I finally tried ChatGPT Plus properly, and I wanted to document how much work I managed to get done on the first day—and what it cost in terms of weekly usage.

I used GPT-5.6 Sol with low reasoning in Codex for development, then GPT-5.6 Sol with medium reasoning on ChatGPT web for research, planning, file conversion, and data processing.

The results from both were fantastic. The model showed strong reasoning, found problems I didn’t know existed, implemented substantial changes, tested its work, and explained its decisions clearly.

Project 1: auditing and improving my inventory app

My first project was NOVASTOCK, an offline inventory, POS, finance, and multi-device application.

I initially asked Codex to perform a complete production-readiness audit covering the stack, features, bugs, security, UI, translations, statistics, tables, and deployment.

It found several important security, synchronization, translation, printing, financial-calculation, and scalability problems. We then worked through many of them.

Codex improved the Parent/Child synchronization system, strengthened backups and authentication, fixed printing and finance bugs, completed Arabic/French/English translations, redesigned the Finance dashboard, corrected promotional-pack calculations, improved licence-key security, added automated tests, and produced Windows and Android builds.

By the end, lint passed, all 37 automated tests passed, the Electron production build succeeded, and the Android build checks passed.

It was also honest about what still required real-world testing, such as physical printers, multiple devices, production credentials, large datasets, and recovery after power loss.

Project 2: experimenting with Unity

The second project was a Unity game.

We first modified an existing 3D tutorial by replacing the robot with a basic low-poly soldier. Codex added a rifle, mouse aiming, shooting, a crosshair, bullet tracers, impact effects, and interaction with physics objects while preserving the existing movement and camera.

Then we created a separate playable dark-gothic 2D side-scroller. Codex and the image generator produced original artwork, an animated knight, enemies, combat, platforms, hazards, health, respawning, camera following, and a completion gate.

Unity successfully imported and compiled the prototype with no detected compiler errors.

Usage after the Codex projects

From the beginning of the inventory audit to the final Codex follow-ups, the work covered roughly a seven-hour first-day session, with the Unity project happening during that same overall period.

At that point, approximately 77% of the weekly allowance remained, meaning all that Codex work had used around 23%.

Considering the amount of auditing, implementation, image generation, testing, troubleshooting, and building completed, I found that impressive.

Switching to ChatGPT on the web

After Codex, I switched to ChatGPT web and used GPT-5.6 Sol with medium reasoning.

It also completed several other audits and business plans, but the heaviest web task involved Forex trading data.

First, it clearly explained the difference between tick data and one-minute candles, including why tick data is more suitable for scalping, tight TP/SL strategies, spread simulation, and cases where the order of price movements matters.

I then asked it to download and process five years of data for:

• EURUSD
• USDJPY
• GBPUSD
• AUDUSD
• USDCAD

It completed 25 annual datasets covering 2021–2025. The data was converted into timestamped Bid/Ask records, with monthly overlaps and consecutive unchanged prices removed.

The final uncompressed size was approximately 6.8 GB, and the task ran for about 46 minutes. Because of the large downloads, conversion, and data manipulation, this work consumed another 7% of the allowance.

First-day usage total

My approximate usage was:

• 23% used in Codex
• 7% used on ChatGPT web
• 30% of the weekly allowance used
• Around 70% remaining

Final impression

For a first day, I’m genuinely impressed.

The most valuable part wasn’t simply generating code. Codex could inspect existing projects, discover architectural problems, implement connected changes, test them, build multiple targets, generate original game assets, and clearly explain limitations.

GPT-5.6 Sol produced excellent results at both reasoning levels. Low reasoning in Codex handled a surprising amount of real development, while medium reasoning on the web worked well for heavier research and data processing.

Using 30% in one day sounds high, but this was not normal casual chatting. It covered two software projects, a production audit and stabilization pass, Windows and Android builds, a playable Unity prototype, several business audits and plans, and approximately 6.8 GB of processed Forex data.

For that amount of completed work, I think the usage was reasonable