What is Memory MCP?
Memory MCP is an official Model Context Protocol server that provides AI agents with persistent memory through a local knowledge graph. It stores entities, relationships, and observations in a JSON file — enabling agents to remember facts, preferences, and context across conversations.
Answer-Ready: Memory MCP is an official MCP server that gives AI agents like Claude Code persistent memory via a local knowledge graph. It stores entities, relationships, and observations in JSON, enabling cross-session context retention.
Best for: Claude Code and Cline users who want their AI to remember project context. Works with: Any MCP-compatible tool (Claude Code, Cline, Cursor). Setup time: Under 1 minute.
Core Features
1. Entity Management
Store and retrieve named entities with types:
Agent creates:
Entity: "Auth Module" (type: component)
Entity: "Alice" (type: team_member)
Entity: "PostgreSQL" (type: technology)2. Relationships
Connect entities with typed relationships:
"Auth Module" --uses--> "PostgreSQL"
"Alice" --maintains--> "Auth Module"
"Auth Module" --depends_on--> "JWT Library"3. Observations
Attach facts to entities that accumulate over time:
Entity: "Auth Module"
Observations:
- "Refactored to use JWT in March 2026"
- "Has 95% test coverage"
- "Handles 10k req/s in production"4. Available Tools
| Tool | Description |
|---|---|
create_entities |
Add new entities with types |
create_relations |
Link entities together |
add_observations |
Attach facts to entities |
search_nodes |
Full-text search across the graph |
open_nodes |
Retrieve specific entities |
delete_entities |
Remove entities |
delete_observations |
Remove specific facts |
delete_relations |
Remove relationships |
5. Storage
Data persists in ~/.claude/memory.json (configurable):
{
"entities": [
{
"name": "Auth Module",
"entityType": "component",
"observations": ["Uses JWT tokens", "95% test coverage"]
}
],
"relations": [
{
"from": "Auth Module",
"to": "PostgreSQL",
"relationType": "uses"
}
]
}Use Cases
| Use Case | How |
|---|---|
| Project context | Remember architecture decisions across sessions |
| Team info | Store who works on what |
| Preferences | Remember coding style and tool preferences |
| Debug history | Track past issues and their solutions |
FAQ
Q: Where is the data stored?
A: In a local JSON file (default: ~/.claude/memory.json). Never sent to external servers.
Q: Does it work with Claude Code? A: Yes, it is an official MCP server designed for Claude Code and other MCP-compatible tools.
Q: How much data can it handle? A: Practical limit is thousands of entities. For larger datasets, consider a database-backed MCP server.