Resource MCP servers

Dette indhold er ikke tilgængeligt i dit sprog endnu.

Aspire resources can expose their own MCP (Model Context Protocol) servers, enabling AI coding agents to interact directly with databases, APIs, and other services. For example, a PostgreSQL resource can expose SQL query tools, allowing an agent to run queries without leaving the conversation.

How it works

When a resource is annotated with WithMcpServer() in the AppHost, Aspire discovers the MCP endpoint and makes its tools available in two ways:

Through the Aspire MCP server — resource tools are automatically proxied alongside the built-in Aspire MCP server tools. AI agents see them in their tool list without any extra configuration.
Through the CLI — use aspire mcp tools and aspire mcp call to discover and invoke resource tools directly from the terminal.

Add an MCP server to a resource

Use the WithMcpServer() extension method to declare that a resource hosts an MCP server:

C#
TypeScript

#pragma warning disable ASPIREMCP001

var builder = DistributedApplication.CreateBuilder(args);

var db = builder.AddPostgres("db")
    .AddDatabase("appdata");

// Expose PostgreSQL MCP tools (SQL queries, schema inspection, etc.)
db.WithPostgresMcp();

builder.Build().Run();

import { 
function createBuilder(): IDistributedApplicationBuilder
Creates a new distributed application builder
createBuilder } from './.modules/aspire.js';

const 
const builder: IDistributedApplicationBuilder
builder = await 
function createBuilder(): IDistributedApplicationBuilder
Creates a new distributed application builder
createBuilder();

const 
const db: PostgresDatabaseResource
db = await 
const builder: IDistributedApplicationBuilder
builder
  .
IDistributedApplicationBuilder.addPostgres(name: string, options?: {
    userName?: string | ParameterResource;
    password?: string | ParameterResource;
    port?: number;
}): PostgresServerResource (+1 overload)
Adds a PostgreSQL server resource
addPostgres("db")
  .
PostgresServerResource.addDatabase(name: string, options?: {
    databaseName?: string;
} | undefined): PostgresDatabaseResource (+1 overload)
Adds a PostgreSQL database
addDatabase("appdata");

// Expose PostgreSQL MCP tools (SQL queries, schema inspection, etc.)
await 
const db: PostgresDatabaseResource
db.
PostgresDatabaseResource.withPostgresMcp(options?: {
    configureContainer?: ((obj: PostgresMcpContainerResource) => Promise<void>) | undefined;
    containerName?: string;
} | undefined): PostgresDatabaseResource (+1 overload)
Adds Postgres MCP server
withPostgresMcp();

await 
const builder: IDistributedApplicationBuilder
builder.
IDistributedApplicationBuilder.build(): DistributedApplication
Builds the distributed application
build().
DistributedApplication.run(cancellationToken?: cancellationToken): void
Runs the distributed application
run();

Discover available tools

Use aspire mcp tools to list all MCP tools exposed by running resources:

aspire mcp tools

For machine-readable output including input schemas:

aspire mcp tools --format Json

Call a tool

Use aspire mcp call to invoke a specific tool on a resource:

aspire mcp call <resource> <tool> --input '{"key": "value"}'

For example, to run a SQL query on a PostgreSQL resource:

aspire mcp call appdata query --input '{"sql": "SELECT * FROM users LIMIT 5"}'

Custom MCP server resources

You can add any container that implements the MCP protocol as an MCP-enabled resource. Use WithMcpServer() to tell Aspire where the MCP endpoint lives:

C#
TypeScript

#pragma warning disable ASPIREMCP001

var builder = DistributedApplication.CreateBuilder(args);

// Add a custom MCP server container
var myMcpServer = builder.AddContainer("my-mcp", "myregistry/my-mcp-server")
    .WithHttpEndpoint(targetPort: 8080)
    .WithMcpServer("/mcp");

builder.Build().Run();

import { 
function createBuilder(): IDistributedApplicationBuilder
Creates a new distributed application builder
createBuilder } from './.modules/aspire.js';

const 
const builder: IDistributedApplicationBuilder
builder = await 
function createBuilder(): IDistributedApplicationBuilder
Creates a new distributed application builder
createBuilder();

// Add a custom MCP server container
const 
const myMcpServer: ContainerResource
myMcpServer = await 
const builder: IDistributedApplicationBuilder
builder
  .
IDistributedApplicationBuilder.addContainer(name: string, image: string): ContainerResource
Adds a container resource
addContainer("my-mcp", "myregistry/my-mcp-server")
  .
ContainerResource.withHttpEndpoint(options?: {
    port?: number;
    targetPort?: number;
    name?: string;
    env?: string;
    isProxied?: boolean;
} | undefined): ContainerResource (+1 overload)
Adds an HTTP endpoint
withHttpEndpoint({ 
targetPort?: number | undefined
targetPort: 8080 })
  .
ContainerResource.withMcpServer(path?: string, endpointName?: string): ContainerResource (+1 overload)
Configures an MCP server endpoint on the resource
withMcpServer("/mcp");

await 
const builder: IDistributedApplicationBuilder
builder.
IDistributedApplicationBuilder.build(): DistributedApplication
Builds the distributed application
build().
DistributedApplication.run(cancellationToken?: cancellationToken): void
Runs the distributed application
run();

The WithMcpServer() method accepts an optional path and endpoint name:

WithMcpServer() — uses the default HTTP endpoint at the root path
WithMcpServer("/mcp") — uses the default HTTP endpoint at /mcp
WithMcpServer("/sse", endpointName: "https") — uses a named endpoint at /sse