Hello, I'm GymCoding!

• "I'm so overwhelmed by the cost of Claude Code tokens"

• I've been getting so many questions like, "I don't know where my tokens are leaking."

So, I’ve put together an additional lecture to properly address this!

This lecture is not just about simple token-saving tips. It is a practical guide that selects only 4 plugins directly related to token saving from the 171 plugins in the Anthropic official marketplace, covering everything from measurement to automatic blocking in one go.

What we will cover in this lesson

• Where tokens are leaking shown on one screen: How to use session-report — How to analyze token usage by project and prompt, and identify the most expensive prompts using an HTML dashboard

• How to reduce the token tax on every turn using two tools from CLAUDE.md management (revise + improver) to keep your claude-md-management clean, which automatically attaches to every request

• serena MCP, which searches for code by meaning rather than just characters — from the reason it was picked as the #1 tool for saving tokens to installing uv package manager dependencies

• hookify, which prevents Claude's mistakes in advance — among the four, this is the only official tool that goes beyond simple token saving to assist with the core of harness engineering

• The entire workflow to install and activate all four with a single-line command from the Anthropic official marketplace

The core of this lecture is a bundle of practical tools that will help you save tokens using official tools curated directly by Anthropic, and even reach harness engineering with the final one!

👉 Go to the lecture!

😊 To those currently enrolled

Those who are taking the Claude Code Perfect Master course can take the new lecture immediately at no additional cost. It has been added to the end of Section 30 of the existing curriculum, so please check it out!

And if the lecture was helpful, a single line of review would be a huge help. If you haven't left a review yet, I would appreciate it if you could leave even a short one! 🙏

👉 Write a course review

🎯 For those who haven't taken the course yet

Now, it is no longer a question of whether you use Claude Code, but an era where how efficiently you use tokens makes the difference in cost and results.

Within 6 months of release, over 6,600 people are taking the course, and a wide range of individuals, including not only developers but also marketers, data analysts, students, and non-developers, are participating.

Recent Reviews

This is the most meaningful lecture of my life. This is the first time I've seen an IT lecture that is so sincere and updated in real-time, and it will probably be the last. It truly is the best lecture, and I want to recommend it to everyone.

You can now enroll at a special discount price at gymcoding.co/vip. Please be sure to check it out before the discount ends!

👉 Enroll now at a special discount price (gymcoding.co/vip)

Thank you! 🙇‍♂

Hello, this is Gym Coding!

Lately, I've been posting card news on Instagram, Threads, and YouTube communities. I've received so many comments like "How do you make these?" and "You're really good at making card news."

So, I have properly organized it as an additional lecture this time!

This lecture is not just about simple card news production tips. You will create a system where you create card news directly with just a Claude subscription—without separate design tools or AI image generators—and package the entire process into a reusable Skill that can be called up anytime with a single line of command.

👉Go to the lecture!

😊 To those currently enrolled

Those who are currently taking the Claude Code Masterclass can take the new lecture at no additional cost. It has been added to the end of Section 30 of the existing curriculum, so please check it out!

And if the lecture was helpful, a single line of review would be a huge source of strength. If you haven't left a review yet, I would be grateful if you could leave even a short one! 🙏

👉Write a course review

Thank you! 🙇‍♂

Hello, this is Gym Coding!

Lately, I've been posting card news on Instagram, Threads, and YouTube communities. Many people have been commenting, asking, "How do you make these?" or saying, "You're really good at making card news."

So I am preparing a proper video about it! To give you the conclusion first, these card news are all being created using Claude code.Without any separate design tools or AI image generators, it's possible with just a Claude subscription for 0 won in additional fees.

The core of this lecture is "direct control instead of outsourcing" — it's not about leaving it to AI and getting different results every time, but about controlling it with rules to systematically produce consistent results!

I plan to upload it as an additional lecture tomorrow (April 21st). For those taking this course, I will provide the actual card news HTML source I use along with card news creation skills, so you can apply them directly to your own brand's card news instead of just watching the video!

👉View card news examples on Gym Coding Instagram

😊 To those currently enrolled

Those who are currently taking the Claude Code Complete Master course can watch the new lecture immediately at no additional cost. It will be added to the existing curriculum tomorrow, so please check it out.

