Back in June, Amazon previewed in-skill purchasing (ISP) — a feature that allows voice app developers to charge for digital content — for kid skill experiences in the U.S. Alexa Skills Store. Today, in-skill purchasing for kids skills launched in general availability alongside supporting APIs and parental purchase controls.

“Alexa developers have already created thousands of kid skills that provide fun and educational experiences for families, such as a skill that encourages kids to brush their teeth and one that teaches kids how to run their own lemonade stand business,” wrote Amazon developer BJ Haverkorn in a previous blog post. “With ISP, you can further enrich these kid skill experiences, offering premium content in the form of one-time purchases or subscriptions for families to enjoy across over 100 million Alexa-enabled devices.”

Kids can’t buy premium voice app content willy-nilly, Amazon says. By default, when a child agrees to an upcharge, the primary Amazon account holder will receive an SMS or email requesting that the transaction be approved or denied within 24 hours. If a parent allows it to go through, the kid will gain access to the content they were attempting to purchase. But if the parent chooses to reject the transaction request more than three times within 30 days, offers from the skill will be suppressed for a month, and if they choose to ignore it for more than 24 hours, the request will be canceled altogether.

Parents can optionally allow kids to make purchases in kid skills without approval by disabling notifications in the Alexa companion app (in Settings > Alexa Account > Voice Purchasing > Kid Skills Purchasing). Alternatively, they can opt out from voice purchasing in kid skills — which disables voice discovery of premium content in kid skills — by switching off the feature altogether in the app.

Amazon says that Alexa customers using FreeTime — a service that allows parents to review their kids’ activity, put time limits on their usage, or block songs with explicit lyrics on Amazon Music — won’t receive offers to purchase premium content within skills. As for subscribers to FreeTime Unlimited, a premium offering that adds access to ad-free radio or playlists, alarms from Disney and Nickelodeon characters, and skills from National Geographic, Nickelodeon, and others, they’ll get many of these premium experiences automatically as part of their plan at no additional cost.

On the developer side, a set of three new tools enables in-skill purchasing functionality within kid skills. VoicePurchasing provides the current status of an account holder’s voice purchasing setting in the Alexa App, while InSkillProducts gets information about the specified product (such as the product type and whether it is purchasable by the account). Lastly, InSkillProductsTransactions provides information about transactions, such as if a previous purchase request was denied.

ISP encompasses two types of goods and services: one-time purchases or entitlements, and subscriptions. (Consumables — i.e., content that can be purchased, depleted, and purchased again — aren’t available for kid skills at this time.) Items run the gamut from hints in a trivia app and expansion packs in an adventure game to a monthly subscription and premium features. Developers supply the list of offerings and prices and receive a 70% cut of the list price.

Earlier this year, Alexa brought in-skill purchasing to the U.K., Germany, and Japan and rolled out new tools designed to make it easier for developers to insert ISP. The Alexa Developers Console — the dashboard from which Alexa skills can be created, modified, and deleted semi-autonomously — can now add in-skill purchasing directly to apps, obviating the need to hand-code them via a command-line interface.