# Webhooks and Forward-Only Data

> For the complete documentation index, see [llms.txt](https://ghost.supermanservices.ca/llms.txt).

Why some sources have no past, and what that means for your reports.

Section: Data Availability. Web version: https://ghost.supermanservices.ca/help/webhooks-and-forward-only-data

A webhook is a message a tool sends Ghost when something happens. It is the fastest way to receive data and it has one consequence that matters: there is nothing to send about events that happened before the webhook existed.

A source like that is **forward-only**. Ghost labels it as such rather than leaving you to notice the hole.

## What it means in practice
- Pages covering dates before the connection will be empty for that source, permanently.
- Totals for earlier periods are not wrong; they are incomplete, and Ghost says so on the page.
- A date range that straddles the connection date mixes a partial period with a complete one. Compare like with like.

## What to do about it
Nothing, usually. The history fills in from the connection date forward, and after a few weeks the forward-only source is the complete one. Where a historical import is possible for the same kind of data through a different tool, Ghost's setup for that source says so.