diff --git a/packages/core/src/agent/profile/types.ts b/packages/core/src/agent/profile/types.ts
index 228a0788..631eb4b1 100644
--- a/packages/core/src/agent/profile/types.ts
+++ b/packages/core/src/agent/profile/types.ts
@@ -31,6 +31,8 @@ export interface ProfileConfig {
   reasoningMode?: "off" | "on" | "stream" | undefined;
   /** Exec approval configuration (security level, ask mode, allowlist) */
   execApproval?: ExecApprovalConfig | undefined;
+  /** Custom workspace directory path (overrides default) */
+  workspaceDir?: string | undefined;
   /** Heartbeat configuration */
   heartbeat?: {
     /** Global heartbeat enable switch */
diff --git a/packages/core/src/agent/runner.ts b/packages/core/src/agent/runner.ts
index 105eee43..74d8edb5 100644
--- a/packages/core/src/agent/runner.ts
+++ b/packages/core/src/agent/runner.ts
@@ -50,6 +50,7 @@ import {
   sanitizeToolUseResultPairing,
 } from "./session/session-transcript-repair.js";
 import { isContextOverflowError } from "./errors.js";
+import { resolveWorkspaceDir, ensureWorkspaceDir } from "./workspace.js";
 
 // ============================================================
 // Error classification for auth profile rotation
@@ -121,6 +122,9 @@ export class Agent {
   private readonly pinnedProfile: boolean;
   private readonly explicitApiKey: boolean;
 
+  /** Resolved workspace directory */
+  readonly workspaceDir: string;
+
   /** Current session ID */
   readonly sessionId: string;
 
@@ -318,13 +322,22 @@ export class Agent {
       this.originalToolsConfig = options.tools;
     }
 
+    // Resolve workspace directory
+    const profileConfig = this.profile?.getProfile()?.config;
+    this.workspaceDir = resolveWorkspaceDir({
+      profileId: options.profileId,
+      configWorkspaceDir: profileConfig?.workspaceDir,
+    });
+    ensureWorkspaceDir(this.workspaceDir);
+    const effectiveCwd = options.cwd ?? this.workspaceDir;
+
     // Merge Profile tools config with options.tools (options takes precedence)
     const profileToolsConfig = this.profile?.getToolsConfig();
     const mergedToolsConfig = mergeToolsConfig(profileToolsConfig, options.tools);
     const profileDir = this.profile?.getProfileDir();
     this.toolsOptions = mergedToolsConfig
-      ? { ...options, tools: mergedToolsConfig, profileDir, provider: this.resolvedProvider }
-      : { ...options, profileDir, provider: this.resolvedProvider };
+      ? { ...options, cwd: effectiveCwd, tools: mergedToolsConfig, profileDir, provider: this.resolvedProvider }
+      : { ...options, cwd: effectiveCwd, profileDir, provider: this.resolvedProvider };
 
     const tools = resolveTools(this.toolsOptions);
     if (this.debug) {
@@ -1155,6 +1168,7 @@ export class Agent {
       agentName: this.profile?.getName(),
       provider: this.resolvedProvider,
       model: this.agent.state.model?.id,
+      cwd: this.toolsOptions.cwd,
     });
 
     return buildStructuredSystemPrompt({
@@ -1168,6 +1182,7 @@ export class Agent {
         config: profile.config,
       },
       profileDir: this.profile!.getProfileDir(),
+      workspaceDir: this.workspaceDir,
       tools: toolNames,
       skillsPrompt,
       runtime,
diff --git a/packages/core/src/agent/system-prompt/builder.ts b/packages/core/src/agent/system-prompt/builder.ts
index 78829ebf..82d01860 100644
--- a/packages/core/src/agent/system-prompt/builder.ts
+++ b/packages/core/src/agent/system-prompt/builder.ts
@@ -46,6 +46,7 @@ export function buildSystemPromptWithReport(options: SystemPromptOptions): {
     mode,
     profile,
     profileDir,
+    workspaceDir,
     tools,
     skillsPrompt,
     runtime,
@@ -58,7 +59,7 @@ export function buildSystemPromptWithReport(options: SystemPromptOptions): {
   const candidates: Array<{ name: string; lines: string[] }> = [
     { name: "identity", lines: buildIdentitySection(profile, mode) },
     { name: "user", lines: buildUserSection(profile, mode) },
-    { name: "workspace", lines: buildWorkspaceSection(profile, mode, profileDir) },
+    { name: "workspace", lines: buildWorkspaceSection(profile, mode, profileDir, workspaceDir) },
     { name: "memory", lines: buildMemoryFileSection(profile, mode) },
     { name: "heartbeat", lines: buildHeartbeatSection(profile, mode) },
     { name: "safety", lines: buildSafetySection(includeSafety) },
diff --git a/packages/core/src/agent/system-prompt/sections.ts b/packages/core/src/agent/system-prompt/sections.ts
index bc0bc6ed..6826aa7e 100644
--- a/packages/core/src/agent/system-prompt/sections.ts
+++ b/packages/core/src/agent/system-prompt/sections.ts
@@ -89,11 +89,23 @@ export function buildWorkspaceSection(
   profile: ProfileContent | undefined,
   mode: SystemPromptMode,
   profileDir?: string,
+  workspaceDir?: string,
 ): string[] {
   if (mode !== "full") return [];
 
   const lines: string[] = [];
 
