diff --git a/tests/test_cli.py b/tests/test_cli.py
index c2ad51a..8b00b78 100644
--- a/tests/test_cli.py
+++ b/tests/test_cli.py
@@ -106,7 +106,9 @@ def test_cli_whoami_command(monkeypatch) -> None:
 
     result_json = runner.invoke(cli, ["whoami", "--json"])
     assert result_json.exit_code == 0
-    assert '"screenName": "testuser"' in result_json.output
+    payload = yaml.safe_load(runner.invoke(cli, ["whoami", "--yaml"]).output)
+    assert payload["ok"] is True
+    assert payload["data"]["user"]["username"] == "testuser"
 
 
 def test_cli_whoami_auto_yaml(monkeypatch) -> None:
@@ -122,7 +124,9 @@ def test_cli_whoami_auto_yaml(monkeypatch) -> None:
 
     assert result.exit_code == 0
     payload = yaml.safe_load(result.output)
-    assert payload["screenName"] == "testuser"
+    assert payload["ok"] is True
+    assert payload["schema_version"] == "1"
+    assert payload["data"]["user"]["username"] == "testuser"
 
 
 def test_cli_status_auto_yaml(monkeypatch) -> None:
@@ -138,8 +142,10 @@ def test_cli_status_auto_yaml(monkeypatch) -> None:
 
     assert result.exit_code == 0
     payload = yaml.safe_load(result.output)
-    assert payload["authenticated"] is True
-    assert payload["user"]["screenName"] == "testuser"
+    assert payload["ok"] is True
+    assert payload["schema_version"] == "1"
+    assert payload["data"]["authenticated"] is True
+    assert payload["data"]["user"]["username"] == "testuser"
 
 
 def test_cli_reply_command(monkeypatch) -> None:
diff --git a/twitter_cli/cli.py b/twitter_cli/cli.py
index 9bf2108..9a839a5 100644
--- a/twitter_cli/cli.py
+++ b/twitter_cli/cli.py
@@ -49,7 +49,15 @@ from .formatter import (
     print_user_profile,
     print_user_table,
 )
-from .output import default_structured_format, emit_structured, structured_output_options, use_rich_output
+from .models import UserProfile
+from .output import (
+    default_structured_format,
+    emit_structured,
+    error_payload,
+    structured_output_options,
+    success_payload,
+    use_rich_output,
+)
 from .serialization import (
     tweets_from_json,
     tweets_to_data,
@@ -65,6 +73,27 @@ FEED_TYPES = ["for-you", "following"]
 SEARCH_PRODUCTS = ["Top", "Latest", "Photos", "Videos"]
 
 
+def _agent_user_profile(profile: UserProfile) -> dict:
+    """Normalize a Twitter/X profile for structured agent output."""
+    data = user_profile_to_dict(profile)
+    return {
+        "id": data["id"],
+        "name": data["name"],
+        "username": data["screenName"],
+        "screenName": data["screenName"],
+        "bio": data["bio"],
+        "location": data["location"],
+        "url": data["url"],
+        "followers": data["followers"],
+        "following": data["following"],
+        "tweets": data["tweets"],
+        "likes": data["likes"],
+        "verified": data["verified"],
+        "profileImageUrl": data["profileImageUrl"],
+        "createdAt": data["createdAt"],
+    }
+
+
 def _setup_logging(verbose):
     # type: (bool) -> None
     level = logging.DEBUG if verbose else logging.WARNING
@@ -684,13 +713,13 @@ def status(as_json, as_yaml):
         client = _get_client_for_output(config, quiet=not rich_output)
         profile = client.fetch_me()
     except RuntimeError as exc:
-        payload = {"authenticated": False, "error": str(exc)}
+        payload = error_payload("not_authenticated", str(exc))
         if emit_structured(payload, as_json=as_json, as_yaml=as_yaml):
             sys.exit(1)
         _exit_with_error(exc)
         return
 
-    payload = {"authenticated": True, "user": user_profile_to_dict(profile)}
+    payload = success_payload({"authenticated": True, "user": _agent_user_profile(profile)})
     if emit_structured(payload, as_json=as_json, as_yaml=as_yaml):
         return
 
@@ -711,9 +740,11 @@ def whoami(as_json, as_yaml):
             console.print("👤 Fetching current user...")
         profile = client.fetch_me()
     except RuntimeError as exc:
+        if emit_structured(error_payload("not_authenticated", str(exc)), as_json=as_json, as_yaml=as_yaml):
+            raise SystemExit(1) from None
         _exit_with_error(exc)
 
-    if not emit_structured(user_profile_to_dict(profile), as_json=as_json, as_yaml=as_yaml):
+    if not emit_structured(success_payload({"user": _agent_user_profile(profile)}), as_json=as_json, as_yaml=as_yaml):
         console.print()
         print_user_profile(profile, console)
 
diff --git a/twitter_cli/client.py b/twitter_cli/client.py
index 4b96245..308cff3 100644
--- a/twitter_cli/client.py
+++ b/twitter_cli/client.py
@@ -5,6 +5,7 @@ from __future__ import annotations
 import json
 import logging
 import math
+import os
 import random
 import re
 import time
diff --git a/twitter_cli/output.py b/twitter_cli/output.py
index b31006c..74d6669 100644
--- a/twitter_cli/output.py
+++ b/twitter_cli/output.py
@@ -11,6 +11,7 @@ import click
 import yaml
 
 _OUTPUT_ENV = "OUTPUT"
+_SCHEMA_VERSION = "1"
 
 
 def default_structured_format(*, as_json: bool, as_yaml: bool) -> str | None:
@@ -66,3 +67,27 @@ def emit_structured(data: Any, *, as_json: bool, as_yaml: bool) -> bool:
             )
         )
     return True
+
+
+def success_payload(data: Any) -> dict[str, Any]:
+    """Wrap structured success data in the shared agent schema."""
+    return {
+        "ok": True,
+        "schema_version": _SCHEMA_VERSION,
+        "data": data,
+    }
+
+
+def error_payload(code: str, message: str, *, details: Any | None = None) -> dict[str, Any]:
+    """Wrap structured error data in the shared agent schema."""
+    error = {
+        "code": code,
+        "message": message,
+    }
+    if details is not None:
+        error["details"] = details
+    return {
+        "ok": False,
+        "schema_version": _SCHEMA_VERSION,
+        "error": error,
+    }