# 03. Feeds and Merged Feeds

This page is a quick navigator for feed topics.

## Recommended order

1. Configure feed source and MLAT behavior.
2. Configure merged feeds.
3. Apply feed filter rules last.

Detailed pages:
1. [09. Feeds Smart Ports & MLAT](https://docs.vrsx.app/books/vrs-x-operators-handbook/page/09-feeds-smart-ports-and-mlat)
2. [10. Feed Filter](https://docs.vrsx.app/books/vrs-x-operators-handbook/page/10-feed-filter)
3. [11. Merged Feeds](https://docs.vrsx.app/books/vrs-x-operators-handbook/page/11-merged-feeds)

## Common issue: selected feed still shows too much

Symptom: selecting a specific feed still shows aircraft from other feeds.

Checklist:
1. Verify `feedId` mapping in output data.
2. Verify frontend sends the correct `feed` parameter.
3. Compare `All feeds` vs single feed for the same bbox.
4. Repeat test on a second feed for the same user.
5. Remember there is a short stability window: aircraft recently seen by selected feed can remain visible briefly to reduce flicker.
6. For merged feeds, filtering remains anchored to selected feed ID (no automatic expansion to all merged sources).