Igor Lins e Silva
dfb22f5345
- 22 content pages across Guide, Concepts, and Reference sections - Custom indigo/cyan theme with Lucide icons and Mermaid diagrams - GitHub Actions workflow for GitHub Pages deployment - Live preview: https://mempalace-docs.netlify.app/
92 lines
2.6 KiB
Markdown
92 lines
2.6 KiB
Markdown
# Knowledge Graph
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MemPalace includes a temporal entity-relationship graph — like Zep's Graphiti, but SQLite instead of Neo4j. Local and free.
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## What It Stores
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Entity-relationship triples with temporal validity:
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```
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Subject → Predicate → Object [valid_from → valid_to]
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```
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Facts have time windows. When something stops being true, you invalidate it — and historical queries still find it.
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## Usage
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### Python API
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```python
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from mempalace.knowledge_graph import KnowledgeGraph
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kg = KnowledgeGraph()
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# Add facts
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kg.add_triple("Kai", "works_on", "Orion", valid_from="2025-06-01")
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kg.add_triple("Maya", "assigned_to", "auth-migration", valid_from="2026-01-15")
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kg.add_triple("Maya", "completed", "auth-migration", valid_from="2026-02-01")
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# Query: everything about Kai
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kg.query_entity("Kai")
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# → [Kai → works_on → Orion (current), Kai → recommended → Clerk (2026-01)]
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# Query: what was true in January?
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kg.query_entity("Maya", as_of="2026-01-20")
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# → [Maya → assigned_to → auth-migration (active)]
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# Timeline
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kg.timeline("Orion")
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# → chronological story of the project
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```
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### Invalidating Facts
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When something stops being true:
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```python
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kg.invalidate("Kai", "works_on", "Orion", ended="2026-03-01")
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```
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Now queries for Kai's current work won't return Orion. Historical queries still will.
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### MCP Tools
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Through the MCP server, the knowledge graph is available as tools:
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| Tool | Description |
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|------|-------------|
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| `mempalace_kg_query` | Query entity relationships with time filtering |
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| `mempalace_kg_add` | Add facts |
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| `mempalace_kg_invalidate` | Mark facts as ended |
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| `mempalace_kg_timeline` | Chronological entity story |
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| `mempalace_kg_stats` | Graph overview |
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## Storage
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The knowledge graph uses SQLite with two tables:
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**`entities`** — people, projects, tools, concepts:
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- `id` — lowercase normalized name
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- `name` — display name
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- `type` — person, project, tool, concept, etc.
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- `properties` — JSON blob for extra metadata
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**`triples`** — relationships between entities:
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- `subject` → `predicate` → `object`
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- `valid_from` — when this became true
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- `valid_to` — when it stopped being true (NULL = still current)
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- `confidence` — 0.0 to 1.0
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- `source_closet` — link back to the verbatim memory
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Database location: `~/.mempalace/knowledge_graph.sqlite3`
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## Comparison
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| Feature | MemPalace | Zep (Graphiti) |
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|---------|-----------|----------------|
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| Storage | SQLite (local) | Neo4j (cloud) |
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| Cost | Free | $25/mo+ |
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| Temporal validity | Yes | Yes |
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| Self-hosted | Always | Enterprise only |
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| Privacy | Everything local | SOC 2, HIPAA |
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