# ADR 0008: Hierarchical Memory Scoping

**Status**: Implemented
**Date**: 2026-02-04
**Memory ID**: 20260204191624-14925ea2

## Context

The hive monorepo contains multiple subprojects. We need:
- Parents see children's memories (downward visibility)
- Children isolated from parents (upward isolation)

## Decision

### Configuration Cascade (local precedence)
```
~/.config/hive.edn              # Global defaults
~/project/.hive-project.edn     # Project overrides
~/project/sub/.hive-project.edn # Submodule overrides (highest)
```

### Memory Visibility (asymmetric scoping)
```
hive-mcp/                    # Sees all below
├── hive-connectors/         # Sees its children only
│   ├── slack/               # Isolated
│   └── github/              # Isolated
└── hive-addons/             # Sees its children only
    ├── diagrams/            # Isolated
    └── presentations/       # Isolated
```

### Hybrid Approach (Option E - Recommended)

Resolution Priority:
1. Check `.hive-project.edn` for explicit `:parent-id`
2. Check persistent index (DataScript) for cached hierarchy
3. If stale or missing, scan filesystem and update index
4. Fall back to string-based inference (colon-delimited)

### Implementation Phases

| Phase | Scope | Effort |
|-------|-------|--------|
| 1 | Add `.hive-project.edn` to subprojects | Low |
| 2 | Persistent DataScript index | Medium |
| 3 | Downward visibility (`descendant-scopes`) | Medium |
| 4 | Multi-repo workspaces (~/.config/hive.edn) | Future |

## NIH Research

| Tool | Hierarchy Model | Key Insight |
|------|-----------------|-------------|
| Nx | workspace.json | "Affected" detection via dep graph |
| Polylith | workspace.edn | Single source of truth |
| deps.edn monorepos | :local/root | Sean Corfield pattern |
| Git submodules | .gitmodules | Recursive traversal |

## Consequences

### Positive
- Subprojects get isolated memories
- Parent aggregates children's memories
- Incremental adoption

### Negative
- Requires adding `.hive-project.edn` to each subproject
- Cache invalidation complexity