I use Google AdSense to earn ad revenue from my blogs. One day I was looking at the dashboard and noticed an unfamiliar line of yellow text next to one of my two blogs.
“ads.txt status: Not found.”
The other blog was green: Authorized. Same person, same account, two blogs — so why was only one of them flagged? And what was ads.txt in the first place?
Honestly, I did not understand a single part of it. This is the record of how I cleared that yellow warning together with my AI partner Kuro (Claude).
So what is ads.txt, anyway?
Since I had no idea, I just asked Kuro plainly: “Where is this even happening?”
Boiled down, the answer was this. ads.txt is a small text file that proves “the ad space on this site really is managed by the owner of this AdSense account.” It exists to prevent ad fraud — people impersonating a site owner to sell someone else’s ad inventory — and Google asks publishers to put one in place.
In other words, it is like a name tag you pin to your blog. By writing your own name on the tag, you prove that the ad space belongs to you. Without it, Google cannot confirm who the owner is, so the status stays unknown.
That was all it was. The green blog had a name tag on it. The yellow one did not. Once I understood the reason, it stopped being scary.
“I definitely did this before” — but I could not remember how
There was one problem. The blog that showed as Authorized must have had that name tag put there by me at some point in the past, while talking things through with Kuro. But I had absolutely no memory of how I did it.
So I asked: “Could you look back through our old chats?” Kuro searched our previous conversations, but the actual steps were not clearly recorded anywhere.
Then Kuro said this:
You don’t need to remember the steps. If we do it together now, we get the same result. And since your server is Xserver, there is an easier and more reliable way to do it.
“You don’t need to remember — let’s just do it now.” That one line is exactly the sort of moment that helps me most when I work with an AI. No lecture about my past mistakes or my bad memory. Just a calm light pointed at the next step.
Xserver had a dedicated screen for it
Following Kuro’s instructions, I opened the Xserver control panel — Xserver is the Japanese hosting service my blogs run on — and looked under the “Domain” menu for an item called ads.txt settings.
This is the convenient part. Xserver provides a dedicated screen just for placing ads.txt. You do not have to upload a file by hand; you only type the text into that screen. For a beginner like me, that is a real relief.
And the moment the screen opened, the answer was obvious at a glance. The row for the Authorized blog had a setting in it. The row for the blog with the yellow warning said: “There is currently no ads.txt setting.”
So the blog marked unknown had simply never had a name tag on it. The cause was clear.
The contents can be identical on both blogs
That raised another question for me. “Should the contents of ads.txt be the same for both blogs?” They are separate blogs, so I assumed each one needed its own version.
Kuro’s answer was unambiguous:
They should be the same — in fact, identical is the correct answer. The publisher ID written in ads.txt (the number starting with pub-) is not a per-site number. It is the number of your AdSense account.
The name tag comparison made this click too. The name you write on the tag is your own name, no matter which blog you pin it to. So not a single character changes. All I had to do was copy the one line already sitting in the Authorized blog and paste it into the other one.
Concretely, it is a single line in this shape (the number part gets replaced with your own account’s):
google.com, pub-XXXXXXXXXXXXXXXX, DIRECT, f08c47fec0942fa0
The f08c47fec0942fa0 at the end is a fixed value that is the same for everyone; only the pub- number is yours. Copying the contents of the Authorized blog exactly meant there was no way to get it wrong.
Paste it, check it, then just wait
I clicked the “Direct edit” button on the blog with the warning, pasted the copied line, and saved. That was the whole job. Just to be safe, I also opened my blog’s URL + /ads.txt in a browser and confirmed that the line I had just pasted showed up there.
Then Kuro told me something important before I could worry about it:
Even after you install it, the “unknown” in the AdSense dashboard will not turn green immediately. It can take a few days to about a week for Google to come and read the file. After you set it, all you have to do is wait for the display to change. No need to rush — leaving it alone is fine.
Being told this in advance is genuinely valuable. If I had not known, I would have looked the next day, thought “it’s still unknown, did I fail?”, started fiddling with things I did not need to touch, and probably broken something. Just hearing “waiting is the right move right now” lets me take my hands off the keyboard with peace of mind.
Not understanding, and moving forward anyway
Looking back, there was almost nothing about this task that I understood at the start. Not what ads.txt is, not why only one blog was flagged, not whether the contents could be the same. I began from complete ignorance on every point.
Even so, I asked Kuro about the things I did not know, one at a time, moved my hands the way I was told, and at some point it was simply solved. I think this is what working with an AI actually means. You do not wait until you understand everything before you act. You have someone show you where you are standing and which way to step next, and then you take that step yourself.
From “where is this even happening?” to pinning on one name tag. On my own, I am fairly sure I would have pretended I never saw that yellow “unknown” and quietly closed the screen.
If you are still at the stage before all this, I wrote about what I got ready in preparing for an AdSense application, and about what I did when the answer came back as a rejection in how to ask AI after an AdSense rejection.
