Notes on my first very simple agentic coding experiment with Google Jules which was successful

Summary

With my recent Jio 4G mobile recharge, I got a free 18 month offer for Google AI Pro which I accepted. Google AI Pro includes Google Jules being used as a coding agent. As a trial, for a very simple Astro landing page site, I gave Google Jules this prompt:

I have a dummy Indian rural school website data in this Astro app. I would like the data in Features and About sections to be changed to a hypothetical (sample) rural Indian school (primary & secondary level/K-12).

It did the job well! While the programming task I asked Google Jules to do was very simple, it had to go through all the steps of:

Studying project code (multiple files)
Modifying the correct components with suitable generated text for Features and About sections which earlier had dummy content
Building the app
Running it and verifying the output
Creating a GitHub PR request

After verifying the changes myself on my PC, I deployed the very simple site with changes at https://ravisiyer.github.io/ssw-astroghp/.

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Details

04:28, 24 February 2026

As part of my recent Jio 4G mobile recharge, I got a free offer for Google AI Pro plan which I accepted.

https://www.jio.com/google-gemini-offer/ : "Eligible users can enjoy full 18 months of Google AI Pro subscription from activation, (strike-through for Rs35,100) free." The link says it is for 5G users but I got the offer even though I am on 4G.

Jules is one of the features of the Google AI Pro plan. https://jules.google/docs/: "Jules is an experimental coding agent that helps you fix bugs, add documentation, and build new features. It integrates with GitHub, understands your codebase, and works autonomously — so you can move on while it handles the task."

I am trying it out. It took some time to get the full repo list from my GitHub a/c (a repo I wanted to work on seemed to get listed in Jules only after 15 minutes to half an hour after giving GitHub access).

It seems to be an agentic coding system/setup like Claude Code.

Quite simple prompt I specified for a private repo (ssw-astro):

I have a dummy Indian rural school website data in this Astro app. I would like the data in Features and About sections to be changed to a hypothetical (sample) rural Indian school (primary & secondary level/K-12).

Note that Jules works asynchronously. So after I gave the above prompt I moved to some other activity.

Within perhaps 10 to 15 minutes, I got a notification that Jules has prepared a plan.

After I approved the plan, within a short time (perhaps 15 minutes or so), I got a notificaton that Jules has done the work!

Jules showed me modified code in two astro components, Jules reported that it:

"Ran npm install && npm run build.

Build was successful.

Updated verification/about_section.png and verification/verify_changes.py

Updated verification/about_section.png verification/features_section.png and verification/verify_changes.py"

[These seem to involve Playwright testing tool. If so, that's awesome!]

It said, "I've inspected the frontend changes visually:" and showed me 2 screenshots of site with changes.

It said, "Running code review" and gave details of what it did for that.

It created a PR which it said is "Ready for review". [It also showed Time: 7 mins. Does that mean it did the work in 7 mins? Probably.]

There was a View PR button which I clicked. It took me to GitHub. It had added the changes in a new branch and I had the option to merge it to main.

I first wanted to pull that branch to my local repo.

ssw-astro> git fetch origin

ssw-astro> git branch

* main

ssw-astro> git branch -r

origin/main

origin/update-about-and-features-content-468962095223529504

ssw-astro> git checkout update-about-and-features-content-468962095223529504

branch 'update-about-and-features-content-468962095223529504' set up to track 'origin/update-about-and-features-content-468962095223529504'.

Switched to a new branch 'update-about-and-features-content-468962095223529504'

ssw-astro>

Me: Now should I do a git pull to pull the remote branch data to my local repo?

GSAI (Google Search AI): Actually, no—you are already good to go!

When you ran git checkout update-about-and-features-content-468962095223529504, Git performed a "guess" and found that the branch existed on your remote. Because of this, it automatically:

Created a local branch with that exact name.

Linked it to track the remote branch (origin).

Downloaded the files and commit history from the remote to your local machine.

Your terminal confirmation "Switched to a new branch..." means your local working directory now matches exactly what Jules created on the server.

==============

I checked and yes, my local VSCode editor showed me the changes made by Jules!

npm run dev

The app ran and I could see the added website sections!

