extensions!

pi/files/agent/extensions/custom-footer.ts

@@ -0,0 +1,64 @@
+/**
+ * Custom Footer Extension - demonstrates ctx.ui.setFooter()
+ *
+ * footerData exposes data not otherwise accessible:
+ * - getGitBranch(): current git branch
+ * - getExtensionStatuses(): texts from ctx.ui.setStatus()
+ *
+ * Token stats come from ctx.sessionManager/ctx.model (already accessible).
+ */
+
+import type { AssistantMessage } from "@mariozechner/pi-ai";
+import type { ExtensionAPI } from "@mariozechner/pi-coding-agent";
+import { truncateToWidth, visibleWidth } from "@mariozechner/pi-tui";
+
+export default function (pi: ExtensionAPI) {
+	let enabled = false;
+
+	pi.registerCommand("footer", {
+		description: "Toggle custom footer",
+		handler: async (_args, ctx) => {
+			enabled = !enabled;
+
+			if (enabled) {
+				ctx.ui.setFooter((tui, theme, footerData) => {
+					const unsub = footerData.onBranchChange(() => tui.requestRender());
+
+					return {
+						dispose: unsub,
+						invalidate() {},
+						render(width: number): string[] {
+							// Compute tokens from ctx (already accessible to extensions)
+							let input = 0,
+								output = 0,
+								cost = 0;
+							for (const e of ctx.sessionManager.getBranch()) {
+								if (e.type === "message" && e.message.role === "assistant") {
+									const m = e.message as AssistantMessage;
+									input += m.usage.input;
+									output += m.usage.output;
+									cost += m.usage.cost.total;
+								}
+							}
+
+							// Get git branch (not otherwise accessible)
+							const branch = footerData.getGitBranch();
+							const fmt = (n: number) => (n < 1000 ? `${n}` : `${(n / 1000).toFixed(1)}k`);
+
+							const left = theme.fg("dim", `↑${fmt(input)} ↓${fmt(output)} $${cost.toFixed(3)}`);
+							const branchStr = branch ? ` (${branch})` : "";
+							const right = theme.fg("dim", `${ctx.model?.id || "no-model"}${branchStr}`);
+
+							const pad = " ".repeat(Math.max(1, width - visibleWidth(left) - visibleWidth(right)));
+							return [truncateToWidth(left + pad + right, width)];
+						},
+					};
+				});
+				ctx.ui.notify("Custom footer enabled", "info");
+			} else {
+				ctx.ui.setFooter(undefined);
+				ctx.ui.notify("Default footer restored", "info");
+			}
+		},
+	});
+}