Add Linear issue worktree workflow

config/pi/extensions/worktree-agent/index.ts

@@ -0,0 +1,75 @@
+import type { ExtensionAPI } from "@earendil-works/pi-coding-agent";
+import { registerWorkerGuard } from "./guard.ts";
+import { WorktreeAgentParameters, type ProgressReporter } from "./types.ts";
+import { runWorker } from "./worker.ts";
+import { isParentClean, prepareWorktree } from "./worktree.ts";
+
+function shellQuote(value: string): string {
+  return `'${value.replace(/'/g, `'"'"'`)}'`;
+}
+
+export default function worktreeAgentExtension(pi: ExtensionAPI) {
+  const workerRoot = process.env.PI_WORKTREE_ROOT;
+  if (process.env.PI_WORKTREE_AGENT === "1" && workerRoot) {
+    registerWorkerGuard(pi, workerRoot);
+    return;
+  }
+
+  pi.registerTool({
+    name: "run_issue_in_worktree",
+    label: "Run issue in worktree",
+    description:
+      "Create an isolated Git worktree for a retrieved Linear issue and run a child Pi agent there. " +
+      "Call this only after retrieving and understanding the Linear issue. The call remains active until the child finishes.",
+    promptSnippet: "Run a retrieved Linear issue in an isolated Git worktree using a child Pi agent",
+    promptGuidelines: [
+      "Use run_issue_in_worktree only after retrieving the Linear issue, then let the child agent perform all repository modifications.",
+      "When run_issue_in_worktree is active, do not modify files in the parent checkout.",
+    ],
+    parameters: WorktreeAgentParameters,
+
+    async execute(_toolCallId, params, signal, onUpdate, ctx) {
+      const report: ProgressReporter = (message, details) => {
+        onUpdate?.({ content: [{ type: "text", text: message }], details });
+      };
+
+      const worktree = await prepareWorktree(pi, ctx.cwd, params, report);
+      const workerReport = await runWorker({
+        input: params,
+        worktree,
+        model: ctx.model,
+        thinkingLevel: pi.getThinkingLevel(),
+        signal,
+        report,
+      });
+
+      const parentClean = await isParentClean(pi, worktree.repoRoot);
+      const resumeCommand =
+        `cd ${shellQuote(worktree.worktreePath)} && ` +
+        'PI_WORKTREE_AGENT=1 PI_WORKTREE_ROOT="$PWD" pi -c';
+      const parentWarning = parentClean
+        ? ""
+        : "\n\nWARNING: The parent working tree is no longer clean; inspect it before continuing.";
+
+      return {
+        content: [
+          {
+            type: "text",
+            text:
+              `Child Pi finished in ${worktree.worktreePath}.\n` +
+              `Branch: ${worktree.branchName}\n` +
+              `Resume: ${resumeCommand}\n\n${workerReport}${parentWarning}`,
+          },
+        ],
+        details: {
+          phase: "complete",
+          branchName: worktree.branchName,
+          worktreePath: worktree.worktreePath,
+          parentClean,
+          resumeCommand,
+          workerReport,
+        },
+      };
+    },
+  });
+}