Astonishing! This is my first agentic coding (system) experience. I am dazzled that I could get this via a free offer from Jio (for 18 months) for my usual Rs.666 70 days 1.5 GB/day 4G mobile recharge plan.

I saw that I have the Playwright .py verification script and associated screenshots as well. Wow! Testing is the hard thing in such stuff. Will check out the test script in detail later. (Don't know python but will figure that out to extent used in script - perhaps will just ask an AI tool to explain it to me).

Me: The changes are good. It works on my local PC. I am ready to merge the PR. Shall I do the merge PR on GitHub itself and then pull in changes from remote to local repo?

GSAI: Yes, merging the Pull Request (PR) directly on GitHub is the standard and cleanest way to proceed.

Since you have already verified the changes locally, follow this workflow to finalize everything:

1. Merge on GitHub

Navigate to your repository on GitHub.
Open the PR created by Jules.
Click the green Merge pull request button (or Squash and merge if you want to combine Jules's commits into one).
Confirm the merge.
Optional: Delete the remote branch on GitHub using the button provided after merging to keep things tidy.

2. Update Your Local Repo

Once the PR is merged into your main branch (or your default branch) on the remote server, you need to bring those changes down to your local machine:

Switch to your main branch:

git checkout main

Pull the latest changes:

git pull origin main

3. Cleanup Local Branch (Optional)

Since the work is now part of main, you can safely delete the temporary branch Jules created to keep your local environment clean:

git branch -d update-about-and-features-content-468962095223529504

====================

Merged PR on GitHub but did not delete the update-about-and-features-content-468962095223529504 branch.

git checkout main

git pull

That pulled in the update on main branch to local repo.

npm run build:ghp

succeeded

ssw-astro> npm run deploy:ghp

> ssw-astro@0.0.1 deploy:ghp

> npx gh-pages --nojekyll -d dist -r https://github.com/ravisiyer/ssw-astroghp

Published

ssw-astro>

Live site: https://ravisiyer.github.io/ssw-astroghp/ is updated with the changes!

The (very simple) site is showing correctly on both PC and my mobile phone. It is responsive and light/dark mode works as expected.

Hmm. While the programming task I asked Google Jules to do was very simple, it had to go through all the steps of

Studying project code (multiple files)
Modifying the correct components with suitable generated text for Features and About sections

which earlier had dummy content:

"Feature One" "Some description of the first feature." etc.
"This is a dummy About section for your landing page. You can replace this with actual content later."

Building the app
Running it and verifying the output
Creating a GitHub PR request

That's an agentic coding workflow, I presume (I am very new to agentic coding and so may not be getting some terms right).

Wow! Without paying any extra money, I now have an agentic coding system to try out! But Google Jules is experimental as per its own docs: https://jules.google/docs/ . So it may not be in the same class as Claude Code with Opus 4.5/4.6 or Open AI Codex.

It is when I try Jules out with medium complexity programming work that I will get a real feel of how good it is.

For this very simple but still fully agentic coding cycle that I tried out, Jules seems to have done a very effective job. I repeat that I am particularly impressed by its verification. However, I need to study that code to know how thoroughly it did the verification.

While I may have come across Google Jules coding agent in the past, it had not registered in my mind. Claude Code and Codex were the two coding agents that had registered in my mind over the past few weeks/months. Browsed the net and found this May 2025 article (quite old given the pace of AI improvement): Codex, Jules, and Claude Code comparison, https://www.jonatkinson.co.uk/blog/codex-jules-claude-comparison/ which is a good and to-the-point comparison article. He says that (then) Google Jules was a "highly beta" product.

Jules is out of beta!, https://jules.google/docs/changelog/2025-08-06/ , Aug. 2025 says, "Today we are thrilled to announce that Jules is no longer in beta!" ... But, as mentioned earlier, the docs site https://jules.google/docs/ (currently in Feb 2026) says Jules is experimental. So I guess Google Jules cannot be viewed today to be in same class as Claude Code and Open AI Codex. But that might change quickly.

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Ravi S. Iyer: Software Development