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Skip AI Frameworks - Use the API and MCP Servers Directly

Fazm Team··2 min read
mcplangchainai-frameworksapisoftware-architecture

Skip AI Frameworks - Use the API and MCP Servers Directly

Every few months a new list of AI frameworks appears. LangChain, LlamaIndex, CrewAI, AutoGen - each promising to simplify building AI applications. And every few months, developers who adopted the previous framework are ripping it out.

The Framework Trap

AI frameworks add abstraction layers on top of APIs that are already simple. The Claude API takes a prompt and returns a response. That is fundamentally all you need. Frameworks wrap this in chains, agents, tools, memory stores, and callback handlers that feel productive but mostly create debugging surface area.

The real problem appears when you need to do something the framework did not anticipate. Suddenly you are reading framework source code, fighting type systems, and working around opinionated abstractions instead of building your product.

The Raw API + MCP Approach

Here is what works instead: the Claude API plus custom MCP servers. You write maybe 500 lines of code for your MCP server and get more out of it than months of fighting framework abstractions.

An MCP server gives you:

  • Direct tool definitions that the model understands natively
  • Full control over what your agent can and cannot do
  • No hidden abstractions - you see every request and response
  • Easy debugging - it is just a JSON-RPC server

Why This Is Faster

With a framework, you spend time learning the framework's way of doing things. With raw API calls and MCP, you spend time building your actual product. The learning curve is a few hours of reading API docs instead of weeks of framework documentation.

When something breaks, you debug your code - not a framework's internals. When you need a new capability, you add a tool to your MCP server - not hunt for a compatible plugin.

When Frameworks Make Sense

If you are prototyping something in an afternoon and will throw it away tomorrow, a framework is fine. But for anything you plan to maintain, the direct approach saves time in the long run.

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Fazm is an open source macOS AI agent. Open source on GitHub.

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