[Latest Claude Opus 5] 10 Changes and Evolution Points of Opus 5 That Went Viral on X [Latest] AI Side Hustle/Side Business/ClaudeCode/CodeX/ChatGPT/Gemini/Monetization/Generative AI/Personal Development/Apps

Introduction

Hello, this is AI Kawaki.

In this post, I will summarize the Claude Opus 5 posts that have been a major topic on X.

This is not just a new model introduction; here are the points you should look at.

This time, I will introduce 10 points.

Table of Contents

1. Claude Code's system prompt has been reduced by about 80%

2. Opus 5 has become significantly more resistant to prompt injection

3. Spreadsheet and slide creation have reached consultant-level quality

4. Ability to handle unknown problems has greatly improved in ARC-AGI-3

5. Performance close to Fable level is now available at about half the cost

6. Using old workflows as-is can actually make it harder to handle

7. It has become a candidate for the default model for daily use

8. It is less likely to be stopped by safety controls

9. One-shot generation of 3D expressions has become quite strong

10. It is clearly better than Opus 4.8, but its role is different from Fable

1. Claude Code's system prompt has been reduced by about 80%

URL:

Posted: July 25, 2026
Likes: Approx. 15K
Author: Thariq

In this post, the Claude Code team explains that they cut the Claude Code system prompt by about 80% for the new Claude 5 generation models.

This is quite significant.

With previous models, it was necessary to write a massive amount of detailed prohibitions, precautions, procedures, and exception handling to strictly guide the model.

However, with the Opus 5 generation, the model's own judgment has improved, making excessive instructions more of a hindrance.

This is quite important for those who use Claude Code.

If you are using it for a side hustle or personal development, rather than increasing CLAUDE.md or skill files, cutting old rules might be more effective.

Especially for those who have AI build apps, detailed instructions written in the past remain.

From now on,

It seems the trend is shifting in that direction.

2. Opus 5 has become significantly stronger against prompt injection

URL:

Posted: July 25, 2026
Likes: Approx. 6K
Author: Boris Cherny

In this post, it is explained that Opus 5 is the most prompt-injection-resistant model in Anthropic's history.

Prompt injection is an attack where malicious instructions are slipped into web pages, GitHub Issues, documents, emails, etc., that the AI reads.

For example, when an AI agent reads a web page,

is a case where it reads such a command.

In previous agent operations, this was quite dangerous.

It is explained that with Opus 5, the combination of the model's own resilience, prompt injection detection, and Claude Code's Auto Mode has significantly reduced the success rate of attacks.

This is also important from a side hustle perspective.

This is because what will grow in AI side hustles from now on is not just chat, but

that is why.

The changes in Opus 5 are an evolution in the direction of making AI agents easier to use commercially.

3. Spreadsheet and slide creation have approached consultant-level quality

URL:

Posted on: July 25, 2026
Likes: Approx. 4K
Posted by: Alex Albert

In this post, it is introduced that Opus 5 has become able to create spreadsheets and slide materials to a very high standard .

The point is not just that it can now create tables.

Previous AI could tidy up the appearance of spreadsheets and slide creations, but it was poor at creating the meaning of numbers, comparison axes, and the persuasiveness of the materials.

In Opus 5, that has evolved significantly.

This is very compatible with AI side hustles.

If Japanese people were to imitate this, they could repurpose it for:

It can be applied to these areas.

Especially when presenting to companies, it is easier to increase the unit price with tables, slides, and analysis included than with just text.

4. Ability to handle unknown problems has greatly improved with ARC-AGI-3

URL:

Posted: July 25, 2026
Likes: Approx. 3K
Author: François Chollet

In this post, it is introduced that Opus 5 recorded 30% on ARC-AGI-3, reaching a new state-of-the-art level .

ARC-AGI-3 is an evaluation that measures how well a model can handle problems it has never seen before.

The fact that it improved here suggests that its ability to think by looking at unknown situations has increased, rather than just rote memorization or template responses.

Previous models were strong at common problems, patterns they had seen before, and tasks that could be found via search, but they tended to break down when the format changed slightly.

This is what you should pay attention to with Opus 5.

If you are using it for a side hustle, it is better suited for the following than simple article generation:

than for simple article generation.

5. Performance close to Fable class is now available at half the price

URL:

Posted: July 25, 2026
Likes: Approx. 2K
Author: Pankaj Kumar

This post summarizes that Opus 5 offers intelligence close to Fable 5 class at a cheaper price .

