fix(pi-subagents): inherit models and finalize provider errors

extensions/pi-subagents/README.md

@@ -1,6 +1,6 @@
 # pi-subagents
 
-Minimal recursive child-Pi spawner for Pi.
+Minimal recursive child-Pi spawner for Pi 0.80.4 or newer.
 
 This extension intentionally does **not** define roles, agent types, chains, or parallel task lists. The parent agent supplies the full prompt and instructions for each child.
 
@@ -22,6 +22,7 @@ spawn_subagent({
 - No wait-for-completion mode exists; calls always return immediately with an ID and resultPath.
 - You will be notified when the subagent completes.
 - The returned ID is also the child Pi session ID and can be used with Pi session lookup/resume behavior.
+- `model` is an explicit override; omitting it inherits the active parent provider/model.
 - `timeout` is optional (default 600s = 10 minutes) and measured in seconds. When reached, the parent is informed that the child is still running; the child is **not killed**.
 - Give `timeout` a healthy margin above expected runtime because child execution time can be wildly unpredictable.
 - Subagents always start with fresh session history. Put any desired context explicitly in `task`.

extensions/pi-subagents/package.json

@@ -51,7 +51,7 @@
   "peerDependencies": {
     "@earendil-works/pi-agent-core": "*",
     "@earendil-works/pi-ai": "*",
-    "@earendil-works/pi-coding-agent": "*",
+    "@earendil-works/pi-coding-agent": ">=0.80.4",
     "@earendil-works/pi-tui": "*"
   },
   "peerDependenciesMeta": {
@@ -73,9 +73,9 @@
     "typebox": "^1.1.24"
   },
   "devDependencies": {
-    "@earendil-works/pi-agent-core": "^0.74.0",
-    "@earendil-works/pi-ai": "^0.74.0",
-    "@earendil-works/pi-coding-agent": "^0.74.0",
-    "@earendil-works/pi-tui": "^0.74.0"
+    "@earendil-works/pi-agent-core": "^0.80.4",
+    "@earendil-works/pi-ai": "^0.80.4",
+    "@earendil-works/pi-coding-agent": "^0.80.4",
+    "@earendil-works/pi-tui": "^0.80.4"
   }
 }

extensions/pi-subagents/skills/pi-subagents/SKILL.md

@@ -11,6 +11,7 @@ Use this tool to launch unrestricted child Pi sessions. The caller must include
 
 - `spawn_subagent({ task, timeout?, cwd?, model? })`
   - Calls return immediately; the parent will be notified when the subagent completes.
+  - `model` is an explicit override; omitting it inherits the active parent provider/model.
   - `timeout` is optional; default is `600` seconds (10 minutes).
   - Timeout is only a notification threshold: the parent is informed that the child is still running; the child is not killed.
   - The returned subagent id is also the child Pi session id.
@@ -37,6 +38,7 @@ Calls return immediately; the parent will be notified when each subagent complet
 - No wait-for-completion mode exists.
 - No subagent types exist.
 - No chain or parallel-list mode exists.
+- `model` is an explicit override; omitting it inherits the active parent provider/model.
 - `timeout` is optional and measured in seconds; omitted timeout defaults to 10 minutes.
 - When `timeout` expires, the parent is informed that the subagent is still running; the child is not killed.
 - Do not kill subagents autonomously to enforce `timeout`.

extensions/pi-subagents/src/extension/index.ts

@@ -37,6 +37,7 @@ interface ToolDetails {
 	timedOut?: boolean;
 	timeoutAt?: number;
 	timeoutMessage?: string;
+	model?: string;
 	subagents?: Array<{ id: string; running: boolean }>;
 }
 
