Build it yourself

Code-first. You own the full stack.

Write the agent yourself: model calls, tool wiring, memory, the orchestration loop, deployment, monitoring. Frameworks give you blocks; the architecture is yours.

builds

You

runs

You

decides

You

When this fits

Your requirements are specific enough that no existing agent or service maps cleanly.
The agent needs deep integration with internal systems you cannot expose externally.
The way you build it is the competitive advantage: proprietary orchestration, custom memory, bespoke tools.
You need to understand every layer because you own debugging it in production.

What it demands

Time and architectural judgment the frameworks do not supply. The gap between a working demo and a production agent is real and large.

Learn this first

01The agent loop: model, tools, memory, prompting
02Pick a stack (LangGraph or the OpenAI Agents SDK)
03Extend with MCP for tools at scale
04Evaluate before you ship, then deploy