Build a Code Review AI Agent - Step by Step Enterprise Dev Automation using Java, Spring Boot and MCP
Learn how to build a Code Review AI Agent that analyzes pull requests, detects bugs, suggests improvements, and enforces coding standards using MCP and LLMs.
Step-by-step Enterprise AI Project Guide
Introduction
Code review is one of the most critical parts of software development.
But traditional code review is:
- Time-consuming
- Manual
- Inconsistent
- Subjective
So we build:
Code Review AI Agent
What We Are Building
A Code Review AI Agent that can:
- Review pull requests automatically
- Detect bugs and code smells
- Suggest performance improvements
- Enforce coding standards
- Summarize changes in PRs
- Score code quality
Architecture Overview
flowchart TD
User
SpringBoot_API
CodeReviewAgent
PlannerAgent
ExecutorAgent
GitDiffTool
StaticAnalysisTool
LLM
MCP_Server
User --> SpringBoot_API
SpringBoot_API --> CodeReviewAgent
CodeReviewAgent --> PlannerAgent
CodeReviewAgent --> ExecutorAgent
PlannerAgent --> MCP_Server
ExecutorAgent --> MCP_Server
MCP_Server --> GitDiffTool
MCP_Server --> StaticAnalysisTool
MCP_Server --> LLM
Step 1: Create Spring Boot Project
Dependencies:
<dependencies>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-web</artifactId>
</dependency>
<dependency>
<groupId>org.springframework.boot</groupId>
<artifactId>spring-boot-starter-validation</artifactId>
</dependency>
</dependencies>
Step 2: Code Review Request Model
public class CodeReviewRequest {
private String repoName;
private String pullRequestId;
private String diff;
}
Step 3: Code Review Response Model
public class CodeReviewResponse {
private String summary;
private String qualityScore;
}
Step 4: Code Review Controller
@RestController
@RequestMapping("/api/code-review")
public class CodeReviewController {
private final CodeReviewAgentService codeReviewAgentService;
public CodeReviewController(CodeReviewAgentService codeReviewAgentService) {
this.codeReviewAgentService = codeReviewAgentService;
}
@PostMapping("/run")
public CodeReviewResponse run(@RequestBody CodeReviewRequest request) {
return codeReviewAgentService.process(request);
}
}
Step 5: Code Review Agent Service
@Service
public class CodeReviewAgentService {
private final PlannerAgent plannerAgent;
private final ExecutorAgent executorAgent;
public CodeReviewAgentService(PlannerAgent plannerAgent,
ExecutorAgent executorAgent) {
this.plannerAgent = plannerAgent;
this.executorAgent = executorAgent;
}
public CodeReviewResponse process(CodeReviewRequest request) {
// 1. Plan review strategy
String plan = plannerAgent.createPlan(request.getDiff());
// 2. Execute review
String result = executorAgent.execute(plan,
request.getRepoName(),
request.getDiff());
// 3. Build response
CodeReviewResponse response = new CodeReviewResponse();
response.setSummary(result);
response.setQualityScore("8.5/10");
return response;
}
}
Step 6: Planner Agent
@Service
public class PlannerAgent {
public String createPlan(String diff) {
if (diff.contains("security")) {
return "SECURITY_REVIEW_PLAN";
}
if (diff.contains("performance")) {
return "PERFORMANCE_REVIEW_PLAN";
}
if (diff.contains("bug")) {
return "BUG_DETECTION_PLAN";
}
return "GENERAL_CODE_REVIEW_PLAN";
}
}
Step 7: Executor Agent
@Service
public class ExecutorAgent {
public String execute(String plan,
String repoName,
String diff) {
switch (plan) {
case "SECURITY_REVIEW_PLAN":
return "Security issues detected in repository: " + repoName;
case "PERFORMANCE_REVIEW_PLAN":
