June 24, 2025
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How Claude's memory and MCP work (and when to use each)

Emma Adler
Contributor @ Hackmamba

Large Language Models (LLMs) like Claude can read files, troubleshoot issues, use external tools, and write tutorials much faster than a human ever could. But they are prone to hallucinations, struggle to follow complex instructions, and miss important context.

These limitations come down to what the LLM “knows.” And when you look under the hood, you see that the information Claude has access to during a conversation shapes the way it behaves.

Claude supports two context management methods: memory and the Model Context Protocol (MCP). Thanks to memory, Claude remembers facts and preferences across sessions. MCP, on the other hand, gives Claude real-time access to external sources such as files, logs, or documentation during a session.

Knowing how to use memory and MCP and what they are for helps developers, tech writers, and customer support engineers working with complex systems get better results.

Let’s start by explaining what defines Claude’s memory.

What is Claude’s memory?

Claude’s memory acts as a vessel for transferring information from one conversation to the next, allowing you to continue right where you left off. It is built to store preferences and retain details, like your tone or technical proficiency.

For example, if you’ve told Claude that you're working in a Python-based file system, or that your logs are stored in a particular format like JSON, Claude can keep that in mind without you needing to repeat it in every session.

Claude can remember things such as:

  • Your preferred programming languages or frameworks
  • File formats you typically use (e.g., JSON, YAML)
  • Your preferred response style and tone
  • Known constraints or requirements in your workflow
  • Any recurring tools, systems, or services
  • Specific terms, acronyms, or jargon relevant to what you do
  • Your general level of technical expertise

Claude uses memory to build a broader context and develop an idea of who you are (which improves the quality of its responses), but it is not primarily designed for extracting task-specific information. That’s what Claude’s MCP is for.

What is Model Context Protocol?

LLMs like Claude use MCP to retrieve scoped information from external sources (e.g., local file systems, logs, documentation, integrated tools). Unlike memory, which is persistent, MCP is task-specific and real-time.

With memory, Claude remembers who you are. On the other hand, MCP provides Claude with access to your docs, file structure, and GitHub repository at the time of your question. When information changes frequently, this can make all the difference.

Claude’s MCP in a nutshell:

  • A developer or team sets up a connection to relevant content (e.g., JSON config files, tutorials, an API reference).
  • This content is made accessible to Claude through an MCP server.
  • During a conversation, Claude queries the content on demand.
  • The session ends, but Claude doesn’t retain the content.

Claude’s MCP can’t be viewed as an alternative to memory because it doesn't actually learn about the user. Instead, it gives the LLM scoped access to a knowledge base in a standardized way through the MCP servers.

As a result of this, Claude’s MCP works great for answering questions that depend on accurate file paths, command syntax, or project-specific documentation.

For Claude’s MCP to operate at its fullest potential, your documents must be well-structured. Clear headings, logical file paths, consistent use of args, a well-defined hierarchy, and metadata provide additional context to the LLM. The best way to understand what this means is to look at examples.

Memory vs. Model Context Protocol: Side-by-side example

To better understand the difference between the ways Claude uses memory and MCP, let's look at two common scenarios that a developer and a customer support engineer might encounter.

Example of Claude’s memory

You have told Claude in previous sessions that you’re a developer who works with Python and prefers instructions broken down into simple, step-by-step lists.

In this scenario, your typical prompt would look something like:

    "Can you show me how to write a script that reads a JSON file?"

When you share your preferences with Claude, they are stored in a persistent memory associated with your profile, typically as a data object (such as a JSON file).

Claude loads this memory object every session, injecting the information into the context of your ongoing conversation with it. Because of this, Claude is able to reference your preferences automatically.

The memory persists across sessions (unless you change or delete it), so whenever you ask Claude a question, it will include a response that matches what you need, without having to fetch external data.

Essentially, because it remembers that you prefer step-by-step instructions, Claude provides the answer in a clear, numbered list tailored to Python. You don't have to state your preferences and provide broad context in every interaction, as Claude knows what you want from it.