The post introduces that the API price for Opus 5 is the same as Opus 4.8, significantly cheaper than Fable 5, and that it has produced strong results across multiple benchmarks.

What is particularly important is the cost rather than the performance itself.

In an AI side hustle, it is not enough for the model to just be smart.

The change in Opus 5 is that it has the potential to partially replace Fable-level tasks at a lower cost.

If you are thinking about a side hustle,

in these areas, it becomes easier to generate profit margins than by using Fable regularly.

6. Using old workflows as-is actually makes it harder to handle

URL:

Posted: July 25, 2026
Likes: Approx. 2K
Author: Dan Shipper

In this post, the author shares their impressions of actually using Opus 5, stating that while it was difficult to handle at first, it improved after they removed existing skills and plugins.

This is quite realistic.

When a new model is released, people usually try it by putting it directly into their existing environment.

However, in the case of Opus 5, the rules accumulated for older models can sometimes get in the way.

In other words,

This is the major change this time.

If you are building a Claude Code environment as a side hustle, instead of just distributing configuration files, you can offer services like:

You can turn these into services.

Opus 5 is a model where cleaning up prompts is more valuable than adding prompts.

7. It has become a candidate for the default model for daily use

URL:

Posted: July 25, 2026
Likes: Approx. 1K
Author: Matt Shumer

This post states that Opus 5 has performance close to Fable, has evolved significantly from Opus 4.8, and is likely to become the default model for many use cases.

What is important here is the perspective of it being a strong model you can use every day rather than just the strongest model.

Previously, it was necessary to separate tasks, such as using Fable for difficult work and Opus 4.8 for everyday use.

However, with Opus 5 becoming significantly stronger, there is a possibility that many daily tasks can be consolidated into Opus 5.

If you are using it for a side hustle, this is quite significant.

Instead of worrying about which model to use every time,

you can fix your workflow like this.

8. Less likely to be stopped by safety controls

URL:

Posted: July 25, 2026
Likes: Approx. 1K
Author: Nathan Lambert

This post introduces Opus 5, touching on the scale and improvement speed of reinforcement learning, and noting that the intervention of safety classifiers is significantly less than in Fable 5.

This is also very important in practical work.

AI models can sometimes be difficult to use if they are only highly safe. Even in normal development work or research, if they stop excessively, you cannot get work done.

Opus 5 may not only have become smarter than before, but also less likely to stop unnecessarily.

If you are using it for a side hustle,

It works for that.

Especially when using it with Claude Code, just reducing strange refusals or excessive confirmations mid-process significantly changes work efficiency.

9. One-shot generation of 3D expressions has become much stronger

URL:

Posted: July 24, 2026
Likes: Approx. 1K
Author: Chetaslua

This post introduces the results of generating 3D expressions with Opus 5, noting a level of detail never seen before.

At the same time, it touches on the caveat that token consumption is quite heavy.

This part is interesting.

Opus 5 is not just strong at text and code, but also quite strong at Three.js and web-based visual expressions.

Previous models could create 3D-like things, but the density of details and visual appeal tended to be lacking.

With Opus 5, the visual persuasiveness has increased significantly.

If you use it for a side hustle, it is suitable for:

.

However, if token consumption is heavy, you need to be selective about where you use it for commercialization.

10. Clearly better than Opus 4.8, but its role is different from Fable

URL:

Posted: July 25, 2026
Likes: 500+
Author: Bindu Reddy

This post offers a calm perspective on Opus 5, noting that while it is better than Opus 4.8, it is slightly different from the overwhelming inspiration of Fable 5.

Specifically, while the cost for similar tasks may be slightly higher than Opus 4.8, the performance has clearly improved.

The important thing here is not to view Opus 5 as an all-purpose, ultimate model, but to view it in terms of its role.

This division is quite realistic.

If you are using it for a side hustle, it is more cost-effective to run the majority of tasks with Opus 5 and only send the parts where you get stuck to Fable, rather than using Fable every time.

Especially in AI side hustles, in order to keep profits, it is important to design your workflow as follows:

This design is essential.

I also tweet on X every day! Please be sure to follow me!

I started a Substack!

I will deliver the latest AI information, useful AI tools, and tips for AI side hustles directly to your email for free.

Information about Membership

Thank you for your continued support.
I currently run a membership program where I deliver weekly member-only articles that lead to monetization, the reality of AI side hustles, and exclusive columns.
If you are interested, please join us.

Click here for related articles ↓

Next time, I will continue to share ideas on AI image generation and prompt design.
See you in the next article.