Code Analysis

Code analysis tools let you navigate and understand C# codebases using Roslyn's semantic analysis — without needing to run the debugger. Find symbol usages, track variable assignments, and get compilation diagnostics statically.

When to Use

Use code analysis tools when you need to understand code structure and relationships. These tools work on the source code directly, so they're available even when the process isn't running.

Typical flow: code_load → code_find_usages or code_find_assignments → code_goto_definition

Use cases:

• Understanding how a class or method is used throughout a codebase
• Finding all places where a variable is assigned
• Navigating to symbol definitions (go-to-definition)
• Checking for compilation errors before running

Tools

code_load

Load a solution or project file into the analysis workspace.

Requires: No session needed (works offline)

When to use: Before using any other code analysis tools. This tool initializes Roslyn's workspace with your codebase.

Parameters:

Name	Type	Required	Description
path	string	Yes	Absolute path to .sln or .csproj file

Response:

{
  "success": true,
  "data": {
    "path": "/app/MyApp.sln",
    "type": "Solution",
    "projects": [
      {
        "name": "MyApp",
        "path": "/app/MyApp/MyApp.csproj",
        "documents_count": 45,
        "target_framework": "net8.0"
      },
      {
        "name": "MyApp.Tests",
        "path": "/app/MyApp.Tests/MyApp.Tests.csproj",
        "documents_count": 23
      }
    ],
    "diagnostics": [],
    "loaded_at": "2026-02-05T10:30:00Z"
  }
}

Errors:

• INVALID_PATH — Path doesn't exist or isn't a .sln/.csproj file
• LOAD_FAILED — MSBuild workspace failed to load

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code_find_usages

Find all usages of a symbol across the workspace.

Requires: No session needed (requires loaded workspace via code_load)

When to use: Understand how a type, method, property, or variable is used throughout the codebase. Useful for refactoring decisions or understanding code impact.

Parameters:

Name	Type	Required	Description
name	string	No*	Fully qualified symbol name (e.g., "Namespace.Class.Method")
symbolKind	string	No	Filter by kind: Namespace, Type, Method, Property, Field, Event, Local, Parameter, TypeParameter
file	string	No*	Absolute path to source file (use with line/column)
line	integer	No*	1-based line number (use with file/column)
column	integer	No*	1-based column number (use with file/line)

*Either name OR file+line+column must be provided.

Example by name:

{
  "name": "MyApp.Services.UserService.GetUser",
  "symbolKind": "Method"
}

Example by location:

{
  "file": "/app/Services/UserService.cs",
  "line": 42,
  "column": 20
}

Response:

{
  "success": true,
  "data": {
    "symbol": {
      "name": "GetUser",
      "fully_qualified_name": "MyApp.Services.UserService.GetUser(string)",
      "kind": "Method",
      "containing_type": "MyApp.Services.UserService",
      "containing_namespace": "MyApp.Services",
      "declaration_file": "/app/Services/UserService.cs",
      "declaration_line": 15,
      "declaration_column": 12
    },
    "usages_count": 5,
    "usages": [
      {
        "file": "/app/Services/UserService.cs",
        "line": 15,
        "column": 12,
        "end_line": 15,
        "end_column": 19,
        "kind": "Declaration",
        "context": "UserService"
      },
      {
        "file": "/app/Controllers/UserController.cs",
        "line": 28,
        "column": 15,
        "end_line": 28,
        "end_column": 22,
        "kind": "Reference",
        "context": "Get"
      },
      {
        "file": "/app/Controllers/AdminController.cs",
        "line": 45,
        "column": 20,
        "end_line": 45,
        "end_column": 27,
        "kind": "Reference",
        "context": "GetUserDetails"
      }
    ]
  }
}

Usage kinds:

• Declaration — Where the symbol is defined
• Reference — Where the symbol is referenced (type/method)
• Read — Where a variable's value is read
• Write — Where a variable's value is written

Errors:

• NO_WORKSPACE — Call code_load first
• SYMBOL_NOT_FOUND — Symbol doesn't exist at name/location
• INVALID_PARAMETER — Missing or conflicting parameters

Real-world use case: An AI agent needs to rename a method. It uses code_find_usages to find all 12 places where the method is called, then generates edits for each location.

