diff --git a/.release-please-manifest.json b/.release-please-manifest.json
index 55f722d..ba6c348 100644
--- a/.release-please-manifest.json
+++ b/.release-please-manifest.json
@@ -1,3 +1,3 @@
 {
-  ".": "0.0.1-alpha.1"
+  ".": "0.1.0-alpha.1"
 }
\ No newline at end of file
diff --git a/CHANGELOG.md b/CHANGELOG.md
index 0fd1943..fb1606d 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,13 @@
 # Changelog
 
+## 0.1.0-alpha.1 (2024-11-29)
+
+Full Changelog: [v0.0.1-alpha.1...v0.1.0-alpha.1](https://github.com/makegov/tango-python/compare/v0.0.1-alpha.1...v0.1.0-alpha.1)
+
+### Features
+
+* **api:** update via SDK Studio ([#4](https://github.com/makegov/tango-python/issues/4)) ([53ec9bd](https://github.com/makegov/tango-python/commit/53ec9bd1e1938224f9fd6ff0036fd61f3bbbcc67))
+
 ## 0.0.1-alpha.1 (2024-11-29)
 
 Full Changelog: [v0.0.1-alpha.0...v0.0.1-alpha.1](https://github.com/makegov/tango-python/compare/v0.0.1-alpha.0...v0.0.1-alpha.1)
diff --git a/README.md b/README.md
index c5e12ed..0240778 100644
--- a/README.md
+++ b/README.md
@@ -24,27 +24,32 @@ pip install --pre tango-python
 The full API of this library can be found in [api.md](api.md).
 
 ```python
+import os
 from tango import Tango
 
 client = Tango(
-    client_id="My Client ID",
-    client_secret="My Client Secret",
+    access_token=os.environ.get("TANGO_API_ACCESS_TOKEN"),  # This is the default and can be omitted
 )
 
 schema = client.schemas.retrieve()
 ```
 
+While you can provide a `access_token` keyword argument,
+we recommend using [python-dotenv](https://pypi.org/project/python-dotenv/)
+to add `TANGO_API_ACCESS_TOKEN="My Access Token"` to your `.env` file
+so that your Access Token is not stored in source control.
+
 ## Async usage
 
 Simply import `AsyncTango` instead of `Tango` and use `await` with each API call:
 
 ```python
+import os
 import asyncio
 from tango import AsyncTango
 
 client = AsyncTango(
-    client_id="My Client ID",
-    client_secret="My Client Secret",
+    access_token=os.environ.get("TANGO_API_ACCESS_TOKEN"),  # This is the default and can be omitted
 )
 
 
@@ -79,10 +84,7 @@ All errors inherit from `tango.APIError`.
 import tango
 from tango import Tango
 
-client = Tango(
-    client_id="My Client ID",
-    client_secret="My Client Secret",
-)
+client = Tango()
 
 try:
     client.schemas.retrieve()
@@ -125,8 +127,6 @@ from tango import Tango
 client = Tango(
     # default is 2
     max_retries=0,
-    client_id="My Client ID",
-    client_secret="My Client Secret",
 )
 
 # Or, configure per-request:
@@ -145,15 +145,11 @@ from tango import Tango
 client = Tango(
     # 20 seconds (default is 1 minute)
     timeout=20.0,
-    client_id="My Client ID",
-    client_secret="My Client Secret",
 )
 
 # More granular control:
 client = Tango(
     timeout=httpx.Timeout(60.0, read=5.0, write=10.0, connect=2.0),
-    client_id="My Client ID",
-    client_secret="My Client Secret",
 )
 
 # Override per-request:
@@ -197,10 +193,7 @@ The "raw" Response object can be accessed by prefixing `.with_raw_response.` to
 ```py
 from tango import Tango
 
-client = Tango(
-    client_id="My Client ID",
-    client_secret="My Client Secret",
-)
+client = Tango()
 response = client.schemas.with_raw_response.retrieve()
 print(response.headers.get('X-My-Header'))
 
@@ -281,8 +274,6 @@ client = Tango(
         proxies="http://my.test.proxy.example.com",
         transport=httpx.HTTPTransport(local_address="0.0.0.0"),
     ),
-    client_id="My Client ID",
-    client_secret="My Client Secret",
 )
 ```
 
diff --git a/pyproject.toml b/pyproject.toml
index 68a70a8..244ba34 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [project]
 name = "tango-python"
-version = "0.0.1-alpha.1"
+version = "0.1.0-alpha.1"
 description = "The official Python library for the tango API"
 dynamic = ["readme"]
 license = "Apache-2.0"
diff --git a/src/tango/_client.py b/src/tango/_client.py
index 7ffae74..a801e7a 100644
--- a/src/tango/_client.py
+++ b/src/tango/_client.py
@@ -66,14 +66,12 @@ class Tango(SyncAPIClient):
     with_streaming_response: TangoWithStreamedResponse
 
     # client options
-    client_id: str
-    client_secret: str
+    access_token: str
 
     def __init__(
         self,
         *,
-        client_id: str | None = None,
-        client_secret: str | None = None,
+        access_token: str | None = None,
         base_url: str | httpx.URL | None = None,
         timeout: Union[float, Timeout, None, NotGiven] = NOT_GIVEN,
         max_retries: int = DEFAULT_MAX_RETRIES,
@@ -95,25 +93,15 @@ def __init__(
     ) -> None:
         """Construct a new synchronous tango client instance.
