The OpenAI API unlocked a whole new layer of building for me

Hi, I’m Andy.

I wanted to share a concrete example of what the OpenAI API can do when it is used as the intelligence layer inside a persistent production system rather than as a normal chat interface.

Over the past year, the OpenAI API has unlocked a whole new layer of building for me. With the API as the foundation and Codex CLI as my main coding partner, I have been able to build systems and workflows that I honestly would not have thought possible when I started.

One of the clearest examples is autonomous long form creative production.

Using ChatGPT 5.4 through my own agentic operating environment, I generated a 40 chapter book from structured creative requirements, then expanded it into a franchise package with season scripts, canon files, repair reports, visual direction, image prompt packs, and exportable artifacts.

The important part is not just that the model wrote prose. The important part is that the work ran through managed, resumable, inspectable production runs with persistence, guardrails, progress tracking, exports, review, iteration, and cost control.

Over the last 7 days, the system recorded 645,069,836 prompt tokens saved, with 95 percent saved, while OpenAI usage showed about 40.3 million total tokens and 1,428 requests.

The potential this unlocks is much bigger than faster writing. It changes the unit of work from a single prompt to a managed production run. A model can be used as the intelligence layer inside a system that plans, drafts, adapts, preserves context, tracks progress, exports artifacts, and keeps the work reusable.

This is already repeatable. I have used the same production system to generate a full book from structured requirements, adapt a draft novel into a screenplay, produce season scripts, preserve canon, create repair reports, and generate visual direction for franchise assets.

My point is simple: OpenAI models are far more capable than many people realize. The missing layer is often the operating environment around them.

I also want to be honest about something: I have a real vested interest in OpenAI continuing to succeed.

The work I am building is possible because the API is good enough to support it. When I say these tools are working, I do not mean that as empty praise. I mean they are enabling real builders to attempt things that were previously out of reach.

That matters to me, because my own work now depends on this ecosystem continuing to improve.

OpenAI provided the intelligence. My system provided the operating environment. Together, they made a new kind of production workflow possible.

That’s an incredible scale, Andy! 645M tokens saved via caching/optimization is a masterclass in cost control. It seems your ‘agentic operating environment’ is exactly what the previous posters are missing — a way to manage GPT-5’s power without letting it drain the quota blindly. Would love to hear more about how you handle state persistence between these long production runs!

Thanks Mate, I really appreciate that.

The big shift for me was treating long runs as production workflows rather than single chat sessions.

At a high level, I persist project state outside the prompt path, then bring back only the active working context needed for the next step. That lets the system continue across larger runs without constantly replaying everything that happened before.

So the pattern is basically: durable project state, managed run progress, reviewable outputs, and selective context rehydration when needed.

That has been one of the biggest unlocks for cost control and repeatability.

That’s a very robust architecture. ‘Selective context rehydration’ is definitely the key to scaling without hitting the token wall.

A quick follow-up: how do you handle the ‘rehydration’ logic? Is it a manual selection of files/data, or do you have an automated layer (like a vector DB or an LLM-based router) that decides which parts of the project state are ‘active’ for the current task?

Your approach to treating runs as ‘durable project states’ is exactly the shift from ‘AI as a toy’ to ‘AI as an industrial engine’.

That is exactly the part I ended up spending the most time thinking about.

For me, it is not fully manual, but I also would not trust a plain vector search or an LLM on its own to decide everything.

The way I think about it is pretty simple: the current task decides what kind of context is needed first. Then the runtime builds a small working view from the durable project state, the current run state, recent events, saved summaries, and any relevant files or artifacts.

Retrieval can help find candidates, and the model can help reason over them, but I still want the runtime to be in charge of what actually enters the prompt.

So the model is not carrying the memory. It is working inside a temporary view of the memory.

After each step, anything important gets written back into durable state, so the next step can continue without replaying the whole history again.

That separation has been the biggest unlock for me: the model reasons, but the runtime owns the memory, state, limits, and continuation logic.

That ‘Model as a Processor, Runtime as Memory’ split is the gold standard. It solves the context drift problem and keeps costs linear instead of exponential.

I’m curious about the ‘write back’ phase. When the system updates the durable state after a step, do you use an LLM to ‘compress/summarize’ the findings into the state, or is it more of a structured data update (like updating a JSON manifest of the project)?

This approach basically makes the context window size irrelevant since you’re managing the ‘RAM’ yourself. Brilliant stuff.