> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://help.getzep.com/llms.txt.
> For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://help.getzep.com/_mcp/server.

# Key Concepts

> Core Zep concepts: agent memory, temporal knowledge graphs, the Context Lake, Context Blocks, facts, and Observations — the primitives behind reliable agents.

Looking to just get coding? Check out our [Quickstart](/quickstart).

Zep delivers agent memory at enterprise scale. From any source — chat, business data, documents, JSON — Zep builds a temporal knowledge graph (its Context Graph) of the entities, relationships, and facts that matter to a user or subject, then assembles token-efficient context (facts, summaries, and Observations) and serves it from a governed Context Lake with sub-200ms retrieval. This reduces hallucinations and improves accuracy.

| Concept                                    | Description                                                                                                                                                                                                          | Docs                                                              |
| ------------------------------------------ | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ----------------------------------------------------------------- |
| Context Graph                              | Zep's temporal Context Graph — the unit of agent memory. Nodes are entities, edges are facts/relationships; the graph updates dynamically as new data arrives, invalidating outdated facts while preserving history. | [Docs](/understanding-the-graph)                                  |
| Zep's Context Block                        | Optimized string containing a user summary and facts from the Context Graph most relevant to the current thread. Also contains dates when facts became valid and invalid. Provide this to your chatbot as context.   | [Docs](/retrieving-context#zeps-context-block)                    |
| Context Types                              | The distinct primitives Zep produces from a user graph: facts, entities, episodes, thread summaries, observations, and user summary. Choose the type that fits the agent's task.                                     | [Docs](/context-types)                                            |
| Fact Invalidation                          | When new data invalidates a prior fact, the time the fact became invalid is stored on that fact's edge in the Context Graph.                                                                                         | [Docs](/facts)                                                    |
| JSON/text/message                          | Types of data that can be ingested into the Context Graph. Can represent business data, documents, chat messages, emails, etc.                                                                                       | [Docs](/adding-data-to-the-graph)                                 |
| Custom Entity/Edge Types                   | Feature allowing use of Pydantic-like classes to customize creation/retrieval of entities and relations in the Context Graph.                                                                                        | [Docs](/customizing-graph-structure#custom-entity-and-edge-types) |
| Graph                                      | Represents a standalone Context Graph for storing up-to-date knowledge about an object or system. For storing up-to-date knowledge about a user, a user graph should be used.                                        | [Docs](/graph-overview)                                           |
| User Graph                                 | Special type of graph for storing personalized context for a user of your application.                                                                                                                               | [Docs](/users)                                                    |
| User                                       | A user in Zep represents a user of your application, and has its own User Graph and thread history.                                                                                                                  | [Docs](/users)                                                    |
| Threads                                    | Conversation threads of a user. By default, all messages added to any thread of that user are ingested into that user's graph.                                                                                       | [Docs](/threads)                                                  |
| `graph.add` & `thread.add_messages`        | Methods for adding data to a graph and user graph respectively.                                                                                                                                                      | [Docs](/adding-data-to-the-graph) [Docs](/adding-messages)        |
| `graph.search` & `thread.get_user_context` | Low level and high level methods respectively for retrieving from the Context Graph.                                                                                                                                 | [Docs](/searching-the-graph) [Docs](/retrieving-context)          |
| User Summary Instructions                  | Customize how Zep generates entity summaries for users in their Context Graph. Up to 5 custom instructions per user to guide summary generation.                                                                     | [Docs](/users#user-summary-instructions)                          |
| Debug mode                                 | Time-limited project mode for capturing per-episode workflow logs. Flex, Flex Plus, and Enterprise accounts also capture LLM reasoning traces for selected ingestion steps.                                          | [Docs](/debug-mode)                                               |
| Agentic Tool                               | Use Zep's context retrieval methods as agentic tools, enabling your agent to query for relevant information from the user's Context Graph.                                                                           | [Docs](/quickstart#use-zep-as-an-agentic-tool)                    |