feat(core): add mcp support (#34513)

packages/schema/src/mcp-event.ts

@@ -18,4 +18,13 @@ export const BrowserOpenFailed = Event.define({
   },
 })
 
-export const Definitions = Event.inventory(ToolsChanged, BrowserOpenFailed)
+// Emitted whenever a server's connection status settles (connected, failed, needs_auth, closed) so
+// observers can refresh status without polling.
+export const StatusChanged = Event.define({
+  type: "mcp.status.changed",
+  schema: {
+    server: Schema.String,
+  },
+})
+
+export const Definitions = Event.inventory(ToolsChanged, BrowserOpenFailed, StatusChanged)

packages/schema/src/mcp.ts

@@ -0,0 +1,39 @@
+export * as Mcp from "./mcp"
+
+import { Schema } from "effect"
+
+const Connected = Schema.Struct({ status: Schema.Literal("connected") }).annotate({
+  identifier: "Mcp.Status.Connected",
+})
+const Disconnected = Schema.Struct({ status: Schema.Literal("disconnected") }).annotate({
+  identifier: "Mcp.Status.Disconnected",
+})
+const Disabled = Schema.Struct({ status: Schema.Literal("disabled") }).annotate({
+  identifier: "Mcp.Status.Disabled",
+})
+const Failed = Schema.Struct({ status: Schema.Literal("failed"), error: Schema.String }).annotate({
+  identifier: "Mcp.Status.Failed",
+})
+const NeedsAuth = Schema.Struct({ status: Schema.Literal("needs_auth") }).annotate({
+  identifier: "Mcp.Status.NeedsAuth",
+})
+const NeedsClientRegistration = Schema.Struct({
+  status: Schema.Literal("needs_client_registration"),
+  error: Schema.String,
+}).annotate({ identifier: "Mcp.Status.NeedsClientRegistration" })
+
+export type Status = typeof Status.Type
+export const Status = Schema.Union([
+  Connected,
+  Disconnected,
+  Disabled,
+  Failed,
+  NeedsAuth,
+  NeedsClientRegistration,
+]).pipe(Schema.toTaggedUnion("status"))
+
+export interface Server extends Schema.Schema.Type<typeof Server> {}
+export const Server = Schema.Struct({
+  name: Schema.String,
+  status: Status,
+}).annotate({ identifier: "Mcp.Server" })