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code_find_assignments

Find all assignments to a variable, field, or property.

Requires: No session needed (requires loaded workspace via code_load)

When to use: Track where a value comes from. Useful for debugging "why does this variable have this value?" questions.

Parameters:

Name	Type	Required	Description
name	string	No*	Fully qualified symbol name
symbolKind	string	No	Filter: Field, Property, Local, Parameter
file	string	No*	Absolute path to source file
line	integer	No*	1-based line number
column	integer	No*	1-based column number

*Either name OR file+line+column must be provided.

Example:

{
  "name": "MyApp.Services.UserService._cache",
  "symbolKind": "Field"
}

Response:

{
  "success": true,
  "data": {
    "symbol": {
      "name": "_cache",
      "fully_qualified_name": "MyApp.Services.UserService._cache",
      "kind": "Field",
      "containing_type": "MyApp.Services.UserService",
      "declaration_file": "/app/Services/UserService.cs",
      "declaration_line": 8
    },
    "assignments_count": 3,
    "assignments": [
      {
        "file": "/app/Services/UserService.cs",
        "line": 8,
        "column": 5,
        "end_line": 8,
        "end_column": 45,
        "kind": "Declaration",
        "context": "UserService",
        "operator": "=",
        "value_expression": "new Dictionary<string, User>()"
      },
      {
        "file": "/app/Services/UserService.cs",
        "line": 35,
        "column": 9,
        "end_line": 35,
        "end_column": 25,
        "kind": "Simple",
        "context": "ClearCache",
        "operator": "=",
        "value_expression": "new Dictionary<string, User>()"
      },
      {
        "file": "/app/Services/UserService.cs",
        "line": 42,
        "column": 9,
        "end_line": 42,
        "end_column": 15,
        "kind": "Simple",
        "context": "Dispose",
        "operator": "=",
        "value_expression": "null"
      }
    ]
  }
}

Assignment kinds:

• Declaration — Declaration with initializer (int x = 5)
• Simple — Simple assignment (x = 5)
• Compound — Compound assignment (x += 5, x -= 3)
• Increment — Increment (x++, ++x)
• Decrement — Decrement (x--, --x)
• OutParameter — Out parameter (Method(out x))
• RefParameter — Ref parameter (Method(ref x))
• Initializer — Object/collection initializer

Errors:

• NO_WORKSPACE — Call code_load first
• SYMBOL_NOT_FOUND — Symbol doesn't exist
• INVALID_PARAMETER — Invalid symbol kind for assignment tracking

Real-world use case: An AI agent is debugging why _connectionString is null. It uses code_find_assignments to find all places where the field is set, discovering it's only assigned in the constructor — which isn't being called due to DI misconfiguration.

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code_get_diagnostics

Get compilation diagnostics (errors and warnings) for projects.

Requires: No session needed (requires loaded workspace via code_load)

When to use: Check for compilation errors before running. Useful for validating code changes or understanding why a build fails.

Parameters:

Name	Type	Required	Description
projectName	string	No	Filter to specific project
minSeverity	string	No	Minimum severity: Hidden, Info, Warning (default), Error
maxResults	integer	No	Max diagnostics to return (default: 100, max: 500)

Example:

{
  "projectName": "MyApp",
  "minSeverity": "Warning",
  "maxResults": 50
}

Response:

