fix: surface config startup failures

packages/ui/stdio-agent/src/index.ts

@@ -102,16 +102,23 @@ export const Config: z<Config> = z.object({
 })
 
 /**
- * Compose the spine with the stdio front door. The console logger comes first
- * (infra), then the agent-core bundle pre-creating one agent from this app's
- * `model`/`resumeSessionId` with the deployment `persona`, then the JSONL
- * backend, then the readline UI rendering that object as `main`. The `hmr` dev-reload plugin is
- * a leaf concern (see the module doc), so it is not mounted here.
+ * Compose the spine with the stdio front door. Console logging, persistence,
+ * and user interaction mount first; the readline UI then waits on the agent
+ * registry and subscribes to config-start failures before agent-core can start
+ * the configured identity. The ask-user tool waits on the completed spine.
+ * The `hmr` dev-reload plugin is a leaf concern (see the module doc), so it is
+ * not mounted here.
  */
 export function apply(ctx: Context, config: Config): void {
   const resumeSessionId = config.resumeSessionId === '' ? undefined : config.resumeSessionId
   const sessionId = SessionId(resumeSessionId ?? `main-session-${randomUUID()}`)
   ctx.plugin(ConsoleExporter)
+  ctx.plugin(SessionPersistenceJsonl, { root: config.persistenceRoot ?? './.sessions' })
+  ctx.plugin(UserInteractionService)
+  ctx.plugin(uiStdio, {
+    welcome: config.welcome ?? 'ready.',
+    sessionId,
+  })
   ctx.plugin(agentCore, {
     ...config.persona !== undefined ? { persona: config.persona } : {},
     ...config.toolOrder !== undefined ? { toolOrder: config.toolOrder } : {},
@@ -124,11 +131,5 @@ export function apply(ctx: Context, config: Config): void {
     }],
     ...config.skills !== undefined ? { skills: config.skills } : {},
   })
-  ctx.plugin(SessionPersistenceJsonl, { root: config.persistenceRoot ?? './.sessions' })
-  ctx.plugin(UserInteractionService)
   ctx.plugin(toolAskUser)
-  ctx.plugin(uiStdio, {
-    welcome: config.welcome ?? 'ready.',
-    sessionId,
-  })
 }

packages/ui/stdio-agent/src/stdio-chat.ts

@@ -21,6 +21,7 @@ import type { Readable, Writable } from 'node:stream'
 import type { Context } from 'cordis'
 import z from 'schemastery'
 import type { Agent } from '@deepseek-ai/dsh-agent'
+import type {} from '@deepseek-ai/dsh-agent-loop'
 import {
   UserInteractionError,
   type AskUserQuestionAnswer,
@@ -173,6 +174,7 @@ export function createStdioChat(ctx: Context, config: Config, runtime: StdioRunt
     const queuedInput: string[] = []
     let targetReady = target !== undefined
     let hadReadyTarget = targetReady
+    let failedStartup: { error: unknown } | undefined
 
     const submit = (agent: Agent, text: string): void => {
       submittedWork = true
@@ -187,6 +189,7 @@ export function createStdioChat(ctx: Context, config: Config, runtime: StdioRunt
       if (!matchesConfiguredIdentity(agent)) return
       target = agent
       targetReady = false
+      failedStartup = undefined
     })
     const disposeSessionStartListener = ctx.on('agent/session-start', (agent) => {
       if (agent !== target) return
@@ -220,6 +223,18 @@ export function createStdioChat(ctx: Context, config: Config, runtime: StdioRunt
       exitTimer = setTimeout(() => { exit(0) }, 200)
     }
 
+    const disposeStartupFailedListener = ctx.on('agent-loop/config-start-failed', (sessionId, error) => {
+      if (sessionId !== config.sessionId || targetReady) return
+      failedStartup = { error }
+      const dropped = queuedInput.length
+      queuedInput.length = 0
+      submittedWork = sawRunning
+      if (dropped > 0) {
+        ctx.logger.error(`ui-stdio: main agent failed to start; dropped queued stdin (${dropped} line(s)): ${String(error)}`)
+      }
+      maybeExit()
+    })
+
     const disposeStatusListener = ctx.on('agent/status', (subject, status) => {
       if (subject !== target) return
       if (status === 'running') sawRunning = true
@@ -374,6 +389,10 @@ export function createStdioChat(ctx: Context, config: Config, runtime: StdioRunt
       }
       const text = line.trim()
       if (!text) return
+      if (failedStartup !== undefined) {
+        ctx.logger.error(`ui-stdio: main agent failed to start; dropped queued stdin (1 line(s)): ${String(failedStartup.error)}`)
+        return
+      }
       const agent = target
       if (agent === undefined || !targetReady) {
         // Initial exact-id restoration is asynchronous. Preserve input until
@@ -407,6 +426,7 @@ export function createStdioChat(ctx: Context, config: Config, runtime: StdioRunt
       disposeCreatedListener()
       disposeSessionStartListener()
       disposeDisposedListener()
+      disposeStartupFailedListener()
       reader.close()
     }
   }, 'ui-stdio')