And if the lecture was helpful, a single line of review would be a huge help. If you haven't left a review yet, I would be grateful if you could leave even a short one! 🙏

👉Write a course review

🎯 For those who haven't taken the course yet

Now is an era where the difference in skill is determined not by whether you use AI coding tools, but by how well you use them.

Since its launch, more than 4,700 people have taken the course, and a wide range of people, including not only developers but also marketers, data analysts, students, and non-developers, are joining us.

I am a complete beginner who knows nothing about development. At first, I started developing with ChatGPT without watching any lectures or having any information. Then, I moved on to Cursor and realized the Claude model is excellent, so I am currently about to start developing with Claude.
I happened to learn about Gym Coding's lectures through someone nearby, and after listening to them, I thought, "I've really been doing this without any plan at all." I feel that after completing this course, I will be able to develop in a more systematic way with a higher level of understanding. Also, the continuous lecture updates!!! I think they will be a huge help. Thank you!^^
— Original Link

You can now enroll at a special discount price at gymcoding.co/vip. Please make sure to check it out before the discount ends!

👉Enroll now at a special discount (gymcoding.co/vip)

Thank you! 🙇‍♂

Hello, I'm GymCoding!

I'm sure everyone has experienced a time when the same AI model works well once but performs poorly another time. Those moments when you wonder why the results are so different even though you used a similar prompt, whether the model is the problem, or if you're missing something.

I feel like many people have been having these concerns lately. So, I've properly organized everything in this additional lecture!

This lecture is not just about prompt tips. I will systematically explain, along with the latest research cases, how the results change completely depending on how you design the environment in which the AI works, even when using the same AI model.

What is covered in this lecture

• Exactly what harness engineering is and why it is gaining attention now

• Anthropic's actual experimental cases — a ruined app for $9 vs. a completed app for$200 with the same model, and what the difference was.

• 3 causes of AI agent errors (Memory loss between sessions, Context Anxiety, Self-Evaluation)

• CLAUDE.md, Permissions, Hooks, MCP, to Subagents — 6 components for designing a harness in Claude Code

• How to re-evaluate harness rules as models evolve

The core of this lecture is not to blame the AI, but to create an environment where the AI can work effectively!

👉Go to the lecture!

😊 To those currently enrolled

Those who are taking the Claude Code Perfect Master course can watch the new lecture immediately at no additional cost. It has been added to the end of the existing curriculum, so please check it out.

And if the lecture was helpful, a single line of review would be a huge help. If you haven't left a review yet, I would appreciate it if you could leave even a short one! 🙏

👉Write a course review

🎯 For those who haven't taken the course yet

Now, we are in an era where the difference in skill is determined not by whether you use AI coding tools, but by how well you use them.

Since its release, over 5,500 people have taken the course, and a wide range of individuals, including not only developers but also marketers, data analysts, students, and non-developers, are participating.

"I am a complete beginner who knows nothing about development.At first, I started developing with ChatGPT without watching any lectures or having any information. Then I moved to Cursor and felt that the Claude model was great, so I am currently at the stage of starting development with Claude. I happened to find out about Gym Coding's lectures through someone nearby, and after listening to them, I thought, 'I have really been doing this without any plan at all.' I feel that after completing this course, I will be able to develop in a more systematic way with a higher level of understanding. Also, the continuous lecture updates!!! I think they will be a huge help. Thank you!^^ " — LExxxx

You can now enroll at a special discount price at gymcoding.co/vip. Please make sure to check it out before the discount ends!

👉Enroll now at a special discount price

Thank you! 🙇‍♂

Hello, I'm GymCoding!

I added a short video.

Why this lecture shows various planning methods,

And it is a lecture that points out the direction of why it is important to deeply understand the specifications rather than a specific tool.

Recently, some people have been requesting additional lectures on various tools such as OpenClaw, Oh My Claude Code, and Superpowers, so I have added this lecture.

👉Go to the lecture!

And the next lecture I am preparing is

This is the Harness Engineering lecture that was requested in the Q&A section. I believe it would be very beneficial for you to understand these concepts!

I would appreciate it if you look forward to it.

Hello, I'm GymCoding!

Harness Engineering is becoming a hot topic, and many people are curious about what exactly it is!

I am currently planning this as an additional lecture.

Harness Engineering is not a new technology. It is a method for systematically designing things you are already using, such as CLAUDE.md, Hooks, and Permissions.

The core point is "change the environment before you change the model." Even with the same Claude, the results vary completely depending on the environment design.

