codebase-memory-reference

Research

This skill should be used when the user asks about "codebase-memory-mcp tools", "graph query syntax", "Cypher query examples", "edge types", "how to use search_graph", "query_graph examples", or needs reference documentation for the codebase knowledge graph tools.

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Codebase Memory MCP — Tool Reference

Tools (14 total)

Tool	Purpose
`index_repository`	Parse and ingest repo into graph (only once — auto-sync keeps it fresh)
`index_status`	Check indexing status (ready/indexing/not found)
`list_projects`	List all indexed projects with timestamps and counts
`delete_project`	Remove a project from the graph
`search_graph`	Structured search with filters (name, label, degree, file pattern)
`search_code`	Grep-like text search within indexed project files
`trace_call_path`	BFS call chain traversal (exact name match required). Supports `risk_labels=true` for impact classification.
`detect_changes`	Map git diff to affected symbols + blast radius with risk scoring
`query_graph`	Cypher-like graph queries (200-row cap)
`get_graph_schema`	Node/edge counts, relationship patterns
`get_code_snippet`	Read source code by qualified name
`read_file`	Read any file from indexed project
`list_directory`	List files/directories with glob filter
`ingest_traces`	Ingest OpenTelemetry traces to validate HTTP_CALLS edges

Edge Types

Type	Meaning
`CALLS`	Direct function call within same service
`HTTP_CALLS`	Synchronous cross-service HTTP request
`ASYNC_CALLS`	Async dispatch (Cloud Tasks, Pub/Sub, SQS, Kafka)
`IMPORTS`	Module/package import
`DEFINES` / `DEFINES_METHOD`	Module/class defines a function/method
`HANDLES`	Route node handled by a function
`IMPLEMENTS`	Type implements an interface
`OVERRIDE`	Struct method overrides an interface method
`USAGE`	Read reference (callback, variable assignment)
`FILE_CHANGES_WITH`	Git history change coupling
`CONTAINS_FILE` / `CONTAINS_FOLDER` / `CONTAINS_PACKAGE`	Structural containment

Node Labels

Project, Package, Folder, File, Module, Class, Function, Method, Interface, Enum, Type, Route

Qualified Name Format

<project>.<path_parts>.<name> — file path with / replaced by ., extension removed.

Examples:

myproject.cmd.server.main.HandleRequest (Go)
myproject.services.orders.ProcessOrder (Python)
myproject.src.components.App.App (TypeScript)

Use search_graph to discover qualified names, then pass them to get_code_snippet.

Cypher Subset (for query_graph)

Supported:

MATCH with node labels and relationship types
Variable-length paths: -[:CALLS*1..3]->
WHERE with =, <>, >, <, >=, <=, =~ (regex), CONTAINS, STARTS WITH
WHERE with AND, OR, NOT
RETURN with property access, COUNT(x), DISTINCT
ORDER BY with ASC/DESC
LIMIT
Edge property access: r.confidence, r.url_path, r.coupling_score

Not supported: WITH, COLLECT, SUM, CREATE/DELETE/SET, OPTIONAL MATCH, UNION

Common Cypher Patterns

# Cross-service HTTP calls with confidence
MATCH (a)-[r:HTTP_CALLS]->(b) RETURN a.name, b.name, r.url_path, r.confidence LIMIT 20

# Filter by URL path
MATCH (a)-[r:HTTP_CALLS]->(b) WHERE r.url_path CONTAINS '/orders' RETURN a.name, b.name

# Interface implementations
MATCH (s)-[r:OVERRIDE]->(i) RETURN s.name, i.name LIMIT 20

# Change coupling
MATCH (a)-[r:FILE_CHANGES_WITH]->(b) WHERE r.coupling_score >= 0.5 RETURN a.name, b.name, r.coupling_score

# Functions calling a specific function
MATCH (f:Function)-[:CALLS]->(g:Function) WHERE g.name = 'ProcessOrder' RETURN f.name LIMIT 20

Regex-Powered Search (No Full-Text Index Needed)

search_graph and search_code support full Go regex, making full-text search indexes unnecessary. Regex patterns provide precise, composable queries that cover all common discovery scenarios:

search_graph — name_pattern / qn_pattern

Pattern	Matches	Use case
`.*Handler$`	names ending in Handler	Find all handlers
`(?i)auth`	case-insensitive "auth"	Find auth-related symbols
`get\|fetch\|load`	any of three words	Find data-loading functions
`^on[A-Z]`	names starting with on + uppercase	Find event handlers
`.Service.Impl`	Service...Impl pattern	Find service implementations
`^(Get\|Set\|Delete)`	CRUD prefixes	Find CRUD operations
`.*_test$`	names ending in _test	Find test functions
`.\\.controllers\\..`	qn_pattern for directory scoping	Scope to controllers dir

search_code — regex=true

Pattern	Matches	Use case
`TODO\|FIXME\|HACK`	multi-pattern scan	Find tech debt markers
`(?i)password\|secret\|token`	case-insensitive secrets	Security scan
`func\\s+Test`	Go test functions	Find test entry points
`api[._/]v[0-9]`	API version references	Find versioned API usage
`import.*from ['"]@`	scoped npm imports	Find package imports

Combining Filters for Surgical Queries

# Find unused auth handlers
search_graph(name_pattern="(?i).*auth.*handler.*", max_degree=0, exclude_entry_points=true)

# Find high fan-out functions in the services directory
search_graph(qn_pattern=".*\\.services\\..*", min_degree=10, relationship="CALLS", direction="outbound")

# Find all route handlers matching a URL pattern
search_code(pattern="(?i)(POST|PUT).*\\/api\\/v[0-9]\\/orders", regex=true)

Critical Pitfalls

search_graph(relationship="HTTP_CALLS") does NOT return edges — it filters nodes by degree. Use query_graph with Cypher to see actual edges.
query_graph has a 200-row cap before aggregation — COUNT queries silently undercount on large codebases. Use search_graph with min_degree/max_degree for counting.
trace_call_path needs exact names — use search_graph(name_pattern=".*Partial.*") first to discover names.
direction="outbound" misses cross-service callers — use direction="both" for full context.

Decision Matrix

Question	Use
Who calls X?	`trace_call_path(direction="inbound")`
What does X call?	`trace_call_path(direction="outbound")`
Full call context	`trace_call_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_call_path(risk_labels=true)`
Text search	`search_code` or Grep