feat: select subagent runner from config

index.ts

@@ -2,8 +2,13 @@ import type { ExtensionAPI } from "@mariozechner/pi-coding-agent";
 import { dirname, join } from "node:path";
 import { fileURLToPath } from "node:url";
 import { createRunArtifacts } from "./src/artifacts.ts";
+import { loadSubagentsConfig } from "./src/config.ts";
 import { monitorRun } from "./src/monitor.ts";
 import { listAvailableModelReferences } from "./src/models.ts";
+import { createProcessSingleRunner } from "./src/process-runner.ts";
+import { createConfiguredRunSingleTask } from "./src/runner.ts";
+import { createSubagentParamsSchema } from "./src/schema.ts";
+import { createSubagentTool } from "./src/tool.ts";
 import { createTmuxSingleRunner } from "./src/tmux-runner.ts";
 import {
   buildCurrentWindowArgs,
@@ -12,31 +17,27 @@ import {
   buildWrapperShellCommand,
   isInsideTmux,
 } from "./src/tmux.ts";
-import { createSubagentParamsSchema } from "./src/schema.ts";
-import { createSubagentTool } from "./src/tool.ts";
 
 const packageRoot = dirname(fileURLToPath(import.meta.url));
 const wrapperPath = join(packageRoot, "src", "wrapper", "cli.mjs");
 
-export default function tmuxSubagentExtension(pi: ExtensionAPI) {
-  if (process.env.PI_TMUX_SUBAGENT_GITHUB_COPILOT_INITIATOR === "agent") {
+export default function subagentsExtension(pi: ExtensionAPI) {
+  if (process.env.PI_SUBAGENTS_GITHUB_COPILOT_INITIATOR === "agent") {
     pi.registerProvider("github-copilot", {
       headers: { "X-Initiator": "agent" },
     });
   }
 
-  // In wrapper/child sessions spawned by the tmux runner we must not register the
-  // subagent tool (that would cause nested subagent registrations). Skip all
-  // subagent-tool registration logic when PI_TMUX_SUBAGENT_CHILD is set. Provider
-  // overrides (above) are still allowed in child runs, so the guard is placed
-  // after provider registration.
-  if (process.env.PI_TMUX_SUBAGENT_CHILD === "1") {
+  // In wrapper/child sessions spawned by subagent runners we must not register
+  // the subagent tool again. Provider overrides above are still allowed in child
+  // runs, so the guard stays after provider registration.
+  if (process.env.PI_SUBAGENTS_CHILD === "1") {
     return;
   }
 
   let lastRegisteredModelsKey: string | undefined;
 
-  const runSingleTask = createTmuxSingleRunner({
+  const tmuxRunner = createTmuxSingleRunner({
     assertInsideTmux() {
       if (!isInsideTmux()) throw new Error("tmux-backed subagents require pi to be running inside tmux.");
     },
@@ -58,6 +59,20 @@ export default function tmuxSubagentExtension(pi: ExtensionAPI) {
     },
   });
 
+  const processRunner = createProcessSingleRunner({
+    createArtifacts: createRunArtifacts,
+    buildWrapperSpawn(metaPath: string) {
+      return { command: process.execPath, args: [wrapperPath, metaPath] };
+    },
+    monitorRun,
+  });
+
+  const runSingleTask = createConfiguredRunSingleTask({
+    loadConfig: (cwd) => loadSubagentsConfig(cwd),
+    processRunner,
+    tmuxRunner,
+  });
+
   const registerSubagentTool = (availableModels: string[]) => {
     // Do not register a tool when no models are available. Remember that the
     // last-registered key is different from the empty sentinel so that a later