AspireC4.Hosting

AspireC4.Hosting is an Aspire extension library that generates live LikeC4 diagrams from the Aspire resource graph.

Prerequisites

• Docker is used by default to run the LikeC4 sidecar container.
• Optional: a local Node.js CLI runtime (npx, pnpm, yarn, bun, or deno) if you call .WithLocalCLI().

Quick start

var builder = DistributedApplication.CreateBuilder(args);

builder.AddAspireC4();

builder.Build().Run();

This writes ./likec4/gen/model.gen.c4, starts the LikeC4 server, and refreshes the diagram as the Aspire app changes.

Configuration

Configure the diagram through AspireC4DiagramOptions:

Property	Default	Description
Title	null	Title shown in the LikeC4 app
ViewTitle	"Architecture"	Title shown in the generated view
ViewDescription	null	Optional view description
OutputDirectory	"./likec4/gen/"	Directory where the generated .c4 file is written
FileName	"model.gen"	Generated file name without extension
DisableHMR	false	Disable Hot Module Replacement
HMRPort	24678	HMR port used by the LikeC4 server and browser
ContainerImageTag	null (latest)	Pin the ghcr.io/likec4/likec4 image tag
AutoIconsEnabled	true	Infer LikeC4 icons from resource type and name
HideFromDashboard	false	Hide the LikeC4 sidecar from the Aspire dashboard
DashboardLinkDisplayName	"Architecture Diagram"	Name used for the diagram link when hidden from the dashboard
IncludeAspireDashboardLinks	true	Add Aspire dashboard links to diagram elements

Common options

Local CLI

builder.AddAspireC4().WithLocalCLI();

Hide from the dashboard

builder.AddAspireC4().WithHideFromDashboard();

Disable HMR

builder.AddAspireC4(options => options.WithHMRDisabled());

Exclude the sidecar from the diagram

The LikeC4 sidecar is excluded automatically. Use WithIncludeAspireC4InternalResource(true) if you want to inspect it.