Six takeaways from a contentious online child safety hearing.

The documents, which are being released in full for the first time, were cited in a lawsuit last year by 33 state attorneys general who accused Meta of getting young users hooked on its apps. They contradict statements from company executives, including the head of global safety and the head of Instagram, who testified in congressional hearings on child safety during that period that they prioritized the well-being of their youngest users and would work harder to combat harmful content on their platform.

Mr. Zuckerberg, who will be testifying before Congress on Wednesday for the eighth time, is in the hot seat to defend Meta’s lack of investment in child safety amid rising complaints of toxic and harmful content online, said Senator Richard Blumenthal, Democrat of Connecticut, who released the emails with Senator Marsha Blackburn, Republican of Tennessee.

“The hypocrisy is mind-boggling,” Mr. Blumenthal said in an interview. “We’ve heard time and time again how much they care and are working on this but the documents show a very different picture.”

Meta has created more than 30 tools to help protect teens, and it has a “robust” team overseeing youth well-being, Andy Stone, a Meta spokesman, said in a statement, adding that “these cherry-picked documents do not provide the full context of how the company operates or what decisions were made.”

Included in the emails were Mr. Zuckerberg; the former chief operating officer, Sheryl Sandberg; and Nick Clegg, the president of global affairs, though they didn’t always reply. The emails show senior executives quibbling over budgets and head counts while also acknowledging regulatory threats related to their handling of teenage users.

One incident revealed in the documents was a request by Mr. Clegg in August 2021 for the 45 new staff members. It was rejected and he returned to Mr. Zuckerberg in November with a scaled-down proposal for 32 new hires. It is unclear what Mr. Zuckerberg decided.

Mr. Clegg wrote that the company was failing to meet goals to prevent bullying and harassment and other harmful activities on Instagram and Facebook and warned that global regulators could take action.

He said the investment in staff would enable the company to “stand behind our external narrative of well-being on our apps.”

Before the release of these documents, Mr. Zuckerberg’s plans for the hearing included speaking about the difficulties of being a parent in the digital age, according to a copy of his prepared remarks. He also planned to defend Meta by pointing to the dozens of tools the company had rolled out over the past eight years to give parents more control.

Meta has roughly 40,000 people working on safety and security issues across its apps, according to the prepared testimony, and it has invested more than $20 billion in those efforts since 2016. Nearly a quarter of that investment was spent over the past year. It is unclear how much of the $20 billion is dedicated to child safety.

A major line of questioning on Wednesday is expected to focus on how apps verify users’ ages, since the company bars users younger than 13.

At the hearing, Mr. Zuckerberg plans to suggest that Apple bear the responsibility for verifying ages via its App Store, according to his prepared remarks. He also plans to encourage legislation that will require teenagers to seek parental approval for downloading apps.

Mr. Zuckerberg has long positioned Meta — and the internet writ large — as a place for both good and ill. He has said that his company’s job is to elevate the good while doing its best to mitigate the harms. He also plans to emphasize how the internet can be a positive place for people, including children, according to his prepared remarks.

“They use our apps to feel more connected, informed and entertained, as well as to express themselves, create things and explore their interests,” he plans to say according to his prepared remarks. “Overall, teens tell us this is a positive part of their lives.”