Snap Kit is being viewed as a direct attack at rival social media platform Facebook, allowing Snapchat users to sync with other apps and post information from elsewhere directly into the Snapchat app.
The feature will also allow users to export their bitmoji, posting their personalised caricatures in other apps, with dating app Tinder announced as one of the launch partners.
Snap Kit will include a Creative Kit feature allowing apps to create personalised filters, stickers and lenses that users can share on Snapchat, similar to an earlier integration with Uber.
For example, food delivery service Postmates will allow users to put an ETA for their delivery onto a picture - so their friends know when the food is arriving.
And in an even more aggressive move against the likes of Google and Facebook, the Login Kit aspect of the feature is designed to protect privacy.
Users who login to third party apps using their Snapchat account will only share their snapchat username and, if they choose to, their bitmoji.
All other personal details, contact lists and data profiling will remain with Snapchat. If the login is not used for 90 days, the connection will be deleted.
Jacob Andreou, a Snap vice-president, told the Guardian newspaper: "Privacy and security have really been at the centre of everything we've done through out the lifetime of the company. This isn't even something that's just the product of the recent changes in the climate."
He added the company developed the features because "it didn't look like there were a lot of great options for our users as they use other services".
Snapchat will directly vet any app that applies to sign up with a human approval assessment.
Katherine Tassi, the company's deputy general counsel, said: "We're building privacy into the design of these developer toolkits from the start."