Publication Dates Corrected on Four Early AgentNotebook Tutorials

Four tutorials published in the first week of agentnotebook.dev carried a stored publication timestamp that predated the site itself. The timestamps have been corrected. No tutorial text, code sample or source citation changed.

What was wrong

agentnotebook.dev was registered on June 16, 2026 at 15:24:16 UTC. That is a matter of public record in the domain's RDAP registration event, which anyone can retrieve without credentials. Four tutorials in the launch set were stamped with published_at values between May 28, 2026 and June 16, 2026 at 09:00 UTC, so all four claimed a publication date at a moment when the domain did not resolve.

Those values were not typos. They came out of the initial content import, which wrote a back-dated schedule onto a batch of records created on June 18, 2026. The stamps then propagated into two crawler-visible surfaces: the datePublished field of the Article JSON-LD block on each tutorial page, and the rendered byline date.

The corrections

Each corrected timestamp sits after the domain's registration, preserves the original relative ordering of the four tutorials, and falls inside the window in which the records actually existed. Each of the four pages now carries a dated editorial note saying the same thing at the foot of the article.

How the check works, if you want to run it yourself

The test is two lookups and a comparison, and it needs nothing but a browser.

1. Fetch the domain's registration event: https://rdap.org/domain/agentnotebook.dev, then read the entry in events where eventAction is registration. The RDAP protocol is specified in RFC 9083 (IETF, 2021).
2. Read the datePublished value out of the Article JSON-LD on any article page. The field is defined by schema.org/datePublished and is the value Google reads for article freshness, per its Article structured data documentation (2026).
3. If the first value is later than the second, the page is claiming a date that cannot be true.

We now run this as a standing check on every article, on every property we publish, rather than as a one-off.

Limitations

The corrected dates are not recovered from a publication log, because no publication log exists for the import. They are the earliest defensible timestamps consistent with three constraints: after the domain existed, within the window the records were created, and in the original order. That is a narrower claim than "this is the day it went up", and it is the strongest claim the surviving evidence supports.

This notice covers published_at only for these four tutorials. It does not restate or revise any technical content in them. Where a tutorial's own text names a date for a model release, an SDK version or a benchmark, that date was sourced separately and is unaffected by this correction.