> For the complete documentation index, see [llms.txt](https://en.help.firstline.cc/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://en.help.firstline.cc/developer.md).

# Developer documentation

- [API documentation](https://en.help.firstline.cc/developer/api.md)
- [Request method description](https://en.help.firstline.cc/developer/api/request-methods.md)
- [Response object data](https://en.help.firstline.cc/developer/api/response-object.md)
- [Customer](https://en.help.firstline.cc/developer/api/contact.md)
- [Customer tags](https://en.help.firstline.cc/developer/api/contact-tag.md)
- [Company](https://en.help.firstline.cc/developer/api/company.md)
- [Customer import schedules](https://en.help.firstline.cc/developer/api/contact-import-task.md): You can add related schedules by specifying an existing "customer import template". The schedule will import according to the specified time, file, and other information. To avoid data conflicts at the same time, if there are schedules in the same time slot, the system will execute the import according to the schedule.
- [Customer custom field import schedules](https://en.help.firstline.cc/developer/api/contact-import-table-task.md): You can add related schedules by specifying an existing "customer custom field import template". The schedule will import according to the specified time, file, and other information. To avoid data conflicts at the same time, if there are schedules in the same time slot, the system will execute the import according to the schedule.
- [Custom field main categories](https://en.help.firstline.cc/developer/api/custom-field-category.md)
- [Custom fields](https://en.help.firstline.cc/developer/api/custom-field.md): Given different industries or different business logics, data requirements will inevitably vary. Fixed form formats on the market are hard to meet everyone's needs, so FIRST LINE lets users create the data they need through custom fields.
- [Custom forms](https://en.help.firstline.cc/developer/api/custom-table.md)
- [Phone number](https://en.help.firstline.cc/developer/api/phone.md)
- [Country, city, and region](https://en.help.firstline.cc/developer/api/country-city.md)
- [Address](https://en.help.firstline.cc/developer/api/address.md)
- [Email](https://en.help.firstline.cc/developer/api/dian-zi-xin-xiang.md)
- [Ticket](https://en.help.firstline.cc/developer/api/gong-chan.md)
- [Service records](https://en.help.firstline.cc/developer/api/service-log.md)
- [Satisfaction survey](https://en.help.firstline.cc/developer/api/man-yi-du-diao-cha.md)
- [Products](https://en.help.firstline.cc/developer/api/product.md)
- [Orders](https://en.help.firstline.cc/developer/api/contact-order.md)
- [Order items](https://en.help.firstline.cc/developer/api/contact-order-item.md)
- [Knowledge base](https://en.help.firstline.cc/developer/api/knowledge-base.md)
- [Advanced](https://en.help.firstline.cc/developer/api/advanced.md)
- [Send message](https://en.help.firstline.cc/developer/api/advanced/send-message.md)
- [Send message via PUSH API](https://en.help.firstline.cc/developer/api/advanced/send-message/push-message.md)
- [Get Text-Call ID via hash](https://en.help.firstline.cc/developer/api/advanced/restore-text-call-id.md)
- [Send message via Text Call ID](https://en.help.firstline.cc/developer/api/advanced/send-message-via-text-call-id.md)
- [Headless Conversation API](https://en.help.firstline.cc/developer/api/advanced/headless-conversation-api.md): Use the Headless Conversation API to send customer messages from your company’s own systems, receive replies, and handle conversation events.
- [Live chat JavaScript API](https://en.help.firstline.cc/developer/live-chat-javascript-api.md)