As recorded at collection: StepFun (阶跃星辰) Flash Plus, up to 75 days

The Flash Plus promotion on the StepFun Open Platform (阶跃星辰开放平台) provides 15 days upon login and an additional 15 days after the first API call. Inviting a new user earns 15 more days per person, with up to 3 people counted, for an official maximum usage period of 75 days. The 15 yuan in API credits is provided separately from subscription credits. Flash Plus provides 1,600M credits per month, presented as approximately 99 yuan worth of free usage, calculated at 1 yuan per 1M credits.

After logging in to your account and receiving the first 15 days, making the first API call adds 15 days. When a new user you invited registers via the invitation link, 15 days are added per person. The invitation link is displayed as 'AFF ： 阶跃星辰开放平台', but the actual access address is not provided. After applying, you should check the expiration date and promotion credit history in your account.

Monthly credits reset at the end of the month and are not carried over to the next month, and there is guidance not to use them all up at the beginning of the month. If you are subscribed, subscription credits are deducted first and promotion credits are used later. For the first API call, guidance advises avoiding excessively long context and reusing repeated system instructions, tool settings, and documents, and stored input is calculated at 0.35 yuan per 1M. For everyday tasks, use the Flash series, and use Step 5 Preview sparingly for difficult tasks. Inviting from multiple accounts carries risk, so follow the official limit of 3 people, and the promotion rules on the platform page take precedence.