Use the MCP tools get_ast_nodes_to_generate_xpath and create_custom_rule to generate custom PMD rules for Apex and Visualforce code in MCP clients such as Agentforce Vibes. Define organization-specific coding standards and detect custom patterns by entering a prompt that describes what to flag, such as deeply nested if statements or System.debug usage in Apex. Code Analyzer uses get_ast_nodes_to_generate_xpath to extract AST nodes and generate XPath with AI, then uses create_custom_rule to create the rule and add it to code-analyzer.yml.
To create a custom PMD rule to flag deeply nested if statement, use these steps
- Access the Code Analyzer MCP tools
- In an MCP client such as Agentforce Vibes, enter a prompt like: “Help me create a rule to flag if statements that are three levels deep.”
- The tool generates a sample code that violates the rule. Approve or refine the sample code.
{
"sampleCode": "public with sharing class NestedIfViolationExample {\n\tpublic static Integer checkDepth(Integer a, Integer b, Integer c, Integer d) {\n \tInteger x = 0;\n \tif (a > 0) { \t// depth 1\n \tif (b > 0) { \t// depth 2\n \tif (c > 0) { \t// depth 3\n \tif (d > 0) {\t// depth 4 -> VIOLATION (>= 4)\n \tx = 1;\n \t}\n \t}\n \t}\n \t}\n \treturn x;\n\t}\n}\n",
"language": "apex",
"engine": "pmd"
}
-
The tool generates the XPath by extracting the relevant AST nodes for your prompt. Modify the query as needed.
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The tool creates the rule in an XML file and updates the code-analyzer.yml with the new rule.
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Verify the rule by running Code Analyzer against your target codebase. For example:
sf code-analyzer run --target "force-app/main/default/classes/NestedIfExample.cls"
You can also ask the tool to generate additional sample code that violates the rule, so you can confirm the analyzer flags the expected violations.