Use Cases

Practical scenarios showing how to get the most out of Agent Nine.

Bug Fixing

Find and fix bugs by describing the problem:

Users report that login fails when they use special characters
in their password. Find and fix the issue.

Agent Nine will:

1. Search the codebase for authentication logic
2. Identify the problematic code
3. Propose and apply a fix
4. Run tests to verify

Code Refactoring

Improve code quality without changing behavior:

Refactor the UserService — it's 500 lines long.
Split it into smaller, focused modules.

Convert all callback-based functions in the auth module to async/await

Replace magic numbers with named constants in the pricing logic

Writing Tests

Generate tests for existing code:

Write tests for the PaymentProcessor class

Add integration tests for all API endpoints in the orders module

We have no tests for the email service. Write comprehensive unit tests.

Understanding Unfamiliar Code

Explore a project you've never seen before:

Explain how authentication works in this project

What happens when a user places an order? Walk me through the entire flow.

Find all database queries and explain the data model

Database Work

Work with databases through natural language:

Write a migration to add a "status" column to the orders table

The query for listing active users is slow. Optimize it.

Create a seed script with realistic test data

API Development

Build and maintain APIs:

Add a new endpoint: POST /api/invitations that sends an email invite

Document all REST endpoints in the project with request/response examples

Add input validation and error handling to the user registration endpoint

Frontend Work

Build UI components and features:

Create a responsive dashboard page with a sidebar, stats cards, and a data table

The mobile menu doesn't close when clicking outside. Fix it.

Add dark mode support to the settings page

DevOps & CI/CD

Automate infrastructure and pipelines:

Write a GitHub Actions workflow that runs tests on every PR

Create a Dockerfile for the backend service

Set up a docker-compose for local development with the API, database, and Redis

Cross-Service Tasks

Use integrations to connect your workflow:

Read the latest Sentry errors, find the ones related to our API,
and fix them in the codebase

Check the Jira board for unfinished tasks in the current sprint
and create a summary

Read the design spec from Google Drive and implement the login page accordingly

Large-Scale Changes

Use agents for big tasks:

Update all API endpoints to use the new authentication middleware.
Use a team of agents — one per service module.

Migrate all class components to functional components with hooks

Add TypeScript types to all JavaScript files in the utils/ directory