 
-        This automatically infers the following arguments from their corresponding environment variables if they are not provided:
-        - `client_id` from `CLIENT_ID`
-        - `client_secret` from `CLIENT_SECRET`
+        This automatically infers the `access_token` argument from the `TANGO_API_ACCESS_TOKEN` environment variable if it is not provided.
         """
-        if client_id is None:
-            client_id = os.environ.get("CLIENT_ID")
-        if client_id is None:
+        if access_token is None:
+            access_token = os.environ.get("TANGO_API_ACCESS_TOKEN")
+        if access_token is None:
             raise TangoError(
-                "The client_id client option must be set either by passing client_id to the client or by setting the CLIENT_ID environment variable"
+                "The access_token client option must be set either by passing access_token to the client or by setting the TANGO_API_ACCESS_TOKEN environment variable"
             )
-        self.client_id = client_id
-
-        if client_secret is None:
-            client_secret = os.environ.get("CLIENT_SECRET")
-        if client_secret is None:
-            raise TangoError(
-                "The client_secret client option must be set either by passing client_secret to the client or by setting the CLIENT_SECRET environment variable"
-            )
-        self.client_secret = client_secret
+        self.access_token = access_token
 
         if base_url is None:
             base_url = os.environ.get("TANGO_BASE_URL")
@@ -155,6 +143,12 @@ def __init__(
     def qs(self) -> Querystring:
         return Querystring(array_format="comma")
 
+    @property
+    @override
+    def auth_headers(self) -> dict[str, str]:
+        access_token = self.access_token
+        return {"Authorization": f"Bearer {access_token}"}
+
     @property
     @override
     def default_headers(self) -> dict[str, str | Omit]:
@@ -167,8 +161,7 @@ def default_headers(self) -> dict[str, str | Omit]:
     def copy(
         self,
         *,
-        client_id: str | None = None,
-        client_secret: str | None = None,
+        access_token: str | None = None,
         base_url: str | httpx.URL | None = None,
         timeout: float | Timeout | None | NotGiven = NOT_GIVEN,
         http_client: httpx.Client | None = None,
@@ -202,8 +195,7 @@ def copy(
 
         http_client = http_client or self._client
         return self.__class__(
-            client_id=client_id or self.client_id,
-            client_secret=client_secret or self.client_secret,
+            access_token=access_token or self.access_token,
             base_url=base_url or self.base_url,
             timeout=self.timeout if isinstance(timeout, NotGiven) else timeout,
             http_client=http_client,
@@ -272,14 +264,12 @@ class AsyncTango(AsyncAPIClient):
     with_streaming_response: AsyncTangoWithStreamedResponse
 
     # client options
-    client_id: str
-    client_secret: str
+    access_token: str
 
     def __init__(
         self,
         *,
-        client_id: str | None = None,
-        client_secret: str | None = None,
+        access_token: str | None = None,
         base_url: str | httpx.URL | None = None,
         timeout: Union[float, Timeout, None, NotGiven] = NOT_GIVEN,
         max_retries: int = DEFAULT_MAX_RETRIES,
@@ -301,25 +291,15 @@ def __init__(
     ) -> None:
         """Construct a new async tango client instance.
 
-        This automatically infers the following arguments from their corresponding environment variables if they are not provided:
-        - `client_id` from `CLIENT_ID`
-        - `client_secret` from `CLIENT_SECRET`
+        This automatically infers the `access_token` argument from the `TANGO_API_ACCESS_TOKEN` environment variable if it is not provided.