@@ -792,14 +793,18 @@ function makeRecord(
 	const id = randomUUID();
 	const parentId = parentSessionId(ctx);
 	const dir = childDir(parentId, id);
+	const inheritedModel = ctx.model
+		? `${ctx.model.provider}/${ctx.model.id}`
+		: undefined;
+	const model = params.model || inheritedModel;
 	fs.mkdirSync(dir, { recursive: true });
 	return {
 		id,
 		parentSessionId: parentId,
 		cwd: params.cwd ? path.resolve(ctx.cwd, params.cwd) : ctx.cwd,
 		taskPreview: params.task.slice(0, 500),
 		timeout: params.timeout ?? DEFAULT_TIMEOUT_SECONDS,
-		...(params.model ? { model: params.model } : {}),
+		...(model ? { model } : {}),
 		running: false,
 		sessionDir: dir,
 		outputFile: path.join(dir, "result.log"),
@@ -1281,7 +1286,7 @@ export default function registerSubagentExtension(pi: ExtensionAPI): void {
 		name: "spawn_subagent",
 		label: "Spawn subagent",
 		description:
-			"Spawn a child Pi subagent for one task. timeout is optional and measured in seconds (default 600 = 10 minutes). This returns immediately, allowing the parent to spawn multiple concurrent subagents by calling spawn_subagent multiple times. Do not kill subagents autonomously to enforce timeout; the parent will be informed when timeout expires. Give a healthy timeout margin above expected runtime because subagent execution may be wildly unpredictable.",
+			"Spawn a child Pi subagent for one task. model is an explicit override; omitting it inherits the active parent provider/model. timeout is optional and measured in seconds (default 600 = 10 minutes). This returns immediately, allowing the parent to spawn multiple concurrent subagents by calling spawn_subagent multiple times. Do not kill subagents autonomously to enforce timeout; the parent will be informed when timeout expires. Give a healthy timeout margin above expected runtime because subagent execution may be wildly unpredictable.",
 		parameters: SpawnSubagentParams,
 		async execute(
 			id,
@@ -1336,13 +1341,14 @@ export default function registerSubagentExtension(pi: ExtensionAPI): void {
 				content: [
 					{
 						type: "text",
-						text: `Spawned subagent ${started.record.id}. Result will be at: ${started.record.outputFile}. You will be notified when this subagent completes. Do not poll for result. Do not sleep for result. Continue with whatever other work you may have.`,
+						text: `Spawned subagent ${started.record.id} using ${started.record.model ?? "Pi's selected model"}. Result will be at: ${started.record.outputFile}. You will be notified when this subagent completes. Do not poll for result. Do not sleep for result. Continue with whatever other work you may have.`,
 					},
 				],
 				details: {
 					id: started.record.id,
 					running: started.record.running,
 					resultPath: started.record.outputFile,
+					...(started.record.model ? { model: started.record.model } : {}),
 				},
 			};
 		},

extensions/pi-subagents/src/extension/schemas.ts

@@ -19,7 +19,10 @@ export const SpawnSubagentParams = Type.Object(
 			}),
 		),
 		model: Type.Optional(
-			Type.String({ description: "Optional model override for the child Pi." }),
+			Type.String({
+				description:
+					"Explicit model override for the child Pi. Omitting it inherits the active parent provider/model.",
+			}),
 		),
 	},
 	{ additionalProperties: false },

extensions/pi-subagents/src/runs/shared/subagent-prompt-runtime.ts

@@ -57,6 +57,31 @@ function setupLifelineWatcher(): void {
 setupLifelineWatcher();
 
 export default function registerSubagentPromptRuntime(pi: ExtensionAPI): void {
+	let settledProviderError: string | undefined;
+	let exitingForProviderError = false;
+
+	pi.on("message_end", (event) => {
+		if (event.message.role !== "assistant") return;
+		if (event.message.stopReason !== "error") {
+			settledProviderError = undefined;
+			return;
+		}
+		settledProviderError =
+			event.message.errorMessage?.trim() ||
+			`Provider/model request failed for ${event.message.provider}/${event.message.model}.`;
+	});
+
+	pi.on("agent_settled", () => {
+		if (!settledProviderError || exitingForProviderError) return;
+		exitingForProviderError = true;
+		process.exitCode = 1;
+		process.stderr.write(`${settledProviderError}\n`);
+		// message_end has been persisted and agent_settled guarantees no retry,
+		// compaction, or queued continuation remains. Force exit because the
+		// dedicated parent lifeline intentionally keeps the event loop alive.
+		setImmediate(() => process.exit(1));
+	});
+
 	pi.on("tool_call", (event) => {
 		if (!FILE_TOOL_NAMES.has(event.toolName)) return;
 		const resultPath = process.env[SUBAGENT_RESULT_PATH_ENV]?.trim();