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Build a CLI Tool With an Agent in an Evening

Learn how to build a CLI tool with an agent in an evening by leveraging infinite canvas workspaces and local-first AI coding agents for faster development.

10 min read

The barrier to entry for creating custom internal utilities has dropped significantly due to the rise of autonomous coding assistants. Many developers find that they can build a CLI tool with an agent in an evening, transforming a repetitive manual task into a streamlined command line interface. This process does not require deep expertise in argument parsing or shell scripting. Instead, it relies on coordinating high-level intent with an agent that understands the boilerplate requirements of modern terminals.

Choosing the Right Scope for an Evening Project

When planning a small win project, the selection of the utility is critical. A successful CLI project should solve a specific, narrow problem. If the scope is too broad, the agent may struggle with context window limits or architectural complexity.

Ideal candidates for this type of development include:

  • A log parser that highlights specific error patterns in local files.
  • A wrapper for a third party API to fetch specific metrics or status updates.
  • An automated file renaming utility that uses logic beyond standard regex.
  • A boilerplate generator for your specific team workflow.

Narrowing the scope ensures you finish the core logic within a few hours. This leaves time for testing and refinement, which are often the parts that get neglected in rapid prototyping.

Setting Up Your Development Environment

Modern developer tools have evolved to support this rapid cadence. Traditionally, you would switch between a terminal, a browser for documentation, and a code editor. This context switching is a primary source of friction. Using an infinite canvas workspace allows you to see all these components at once.

In Deska, you can arrange your environment to optimize for agentic interaction. You might place a terminal panel next to a code editor and a browser widget. This layout allows you to watch the agent execute commands while you inspect the generated code in real time. Because Deska is a local-first application, your source code and session data remain on your machine. This is vital when building tools that might interact with sensitive local file systems.

Working With AI Coding Agents

There are several agents available today that can handle the heavy lifting of CLI construction. Each has different strengths, and sometimes running them side by side provides the best results.

AgentCore StrengthIntegration Style
Claude CodeHigh reasoning and file manipulationTerminal based interaction
Codex CLIQuick command generationInline shell completions
OpenCodeOpen source model flexibilityCustomizable panel execution

These agents differ in approach when it comes to how they handle file system permissions and state management. When you use them within agents panels, you get a bird's eye view of how they are constructing your project. You can ask an agent to scaffold a Node.js project using Yargs or a Python project using Typer. The agent handles the mundane tasks of setting up the package.json or requirements.txt while you focus on the business logic.

The Iterative Build Process

Once the project is scaffolded, the evening becomes a series of prompts and tests. Start by describing the primary input and output of the tool.

  1. Initialize the project: Tell the agent to create the directory structure and main entry point.
  2. Define arguments: Specify what flags the CLI needs, such as --verbose or --output.
  3. Implement core logic: Provide the agent with snippets of the logic or ask it to research the API you are interacting with.
  4. Test in situ: Run the generated command in a terminal panel immediately.

If the command fails, you do not need to copy and paste the error. An agent running in a workspace like Deska can often see the command output directly. If you are away from your desk, you can use the mobile app to check the progress of a long running test or a build script via the secure relay.

Managing Context and History

One challenge of building even a small tool is keeping track of what the agent has already done. As the history grows, the agent might forget earlier constraints. This is where agent-threads become useful. By separating the scaffolding phase from the logic implementation phase into different threads, you keep the context clean.

If you encounter a complex bug, you can use ask-deska to help manage your workspace. You can use voice commands or chat to open new panels, search through your notes, or compare two different versions of a file without manual navigation. This keeps your hands on the keyboard or your eyes on the code, maintaining the flow state necessary for a one-evening build.

Refining and Documentation

A CLI tool is only useful if you remember how to use it next week. In the final hour of your project, task the agent with generating a README.md and automated help text. You can use the notes-notebook panel to draft usage examples.

Since Deska allows you to place notes and terminals on the same canvas, you can verify the documentation examples by running them in the adjacent panel. This eliminates the "it worked in my head" problem common in late night coding sessions.

Frequently Asked Questions

build a cli tool with ai agents safely

Safety in local development requires ensuring the agent does not delete files unintentionally. Using a local-first workspace keeps your API keys and source code on your hardware. Always review the commands an agent proposes before allowing execution, especially those involving rm or chmod.

best language for quick cli tools

Python and Node.js are the most common choices because their libraries for argument parsing are mature. Agents perform exceptionally well with these languages due to the high volume of training data. Go is also a strong candidate if you need a single binary for distribution.

how to debug ai generated cli code

The best way to debug is to use a multi panel layout. Keep the source code open in a Monaco based editor panel, the terminal running the tool in another, and the agent chat in a third. This allows you to see the file changes the moment the agent applies them and catch logic errors before they compound.

Starting Your Next Project

Building your own tools provides a sense of agency over your digital environment. Whether you are automating a simple file backup or creating a complex data processor, the combination of autonomous agents and a flexible workspace makes the process accessible.

To start building your own utilities with a suite of AI tools in a unified environment, you can download the free desktop app for Mac, Windows, or Linux. Using the infinite canvas to organize your thoughts and your code ensures that your evening project remains a small win rather than a long night of frustration. If you need more advanced features or managed inference, you can explore the various pricing tiers available.