         """
-        if client_id is None:
-            client_id = os.environ.get("CLIENT_ID")
-        if client_id is None:
+        if access_token is None:
+            access_token = os.environ.get("TANGO_API_ACCESS_TOKEN")
+        if access_token is None:
             raise TangoError(
-                "The client_id client option must be set either by passing client_id to the client or by setting the CLIENT_ID environment variable"
+                "The access_token client option must be set either by passing access_token to the client or by setting the TANGO_API_ACCESS_TOKEN environment variable"
             )
-        self.client_id = client_id
-
-        if client_secret is None:
-            client_secret = os.environ.get("CLIENT_SECRET")
-        if client_secret is None:
-            raise TangoError(
-                "The client_secret client option must be set either by passing client_secret to the client or by setting the CLIENT_SECRET environment variable"
-            )
-        self.client_secret = client_secret
+        self.access_token = access_token
 
         if base_url is None:
             base_url = os.environ.get("TANGO_BASE_URL")
@@ -361,6 +341,12 @@ def __init__(
     def qs(self) -> Querystring:
         return Querystring(array_format="comma")
 
+    @property
+    @override
+    def auth_headers(self) -> dict[str, str]:
+        access_token = self.access_token
+        return {"Authorization": f"Bearer {access_token}"}
+
     @property
     @override
     def default_headers(self) -> dict[str, str | Omit]:
@@ -373,8 +359,7 @@ def default_headers(self) -> dict[str, str | Omit]:
     def copy(
         self,
         *,
-        client_id: str | None = None,
-        client_secret: str | None = None,
+        access_token: str | None = None,
         base_url: str | httpx.URL | None = None,
         timeout: float | Timeout | None | NotGiven = NOT_GIVEN,
         http_client: httpx.AsyncClient | None = None,
@@ -408,8 +393,7 @@ def copy(
 
         http_client = http_client or self._client
         return self.__class__(
-            client_id=client_id or self.client_id,
-            client_secret=client_secret or self.client_secret,
+            access_token=access_token or self.access_token,
             base_url=base_url or self.base_url,
             timeout=self.timeout if isinstance(timeout, NotGiven) else timeout,
             http_client=http_client,
diff --git a/src/tango/_version.py b/src/tango/_version.py
index 2c3d870..79abdde 100644
--- a/src/tango/_version.py
+++ b/src/tango/_version.py
@@ -1,4 +1,4 @@
 # File generated from our OpenAPI spec by Stainless. See CONTRIBUTING.md for details.
 
 __title__ = "tango"
-__version__ = "0.0.1-alpha.1"  # x-release-please-version
+__version__ = "0.1.0-alpha.1"  # x-release-please-version
diff --git a/tests/conftest.py b/tests/conftest.py
index 1824979..bddaa40 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -28,8 +28,7 @@ def pytest_collection_modifyitems(items: list[pytest.Function]) -> None:
 
 base_url = os.environ.get("TEST_API_BASE_URL", "http://127.0.0.1:4010")
 
-client_id = "My Client ID"
-client_secret = "My Client Secret"
+access_token = "My Access Token"
 
 
 @pytest.fixture(scope="session")
@@ -38,9 +37,7 @@ def client(request: FixtureRequest) -> Iterator[Tango]:
     if not isinstance(strict, bool):
         raise TypeError(f"Unexpected fixture parameter type {type(strict)}, expected {bool}")
 
-    with Tango(
-        base_url=base_url, client_id=client_id, client_secret=client_secret, _strict_response_validation=strict
-    ) as client:
+    with Tango(base_url=base_url, access_token=access_token, _strict_response_validation=strict) as client:
         yield client
 
 
@@ -50,7 +47,5 @@ async def async_client(request: FixtureRequest) -> AsyncIterator[AsyncTango]:
     if not isinstance(strict, bool):
         raise TypeError(f"Unexpected fixture parameter type {type(strict)}, expected {bool}")
 
-    async with AsyncTango(
-        base_url=base_url, client_id=client_id, client_secret=client_secret, _strict_response_validation=strict
-    ) as client:
+    async with AsyncTango(base_url=base_url, access_token=access_token, _strict_response_validation=strict) as client:
         yield client
diff --git a/tests/test_client.py b/tests/test_client.py
index 5a92a10..c59b560 100644
--- a/tests/test_client.py
+++ b/tests/test_client.py
@@ -24,14 +24,13 @@
 from tango._types import Omit
 from tango._models import BaseModel, FinalRequestOptions
 from tango._constants import RAW_RESPONSE_HEADER
-from tango._exceptions import APIStatusError, APITimeoutError, APIResponseValidationError
+from tango._exceptions import TangoError, APIStatusError, APITimeoutError, APIResponseValidationError
 from tango._base_client import DEFAULT_TIMEOUT, HTTPX_DEFAULT_TIMEOUT, BaseClient, make_request_options
 
 from .utils import update_env
 
 base_url = os.environ.get("TEST_API_BASE_URL", "http://127.0.0.1:4010")
-client_id = "My Client ID"
-client_secret = "My Client Secret"
+access_token = "My Access Token"
 
 
 def _get_params(client: BaseClient[Any, Any]) -> dict[str, str]:
@@ -53,9 +52,7 @@ def _get_open_connections(client: Tango | AsyncTango) -> int:
 
 
 class TestTango:
-    client = Tango(