+  // Working directory info
+  if (workspaceDir) {
+    lines.push(
+      "## Working Directory",
+      "",
+      `Your working directory is: \`${workspaceDir}\``,
+      "Use this as the default location for file operations unless the user specifies a different path.",
+      "",
+    );
+  }
+
   // Add profile directory context first
   if (profileDir) {
     lines.push(
diff --git a/packages/core/src/agent/system-prompt/types.ts b/packages/core/src/agent/system-prompt/types.ts
index 9f75788e..cf1cc1ba 100644
--- a/packages/core/src/agent/system-prompt/types.ts
+++ b/packages/core/src/agent/system-prompt/types.ts
@@ -75,6 +75,8 @@ export interface SystemPromptOptions {
   runtime?: RuntimeInfo | undefined;
   /** Subagent context (for minimal/none modes) */
   subagent?: SubagentContext | undefined;
+  /** Workspace directory path (for agent working directory info) */
+  workspaceDir?: string | undefined;
   /** Extra system prompt to append */
   extraSystemPrompt?: string | undefined;
   /** Whether to include the safety constitution (default: true) */
diff --git a/packages/core/src/agent/workspace.test.ts b/packages/core/src/agent/workspace.test.ts
new file mode 100644
index 00000000..451a92d8
--- /dev/null
+++ b/packages/core/src/agent/workspace.test.ts
@@ -0,0 +1,107 @@
+import { describe, it, expect, beforeEach, afterEach, vi } from "vitest";
+import fs from "node:fs";
+import os from "node:os";
+import path from "node:path";
+import { resolveWorkspaceDir, ensureWorkspaceDir } from "./workspace.js";
+import { DATA_DIR, DEFAULT_WORKSPACE_DIR } from "@multica/utils";
+
+describe("resolveWorkspaceDir", () => {
+  const originalEnv = process.env.MULTICA_WORKSPACE_DIR;
+
+  afterEach(() => {
+    if (originalEnv === undefined) {
+      delete process.env.MULTICA_WORKSPACE_DIR;
+    } else {
+      process.env.MULTICA_WORKSPACE_DIR = originalEnv;
+    }
+  });
+
+  it("returns ~/.super-multica/workspace/default for default profile", () => {
+    delete process.env.MULTICA_WORKSPACE_DIR;
+    expect(resolveWorkspaceDir()).toBe(path.join(DEFAULT_WORKSPACE_DIR, "default"));
+    expect(resolveWorkspaceDir({ profileId: "default" })).toBe(path.join(DEFAULT_WORKSPACE_DIR, "default"));
+  });
+
+  it("returns ~/.super-multica/workspace/{id} for named profile", () => {
+    delete process.env.MULTICA_WORKSPACE_DIR;
+    const result = resolveWorkspaceDir({ profileId: "research" });
+    expect(result).toBe(path.join(DEFAULT_WORKSPACE_DIR, "research"));
+  });
+
+  it("prioritizes MULTICA_WORKSPACE_DIR env var", () => {
+    process.env.MULTICA_WORKSPACE_DIR = "/tmp/custom-ws";
+    expect(resolveWorkspaceDir({ profileId: "default" })).toBe("/tmp/custom-ws");
+  });
+
+  it("prioritizes config workspaceDir over profile default", () => {
+    delete process.env.MULTICA_WORKSPACE_DIR;
+    const result = resolveWorkspaceDir({
+      profileId: "default",
+      configWorkspaceDir: "/tmp/config-ws",
+    });
+    expect(result).toBe("/tmp/config-ws");
+  });
+
+  it("env var takes precedence over config", () => {
+    process.env.MULTICA_WORKSPACE_DIR = "/tmp/env-ws";
+    const result = resolveWorkspaceDir({
+      profileId: "default",
+      configWorkspaceDir: "/tmp/config-ws",
+    });
+    expect(result).toBe("/tmp/env-ws");
+  });
+
+  it("expands ~ in env var", () => {
+    process.env.MULTICA_WORKSPACE_DIR = "~/my-workspace";
+    const result = resolveWorkspaceDir();
+    expect(result).toBe(path.resolve(path.join(os.homedir(), "my-workspace")));
+  });
+
+  it("expands ~ in config workspaceDir", () => {
+    delete process.env.MULTICA_WORKSPACE_DIR;
+    const result = resolveWorkspaceDir({ configWorkspaceDir: "~/my-ws" });
