# Implementation Questions

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

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## Open Questions

### Phase 7: Integrations

| # | Question | Context | Impact | Status |
|---|----------|---------|--------|--------|
| Q12 | What Microsoft 365 tenant/app registration is available for SMTP OAuth2 testing? | Affects Notification Service OAuth2 implementation. | Phase 7. | Deferred — won't be known during development. Implement against Basic Auth first; OAuth2 tested when tenant available. |

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## 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 |
| Q9 | What is the custom protocol? Is there an existing specification or SDK? | LmxProxy — gRPC-based protocol (protobuf-net code-first, port 5050, API key auth). Client SDK: `LmxProxyClient` NuGet package. See Component-DataConnectionLayer.md for full API mapping and protocol details. | 2026-03-16 |
| Q11 | Are there specific external systems (MES, recipe manager) to integrate with for initial testing? | REST API test server (`infra/restapi/`) provides simulated external endpoints for External System Gateway and Inbound API testing. No real MES/recipe system needed for initial phases. | 2026-03-16 |
| Q15 | Should the Machine Data Database schema be designed in this project, or is it out of scope? | Out of scope — Machine Data Database is a pre-existing database at customer sites. Test infra seeds sample tables/data in `infra/mssql/machinedata_seed.sql`. | 2026-03-16 |
| Q13 | Who is the development team? | Solo developer with extensive Akka.NET experience and full availability. No parallelization constraints — phases are sequential. | 2026-03-16 |
| Q14 | Is there an existing deployment target environment for early pilot testing? | Yes — developer can test directly. No separate pilot environment needed. | 2026-03-16 |