Code completion vs Coding agent

Why they differ

Completion offers a few lines at the exact spot being typed; a coding agent plans and changes many files toward a goal.

AI-assisted coding

Greyed-out code that appears as you type, predicting the next line or block so you can accept it with one key.

Formal

A feature that, after each pause in typing, sends the code before and after the editing point to a model trained with fill-in-the-middle and shows the most likely continuation inline; older forms only listed matching names from the project.

In plain English

Like a friend who finishes your sentences as you talk - nod and their ending is yours, or just keep talking and it is forgotten.

In practice

A developer at a Danish web shop types the name of a function that checks phone numbers; before she writes the body, a ten-line version appears in grey and she presses Tab.

Why it matters

Suggestions arrive many times an hour and each takes one key press to accept, so weak or unsafe lines slip in easily unless someone reads them.

Coding agent

AI-assisted coding

An AI that is given a programming task and carries it out itself - reading files, running commands and editing code until done.

Formal

An AI agent whose tools act on a code project - reading and writing files, searching, running shell commands and tests, and using version control - and which loops through plan, act and check steps via tool calling until the task is done or it hands back to a person.

In plain English

Like leaving a carpenter alone in your house with a list of repairs - he gets on with it by himself, but he can also open any cupboard you left unlocked.

In practice

A developer in a municipality asks the agent to add a date filter to the report page of the housing benefit system; it finds the files, makes the change, runs the tests, fixes one failure and opens a change request.

Why it matters

It can do hours of routine work alone, but it runs real commands with the developer's rights, so a mistake or a planted order can delete work, leak keys or push harmful code.

Shared connections

AI coding assistant