Example of Claude’s MCP

You are a customer support engineer who works with a product that has API documentation and needs to be updated frequently, so you always need the latest information to support customer integration. You ask Claude:

    "What is the correct API endpoint and required fields for creating a new user?"

In this case, Claude's MCP would access the latest version of your team’s API documentation, retrieve the current endpoint, and make sure its answer reflects any recent updates.

When you use MCP, your documentation needs to be available to Claude in a structured way, so that it can access and read it properly.

When you ask your question, Claude sends a real-time HTTP request to the MCP server. Upon receiving the response, Claude extracts the relevant information from the data the MCP server returns. It then uses those details to generate an answer that’s accurate and up to date.

This information is not stored in memory after the session ends. The next time you ask Claude a question, the whole process repeats from scratch, with the AI always fetching the latest data from the MCP source.

These examples demonstrate how Claude’s memory personalizes responses and MCP provides hyper-specific answers, but when should you use memory and when should you rely on Claude's MCP instead?

When to use memory vs. MCP

Memory is not a superior context management method to MCP, and MCP is not a superior method to memory. They serve different use cases and address different needs. If you frequently work with AI models like Claude, for example,in customer support settings or as part of a documentation team, you'll want to know when to rely on each.

Use Claude’s memory if:

  • You need continuity (e.g., you're working on a long-term project).
  • You want Claude to remember details across sessions (writing tone, role, preferred structure).
  • You want to avoid repeating yourself and providing context in every conversation.

Use Claude’s MCP servers if:

  • You need Claude to pull from up-to-date, scoped information (API docs, command references, tutorials) from external systems.
  • Maintaining accuracy, file structure, and command syntax is imperative.
  • You want the AI model to respond using precise and specific answers, as opposed to relying on assumptions from previous chats.

Combining Claude’s MCP with its memory delivers the best results. Memory provides personalization and continuity, while MCP reliably pulls relevant information from your systems. However, to maximize the effectiveness of this approach, you need to structure your documentation properly.

Structuring your documentation for reliable AI retrieval

The stakes are always high in customer support environments, where access to relevant, accurate, and up-to-date information makes the difference between a quick resolution of an issue and added frustration.

If your docs are outdated, incomplete, or poorly structured, Claude may return unhelpful or, worse yet, entirely inaccurate information.

On the other hand, if your documentation is organized with clear paths, metadata, logical hierarchy, and standardized formats, Claude can quickly surface the correct answers, reference the latest updates, and avoid any confusion that would otherwise stem ambiguous file structures, inconsistent terminology, or a lack of standardized context.

Ultimately, Claude can only be as helpful as your docs let it be. This means that you need to structure your documentation so that it is readable for AI, not just humans.

Tools like Mintlify are built for teams that want to create documentation that Claude and other LLMs can parse more easily. Mintlify makes documentation more digestible for AI by supporting:

  • Hierarchy: Clear headings and logical sections make it easier for Claude to retrieve relevant content.
  • Metadata: Tags, descriptions, and versioning help distinguish between similar commands and API versions during retrieval.
  • Readable formats: Clean, consistent formatting improves LLM comprehension, particularly in development environments.
  • llms.txt support: Mintlify supports an llms.txt manifest file, which provides a reliable index of your documentation.
  • Navigation structures: Consistent navigation structures provide a clear roadmap of your documentation.

The bottom line is that no matter how well-written, accurate, and well-maintained your documentation is, AI may still struggle to interpret and retrieve it accurately if it is not structured.

Claude needs access to consistent and well-scoped documentation that is regularly updated. That is what drives the best results.

Final thoughts

Claude's MCP provides access to structured knowledge, while memory creates continuity and allows the model to understand what you need from it.

Used together, memory and MCP make Claude better at delivering precise and personalized responses. The quality of your docs directly shapes the quality of Claude’s responses, so the best way to get the most out of Claude is to feed it well-maintained and AI-readable documents.

To see how a structured documentation platform can make your content AI-friendly, get a Mintlify demo from an expert.