How to build post tagging in Bubble

You create post tagging in Bubble by making a Tag data type and storing a list of Tags inside each Post. When a user picks tags (from a repeating group, a search box, or an input that creates new tags), you simply “add” or “remove” Tag things to that list. Bubble automatically handles the many‑to‑many relationship, so a Tag can belong to many Posts and a Post can have many Tags.

Data Setup

Create two data types:

• Post
  • Field: tags (type: Tag, list: yes)
• Tag
  • Field: name (text)

This structure lets each Post store multiple Tags, and any Tag can be reused on many Posts.

Tag Selection UI

Most beginners use a Repeating Group listing all Tags. Each cell has a button saying “Add” or “Remove”. When clicking, run a workflow that updates the Post’s tag list.

• If the Post does not contain this Tag → add it.
• If it already contains this Tag → remove it.

Make changes to Post
tags add Current cell's Tag

Make changes to Post
tags remove Current cell's Tag

Creating New Tags On The Fly

If the user types a tag name that doesn’t exist yet, run:

• Create a new Tag (name = Input's value)
• Make changes to Post → tags add Result of step 1

Showing Posts By Tag

To filter posts by a chosen tag, set the Repeating Group’s data source:

Search for Posts
Constraint: tags contains Dropdown's value

This finds all posts linked to that Tag.

Privacy Rules

In Privacy, allow users to read Tag names and read Posts if they are allowed to view posts normally. Tagging doesn’t need special extra rules unless tags are sensitive.

That’s the entire core pattern: Tags are their own data type, Posts store a list of them, and workflows simply add or remove Tag things. This is the standard, scalable way to build tagging in Bubble.