---
phase: 05-retrieval-orchestrator
plan: "02"
subsystem: retrieval
tags: [networkx, dependency-resolution, conflict-detection, transitive-closure]
# Dependency graph
requires:
- phase: 05-01
provides: RetrievalPipeline coordinator with LRU caching
- phase: 04-03
provides: RRF score fusion and context assembler
provides:
- Transitive dependency resolution via nx.descendants()
- Conflict detection for CONFLICTS_WITH edges
- Complete component sets with no missing pieces
- PipelineResult with dependencies_added and conflicts populated
affects: [06-serving-layer, 07-integration]
# Tech tracking
tech-stack:
added: []
patterns:
- "nx.descendants() for transitive closure on edge-type subgraph"
- "frozenset for bidirectional conflict deduplication"
- "Dependency resolution BEFORE token budget check"
- "_CachedResult dataclass for caching context + metadata together"
key-files:
created:
- src/skill_retriever/workflows/dependency_resolver.py
- tests/test_dependency_resolver.py
modified:
- src/skill_retriever/workflows/pipeline.py
- src/skill_retriever/workflows/__init__.py
- tests/test_pipeline.py
key-decisions:
- "Dependencies resolved BEFORE context assembly so token budget includes deps"
- "Dependencies added as RankedComponent with source='dependency' and min score 0.1"
- "Conflicts use frozenset{a,b} to avoid duplicate detection from both directions"
- "Cycle detection logs warning but continues gracefully via nx.descendants()"
patterns-established:
- "Edge-type filtering: Build subgraph of only relevant edges before traversal"
- "pyright ignores for nx.descendants (no type stubs) matching earlier patterns"
# Metrics
duration: 8min
completed: 2026-02-03
---
# Phase 5 Plan 02: Dependency Resolver Summary
**Transitive dependency resolution via nx.descendants() on DEPENDS_ON subgraph with bidirectional conflict detection**
## Performance
- **Duration:** 8 min
- **Started:** 2026-02-03T08:05:52Z
- **Completed:** 2026-02-03T08:13:52Z
- **Tasks:** 2
- **Files modified:** 5
## Accomplishments
- resolve_transitive_dependencies() using nx.descendants() on filtered DEPENDS_ON subgraph
- detect_conflicts() with frozenset deduplication for bidirectional CONFLICTS_WITH edges
- Pipeline integration with dependency resolution BEFORE context assembly
- 21 new tests (16 for dependency_resolver, 5 for pipeline integration)
- Latency SLA verified: <1000ms for complex queries, <500ms for simple queries
## Task Commits
Each task was committed atomically:
1. **Task 1: Create dependency resolver** - `8ef79f5` (feat)
2. **Task 2: Integrate into pipeline** - `76e666a` (feat)
## Files Created/Modified
- `src/skill_retriever/workflows/dependency_resolver.py` - resolve_transitive_dependencies() and detect_conflicts() functions
- `src/skill_retriever/workflows/pipeline.py` - Integration with _CachedResult dataclass
- `src/skill_retriever/workflows/__init__.py` - Export new functions
- `tests/test_dependency_resolver.py` - 16 tests for resolution and conflict detection
- `tests/test_pipeline.py` - 5 new tests for pipeline integration
## Decisions Made
1. **Dependencies resolved BEFORE context assembly** - Ensures token budget includes transitive deps, not just initially retrieved components
2. **_CachedResult dataclass** - Cache context + deps + conflicts together for consistent cache behavior
3. **Dependencies get source='dependency'** - Distinguishes auto-added deps from directly retrieved components
4. **frozenset for conflict pairs** - Ensures A-conflicts-B and B-conflicts-A detected as same conflict
5. **Edge-type subgraph filtering** - Build subgraph with only DEPENDS_ON edges before running nx.descendants()
## Deviations from Plan
None - plan executed exactly as written.
## Issues Encountered
None.
## User Setup Required
None - no external service configuration required.
## Next Phase Readiness
- Orchestration layer complete with full dependency resolution and conflict detection
- Phase 05 complete - ready for Phase 06 Serving Layer (MCP server)
- All 156 tests passing, lint clean, types clean
- Latency SLAs verified: <500ms simple, <1000ms complex
---
*Phase: 05-retrieval-orchestrator*
*Completed: 2026-02-03*
