feat(core): add native skill activation

packages/schema/src/session-event.ts

@@ -141,6 +141,20 @@ export const Synthetic = Event.define({
 })
 export type Synthetic = typeof Synthetic.Type
 
+export namespace Skill {
+  export const Activated = Event.define({
+    type: "session.next.skill.activated",
+    ...options,
+    schema: {
+      ...Base,
+      messageID: SessionMessage.ID,
+      name: Schema.String,
+      text: Schema.String,
+    },
+  })
+  export type Activated = typeof Activated.Type
+}
+
 export namespace Shell {
   export const Started = Event.define({
     type: "session.next.shell.started",
@@ -476,6 +490,7 @@ export const DurableDefinitions = Event.inventory(
   PromptAdmitted,
   ContextUpdated,
   Synthetic,
+  Skill.Activated,
   Shell.Started,
   Shell.Ended,
   Step.Started,
@@ -509,6 +524,7 @@ export const Definitions = Event.inventory(
   PromptAdmitted,
   ContextUpdated,
   Synthetic,
+  Skill.Activated,
   Shell.Started,
   Shell.Ended,
   Step.Started,

packages/schema/src/session-message.ts

@@ -65,6 +65,14 @@ export const System = Schema.Struct({
   text: Schema.String,
 }).annotate({ identifier: "Session.Message.System" })
 
+export interface Skill extends Schema.Schema.Type<typeof Skill> {}
+export const Skill = Schema.Struct({
+  ...Base,
+  type: Schema.Literal("skill"),
+  name: Schema.String,
+  text: Schema.String,
+}).annotate({ identifier: "Session.Message.Skill" })
+
 export interface Shell extends Schema.Schema.Type<typeof Shell> {}
 export const Shell = Schema.Struct({
   ...Base,
@@ -203,11 +211,12 @@ export const Message = Schema.Union([
   User,
   Synthetic,
   System,
+  Skill,
   Shell,
   Assistant,
   Compaction,
 ])
   .pipe(Schema.toTaggedUnion("type"))
   .annotate({ identifier: "Session.Message" })
-export type Message = AgentSwitched | ModelSwitched | User | Synthetic | System | Shell | Assistant | Compaction
+export type Message = AgentSwitched | ModelSwitched | User | Synthetic | System | Skill | Shell | Assistant | Compaction
 export type Type = Message["type"]