feat(web): rewrite subagent conversations for FIFO activation

packages/host/apiproxy/src/api/rpc.schema.ts

@@ -65,7 +65,7 @@ export const rpcErrorSchema: z.ZodType<RpcError> = z.discriminatedUnion('code',
   }) }),
   z.object({ code: z.literal('subagent-not-resumable'), message: z.string(), details: z.object({ childSessionId: z.string() }) }),
   z.object({ code: z.literal('subagent-unauthorized'), message: z.string(), details: z.object({ childSessionId: z.string() }) }),
-  z.object({ code: z.literal('subagent-not-delivered'), message: z.string(), details: z.object({ childSessionId: z.string() }) }),
+  z.object({ code: z.literal('subagent-delivery-unavailable'), message: z.string(), details: z.object({ childSessionId: z.string() }) }),
   z.object({ code: z.literal('internal'), message: z.string(), details: z.object({}) }),
 ]) as unknown as z.ZodType<RpcError>
 

packages/host/apiproxy/src/api/rpc.ts

@@ -80,7 +80,7 @@ export interface RpcErrorDetailsMap {
   }
   'subagent-not-resumable': { childSessionId: SessionId }
   'subagent-unauthorized': { childSessionId: SessionId }
-  'subagent-not-delivered': { childSessionId: SessionId }
+  'subagent-delivery-unavailable': { childSessionId: SessionId }
   'internal': {}
 }
 

packages/host/apiproxy/src/api/subagents.schema.ts

@@ -1,19 +1,29 @@
 /** Zod schemas for the browser-safe subagent domain. */
 
 import { z } from 'zod'
+import type { MessageId } from '@deepseek-ai/dsh-llm/brand'
 import type { RequestPayload, ResponseValue } from './rpc-map.ts'
 import type { Wire } from './rpc.schema.ts'
-import { contentBlockSchema, historyEntrySchema, sessionIdSchema } from './sessions.schema.ts'
-import type { MessageId } from '@deepseek-ai/dsh-llm/brand'
+import {
+  contentBlockSchema, historyEntrySchema, sessionIdSchema, sessionProjectionsBlockSchema,
+} from './sessions.schema.ts'
 import type { SubagentListEntry } from './subagents.ts'
 
 /** Healthy and diagnostic durable catalog rows. */
-export const subagentListEntrySchema = z.discriminatedUnion('kind', [
+export const subagentListEntrySchema = z.union([
   z.object({
     kind: z.literal('child'),
     id: sessionIdSchema,
-    label: z.string(),
+    mode: z.literal('one-shot'),
     activity: z.union([z.literal('running'), z.literal('inactive')]),
+    label: z.string().optional(),
+  }),
+  z.object({
+    kind: z.literal('child'),
+    id: sessionIdSchema,
+    mode: z.literal('continuable'),
+    activity: z.union([z.literal('running'), z.literal('inactive')]),
+    label: z.string(),
   }),
   z.object({
     kind: z.literal('diagnostic'),
@@ -37,6 +47,7 @@ export const subagentListValueSchema = z.object({
 export const subagentHistoryRequestSchema = z.object({
   parentSessionId: sessionIdSchema,
   childSessionId: sessionIdSchema,
+  mode: z.union([z.literal('one-shot'), z.literal('continuable')]),
   beforeSeq: z.number().int().nonnegative().optional(),
   maxMessages: z.number().int().positive().optional(),
 }) satisfies z.ZodType<Wire<RequestPayload<'subagent.history'>>>
@@ -45,12 +56,14 @@ export const subagentHistoryRequestSchema = z.object({
 export const subagentHistoryValueSchema = z.object({
   events: z.array(historyEntrySchema),
   hasMore: z.boolean(),
+  projections: sessionProjectionsBlockSchema.optional(),
 }) as unknown as z.ZodType<Wire<ResponseValue<'subagent.history'>>>
 
