The 403 That Had Nothing to Do With Our Credentials

This is the first post in a series I am starting without much ceremony, because the premise does not need any. I run a real engineering pipeline through Claude Code most days — forms, content, infrastructure, the actual plumbing behind five live websites — and some of what happens in those sessions is worth writing down. Not the polished version. The actual sequence: wrong guess, real fix, wrong again, right.

No staged demos. If a session takes three attempts to find the cause, this series says it took three.

Here is the first one.

The request that should have worked

We needed to read data out of our CRM — a straightforward authenticated API call. Username and password, both correct, sent as HTTP Basic Auth to an endpoint we had used before.

It came back 403.

The body named the problem plainly enough, which is unusual and turned out to matter: Error 1010: Access denied, with a link to Cloudflare’s own documentation. Not a generic “unauthorized”. Not “invalid credentials”. A different kind of rejection, from a different layer, and the message said so if you read it rather than assumed it.

The first fix was real, and it was not the fix

The credentials file had the API host stored without a scheme — mautic.example.com.au, no https:// in front of it. That is a genuine bug: a bare hostname fed to a URL-opening function fails, sometimes with a confusing error that looks unrelated to the actual problem.

We fixed it. Added the scheme. Ran the request again.

Same 403. Same Error 1010.

This is worth sitting with for a second, because it is the point where a less careful session stops. We found a real defect, fixed it correctly, and the symptom did not change. That is good evidence the defect we found was real but not the one causing the failure in front of us — two separate things can both be true and wrong at once, and the honest move is to say so rather than count the unrelated fix as the win and move on.

The actual cause had nothing to do with authentication

Cloudflare’s 1010 response is specific: the request was blocked by a rule that evaluates something about the request itself, independent of whether the credentials in it are valid. In this case, the rejected signal was the HTTP client’s default identity string — the generic value a programming language’s standard library sends when nothing overrides it.

The fix was one line: set a real, named value for that field before sending the request.

The very same request — same host, same credentials, same endpoint — returned 200 immediately. Fifty-one forms. Fifty-one thousand, eight hundred and sixty-six contacts. Nothing about the authentication had ever been wrong.

Why the error message did not say this directly

It did, actually — more than most errors do. Error 1010: Access denied is a specific code, not a bare 403, and it links to a page that explains exactly this class of block. The information was there.

What it does not do is distinguish “your credentials are wrong” from “something about how you are asking is wrong” in the three characters most people actually read — the status code. Both arrive as 403 at the point where a script decides whether to retry, log, or give up, and most retry logic is written against the status code, not the body.

The general shape, not specific to this one API: a rejection at the edge of a system and a rejection from the system’s own logic can look identical from the outside, and the two need completely different fixes. One is about who you are. The other is about what you look like while asking. Conflating them means fixing the wrong thing confidently, the way the scheme fix above was a real improvement that fixed nothing.

What changed afterward

Every script in this pipeline that talks to that API now sends an explicit, named value in that identity field — not because it is required by the API’s own authentication, but because the infrastructure in front of it is making a judgement based on it, and a default value does not give that judgement anything to work with.

It also went into the running notes for this project: when a request is correctly authenticated and still rejected, check whether the rejection is coming from the destination or from something sitting in front of it, before touching the credentials again.

Why this is post one

Nothing about this incident is dramatic. That is roughly the point. The useful detail in a real debugging session is rarely the eventual fix — it is the wrong turn that came first, and why it looked reasonable at the time. A write-up that only shows the one-line fix teaches “add this header.” A write-up that shows the scheme fix first, failing, teaches something that transfers: two things can be broken, fixing one does not mean you found the right one, and a status code is not the whole error.

More of these as they happen.

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Ash Ganda is the founder of Ganda Tech Services. This series documents real sessions building and operating the engineering pipeline behind Cosmos Web Tech, Cloud Geeks and Awesome Apps through Claude Code.