track questions and ambiguities discovered during plan generation that require follow-up before or during implementation.

---

## Open Questions

### Phase 3: Site Execution

| # | Question | Context | Impact | Status |
|---|----------|---------|--------|--------|
| Q9 | What is the custom protocol? Is there an existing specification or SDK? | The design mentions "custom protocol" as a second adapter alongside OPC UA. Need details to implement. | Phase 3. | Deferred — owner will provide details later |

### Phase 7: Integrations

| # | Question | Context | Impact | Status |
|---|----------|---------|--------|--------|
| Q11 | Are there specific external systems (MES, recipe manager) to integrate with for initial testing? | Affects External System Gateway and Inbound API test scenarios. | Phase 7. | Open |
| Q12 | What Microsoft 365 tenant/app registration is available for SMTP OAuth2 testing? | Affects Notification Service OAuth2 implementation. | Phase 7. | Open |

### Cross-Phase

| # | Question | Context | Impact | Status |
|---|----------|---------|--------|--------|
| Q13 | Who is the development team? (Size, experience with Akka.NET, availability) | Affects phase sizing, parallelization, and timeline estimates. | All phases. | Open |
| Q14 | Is there an existing deployment target environment for early pilot testing? | Affects Phase 4 (minimal UI for pilot operations) timing. | Phase 4+. | Open |
| Q15 | Should the Machine Data Database schema be designed in this project, or is it out of scope? | HighLevelReqs 2.1 mentions it but no component owns it. | Phase 3 or later. | Open |

---

## Resolved Questions

| # | Question | Resolution | Date |
|---|----------|------------|------|
| Q1 | What .NET version should we target? | .NET 10 LTS (released November 2025, supported through 2028). | 2026-03-16 |
| Q2 | What Akka.NET version? | Latest stable 1.5.x (currently 1.5.62). | 2026-03-16 |
| Q3 | Monorepo or separate repos? | Single monorepo with SLNX solution file (`.slnx`, the new XML-based format default in .NET 10). | 2026-03-16 |
| Q4 | What CI/CD platform? | None for now. No CI/CD pipeline. | 2026-03-16 |
| Q5 | What LDAP server for dev/test? | GLAuth (lightweight LDAP) in Docker. See `infra/glauth/config.toml` and `test_infra_ldap.md`. | 2026-03-16 |
| Q6 | What MS SQL version and hosting? | SQL Server 2022 Developer Edition in Docker. See `infra/docker-compose.yml` and `test_infra_db.md`. | 2026-03-16 |
| Q7 | JWT signing key storage? | `appsettings.json` (per environment). | 2026-03-16 |
| Q8 | OPC UA server for dev/test? | Azure IoT OPC PLC simulator in Docker. See `infra/opcua/nodes.json` and `test_infra_opcua.md`. | 2026-03-16 |
| Q10 | Target site hardware? | Windows Server 2022, 24 GB RAM, 1 TB drive, 16-core Xeon. | 2026-03-16 |