-        base_url=base_url, client_id=client_id, client_secret=client_secret, _strict_response_validation=True
-    )
+    client = Tango(base_url=base_url, access_token=access_token, _strict_response_validation=True)
 
     @pytest.mark.respx(base_url=base_url)
     def test_raw_response(self, respx_mock: MockRouter) -> None:
@@ -81,13 +78,9 @@ def test_copy(self) -> None:
         copied = self.client.copy()
         assert id(copied) != id(self.client)
 
-        copied = self.client.copy(client_id="another My Client ID")
-        assert copied.client_id == "another My Client ID"
-        assert self.client.client_id == "My Client ID"
-
-        copied = self.client.copy(client_secret="another My Client Secret")
-        assert copied.client_secret == "another My Client Secret"
-        assert self.client.client_secret == "My Client Secret"
+        copied = self.client.copy(access_token="another My Access Token")
+        assert copied.access_token == "another My Access Token"
+        assert self.client.access_token == "My Access Token"
 
     def test_copy_default_options(self) -> None:
         # options that have a default are overridden correctly
@@ -108,8 +101,7 @@ def test_copy_default_options(self) -> None:
     def test_copy_default_headers(self) -> None:
         client = Tango(
             base_url=base_url,
-            client_id=client_id,
-            client_secret=client_secret,
+            access_token=access_token,
             _strict_response_validation=True,
             default_headers={"X-Foo": "bar"},
         )
@@ -145,11 +137,7 @@ def test_copy_default_headers(self) -> None:
 
     def test_copy_default_query(self) -> None:
         client = Tango(
-            base_url=base_url,
-            client_id=client_id,
-            client_secret=client_secret,
-            _strict_response_validation=True,
-            default_query={"foo": "bar"},
+            base_url=base_url, access_token=access_token, _strict_response_validation=True, default_query={"foo": "bar"}
         )
         assert _get_params(client)["foo"] == "bar"
 
@@ -274,11 +262,7 @@ def test_request_timeout(self) -> None:
 
     def test_client_timeout_option(self) -> None:
         client = Tango(
-            base_url=base_url,
-            client_id=client_id,
-            client_secret=client_secret,
-            _strict_response_validation=True,
-            timeout=httpx.Timeout(0),
+            base_url=base_url, access_token=access_token, _strict_response_validation=True, timeout=httpx.Timeout(0)
         )
 
         request = client._build_request(FinalRequestOptions(method="get", url="/foo"))
@@ -289,11 +273,7 @@ def test_http_client_timeout_option(self) -> None:
         # custom timeout given to the httpx client should be used
         with httpx.Client(timeout=None) as http_client:
             client = Tango(
-                base_url=base_url,
-                client_id=client_id,
-                client_secret=client_secret,
-                _strict_response_validation=True,
-                http_client=http_client,
+                base_url=base_url, access_token=access_token, _strict_response_validation=True, http_client=http_client
             )
 
             request = client._build_request(FinalRequestOptions(method="get", url="/foo"))
@@ -303,11 +283,7 @@ def test_http_client_timeout_option(self) -> None:
         # no timeout given to the httpx client should not use the httpx default
         with httpx.Client() as http_client:
             client = Tango(
-                base_url=base_url,
-                client_id=client_id,
-                client_secret=client_secret,
-                _strict_response_validation=True,
-                http_client=http_client,
+                base_url=base_url, access_token=access_token, _strict_response_validation=True, http_client=http_client
             )
 
             request = client._build_request(FinalRequestOptions(method="get", url="/foo"))
@@ -317,11 +293,7 @@ def test_http_client_timeout_option(self) -> None:
         # explicitly passing the default timeout currently results in it being ignored
         with httpx.Client(timeout=HTTPX_DEFAULT_TIMEOUT) as http_client:
             client = Tango(
-                base_url=base_url,
-                client_id=client_id,
-                client_secret=client_secret,
-                _strict_response_validation=True,
-                http_client=http_client,
+                base_url=base_url, access_token=access_token, _strict_response_validation=True, http_client=http_client
             )
 
             request = client._build_request(FinalRequestOptions(method="get", url="/foo"))
@@ -333,8 +305,7 @@ async def test_invalid_http_client(self) -> None:
             async with httpx.AsyncClient() as http_client:
                 Tango(
                     base_url=base_url,
-                    client_id=client_id,
-                    client_secret=client_secret,
+                    access_token=access_token,
                     _strict_response_validation=True,
                     http_client=cast(Any, http_client),
                 )
@@ -342,8 +313,7 @@ async def test_invalid_http_client(self) -> None:
     def test_default_headers_option(self) -> None:
         client = Tango(
             base_url=base_url,
-            client_id=client_id,
