# Data Model: Upgrade MCP SDK to 0.5.0-preview.1
**Date**: 2025-12-13
**Spec**: `specs/001-upgrade-mcp-sdk/spec.md`
---
## Overview
This upgrade is primarily dependency and code migration work; it does not introduce new domain entities stored on disk. The "entities" below are conceptual and document the artifacts used during the upgrade process.
---
## Entity: DependencySet
| Field | Type | Description |
|-----------------|----------|---------------------------------------------------|
| PackageId | string | NuGet package identifier (e.g., `ModelContextProtocol`) |
| OldVersion | string | Currently pinned version |
| NewVersion | string | Target version (`0.5.0-preview.1`) |
| BreakingChanges | string[] | List of breaking change identifiers from changelog |
### Validation Rules
- `NewVersion` must be a valid SemVer string.
- `BreakingChanges` populated from SDK changelog.
### Relationships
- One-to-many: DependencySet → ImpactReport (each breaking change → one or more impacted locations).
---
## Entity: ImpactReport
| Field | Type | Description |
|---------------|--------|-----------------------------------------------|
| BreakingChange| string | Identifier of a specific breaking change |
| FilePath | string | Relative path to impacted file |
| LineNumber | int? | Line number if applicable |
| FixApplied | bool | Whether the fix has been implemented |
### Validation Rules
- `FilePath` must exist in repository.
- `FixApplied` = true only after build succeeds post-fix.
### State Transitions
1. Identified (compiler error) → FixApplied = false
2. Fixed → FixApplied = true
3. Verified (build succeeds, tests pass)
---
## Entity: ValidationMatrix
| Field | Type | Description |
|--------------|----------|--------------------------------------------|
| Criterion | string | Success-criterion identifier (SC-*) |
| Command | string | Shell command or test filter |
| ExpectedOutcome | string | Expected result (e.g., "0 warnings", "exit 0") |
| Passed | bool | Whether criterion passed last run |
### Relationships
- One-to-many: ValidationMatrix → ImpactReport (criterion may verify multiple fixes).
---
## Entity: RollbackPlan
| Field | Type | Description |
|--------------|--------|------------------------------------------------|
| Trigger | string | Condition that triggers rollback |
| Action | string | Rollback action (e.g., revert package bump) |
| Owner | string | Person responsible for rollback decision |
| Tested | bool | Whether rollback action has been dry-run |
### Validation Rules
- Each critical path must have a rollback plan entry.
---
## Diagram (Conceptual)
```text
DependencySet ─────┐
│ 1..*
▼
ImpactReport
▲
│ verified by
│
ValidationMatrix
│
│ rollback via
▼
RollbackPlan
```
---
## Notes
- These entities exist as mental/document models; no database or runtime persistence is required.
- Use this model when populating `tasks.md` to track fixes and validation checkpoints.
