MCP Tools

Lucerna exposes two tools over the Model Context Protocol that AI coding assistants can call directly.

Tools

Tool	Description
search_codebase	Hybrid semantic + BM25 search with optional graph context expansion. Returns { results, warning? }.
get_neighbors	Get the knowledge-graph neighborhood for a chunk ID from search results.

search_codebase parameters

Parameter	Type	Default	Description
query	string	—	Search query
includeGraphContext	boolean	true	Expand results with related symbols from the knowledge graph
graphDepth	number	1	Hops to follow when expanding graph context (0–3)
limit	number	10	Maximum results to return
offset	number	0	Results to skip for pagination. Use with hasMore: true to fetch the next page.
includeContent	boolean	true	Include chunk source code in results. Set false for a lightweight metadata-only response.
language	string	—	Restrict to a language (e.g. "typescript")
type	string	—	Restrict to a chunk type ("function", "class", etc.)
filePath	string	—	Filter by file path (supports glob patterns)

Note

First-time indexing: If the project has never been indexed, search_codebase returns { results: [], warning: "Lucerna is still initializing…" }. Results become available once the initial index completes (typically a few seconds for small projects).

get_neighbors parameters

Parameter	Type	Default	Description
chunkId	string	—	The chunk ID from a search_codebase result
depth	number	1	How many hops to traverse (1–3)