-            client_secret=client_secret,
+            access_token=access_token,
             _strict_response_validation=True,
             default_headers={"X-Foo": "bar"},
         )
@@ -353,8 +323,7 @@ def test_default_headers_option(self) -> None:
 
         client2 = Tango(
             base_url=base_url,
-            client_id=client_id,
-            client_secret=client_secret,
+            access_token=access_token,
             _strict_response_validation=True,
             default_headers={
                 "X-Foo": "stainless",
@@ -365,11 +334,20 @@ def test_default_headers_option(self) -> None:
         assert request.headers.get("x-foo") == "stainless"
         assert request.headers.get("x-stainless-lang") == "my-overriding-header"
 
+    def test_validate_headers(self) -> None:
+        client = Tango(base_url=base_url, access_token=access_token, _strict_response_validation=True)
+        request = client._build_request(FinalRequestOptions(method="get", url="/foo"))
+        assert request.headers.get("Authorization") == f"Bearer {access_token}"
+
+        with pytest.raises(TangoError):
+            with update_env(**{"TANGO_API_ACCESS_TOKEN": Omit()}):
+                client2 = Tango(base_url=base_url, access_token=None, _strict_response_validation=True)
+            _ = client2
+
     def test_default_query_option(self) -> None:
         client = Tango(
             base_url=base_url,
-            client_id=client_id,
-            client_secret=client_secret,
+            access_token=access_token,
             _strict_response_validation=True,
             default_query={"query_param": "bar"},
         )
@@ -572,10 +550,7 @@ class Model(BaseModel):
 
     def test_base_url_setter(self) -> None:
         client = Tango(
-            base_url="https://example.com/from_init",
-            client_id=client_id,
-            client_secret=client_secret,
-            _strict_response_validation=True,
+            base_url="https://example.com/from_init", access_token=access_token, _strict_response_validation=True
         )
         assert client.base_url == "https://example.com/from_init/"
 
@@ -585,7 +560,7 @@ def test_base_url_setter(self) -> None:
 
     def test_base_url_env(self) -> None:
         with update_env(TANGO_BASE_URL="http://localhost:5000/from/env"):
-            client = Tango(client_id=client_id, client_secret=client_secret, _strict_response_validation=True)
+            client = Tango(access_token=access_token, _strict_response_validation=True)
             assert client.base_url == "http://localhost:5000/from/env/"
 
     @pytest.mark.parametrize(
@@ -593,14 +568,12 @@ def test_base_url_env(self) -> None:
         [
             Tango(
                 base_url="http://localhost:5000/custom/path/",
-                client_id=client_id,
-                client_secret=client_secret,
+                access_token=access_token,
                 _strict_response_validation=True,
             ),
             Tango(
                 base_url="http://localhost:5000/custom/path/",
-                client_id=client_id,
-                client_secret=client_secret,
+                access_token=access_token,
                 _strict_response_validation=True,
                 http_client=httpx.Client(),
             ),
@@ -622,14 +595,12 @@ def test_base_url_trailing_slash(self, client: Tango) -> None:
         [
             Tango(
                 base_url="http://localhost:5000/custom/path/",
-                client_id=client_id,
-                client_secret=client_secret,
+                access_token=access_token,
                 _strict_response_validation=True,
             ),
             Tango(
                 base_url="http://localhost:5000/custom/path/",
-                client_id=client_id,
-                client_secret=client_secret,
+                access_token=access_token,
                 _strict_response_validation=True,
                 http_client=httpx.Client(),
             ),
@@ -651,14 +622,12 @@ def test_base_url_no_trailing_slash(self, client: Tango) -> None:
         [
             Tango(
                 base_url="http://localhost:5000/custom/path/",
-                client_id=client_id,
-                client_secret=client_secret,
+                access_token=access_token,
                 _strict_response_validation=True,
             ),
             Tango(
                 base_url="http://localhost:5000/custom/path/",
-                client_id=client_id,
-                client_secret=client_secret,
+                access_token=access_token,
                 _strict_response_validation=True,
                 http_client=httpx.Client(),
             ),
@@ -676,9 +645,7 @@ def test_absolute_request_url(self, client: Tango) -> None:
         assert request.url == "https://myapi.com/foo"
 
     def test_copied_client_does_not_close_http(self) -> None:
-        client = Tango(
-            base_url=base_url, client_id=client_id, client_secret=client_secret, _strict_response_validation=True
-        )
+        client = Tango(base_url=base_url, access_token=access_token, _strict_response_validation=True)
         assert not client.is_closed()
 
         copied = client.copy()
@@ -689,9 +656,7 @@ def test_copied_client_does_not_close_http(self) -> None:
         assert not client.is_closed()
 