+    expect(result).toBe(path.resolve(path.join(os.homedir(), "my-ws")));
+  });
+});
+
+describe("ensureWorkspaceDir", () => {
+  let tmpDir: string;
+
+  beforeEach(() => {
+    tmpDir = fs.mkdtempSync(path.join(os.tmpdir(), "multica-ws-test-"));
+  });
+
+  afterEach(() => {
+    fs.rmSync(tmpDir, { recursive: true, force: true });
+  });
+
+  it("creates directory and README.md", () => {
+    const wsDir = path.join(tmpDir, "workspace");
+    ensureWorkspaceDir(wsDir);
+
+    expect(fs.existsSync(wsDir)).toBe(true);
+    const readmePath = path.join(wsDir, "README.md");
+    expect(fs.existsSync(readmePath)).toBe(true);
+    const content = fs.readFileSync(readmePath, "utf-8");
+    expect(content).toContain("Multica Workspace");
+  });
+
+  it("does not overwrite existing README.md", () => {
+    const wsDir = path.join(tmpDir, "workspace");
+    fs.mkdirSync(wsDir, { recursive: true });
+    const readmePath = path.join(wsDir, "README.md");
+    fs.writeFileSync(readmePath, "custom content");
+
+    ensureWorkspaceDir(wsDir);
+
+    const content = fs.readFileSync(readmePath, "utf-8");
+    expect(content).toBe("custom content");
+  });
+
+  it("succeeds when directory already exists", () => {
+    const wsDir = path.join(tmpDir, "workspace");
+    fs.mkdirSync(wsDir, { recursive: true });
+
+    expect(() => ensureWorkspaceDir(wsDir)).not.toThrow();
+  });
+});
diff --git a/packages/core/src/agent/workspace.ts b/packages/core/src/agent/workspace.ts
new file mode 100644
index 00000000..c30eb271
--- /dev/null
+++ b/packages/core/src/agent/workspace.ts
@@ -0,0 +1,45 @@
+import { mkdirSync, writeFileSync } from "node:fs";
+import os from "node:os";
+import path from "node:path";
+import { DATA_DIR, DEFAULT_WORKSPACE_DIR } from "@multica/utils";
+
+/**
+ * Resolve the workspace directory for a given profile.
+ * Priority: env var > config > profile-based default
+ */
+export function resolveWorkspaceDir(options?: {
+  profileId?: string;
+  configWorkspaceDir?: string;
+}): string {
+  // 1. Env var override
+  const envDir = process.env.MULTICA_WORKSPACE_DIR?.trim();
+  if (envDir) return path.resolve(envDir.replace(/^~/, os.homedir()));
+
+  // 2. Config override (from profile config.json)
+  if (options?.configWorkspaceDir?.trim()) {
+    return path.resolve(options.configWorkspaceDir.replace(/^~/, os.homedir()));
+  }
+
+  // 3. Profile-based default: ~/.super-multica/workspace/{profileId}
+  const profileId = options?.profileId ?? "default";
+  return path.join(DEFAULT_WORKSPACE_DIR, profileId);
+}
+
+/**
+ * Ensure workspace directory exists. Creates README.md on first creation.
+ */
+export function ensureWorkspaceDir(dir: string): void {
+  mkdirSync(dir, { recursive: true });
+  const readmePath = path.join(dir, "README.md");
+  try {
+    writeFileSync(readmePath, README_CONTENT, { encoding: "utf-8", flag: "wx" });
+  } catch (err) {
+    if ((err as { code?: string }).code !== "EEXIST") throw err;
+  }
+}
+
+const README_CONTENT = `# Multica Workspace
+
+This directory is the default workspace for your Multica agent.
+Files created by the agent will be saved here unless you specify a different directory.
+`;
diff --git a/packages/utils/src/paths.ts b/packages/utils/src/paths.ts
index 3c047312..da5ebece 100644
--- a/packages/utils/src/paths.ts
+++ b/packages/utils/src/paths.ts
@@ -6,3 +6,6 @@ export const DATA_DIR = join(homedir(), ".super-multica");
 
 /** Cache directory for downloaded media files */
 export const MEDIA_CACHE_DIR = join(DATA_DIR, "cache", "media");
+
+/** Default workspace directory for the default profile */
+export const DEFAULT_WORKSPACE_DIR = join(DATA_DIR, "workspace");