diff --git a/.release-please-manifest.json b/.release-please-manifest.json
index ee49ac2..fd0ccba 100644
--- a/.release-please-manifest.json
+++ b/.release-please-manifest.json
@@ -1,3 +1,3 @@
 {
-  ".": "0.1.0-alpha.11"
+  ".": "0.1.0-alpha.12"
 }
\ No newline at end of file
diff --git a/CHANGELOG.md b/CHANGELOG.md
index ead8e23..b5ab3d2 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,18 @@
 # Changelog
 
+## 0.1.0-alpha.12 (2025-07-12)
+
+Full Changelog: [v0.1.0-alpha.11...v0.1.0-alpha.12](https://github.com/sst/opencode-sdk-python/compare/v0.1.0-alpha.11...v0.1.0-alpha.12)
+
+### Bug Fixes
+
+* **client:** don't send Content-Type header on GET requests ([d52fbac](https://github.com/sst/opencode-sdk-python/commit/d52fbac0f4e2ae7f3338272eb7075f1401912fe4))
+
+
+### Chores
+
+* **readme:** fix version rendering on pypi ([d7ae516](https://github.com/sst/opencode-sdk-python/commit/d7ae5162cc2346314e69fd7609050d0e97eecf6c))
+
 ## 0.1.0-alpha.11 (2025-07-09)
 
 Full Changelog: [v0.1.0-alpha.10...v0.1.0-alpha.11](https://github.com/sst/opencode-sdk-python/compare/v0.1.0-alpha.10...v0.1.0-alpha.11)
diff --git a/README.md b/README.md
index 47fa0b6..c6ee56a 100644
--- a/README.md
+++ b/README.md
@@ -1,6 +1,7 @@
 # Opencode Python API library
 
-[![PyPI version](<https://img.shields.io/pypi/v/opencode-ai.svg?label=pypi%20(stable)>)](https://pypi.org/project/opencode-ai/)
+<!-- prettier-ignore -->
+[![PyPI version](https://img.shields.io/pypi/v/opencode-ai.svg?label=pypi%20(stable))](https://pypi.org/project/opencode-ai/)
 
 The Opencode Python library provides convenient access to the Opencode REST API from any Python 3.8+
 application. The library includes type definitions for all request params and response fields,
diff --git a/pyproject.toml b/pyproject.toml
index 454d8fd..30dbe57 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -1,6 +1,6 @@
 [project]
 name = "opencode-ai"
-version = "0.1.0-alpha.11"
+version = "0.1.0-alpha.12"
 description = "The official Python library for the opencode API"
 dynamic = ["readme"]
 license = "Apache-2.0"
@@ -39,7 +39,7 @@ Homepage = "https://github.com/sst/opencode-sdk-python"
 Repository = "https://github.com/sst/opencode-sdk-python"
 
 [project.optional-dependencies]
-aiohttp = ["aiohttp", "httpx_aiohttp>=0.1.6"]
+aiohttp = ["aiohttp", "httpx_aiohttp>=0.1.8"]
 
 [tool.rye]
 managed = true
diff --git a/src/opencode_ai/_base_client.py b/src/opencode_ai/_base_client.py
index f7025f4..f52a9ac 100644
--- a/src/opencode_ai/_base_client.py
+++ b/src/opencode_ai/_base_client.py
@@ -529,6 +529,15 @@ def _build_request(
             # work around https://github.com/encode/httpx/discussions/2880
             kwargs["extensions"] = {"sni_hostname": prepared_url.host.replace("_", "-")}
 
+        is_body_allowed = options.method.lower() != "get"
+
+        if is_body_allowed:
+            kwargs["json"] = json_data if is_given(json_data) else None
+            kwargs["files"] = files
+        else:
+            headers.pop("Content-Type", None)
+            kwargs.pop("data", None)
+
         # TODO: report this error to httpx
         return self._client.build_request(  # pyright: ignore[reportUnknownMemberType]
             headers=headers,
@@ -540,8 +549,6 @@ def _build_request(
             # so that passing a `TypedDict` doesn't cause an error.
             # https://github.com/microsoft/pyright/issues/3526#event-6715453066
             params=self.qs.stringify(cast(Mapping[str, Any], params)) if params else None,
-            json=json_data if is_given(json_data) else None,
-            files=files,
             **kwargs,
         )
 
diff --git a/src/opencode_ai/_version.py b/src/opencode_ai/_version.py
index 178ea4c..5f662ba 100644
--- a/src/opencode_ai/_version.py
+++ b/src/opencode_ai/_version.py
@@ -1,4 +1,4 @@
 # File generated from our OpenAPI spec by Stainless. See CONTRIBUTING.md for details.
 
 __title__ = "opencode_ai"
-__version__ = "0.1.0-alpha.11"  # x-release-please-version
+__version__ = "0.1.0-alpha.12"  # x-release-please-version
diff --git a/tests/test_client.py b/tests/test_client.py
index 0cf7c41..5fb4ca7 100644
--- a/tests/test_client.py
+++ b/tests/test_client.py
@@ -428,7 +428,7 @@ def test_request_extra_query(self) -> None:
     def test_multipart_repeating_array(self, client: Opencode) -> None:
         request = client._build_request(
             FinalRequestOptions.construct(
-                method="get",
+                method="post",
                 url="/foo",
                 headers={"Content-Type": "multipart/form-data; boundary=6b7ba517decee4a450543ea6ae821c82"},
                 json_data={"array": ["foo", "bar"]},
@@ -1203,7 +1203,7 @@ def test_request_extra_query(self) -> None:
     def test_multipart_repeating_array(self, async_client: AsyncOpencode) -> None:
         request = async_client._build_request(
             FinalRequestOptions.construct(
-                method="get",
+                method="post",
                 url="/foo",
                 headers={"Content-Type": "multipart/form-data; boundary=6b7ba517decee4a450543ea6ae821c82"},
                 json_data={"array": ["foo", "bar"]},