Build a Better Edit Tool in Cursor with Custom Agent Modes

Cursor's default inline edit (Cmd+K) has scope limitations, and using the full chat (Cmd+I) for simple refactors can be overly conversational. This lesson demonstrates how to create a custom chat mode specifically configured for direct code editing. By setting up a dedicated mode with custom instructions and a keybinding (like Cmd+E), you can bypass unnecessary AI chatter and apply targeted, file-aware modifications more efficiently than standard methods.

Workflow Demonstrated in this Lesson:

Create a "Custom Mode" within Cursor's chat interface.
Assign a name (e.g., "Edit") and a preferred AI model.
Set a dedicated keybinding (e.g., Cmd+E).
Configure allowed tools (enable Edit, disable Run/MCP).
Use "Advanced options" to enable auto-run.
Add "Custom instructions" to prompt the AI for direct edits without explanation.
Trigger the mode with the keybinding on a code selection to perform edits beyond the selection's scope (e.g., hoisting variables).

Key Benefits:

Perform refactors and edits beyond the scope of the initial selection, overcoming Cmd+K limitations.
Achieve a more direct, less "chatty" AI editing experience compared to standard chat (Cmd+I).
Streamline common AI-assisted modifications with a dedicated keybinding.
Gain fine-grained control over the AI's editing behavior using custom instructions.

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Transcript

[00:00] There are many scenarios when you want to select a block of code and you want to edit it like Command-K, but Command-K is only capable of editing code inside of its own selection. So if I wanted to hoist this up to the module scope up here, it just couldn't do it. Now instead, you could press command-I by selecting this, hitting command-I, and opening up agent mode. But agent mode sometimes talks too much when you're just trying to make a simple edit. So what you can do is create a new custom mode.

[00:28] We'll call this edit mode. You can pick your favorite model. I'll click on set default to 4.0 which has a nice combination of speed and smarts. We'll go back by clicking here. We'll give it a key binding by clicking here and command e then click again and then I'm going to turn off run and MCP so we will allow it to edit and check the rest of the code base and for advanced options we'll let it auto run and for custom instructions I'll dictate you are strictly an editing tool do not explain anything avoid all conversation Your only task is to make the requested modifications to the code.

[01:05] Then paste that in. I've yet to find a prompt that avoids all speaking, but most of them can keep this speaking to a minimum. So we'll go ahead and click done and now we can close this out and with any selection we make I can hit command E. So now the entire file is in context, the selected lines are in context, so it has focus, and it's set to our editing mode. So if I dictate extract the values in the array to constants in the module scope, paste that in, hit enter, it'll start generating, and you can see it skipped describing what it's doing and it just invoked the edit tool.

[01:40] And it did add some text after. I'll keep tweaking my prompt to figure out if there's a way to completely mute that, but for now I can accept and this refactor is done. I'll command click to jump up to where these are defined now, and now we have what is essentially a much improved command k that doesn't try to explain anything that's doing, it just makes the edit. So you can jump around and do these quick AI refactors.