Last updated: 9/25/2026
What is GBrain?
GBrain is an AI agent memory layer described as a markdown-first knowledge system for persistent agent memory. Built by YC CEO Garry Tan, it is designed to help AI agents store, connect, and retrieve knowledge across sessions. Its core capabilities include an auto-wiring knowledge graph, semantic search with hybrid retrieval, and MCP integration for agent workflows.
Key Features
- Persistent agent memory for retaining useful context across AI agent interactions
- Markdown-first knowledge system that keeps information in a readable and portable format
- Auto-wiring knowledge graph for connecting related notes, concepts, and context
- Semantic search with hybrid retrieval to help agents find relevant information
- MCP integration for connecting GBrain with compatible AI agent environments
Best For
Pricing
GBrain is listed as free based on the provided tool information. Because it is hosted on GitHub, users should review the repository directly for current licensing details, setup requirements, and any future changes.
Pros & Cons
Pros
- Free to use according to the provided pricing information
- Markdown-first approach makes stored knowledge easier to inspect and edit
- Persistent memory can help reduce repeated context-setting for AI agents
- Knowledge graph functionality may improve organization of connected information
- MCP integration makes it relevant for modern AI agent workflows
Cons
- Requires users to be comfortable working with a GitHub-hosted project
- May need technical setup before it can be used in an agent workflow
- Available information does not specify hosted service options or support levels
- Effectiveness may depend on how well the user structures and maintains markdown knowledge
- No verified enterprise, compliance, or security claims are provided in the supplied information
Alternatives
Mem0 is an AI memory platform focused on adding long-term memory to AI applications and agents.
Letta provides infrastructure for stateful AI agents, including memory management and agent development tools.
LangGraph is a framework for building stateful, multi-step AI agent workflows and can be used where persistent agent context is needed.
LlamaIndex helps developers connect AI applications to external data sources using retrieval, indexing, and knowledge management workflows.
Obsidian is a markdown-based knowledge management tool that can support AI-assisted research and note organization through plugins and integrations.
FAQ
Details
Platform
Features
- Persistent agent memory
- Auto-wiring knowledge graph
- Semantic search with hybrid retrieval
- MCP integration for AI agents