     def test_client_context_manager(self) -> None:
-        client = Tango(
-            base_url=base_url, client_id=client_id, client_secret=client_secret, _strict_response_validation=True
-        )
+        client = Tango(base_url=base_url, access_token=access_token, _strict_response_validation=True)
         with client as c2:
             assert c2 is client
             assert not c2.is_closed()
@@ -714,8 +679,7 @@ def test_client_max_retries_validation(self) -> None:
         with pytest.raises(TypeError, match=r"max_retries cannot be None"):
             Tango(
                 base_url=base_url,
-                client_id=client_id,
-                client_secret=client_secret,
+                access_token=access_token,
                 _strict_response_validation=True,
                 max_retries=cast(Any, None),
             )
@@ -727,16 +691,12 @@ class Model(BaseModel):
 
         respx_mock.get("/foo").mock(return_value=httpx.Response(200, text="my-custom-format"))
 
-        strict_client = Tango(
-            base_url=base_url, client_id=client_id, client_secret=client_secret, _strict_response_validation=True
-        )
+        strict_client = Tango(base_url=base_url, access_token=access_token, _strict_response_validation=True)
 
         with pytest.raises(APIResponseValidationError):
             strict_client.get("/foo", cast_to=Model)
 
-        client = Tango(
-            base_url=base_url, client_id=client_id, client_secret=client_secret, _strict_response_validation=False
-        )
+        client = Tango(base_url=base_url, access_token=access_token, _strict_response_validation=False)
 
         response = client.get("/foo", cast_to=Model)
         assert isinstance(response, str)  # type: ignore[unreachable]
@@ -764,9 +724,7 @@ class Model(BaseModel):
     )
     @mock.patch("time.time", mock.MagicMock(return_value=1696004797))
     def test_parse_retry_after_header(self, remaining_retries: int, retry_after: str, timeout: float) -> None:
-        client = Tango(
-            base_url=base_url, client_id=client_id, client_secret=client_secret, _strict_response_validation=True
-        )
+        client = Tango(base_url=base_url, access_token=access_token, _strict_response_validation=True)
 
         headers = httpx.Headers({"retry-after": retry_after})
         options = FinalRequestOptions(method="get", url="/foo", max_retries=3)
@@ -874,9 +832,7 @@ def retry_handler(_request: httpx.Request) -> httpx.Response:
 
 
 class TestAsyncTango:
-    client = AsyncTango(
-        base_url=base_url, client_id=client_id, client_secret=client_secret, _strict_response_validation=True
-    )
+    client = AsyncTango(base_url=base_url, access_token=access_token, _strict_response_validation=True)
 
     @pytest.mark.respx(base_url=base_url)
     @pytest.mark.asyncio
@@ -904,13 +860,9 @@ def test_copy(self) -> None:
         copied = self.client.copy()
         assert id(copied) != id(self.client)
 
-        copied = self.client.copy(client_id="another My Client ID")
-        assert copied.client_id == "another My Client ID"
-        assert self.client.client_id == "My Client ID"
-
-        copied = self.client.copy(client_secret="another My Client Secret")
-        assert copied.client_secret == "another My Client Secret"
-        assert self.client.client_secret == "My Client Secret"
+        copied = self.client.copy(access_token="another My Access Token")
+        assert copied.access_token == "another My Access Token"
+        assert self.client.access_token == "My Access Token"
 
     def test_copy_default_options(self) -> None:
         # options that have a default are overridden correctly
@@ -931,8 +883,7 @@ def test_copy_default_options(self) -> None:
     def test_copy_default_headers(self) -> None:
         client = AsyncTango(
             base_url=base_url,
-            client_id=client_id,
-            client_secret=client_secret,
+            access_token=access_token,
             _strict_response_validation=True,
             default_headers={"X-Foo": "bar"},
         )
@@ -968,11 +919,7 @@ def test_copy_default_headers(self) -> None:
 
     def test_copy_default_query(self) -> None:
         client = AsyncTango(
-            base_url=base_url,
-            client_id=client_id,
-            client_secret=client_secret,
-            _strict_response_validation=True,
-            default_query={"foo": "bar"},
+            base_url=base_url, access_token=access_token, _strict_response_validation=True, default_query={"foo": "bar"}
         )
         assert _get_params(client)["foo"] == "bar"
 
@@ -1097,11 +1044,7 @@ async def test_request_timeout(self) -> None:
 
     async def test_client_timeout_option(self) -> None:
         client = AsyncTango(
-            base_url=base_url,
-            client_id=client_id,
-            client_secret=client_secret,
-            _strict_response_validation=True,
-            timeout=httpx.Timeout(0),
+            base_url=base_url, access_token=access_token, _strict_response_validation=True, timeout=httpx.Timeout(0)
         )
 
         request = client._build_request(FinalRequestOptions(method="get", url="/foo"))
@@ -1112,11 +1055,7 @@ async def test_http_client_timeout_option(self) -> None:
         # custom timeout given to the httpx client should be used
