Minimal APIs are often introduced as the newer, more lightweight alternative to Controllers in ASP.NET Core, which makes the comparison sound like a decision about which style to adopt going forward. A more useful framing is that the two solve differently shaped problems, and the right choice depends on the shape of the API being built, not on which approach is more recent.

The Same Logic, Two Structures

Take a straightforward endpoint that retrieves workflow role mappings for an employee. Written as a Controller action:

csharp

[ApiController]
[Route("api/[controller]")]
public class WorkFlowController : ControllerBase
{
    private readonly IclsWorkFlow _workFlowDataAccess;

    public WorkFlowController(IclsWorkFlow workFlowDataAccess)
    {
        _workFlowDataAccess = workFlowDataAccess;
    }

    [HttpGet("get-add-rolemapping")]
    public IActionResult GetAddRoleMapping(int employeeSlno, int createdBy)
    {
        var result = _workFlowDataAccess.GetAddWorkFlows(employeeSlno, createdBy);
        return Ok(result);
    }
}

The same behavior as a Minimal API:

csharp

app.MapGet("/api/workflow/get-add-rolemapping",
    (int employeeSlno, int createdBy, IclsWorkFlow workFlowDataAccess) =>
{
    var result = workFlowDataAccess.GetAddWorkFlows(employeeSlno, createdBy);
    return Results.Ok(result);
});

Functionally, these are identical. The Minimal API version omits the class, the routing attributes, and the constructor, registering the endpoint through a single call instead. Dependency injection still supplies IclsWorkFlow automatically; it simply arrives as a parameter rather than through a constructor.

The Reason Minimal APIs Were Introduced

A Controller carries a baseline amount of structure no matter how small the endpoint is: a class definition, class-level attributes, and a constructor, all before any endpoint-specific logic appears. For a small service with only a handful of endpoints, that structure can outweigh what it actually provides. Minimal APIs address exactly this case, trimming the ceremony for scenarios such as small microservices, lightweight utility endpoints, or a standalone health check sitting beside a larger system.

Where the Comparison Shifts

The picture changes once an API has several related endpoints to manage. Four workflow operations as Controller actions stay grouped naturally within one class:

csharp

public class WorkFlowController : ControllerBase
{
    [HttpGet("get-add-rolemapping")]
    public IActionResult GetAddRoleMapping(...) { ... }

    [HttpGet("get-delete-rolemappings")]
    public IActionResult GetDeleteRoleMappings(...) { ... }

    [HttpPost("save-add-role-mapping")]
    public IActionResult SaveAddRoleMapping(...) { ... }

    [HttpPost("save-delete-role-mapping")]
    public IActionResult SaveDeleteRoleMapping(...) { ... }
}

The same four operations as Minimal API registrations each need their own app.MapGet or app.MapPost call, typically accumulating in Program.cs or a comparable central file:

csharp

app.MapGet("/api/workflow/get-add-rolemapping", (...) => { ... });
app.MapGet("/api/workflow/get-delete-rolemappings", (...) => { ... });
app.MapPost("/api/workflow/save-add-role-mapping", (...) => { ... });
app.MapPost("/api/workflow/save-delete-role-mapping", (...) => { ... });

As more endpoints accumulate this way, the central registration file grows and loses the grouping a Controller class provides inherently. Minimal API endpoints can be organized into extension methods or separate files to manage this, but that reintroduces structure to address a problem Controllers already solve through the class itself.

A Practical Basis for the Decision

The deciding factor is the shape of the API, not which style is more current. A small, self-contained service with a few endpoints and little shared context between them fits Minimal APIs reasonably well, since there's little organizational benefit being given up. A larger, cohesive application with numerous related endpoints, shared dependencies, and consistent conventions across them tends to remain easier to navigate as Controllers, where the class continues to group related operations as the codebase grows.

The two approaches also coexist within a single application without conflict. Controllers commonly handle the substantial business logic of a larger system, while a Minimal API endpoint or two covers something small and self-contained alongside it, such as a status or health-check endpoint that doesn't warrant a dedicated class.

Takeaway

The choice between Minimal APIs and Controllers comes down to fit rather than novelty. A handful of small, loosely connected endpoints generally suit Minimal APIs, trading away structure that wasn't adding meaningful value. A larger set of related, interdependent endpoints tends to stay more maintainable as Controllers, where the class performs organizational work that would otherwise need to be rebuilt through other means. The number of endpoints and how closely related they are should drive the decision, not which approach happens to be newer.