Skip to main content

​
Overview

Nelson has access to powerful tools that let him interact with your filesystem and execute commands. These tools are what make Nelson a true coding assistant, not just a chatbot.
When Nelson uses a tool, you’ll see an indicator in the output:🔧 Tool: tool_name (running) ✅ Tool: tool_name (success)

​
Available Tools

​
read_file

Read the contents of any file in your project. 
You: Read the package.json file
​
path
string
required
Path to the file (relative or absolute)
Use cases:
  • Understanding existing code
  • Checking configuration files
  • Reviewing changes before editing

​
write_file

Create or overwrite a file with new content. 
You: Create a new file called utils.js with a helper function
​
path
string
required
Path where the file should be written
​
content
string
required
Content to write to the file
Features:
  • Creates parent directories automatically
  • Overwrites existing files
  • Works with any file type

​
edit_file

Make targeted edits to existing files by replacing specific text. 
You: In app.js, change the port from 3000 to 8080
​
path
string
required
Path to the file
​
old_string
string
required
Exact text to find and replace
​
new_string
string
required
Text to replace it with
Best for:
  • Small, precise changes
  • Updating specific values
  • Fixing bugs in existing code

​
list_directory

List files and folders in a directory. 
You: What files are in the src directory?
​
path
string
default:"."
Directory path to list
Output format: 
[DIR] components
[DIR] utils
[FILE] index.js
[FILE] App.js

​
bash

Execute any bash command and see the output. 
You: Run the tests
You: Install lodash
You: Check git status
​
command
string
required
The bash command to execute
​
timeout
number
default:"30000"
Timeout in milliseconds
Common uses:
  • Running tests (npm test, pytest)
  • Installing packages (npm install, pip install)
  • Git operations (git status, git commit)
  • Building projects (npm run build)
  • Starting servers (npm start)

​
search_files

Find files matching a pattern. 
You: Find all TypeScript files in the project
​
pattern
string
required
Glob pattern (e.g., *.js, **/*.tsx)
​
path
string
default:"."
Base directory to search

​
grep

Search for text patterns across files. 
You: Find all files that import the auth module
​
pattern
string
required
Regex pattern to search for
​
path
string
default:"."
File or directory to search
​
file_pattern
string
Optional glob to filter files (e.g., *.js)

​
Tool Usage Examples

​
Creating a New Project

You: Set up a new Node.js project with Express

Nelson: HA-HA! Let's get this project started...

🔧 Tool: bash
✅ Tool: bash (npm init -y)

🔧 Tool: bash
✅ Tool: bash (npm install express)

🔧 Tool: write_file
✅ Tool: write_file (index.js)

🔧 Tool: write_file
✅ Tool: write_file (.gitignore)

Done! I've created:
- package.json with dependencies
- index.js with a basic Express server
- .gitignore for node_modules

​
Debugging a Test Failure

You: The tests are failing, can you fix them?

Nelson: Let me investigate...

🔧 Tool: bash
✅ Tool: bash (npm test)

I see the issue. The auth.test.js is failing because...

🔧 Tool: read_file
✅ Tool: read_file (src/auth.js)

🔧 Tool: edit_file
✅ Tool: edit_file (src/auth.js)

🔧 Tool: bash
✅ Tool: bash (npm test)

HA-HA! Tests are passing now. The bug was...

​
Best Practices

Let Nelson Read First

Before editing, let Nelson read the file to understand context

Review Changes

Nelson shows what tools are used - review file changes

Use Specific Paths

Provide clear file paths to avoid ambiguity

Trust the Process

Nelson chains tools together intelligently to accomplish complex tasks