         async with httpx.AsyncClient(timeout=None) as http_client:
             client = AsyncTango(
-                base_url=base_url,
-                client_id=client_id,
-                client_secret=client_secret,
-                _strict_response_validation=True,
-                http_client=http_client,
+                base_url=base_url, access_token=access_token, _strict_response_validation=True, http_client=http_client
             )
 
             request = client._build_request(FinalRequestOptions(method="get", url="/foo"))
@@ -1126,11 +1065,7 @@ async def test_http_client_timeout_option(self) -> None:
         # no timeout given to the httpx client should not use the httpx default
         async with httpx.AsyncClient() as http_client:
             client = AsyncTango(
-                base_url=base_url,
-                client_id=client_id,
-                client_secret=client_secret,
-                _strict_response_validation=True,
-                http_client=http_client,
+                base_url=base_url, access_token=access_token, _strict_response_validation=True, http_client=http_client
             )
 
             request = client._build_request(FinalRequestOptions(method="get", url="/foo"))
@@ -1140,11 +1075,7 @@ async def test_http_client_timeout_option(self) -> None:
         # explicitly passing the default timeout currently results in it being ignored
         async with httpx.AsyncClient(timeout=HTTPX_DEFAULT_TIMEOUT) as http_client:
             client = AsyncTango(
-                base_url=base_url,
-                client_id=client_id,
-                client_secret=client_secret,
-                _strict_response_validation=True,
-                http_client=http_client,
+                base_url=base_url, access_token=access_token, _strict_response_validation=True, http_client=http_client
             )
 
             request = client._build_request(FinalRequestOptions(method="get", url="/foo"))
@@ -1156,8 +1087,7 @@ def test_invalid_http_client(self) -> None:
             with httpx.Client() as http_client:
                 AsyncTango(
                     base_url=base_url,
-                    client_id=client_id,
-                    client_secret=client_secret,
+                    access_token=access_token,
                     _strict_response_validation=True,
                     http_client=cast(Any, http_client),
                 )
@@ -1165,8 +1095,7 @@ def test_invalid_http_client(self) -> None:
     def test_default_headers_option(self) -> None:
         client = AsyncTango(
             base_url=base_url,
-            client_id=client_id,
-            client_secret=client_secret,
+            access_token=access_token,
             _strict_response_validation=True,
             default_headers={"X-Foo": "bar"},
         )
@@ -1176,8 +1105,7 @@ def test_default_headers_option(self) -> None:
 
         client2 = AsyncTango(
             base_url=base_url,
-            client_id=client_id,
-            client_secret=client_secret,
+            access_token=access_token,
             _strict_response_validation=True,
             default_headers={
                 "X-Foo": "stainless",
@@ -1188,11 +1116,20 @@ def test_default_headers_option(self) -> None:
         assert request.headers.get("x-foo") == "stainless"
         assert request.headers.get("x-stainless-lang") == "my-overriding-header"
 
+    def test_validate_headers(self) -> None:
+        client = AsyncTango(base_url=base_url, access_token=access_token, _strict_response_validation=True)
+        request = client._build_request(FinalRequestOptions(method="get", url="/foo"))
+        assert request.headers.get("Authorization") == f"Bearer {access_token}"
+
+        with pytest.raises(TangoError):
+            with update_env(**{"TANGO_API_ACCESS_TOKEN": Omit()}):
+                client2 = AsyncTango(base_url=base_url, access_token=None, _strict_response_validation=True)
+            _ = client2
+
     def test_default_query_option(self) -> None:
         client = AsyncTango(
             base_url=base_url,
-            client_id=client_id,
-            client_secret=client_secret,
+            access_token=access_token,
             _strict_response_validation=True,
             default_query={"query_param": "bar"},
         )
@@ -1395,10 +1332,7 @@ class Model(BaseModel):
 
     def test_base_url_setter(self) -> None:
         client = AsyncTango(
-            base_url="https://example.com/from_init",
-            client_id=client_id,
-            client_secret=client_secret,
-            _strict_response_validation=True,
+            base_url="https://example.com/from_init", access_token=access_token, _strict_response_validation=True
         )
         assert client.base_url == "https://example.com/from_init/"
 
@@ -1408,7 +1342,7 @@ def test_base_url_setter(self) -> None:
 
     def test_base_url_env(self) -> None:
         with update_env(TANGO_BASE_URL="http://localhost:5000/from/env"):
-            client = AsyncTango(client_id=client_id, client_secret=client_secret, _strict_response_validation=True)
+            client = AsyncTango(access_token=access_token, _strict_response_validation=True)
             assert client.base_url == "http://localhost:5000/from/env/"
 
     @pytest.mark.parametrize(
