graphthulhu

MCP server that gives AI full access to your knowledge graph. Supports Logseq and Obsidian — both with full read-write support. Navigate pages, search blocks, analyze link structure, track decisions, manage flashcards, and write content — all through the Model Context Protocol.

Built in Go with the official MCP Go SDK.

Why

Your knowledge graph stores interconnected pages, blocks, and links. But AI assistants can't see any of it — they're blind to your second brain.

graphthulhu fixes that. It exposes your entire knowledge graph through MCP, so Claude (or any MCP client) can:

• Read any page with its full block tree, parsed links, tags, and properties
• Search across all blocks with contextual results (parent chain + siblings)
• Traverse the link graph to discover how concepts connect
• Find knowledge gaps — orphan pages, dead ends, weakly-linked areas
• Discover topic clusters through connected component analysis
• Create pages, write blocks, build hierarchies, link pages bidirectionally (Logseq)
• Query with raw DataScript/Datalog for anything the built-in tools don't cover (Logseq)
• Review flashcards with spaced repetition statistics (Logseq)
• Explore whiteboards and their spatial connections (Logseq)

It turns "tell me about X" into an AI that actually understands your knowledge graph's structure.

Tools

37 tools across 9 categories. Most work with both backends; some are Logseq-only (DataScript queries, flashcards, whiteboards).

Navigate

Tool	Backend	Description
get_page	Both	Full recursive block tree with parsed links, tags, properties
get_block	Both	Block by UUID with ancestor chain, children, siblings
list_pages	Both	Filter by namespace, property, or tag; sort by name/modified/created
get_links	Both	Forward and backward links with the blocks that contain them
get_references	Logseq	All blocks referencing a specific block via ((uuid))
traverse	Both	BFS path-finding between two pages through the link graph

Search

Tool	Backend	Description
search	Both	Full-text search with parent chain + sibling context
query_properties	Both	Find by property values with operators (eq, contains, gt, lt)
query_datalog	Logseq	Raw DataScript/Datalog queries against the Logseq database
find_by_tag	Both	Tag search with child tag hierarchy support

Analyze

Tool	Backend	Description
graph_overview	Both	Global stats: pages, blocks, links, most connected, namespaces
find_connections	Both	Direct links, shortest paths, shared connections between pages
knowledge_gaps	Both	Orphan pages, dead ends, weakly-linked areas
list_orphans	Both	List orphan page names with block counts and property status
topic_clusters	Both	Connected components with hub identification

Write

Tool	Backend	Description
create_page	Both	New page with properties and initial blocks
append_blocks	Both	Append plain-text blocks (simpler than upsert_blocks)
upsert_blocks	Both	Batch create with nested children for deep hierarchies
update_block	Both	Replace block content by UUID
delete_block	Both	Remove block and all children
move_block	Both	Reposition before, after, or as child of another block (cross-page supported)
link_pages	Both	Bidirectional link with optional relationship context
delete_page	Both	Remove a page and all its blocks
rename_page	Both	Rename page and update all [[links]] across the graph
bulk_update_properties	Both	Set a property on multiple pages in one call

Decision

Tool	Backend	Description

... View full README on GitHub