Codebase Memory — Knowledge Graph Tools

Graph tools return precise structural results in ~500 tokens vs ~80K for grep.

Quick Decision Matrix

Question	Tool call
Who calls X?	trace_path(direction="inbound")
What does X call?	trace_path(direction="outbound")
Full call context	trace_path(direction="both")
Find by name pattern	search_graph(name_pattern="...")
Dead code	search_graph(max_degree=0, exclude_entry_points=true)
Cross-service edges	query_graph with Cypher
Impact of local changes	detect_changes()
Risk-classified trace	trace_path(risk_labels=true)
Text search	search_code or Grep

Exploration Workflow

1. list_projects — check if project is indexed
2. get_graph_schema — understand node/edge types
3. search_graph(label="Function", name_pattern=".*Pattern.*") — find code
4. get_code_snippet(qualified_name="project.path.FuncName") — read source

Tracing Workflow

1. search_graph(name_pattern=".*FuncName.*") — discover exact name
2. trace_path(function_name="FuncName", direction="both", depth=3) — trace
3. detect_changes() — map git diff to affected symbols

Quality Analysis

• Dead code: search_graph(max_degree=0, exclude_entry_points=true)
• High fan-out: search_graph(min_degree=10, relationship="CALLS", direction="outbound")
• High fan-in: search_graph(min_degree=10, relationship="CALLS", direction="inbound")

14 MCP Tools

index_repository, index_status, list_projects, delete_project, search_graph, search_code, trace_path, detect_changes, query_graph, get_graph_schema, get_code_snippet, get_architecture, manage_adr, ingest_traces

Edge Types

CALLS, HTTP_CALLS, ASYNC_CALLS, IMPORTS, DEFINES, DEFINES_METHOD, HANDLES, IMPLEMENTS, OVERRIDE, USAGE, FILE_CHANGES_WITH, CONTAINS_FILE, CONTAINS_FOLDER, CONTAINS_PACKAGE

Cypher Examples (for query_graph)

MATCH (a)-[r:HTTP_CALLS]->(b) RETURN a.name, b.name, r.url_path, r.confidence LIMIT 20
MATCH (f:Function) WHERE f.name =~ '.*Handler.*' RETURN f.name, f.file_path
MATCH (a)-[r:CALLS]->(b) WHERE a.name = 'main' RETURN b.name

Gotchas

1. search_graph(relationship="HTTP_CALLS") filters nodes by degree — use query_graph with Cypher to see actual edges.
2. query_graph has a 200-row cap — use search_graph with degree filters for counting.
3. trace_path needs exact names — use search_graph(name_pattern=...) first.
4. direction="outbound" misses cross-service callers — use direction="both".
5. Results default to 10 per page — check has_more and use offset.