diff --git a/packages/coding-agent/CHANGELOG.md b/packages/coding-agent/CHANGELOG.md
index 2aaa98a1..90ce4736 100644
--- a/packages/coding-agent/CHANGELOG.md
+++ b/packages/coding-agent/CHANGELOG.md
@@ -5,6 +5,7 @@
 ### Fixed
 
 - Fixed `ctrl+z` suspend and `fg` resume reliability by keeping the process alive until the `SIGCONT` handler restores the TUI, avoiding immediate process exit in environments with no other live event-loop handles ([#2454](https://github.com/badlogic/pi-mono/issues/2454))
+- Fixed `createAgentSession({ agentDir })` to derive the default persisted session path from the provided `agentDir`, keeping session storage aligned with settings, auth, models, and resource loading ([#2457](https://github.com/badlogic/pi-mono/issues/2457))
 
 ## [0.61.0] - 2026-03-20
 
diff --git a/packages/coding-agent/src/core/sdk.ts b/packages/coding-agent/src/core/sdk.ts
index 7ef0ac7f..a67ab3f3 100644
--- a/packages/coding-agent/src/core/sdk.ts
+++ b/packages/coding-agent/src/core/sdk.ts
@@ -11,7 +11,7 @@ import { ModelRegistry } from "./model-registry.js";
 import { findInitialModel } from "./model-resolver.js";
 import type { ResourceLoader } from "./resource-loader.js";
 import { DefaultResourceLoader } from "./resource-loader.js";
-import { SessionManager } from "./session-manager.js";
+import { getDefaultSessionDir, SessionManager } from "./session-manager.js";
 import { SettingsManager } from "./settings-manager.js";
 import { time } from "./timings.js";
 import {
@@ -176,7 +176,7 @@ export async function createAgentSession(options: CreateAgentSessionOptions = {}
 	const modelRegistry = options.modelRegistry ?? new ModelRegistry(authStorage, modelsPath);
 
 	const settingsManager = options.settingsManager ?? SettingsManager.create(cwd, agentDir);
-	const sessionManager = options.sessionManager ?? SessionManager.create(cwd);
+	const sessionManager = options.sessionManager ?? SessionManager.create(cwd, getDefaultSessionDir(cwd, agentDir));
 
 	if (!resourceLoader) {
 		resourceLoader = new DefaultResourceLoader({ cwd, agentDir, settingsManager });
diff --git a/packages/coding-agent/src/core/session-manager.ts b/packages/coding-agent/src/core/session-manager.ts
index e22a2e0a..1f908e46 100644
--- a/packages/coding-agent/src/core/session-manager.ts
+++ b/packages/coding-agent/src/core/session-manager.ts
@@ -418,9 +418,9 @@ export function buildSessionContext(
  * Compute the default session directory for a cwd.
  * Encodes cwd into a safe directory name under ~/.pi/agent/sessions/.
  */
-function getDefaultSessionDir(cwd: string): string {
+export function getDefaultSessionDir(cwd: string, agentDir: string = getDefaultAgentDir()): string {
 	const safePath = `--${cwd.replace(/^[/\\]/, "").replace(/[/\\:]/g, "-")}--`;
-	const sessionDir = join(getDefaultAgentDir(), "sessions", safePath);
+	const sessionDir = join(agentDir, "sessions", safePath);
 	if (!existsSync(sessionDir)) {
 		mkdirSync(sessionDir, { recursive: true });
 	}
diff --git a/packages/coding-agent/test/sdk-session-manager.test.ts b/packages/coding-agent/test/sdk-session-manager.test.ts
new file mode 100644
index 00000000..554660b5
--- /dev/null
+++ b/packages/coding-agent/test/sdk-session-manager.test.ts
@@ -0,0 +1,66 @@
+import { existsSync, mkdirSync, rmSync } from "node:fs";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import { getModel } from "@mariozechner/pi-ai";
+import { afterEach, beforeEach, describe, expect, it } from "vitest";
+import { createAgentSession } from "../src/core/sdk.js";
+import { SessionManager } from "../src/core/session-manager.js";
+
+describe("createAgentSession session manager defaults", () => {
+	let tempDir: string;
+	let cwd: string;
+	let agentDir: string;
+
+	beforeEach(() => {
+		tempDir = join(tmpdir(), `pi-sdk-session-test-${Date.now()}-${Math.random().toString(36).slice(2)}`);
+		cwd = join(tempDir, "project");
+		agentDir = join(tempDir, "agent");
+		mkdirSync(cwd, { recursive: true });
+		mkdirSync(agentDir, { recursive: true });
+	});
+
+	afterEach(() => {
+		if (tempDir && existsSync(tempDir)) {
+			rmSync(tempDir, { recursive: true, force: true });
+		}
+	});
+
+	it("uses agentDir for the default persisted session path", async () => {
+		const model = getModel("anthropic", "claude-sonnet-4-5");
+		expect(model).toBeTruthy();
+
+		const { session } = await createAgentSession({
+			cwd,
+			agentDir,
+			model: model!,
+		});
+
+		const safePath = `--${cwd.replace(/^[/\\]/, "").replace(/[/\\:]/g, "-")}--`;
+		const expectedSessionDir = join(agentDir, "sessions", safePath);
+		const sessionDir = session.sessionManager.getSessionDir();
+		const sessionFile = session.sessionManager.getSessionFile();
+
+		expect(sessionDir).toBe(expectedSessionDir);
+		expect(sessionFile?.startsWith(`${expectedSessionDir}/`)).toBe(true);
+
+		session.dispose();
+	});
+
+	it("keeps an explicit sessionManager override", async () => {
+		const model = getModel("anthropic", "claude-sonnet-4-5");
+		expect(model).toBeTruthy();
+
+		const sessionManager = SessionManager.inMemory(cwd);
+		const { session } = await createAgentSession({
+			cwd,
+			agentDir,
+			model: model!,
+			sessionManager,
+		});
+
+		expect(session.sessionManager).toBe(sessionManager);
+		expect(session.sessionManager.isPersisted()).toBe(false);
+
+		session.dispose();
+	});
+});