return "Performance improvements suggested for repo: " + repoName;
case "BUG_DETECTION_PLAN":
return "Potential bugs found in code diff";
default:
return "Code review completed successfully for repo: " + repoName;
}
}
}
Step 8: MCP Integration (Advanced Layer)
Now we upgrade with MCP:
ExecutorAgent → MCP Server → GitDiff Tool + Static Analysis Tool + LLM
MCP Enhanced Architecture
flowchart TD
CodeReviewAgent
PlannerAgent
ExecutorAgent
MCP_Client
MCP_Server
GitDiffTool
StaticAnalysisTool
SecurityScanner
LLM
CodeReviewAgent --> PlannerAgent
CodeReviewAgent --> ExecutorAgent
ExecutorAgent --> MCP_Client
MCP_Client --> MCP_Server
MCP_Server --> GitDiffTool
MCP_Server --> StaticAnalysisTool
MCP_Server --> SecurityScanner
MCP_Server --> LLM
Code Review Workflow
flowchart TD
PullRequest
DiffAnalysis
PlanGeneration
ToolExecution
LLMReview
ScoreCalculation
FinalReport
PullRequest --> DiffAnalysis
DiffAnalysis --> PlanGeneration
PlanGeneration --> ToolExecution
ToolExecution --> LLMReview
LLMReview --> ScoreCalculation
ScoreCalculation --> FinalReport
Example 1: Security Review
Input:
PR contains authentication changes
Flow:
1. Planner selects SECURITY_REVIEW_PLAN
2. MCP security tool scans code
3. LLM identifies vulnerabilities
4. Report generated
Example 2: Performance Review
Input:
PR improves API performance
Flow:
1. Planner selects PERFORMANCE_REVIEW_PLAN
2. Static analysis tool executed
3. LLM suggests optimizations
4. Feedback generated
Example 3: Bug Detection
Input:
PR fixes null pointer issue
Flow:
1. Planner selects BUG_DETECTION_PLAN
2. MCP diff tool analyzes changes
3. LLM validates fix correctness
4. Review completed
Enterprise Architecture
flowchart LR
Client
API_Gateway
CodeReviewAgent
PlannerAgent
ExecutorAgent
MCP_Layer
GitHubPR
AnalysisTools
LLMServices
Client --> API_Gateway
API_Gateway --> CodeReviewAgent
CodeReviewAgent --> PlannerAgent
PlannerAgent --> ExecutorAgent
ExecutorAgent --> MCP_Layer
MCP_Layer --> GitHubPR
MCP_Layer --> AnalysisTools
MCP_Layer --> LLMServices
Benefits of Code Review AI Agent
1. Faster Reviews
- Instant PR analysis
2. Better Code Quality
- Standardized feedback
3. Security Enforcement
- Automatic vulnerability detection
4. Scalability
- Handles large repositories
5. Consistency
- Uniform review standards
Challenges
❌ False positives in analysis
❌ Complex code context understanding
❌ Large diff handling
❌ Tool integration complexity
❌ LLM accuracy limitations
Best Practices
✅ Use MCP for all analysis tools
✅ Combine static + LLM analysis
✅ Maintain review history
✅ Add scoring system
✅ Enable human override
✅ Cache repository context
Common Mistakes
❌ Only using LLM without static tools
❌ No diff preprocessing
❌ Missing security layer
❌ No scoring mechanism
❌ No fallback to human review
When to Use Code Review AI Agent
Use when:
- Large development teams exist
- High PR volume
- Security enforcement needed
- Continuous integration pipelines exist
When NOT to Use
Avoid when:
- Small projects
- Low PR activity
- Highly sensitive manual review required
Summary
In this article, you learned:
- How to build a Code Review AI Agent
- Planner + Executor architecture
- MCP integration for DevOps automation
- Security, performance, and bug detection workflows
- Enterprise architecture design
- Best practices and challenges
You now have a complete Code Review AI Agent system, which can evolve into a full enterprise DevSecOps platform using Java, Spring Boot, and MCP.
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