> For the complete documentation index, see [llms.txt](https://docs.httpsms.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.httpsms.com/features.md).

# Features

- [Phone API Keys](https://docs.httpsms.com/features/phone-api-keys.md): Manage multiple Android phones under one httpSMS account by creating unique API keys per phone.
- [Control SMS Send Rate](https://docs.httpsms.com/features/control-sms-send-rate.md): Whether you're sending hundreds or thousands of messages, our intelligent queue system ensures reliable delivery at your chosen pace.
- [Scheduling SMS Messages](https://docs.httpsms.com/features/scheduling-sms-messages.md): Complete guide on scheduling SMS messages to be sent in the future on the httpSMS platform
- [Outgoing Message Queue](https://docs.httpsms.com/features/outgoing-message-queue.md): Complete guide on how httpSMS queues outgoing SMS messages for reliable delivery, including rate-based dispatch, scheduled sending, and send schedule windows.