fix(coding-agent): handle frontmatter prompts in print mode

closes #4163

packages/coding-agent/CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## [Unreleased]
 
+### Fixed
+
+- Fixed `pi -p` treating prompts that start with YAML frontmatter as extension flags instead of user messages ([#4163](https://github.com/badlogic/pi-mono/issues/4163)).
+
 ## [0.73.0] - 2026-05-04
 
 ### New Features

packages/coding-agent/src/cli/args.ts

@@ -122,6 +122,11 @@ export function parseArgs(args: string[]): Args {
 			}
 		} else if (arg === "--print" || arg === "-p") {
 			result.print = true;
+			const next = args[i + 1];
+			if (next !== undefined && !next.startsWith("@") && (!next.startsWith("-") || next.startsWith("---"))) {
+				result.messages.push(next);
+				i++;
+			}
 		} else if (arg === "--export" && i + 1 < args.length) {
 			result.export = args[++i];
 		} else if ((arg === "--extension" || arg === "-e") && i + 1 < args.length) {

packages/coding-agent/test/args.test.ts

@@ -43,6 +43,21 @@ describe("parseArgs", () => {
 			const result = parseArgs(["-p"]);
 			expect(result.print).toBe(true);
 		});
+
+		test("parses prompt after -p even when it starts with YAML frontmatter", () => {
+			const prompt = "---\ntitle: hello\n---\nSay hi.";
+			const result = parseArgs(["-p", prompt]);
+			expect(result.print).toBe(true);
+			expect(result.messages).toEqual([prompt]);
+			expect(result.unknownFlags.size).toBe(0);
+		});
+
+		test("does not consume options after -p as prompts", () => {
+			const result = parseArgs(["-p", "--provider", "openai", "Say hi."]);
+			expect(result.print).toBe(true);
+			expect(result.provider).toBe("openai");
+			expect(result.messages).toEqual(["Say hi."]);
+		});
 	});
 
 	describe("--continue flag", () => {