Anonymous Block, Apex
An Anonymous Block in Apex is a segment of Apex code that is not stored in Salesforce metadata and is executed on the fly.
Definition
An Anonymous Block in Apex is a segment of Apex code that is not stored in Salesforce metadata and is executed on the fly. Anonymous blocks can be run using the Developer Console's Execute Anonymous window, the Salesforce CLI, or the SOAP API. They are commonly used for one-time data fixes, testing code snippets, and debugging, and they execute in the context of the running user.
In plain English
“An Anonymous Block is a snippet of Apex code you run once, on the spot, without saving it to your org. Think of it like typing a quick calculation into a calculator rather than writing a full program. Developers use it for one-off fixes and experiments.”
Worked example
Quartz Analytics imported 1,200 Case records last night with the wrong owner. Mei, the Apex developer on call, opens the Developer Console and pastes a six-line Anonymous Block: a SOQL query for the affected Cases, a loop reassigning the OwnerId, and an update DML. She clicks Execute Anonymous, the job runs as her user, and 1,200 Cases are corrected in eight seconds. The block was never saved to metadata - once the window closes the code is gone, but the data fix sticks. For a one-time correction like this, an Anonymous Block beats writing, deploying, and later removing a real Apex class.
Why Anonymous Block, Apex matters
Anonymous Apex blocks are pieces of code executed on the fly without being saved as a class or trigger in the org's metadata. They run from the Developer Console's Execute Anonymous window, the Salesforce CLI (sf apex run), or the SOAP API, and they execute in the context of the running user, respecting that user's profile and sharing rules.
Common uses include one-time data fixes (like updating a field on a specific set of records), debugging code paths by calling methods and inspecting results, and quick prototyping before committing code to a class. Because anonymous blocks aren't saved, they don't affect code coverage, don't require deployment, and can't be called from other code, which is exactly what makes them useful for short-lived tasks that shouldn't live permanently in the org.
How organizations use Anonymous Block, Apex
Uses anonymous Apex blocks for one-time data corrections after a data migration. When 500 records land with a wrong Record Type, a developer writes a short block in the Developer Console, runs it, verifies the result, and moves on without leaving any code behind.
Debugs complex Apex logic by writing anonymous blocks that call the class methods with specific inputs and log the results. It's faster than writing a full test class for exploratory debugging, and the blocks get discarded once the bug is understood.
Runs scheduled anonymous block scripts through the Salesforce CLI as part of their deployment process to reset sandbox data after each refresh. The script populates test data, configures settings, and exits without leaving metadata behind.
Trust & references
Straight from the source - Salesforce's reference material on Anonymous Block, Apex.
- Anonymous BlocksSalesforce Developers
- Execute Anonymous ApexSalesforce Developers
Hands-on resources to go deeper on Anonymous Block, Apex.
Test your knowledge
Q1. What is an Anonymous Apex Block?
Q2. Which tool can you use to run an Anonymous Apex Block?
Q3. Why don't Anonymous Apex Blocks count toward code coverage?
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