What is a coding agent?
A coding agent is an AI agent specialized for development. It reads a codebase and automatically carries out development work across multiple steps, including editing files, running commands, testing, and creating pull requests.
Unlike autocomplete, which just suggests code snippets, it works on a real project and breaks the goal into steps on its own.
How does a coding agent work?
Given a goal (for example, fixing a bug), it finds and reads the relevant files, applies a fix, runs tests or a build to check the result, and repeats the fix if it fails. The execution scaffolding behind this loop is the harness.
As a result, it can push toward a reasonably finished result on its own without a person directing every step.
How do you compare and choose a coding agent?
Products differ a lot in free versus paid plans, supported languages, integrated tools, and the scope of autonomy. You can consult coding benchmarks for performance, but scores and rankings change over time, so it is more accurate to check public leaderboards directly.
Before adopting one, it is a good idea to give it a small task in your own language and project and weigh the quality of the result and the cost together.
How to use a coding agent well
Results improve when you split the work into small units and clearly state what you want and the constraints. Telling the agent about relevant files or rules in advance means it wanders less.
Also, instead of trusting generated code as is, build the habit of checking it with tests and code review. Automation complements review rather than replacing it.