get_cross_project_dependents
Traverse the full downstream dependency graph of a context using breadth-first search — across all projects.
Overview
The get_cross_project_dependents tool returns every context that was directly or indirectly caused by a given context, regardless of which project it belongs to. It follows caused_by links forward in time using BFS, making it possible to map the full ripple effect of a decision across your entire knowledge graph.
Layer: Layer 1 (Causality Engine)
Purpose: Map the complete downstream impact of a context across project boundaries
Parameters
| Parameter | Type | Required | Description |
|---|---|---|---|
contextId | string | Yes | UUID of the root context to trace from |
Returns
Formatted text listing all downstream dependents in BFS order (breadth-first, level by level):
Downstream dependents of "550e8400-e29b-41d4-a716-446655440000":
Found 4 dependent context(s):
Level 1 (direct children):
**api-service** — 2025-10-18T09:00:00Z
Chose REST over GraphQL based on authentication architecture decision
Tags: rest, api, architecture, decision
**mobile-app** — 2025-10-18T09:15:00Z
Updated mobile auth flow to align with new REST API structure
Tags: mobile, auth, rest, refactor
Level 2 (grandchildren):
**api-service** — 2025-10-18T11:30:00Z
Implemented JWT middleware for REST endpoints
Tags: jwt, middleware, rest, implementation
**docs-site** — 2025-10-18T12:00:00Z
Updated API documentation to reflect REST architecture
Tags: docs, rest, api, updateIf no dependents exist:
No downstream dependents found for "550e8400-e29b-41d4-a716-446655440000".Examples
Trace a Decision's Impact
get_cross_project_dependents({
contextId: "550e8400-e29b-41d4-a716-446655440000"
})Audit Before Changing an Architecture Decision
Before revising a foundational context, see what it influenced:
// Find the original decision
const results = search_context({ query: "REST API architecture decision" });
// → "550e8400-e29b-41d4-a716-446655440000"
// Trace all downstream impact
get_cross_project_dependents({ contextId: "550e8400-e29b-41d4-a716-446655440000" });How BFS Traversal Works
The tool uses breadth-first search to follow caused_by links:
Root context
├── Direct child A (Level 1)
│ ├── Grandchild A1 (Level 2)
│ └── Grandchild A2 (Level 2)
└── Direct child B (Level 1)
└── Grandchild B1 (Level 2)Cycle guard: The BFS maintains a visited set to prevent infinite loops if circular causality exists in your data. Each context ID is visited at most once.
Cross-project: Unlike build_causal_chain (which goes backward) and is scoped to one project, get_cross_project_dependents goes forward and crosses project boundaries, making it the right tool for impact analysis.
Comparison with Related Tools
| Tool | Direction | Scope | Purpose |
|---|---|---|---|
build_causal_chain | Backward (ancestry) | Single project | "What led to this?" |
reconstruct_reasoning | Backward (WHY) | Single context | "Why was this created?" |
get_cross_project_dependents | Forward (descendants) | All projects | "What did this cause?" |
Use Cases
1. Impact Analysis Before Deletion
Before pruning or changing a context, see what downstream contexts depend on it.
2. Audit Decision Ripples
After a major architecture decision, see how far its influence has spread across projects.
3. Documentation Consistency
Find all documentation contexts that reference an API decision, to update them consistently.
4. Knowledge Graph Exploration
Explore the full dependency graph from a root decision to understand the complete causal history of your system.
Setting Up Cross-Project Causality
To use this tool effectively, save contexts with crossProject: true when a decision spans project boundaries:
save_context({
project: "architecture-decisions",
content: "Decided to use REST for all new services.",
crossProject: true,
metadata: {
actionType: "decision",
causedBy: "prior-context-id"
}
});With crossProject: true, Layer 1 searches the entire context graph (not just the current project) when detecting dependencies.
See Also
- build_causal_chain - Trace decision history backwards
- reconstruct_reasoning - Explain WHY a context was created
- get_causality_stats - Analytics on causal relationships
- save_context - Save context with
crossProjectflag