 /** subagent.prompt request payload. */
 export const subagentPromptRequestSchema = z.object({
   parentSessionId: sessionIdSchema,
   childSessionId: sessionIdSchema,
+  mode: z.literal('continuable'),
   content: z.array(contentBlockSchema),
 }) as unknown as z.ZodType<RequestPayload<'subagent.prompt'>>
 

packages/host/apiproxy/src/api/subagents.ts

@@ -1,23 +1,31 @@
 /**
  * Browser-safe subagent domain contract. Persisted transcript reads never
- * activate an Agent, while prompts route through the direct parent's
- * Activation-backed continuation owner.
+ * activate an Agent, while continuable prompts route through the exact live
+ * direct parent into the child's Agent inbox.
  */
 
 import type { MessageId } from '@deepseek-ai/dsh-llm/brand'
 import type { ContentBlock } from '@deepseek-ai/dsh-llm/types'
 import type { SessionId } from '@deepseek-ai/dsh-session/types'
 import type { RpcRequest, RpcResponse } from './rpc.ts'
-import type { HistoryEntry } from './sessions.ts'
+import type { HistoryEntry, SessionProjectionsBlock } from './sessions.ts'
 
 /** Complete durable direct-child catalog row. */
 export type SubagentListEntry =
   | {
     kind: 'child'
     id: SessionId
-    label: string
     activity: 'running' | 'inactive'
-  }
+  } & (
+    | {
+      mode: 'one-shot'
+      label?: string
+    }
+    | {
+      mode: 'continuable'
+      label: string
+    }
+  )
   | {
     kind: 'diagnostic'
     id: SessionId
@@ -30,10 +38,15 @@ export interface SubagentPromptReceipt {
 }
 
 /** Durable parent/child address that selects subagent transport in the client. */
-export interface SubagentAddress {
-  parentSessionId: SessionId
-  childSessionId: SessionId
-}
+export type SubagentAddress =
+  & {
+    parentSessionId: SessionId
+    childSessionId: SessionId
+  }
+  & (
+    | { mode: 'one-shot' }
+    | { mode: 'continuable' }
+  )
 
 /** Complete direct-child catalog plus the delivery-time parent availability hint. */
 export interface SubagentCatalog {
@@ -44,8 +57,9 @@ export interface SubagentCatalog {
 /** Subagent-domain unary methods. */
 export interface SubagentsApi {
   /**
-   * Lists direct continuable children without loading either side. Parent
-   * availability is a hint; prompt performs the authoritative check.
+   * Lists direct session-backed children without loading either side. Parent
+   * availability is a hint; continuable prompt performs the authoritative
+   * check.
    */
   list(
     request: RpcRequest<{ parentSessionId: SessionId }>,
@@ -59,14 +73,21 @@ export interface SubagentsApi {
   history(
     request: RpcRequest<SubagentAddress & { beforeSeq?: number; maxMessages?: number }>,
     signal?: AbortSignal,
-  ): Promise<RpcResponse<{ events: HistoryEntry[]; hasMore: boolean }>>
+  ): Promise<RpcResponse<{
+    events: HistoryEntry[]
+    hasMore: boolean
+    projections?: SessionProjectionsBlock
+  }>>
 
   /**
-   * Delivers human content through the exact live parent's continuation
-   * owner. Success identifies the accepted inbox message.
+   * Delivers human content to a continuable child through the exact live
+   * parent's continuation owner. Success identifies the message accepted by
+   * the child's FIFO inbox; later execution is independent of this request.
    */
   prompt(
-    request: RpcRequest<SubagentAddress & { content: ContentBlock[] }>,
-    signal?: AbortSignal,
+    request: RpcRequest<
+      Extract<SubagentAddress, { mode: 'continuable' }> & { content: ContentBlock[] }
+    >,
+    signal: AbortSignal,
   ): Promise<RpcResponse<SubagentPromptReceipt>>
 }