@@ -1416,14 +1350,12 @@ def test_base_url_env(self) -> None:
         [
             AsyncTango(
                 base_url="http://localhost:5000/custom/path/",
-                client_id=client_id,
-                client_secret=client_secret,
+                access_token=access_token,
                 _strict_response_validation=True,
             ),
             AsyncTango(
                 base_url="http://localhost:5000/custom/path/",
-                client_id=client_id,
-                client_secret=client_secret,
+                access_token=access_token,
                 _strict_response_validation=True,
                 http_client=httpx.AsyncClient(),
             ),
@@ -1445,14 +1377,12 @@ def test_base_url_trailing_slash(self, client: AsyncTango) -> None:
         [
             AsyncTango(
                 base_url="http://localhost:5000/custom/path/",
-                client_id=client_id,
-                client_secret=client_secret,
+                access_token=access_token,
                 _strict_response_validation=True,
             ),
             AsyncTango(
                 base_url="http://localhost:5000/custom/path/",
-                client_id=client_id,
-                client_secret=client_secret,
+                access_token=access_token,
                 _strict_response_validation=True,
                 http_client=httpx.AsyncClient(),
             ),
@@ -1474,14 +1404,12 @@ def test_base_url_no_trailing_slash(self, client: AsyncTango) -> None:
         [
             AsyncTango(
                 base_url="http://localhost:5000/custom/path/",
-                client_id=client_id,
-                client_secret=client_secret,
+                access_token=access_token,
                 _strict_response_validation=True,
             ),
             AsyncTango(
                 base_url="http://localhost:5000/custom/path/",
-                client_id=client_id,
-                client_secret=client_secret,
+                access_token=access_token,
                 _strict_response_validation=True,
                 http_client=httpx.AsyncClient(),
             ),
@@ -1499,9 +1427,7 @@ def test_absolute_request_url(self, client: AsyncTango) -> None:
         assert request.url == "https://myapi.com/foo"
 
     async def test_copied_client_does_not_close_http(self) -> None:
-        client = AsyncTango(
-            base_url=base_url, client_id=client_id, client_secret=client_secret, _strict_response_validation=True
-        )
+        client = AsyncTango(base_url=base_url, access_token=access_token, _strict_response_validation=True)
         assert not client.is_closed()
 
         copied = client.copy()
@@ -1513,9 +1439,7 @@ async def test_copied_client_does_not_close_http(self) -> None:
         assert not client.is_closed()
 
     async def test_client_context_manager(self) -> None:
-        client = AsyncTango(
-            base_url=base_url, client_id=client_id, client_secret=client_secret, _strict_response_validation=True
-        )
+        client = AsyncTango(base_url=base_url, access_token=access_token, _strict_response_validation=True)
         async with client as c2:
             assert c2 is client
             assert not c2.is_closed()
@@ -1539,8 +1463,7 @@ async def test_client_max_retries_validation(self) -> None:
         with pytest.raises(TypeError, match=r"max_retries cannot be None"):
             AsyncTango(
                 base_url=base_url,
-                client_id=client_id,
-                client_secret=client_secret,
+                access_token=access_token,
                 _strict_response_validation=True,
                 max_retries=cast(Any, None),
             )
@@ -1553,16 +1476,12 @@ class Model(BaseModel):
 
         respx_mock.get("/foo").mock(return_value=httpx.Response(200, text="my-custom-format"))
 
-        strict_client = AsyncTango(
-            base_url=base_url, client_id=client_id, client_secret=client_secret, _strict_response_validation=True
-        )
+        strict_client = AsyncTango(base_url=base_url, access_token=access_token, _strict_response_validation=True)
 
         with pytest.raises(APIResponseValidationError):
             await strict_client.get("/foo", cast_to=Model)
 
-        client = AsyncTango(
-            base_url=base_url, client_id=client_id, client_secret=client_secret, _strict_response_validation=False
-        )
+        client = AsyncTango(base_url=base_url, access_token=access_token, _strict_response_validation=False)
 
         response = await client.get("/foo", cast_to=Model)
         assert isinstance(response, str)  # type: ignore[unreachable]
@@ -1591,9 +1510,7 @@ class Model(BaseModel):
     @mock.patch("time.time", mock.MagicMock(return_value=1696004797))
     @pytest.mark.asyncio
     async def test_parse_retry_after_header(self, remaining_retries: int, retry_after: str, timeout: float) -> None:
-        client = AsyncTango(
-            base_url=base_url, client_id=client_id, client_secret=client_secret, _strict_response_validation=True
-        )
+        client = AsyncTango(base_url=base_url, access_token=access_token, _strict_response_validation=True)
 
         headers = httpx.Headers({"retry-after": retry_after})
         options = FinalRequestOptions(method="get", url="/foo", max_retries=3)