I will be uploading it as an additional lecture soon.

😊 To those currently taking the course

The additional lectures will be provided to existing students at no extra cost.

And if the lecture was helpful, a one-line review would be a huge source of strength. If you haven't left a review yet, I would be grateful if you could leave a short one! 🙏

👉Write a course review

🎯 For those who haven't taken the course yet

Now, we are in an era where the difference in skill is determined not by whether you use AI coding tools, but by how well you use them.

Within just 4 months of its release, more than 5,000 people have taken the course, and a wide range of individuals, including not only developers but also marketers, data analysts, students, and non-developers, are participating.

Recent Reviews

I've taken dozens of courses on Inflearn, but this course was on another level. It's absolutely insane!!
I've watched a few Claude Code-related lectures on YouTube and Inflearn, but this is the first time I've seen a course that covers everything so systematically, from the basics to the latest updates. It was really impressive how it didn't just stop at introducing features but also pointed out why things are used this way. I am confident that it will be of practical help to everyone, from those who know nothing about Vibe Coding to those who already have experience.
...
Even though I only applied a part of this course, my development speed and depth have completely changed. It's not just about coding fast; I feel like the level of design itself has improved. I truly felt like I had grown wings.

...
To be honest, it's so good that I almost want to keep it to myself, but I still highly recommend it. I will definitely buy Gym Coding's new lectures as soon as they are released. I've already purchased the Next.js and React courses as well. I would be grateful if you continue to create more lectures like this in the future!

View original review

And right now, we are having a 25% discount on all courses to celebrate reaching 5,000 students! This discount is only valid until midnight tonight. Many people contacted me saying they missed the previous discount, so I'm making sure to let you know this time.

👉Enroll now at the discounted price

Thank you! 🙇‍♂

Hello, I'm GymCoding!

While listening to the lectures, there will be times when you have thoughts like this.

"Why don't I understand this?" "It seems like everyone else is following along just fine..."

I wanted to share something helpful for those of you feeling this way, so I have updated a new mindset bonus lecture!

This lecture is not about new features or specifications, but about the best way to take the course.

👉 Go to the lecture!

Thank you so much for taking my course.

🙇‍♂

Hello, I'm GymCoding!

As the project grows, CLAUDE.md grows with it, causing Claude to follow the wrong rules... I'm feeling the limits of trying to manage everything with a single CLAUDE.md in a monorepo...

I've noticed many people have been sharing these concerns lately. So, I've put together a proper explanation in this additional lecture!

This lecture is not just a tip for splitting CLAUDE.md into multiple files. It is a proven strategy that allows Claude to automatically read manuals only when working on a specific folder by dividing them accordingly.

What is covered in this lecture

• The core principle of sub-CLAUDE.md — a structure that automatically loads only when working in that specific folder

• Umbraco CMS Real-world Case Study — How to manage large-scale projects with 23 CLAUDE.md files

• Braintree/PayPal Real-world Case Study — 26 CLAUDE.md Operation Patterns by Payment Feature

• .claude/rules/ vs sub-directory CLAUDE.md — Comparison table on when to use which

• File Size Guidelines — The 30-line root CLAUDE.md case study from CopilotKit (29K ⭐)

The core of this lecture is not about reducing rules, but how to make only the rules of the folder you are currently working in visible to Claude!

👉Go to the lecture!

😊 To those currently taking the course

Existing students can take this additional lecture immediately at no extra cost!

If the lecture was helpful, a single line of review would be a huge help. If you haven't left a review yet, I would appreciate it if you could leave even a short one! 🙏

👉Write a course review

🎯 For those who haven't taken the course yet

We are now in an era where the difference in skill is determined not by whether you use AI coding tools, but by how well you use them.

Within just 4 months of its release, more than 4,500 people are taking the course, including not only developers but also a wide range of individuals such as marketers, data analysts, students, and non-developers.

Recent Reviews

This is just insaneThere are so many things I didn't know. Honestly, there's a lot to study, but the instructor explains it so easily and it's very useful. Highly recommended, for real.

To celebrate surpassing 4,000 students within just 4 months of launch, all Gym Coding courses are currently 25% off. This is the maximum discount rate a knowledge sharer can set. It runs only until 4/6 (Mon), so don't miss out!

👉Enroll now at a discounted price

Thank you! 🙇‍♂~~!!