{
  "success": true,
  "data": {
    "total_count": 3,
    "limited_to": 50,
    "summary": {
      "error": 1,
      "warning": 2
    },
    "diagnostics": [
      {
        "id": "CS0246",
        "message": "The type or namespace name 'UserDto' could not be found",
        "severity": "Error",
        "category": "Compiler",
        "file": "/app/Controllers/UserController.cs",
        "line": 15,
        "column": 20,
        "end_line": 15,
        "end_column": 27,
        "project": "MyApp",
        "help_link": "https://docs.microsoft.com/en-us/dotnet/csharp/misc/cs0246"
      },
      {
        "id": "CS0168",
        "message": "The variable 'ex' is declared but never used",
        "severity": "Warning",
        "category": "Compiler",
        "file": "/app/Services/UserService.cs",
        "line": 42,
        "column": 12,
        "project": "MyApp"
      }
    ]
  }
}

Errors:

• NO_WORKSPACE — Call code_load first
• PROJECT_NOT_FOUND — Specified project doesn't exist

Real-world use case: After making code edits, an AI agent runs code_get_diagnostics to verify there are no compilation errors before suggesting the changes are complete.

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code_goto_definition

Navigate to the definition of a symbol.

Requires: No session needed (requires loaded workspace via code_load)

When to use: Find where a type, method, or property is defined. Essential for understanding code and navigating large codebases.

Parameters:

Name	Type	Required	Description
file	string	Yes	Absolute path to source file
line	integer	Yes	1-based line number where symbol appears
column	integer	Yes	1-based column number where symbol appears

Example:

{
  "file": "/app/Controllers/UserController.cs",
  "line": 28,
  "column": 15
}

Response (source symbol):

{
  "success": true,
  "data": {
    "symbol": {
      "name": "GetUser",
      "fully_qualified_name": "MyApp.Services.UserService.GetUser(string)",
      "kind": "Method",
      "containing_type": "MyApp.Services.UserService",
      "containing_namespace": "MyApp.Services"
    },
    "definitions_count": 1,
    "definitions": [
      {
        "file": "/app/Services/UserService.cs",
        "line": 15,
        "column": 12,
        "end_line": 15,
        "end_column": 19,
        "is_source": true
      }
    ]
  }
}

Response (metadata symbol):

{
  "success": true,
  "data": {
    "symbol": {
      "name": "WriteLine",
      "fully_qualified_name": "System.Console.WriteLine(string)",
      "kind": "Method",
      "containing_type": "System.Console",
      "containing_namespace": "System"
    },
    "definitions_count": 1,
    "definitions": [
      {
        "is_source": false,
        "assembly_name": "System.Console",
        "assembly_version": "8.0.0.0"
      }
    ]
  }
}

Note: For metadata symbols (types from NuGet packages or the BCL), the definition returns assembly information instead of a source location.

Errors:

• NO_WORKSPACE — Call code_load first
• SYMBOL_NOT_FOUND — No symbol at the specified location

Real-world use case: An AI agent sees a method call _userService.GetUser(id) and needs to understand what it does. It uses code_goto_definition to navigate to the method implementation.

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Workflow Examples

Understanding a Bug Report

1. Load the codebase:

   { "tool": "code_load", "path": "/app/MyApp.sln" }

2. Find where the problematic variable is assigned:

   { "tool": "code_find_assignments", "name": "MyApp.Services.OrderService._taxRate" }

3. Navigate to the assignment location:

   { "tool": "code_goto_definition", "file": "/app/Services/OrderService.cs", "line": 45, "column": 10 }

Pre-flight Check Before Running

1. Load the project:

   { "tool": "code_load", "path": "/app/MyApp.csproj" }

2. Check for compilation errors:

   { "tool": "code_get_diagnostics", "minSeverity": "Error" }

3. If errors exist, investigate the first one:

   { "tool": "code_goto_definition", "file": "/app/Controllers/UserController.cs", "line": 15, "column": 20 }

Impact Analysis for Refactoring

1. Load the solution:

   { "tool": "code_load", "path": "/app/MyApp.sln" }

2. Find all usages of the method to rename:

   { "tool": "code_find_usages", "name": "MyApp.Services.UserService.GetUserById" }

3. Review each usage location to plan the refactoring.