Apex Development Setup: VS Code, Salesforce CLI and Orgs

You can write a few lines of Apex in the browser, but real development happens in VS Code with the Salesforce CLI: your code lives in files under version control, you deploy with one command, and tests run from the editor. This lesson sets that up and shows the three ways you'll run Apex day to day.

Step 1: get an org

Step 2: install the tools

1. VS Code from code.visualstudio.com.
2. The Salesforce Extension Pack (Expanded) from the VS Code marketplace – Apex language support, debugger, test runner and more.
3. The Salesforce CLI (sf) from developer.salesforce.com/tools/salesforcecli.
4. A Java JDK (17 or 21), which the Apex language server needs.

# check the CLI
sf --version

# create a project
sf project generate --name apex-course
cd apex-course

# log in to your Developer Edition org and make it the default
sf org login web --alias devorg --set-default

Step 3: the project structure

# create a class (or use Command Palette → "SFDX: Create Apex Class")
sf apex generate class --name HelloApex --output-dir force-app/main/default/classes

# deploy your changes to the org
sf project deploy start --source-dir force-app

# run tests
sf apex run test --class-names HelloApexTest --result-format human --synchronous

Step 4: run anonymous Apex

Put a snippet in scripts/apex/hello.apex and run it – from VS Code (select the code → "SFDX: Execute Anonymous Apex with Editor Contents") or from the terminal:

sf apex run --file scripts/apex/hello.apex

// hello.apex – saved in scripts/apex
System.debug('Running as a ' + UserInfo.getUserType() + ' user');
System.debug('Org edition: ' + [SELECT OrganizationType FROM Organization].OrganizationType);
System.debug('SOQL queries used: ' + Limits.getQueries() + ' of ' + Limits.getLimitQueries());

Running as a Standard user
Org edition: Developer Edition
SOQL queries used: 1 of 100

The CLI prints the full debug log. In this course, result panels show just the System.debug lines – the part you care about – plus any error that stopped the code.

Debug logs and log levels

• A debug log records what happened in a transaction: SOQL queries, DML, method calls, limits used and your System.debug output.
• To capture logs for code that runs on its own (a trigger fired by a user, a batch job), add a trace flag for that user: Setup → Debug Logs, or sf apex tail log to stream logs live.
• Log levels (per category: Apex Code, Database, Workflow…) control detail. Higher levels mean bigger logs; logs are capped at 20 MB.
• System.debug(LoggingLevel.ERROR, 'message') lets you set a level per message.

Developer Console: the quick option

In any org, the gear menu → Developer Console gives you a browser-based editor: Debug → Open Execute Anonymous Window to run snippets, the Query Editor tab for SOQL, and the Logs tab for debug logs. It's handy for a quick check, but for real work use VS Code: your code is in files, under Git, and deployable to any org.

Practice

Summary