remove OpenCode serve+attach workaround for stateless CLI

sdk/python/agentfield/harness/_runner.py

@@ -70,7 +70,6 @@ def _resolve_options(
             "codex_bin",
             "gemini_bin",
             "opencode_bin",
-            "opencode_server",
             "schema_max_retries",
         ]:
             val = getattr(config, field_name, None)
@@ -146,17 +145,7 @@ async def run(
         resolved_cwd = str(options.get("cwd", "."))
         provider_instance = self._build_provider(str(resolved_provider), options)
 
-        # When project_dir is set (opencode provider), place the output file
-        # inside project_dir so the coding agent's Write tool can reach it.
-        # Use a unique subdir to avoid collisions from parallel calls.
-        project_dir = options.get("project_dir")
         output_dir = resolved_cwd
-        _temp_output_dir: Optional[str] = None
-        if isinstance(project_dir, str) and project_dir:
-            import tempfile as _tempfile
-
-            _temp_output_dir = _tempfile.mkdtemp(prefix=".secaf-out-", dir=project_dir)
-            output_dir = _temp_output_dir
 
         effective_prompt = prompt
         if schema is not None:
@@ -195,10 +184,6 @@ async def run(
         finally:
             if schema is not None:
                 cleanup_temp_files(output_dir)
-            if _temp_output_dir:
-                import shutil as _shutil
-
-                _shutil.rmtree(_temp_output_dir, ignore_errors=True)
 
     def _build_provider(
         self, provider_name: str, options: Dict[str, Any]

sdk/python/agentfield/harness/providers/_factory.py

@@ -33,6 +33,5 @@ def build_provider(config: "HarnessConfig") -> "HarnessProvider":
 
         return OpenCodeProvider(
             bin_path=getattr(config, "opencode_bin", "opencode"),
-            server_url=getattr(config, "opencode_server", None),
         )
     raise NotImplementedError(f"Provider {provider_name!r} is not yet implemented.")

sdk/python/agentfield/harness/providers/opencode.py

@@ -26,13 +26,8 @@ class OpenCodeProvider:
     _MAX_CONCURRENT: ClassVar[int] = int(os.environ.get("OPENCODE_MAX_CONCURRENT", "3"))
     _concurrency_sem: ClassVar[Optional[asyncio.Semaphore]] = None
 
-    def __init__(
-        self,
-        bin_path: str = "opencode",
-        server_url: Optional[str] = None,
-    ):
+    def __init__(self, bin_path: str = "opencode"):
         self._bin = bin_path
-        self._explicit_server = server_url or os.environ.get("OPENCODE_SERVER")
 
     @classmethod
     def _get_semaphore(cls) -> asyncio.Semaphore:

sdk/python/agentfield/types.py

@@ -326,15 +326,6 @@ class HarnessConfig(BaseModel):
     opencode_bin: str = Field(
         default="opencode", description="Path to opencode binary."
     )
-    opencode_server: Optional[str] = Field(
-        default=None,
-        description=(
-            "URL of a running ``opencode serve`` instance "
-            '(e.g. "http://127.0.0.1:4096"). When set, the opencode provider '
-            "uses ``--attach`` mode which avoids the standalone session bug. "
-            "Falls back to OPENCODE_SERVER env var."
-        ),
-    )
 
 
 class AIConfig(BaseModel):

sdk/python/tests/test_harness_provider_opencode.py

@@ -29,7 +29,6 @@ async def fake_run_cli(cmd, *, env=None, cwd=None, timeout=None):
 
     provider = OpenCodeProvider(
         bin_path="/usr/local/bin/opencode",
-        server_url="http://127.0.0.1:9999",
     )
     raw = await provider.execute(
         "hello",
@@ -65,7 +64,6 @@ async def fake_run_cli(*_args, **_kwargs):
 
     provider = OpenCodeProvider(
         bin_path="opencode-missing",
-        server_url="http://127.0.0.1:9999",
     )
     raw = await provider.execute("hello", {})
 
@@ -84,7 +82,7 @@ async def fake_run_cli(*_args, **_kwargs):
 
     monkeypatch.setattr("agentfield.harness.providers.opencode.run_cli", fake_run_cli)
 
-    provider = OpenCodeProvider(server_url="http://127.0.0.1:9999")
+    provider = OpenCodeProvider()
     raw = await provider.execute("hello", {})
 
     assert raw.is_error is True
@@ -97,13 +95,11 @@ def test_factory_builds_opencode_provider_with_config_bin() -> None:
         HarnessConfig(
             provider="opencode",
             opencode_bin="/opt/opencode",
-            opencode_server="http://127.0.0.1:4096",
         )
     )
 
     assert isinstance(provider, OpenCodeProvider)
     assert provider._bin == "/opt/opencode"
-    assert provider._explicit_server == "http://127.0.0.1:4096"
 
 
 @pytest.mark.asyncio
@@ -117,7 +113,7 @@ async def fake_run_cli(cmd, *, env=None, cwd=None, timeout=None):
 
     monkeypatch.setattr("agentfield.harness.providers.opencode.run_cli", fake_run_cli)
 
-    provider = OpenCodeProvider(server_url="http://127.0.0.1:9999")
+    provider = OpenCodeProvider()
     raw = await provider.execute("hello", {"model": "openai/gpt-5"})
 
     assert captured["cmd"] == [
@@ -143,7 +139,7 @@ async def fake_run_cli(cmd, *, env=None, cwd=None, timeout=None):
     with patch(
         "agentfield.harness.providers.opencode.estimate_cli_cost", return_value=0.0035
     ):
-        provider = OpenCodeProvider(server_url="http://127.0.0.1:9999")
+        provider = OpenCodeProvider()
         raw = await provider.execute("hello", {"model": "openai/gpt-4o"})
 
     assert raw.metrics.total_cost_usd == 0.0035
@@ -160,8 +156,33 @@ async def fake_run_cli(cmd, *, env=None, cwd=None, timeout=None):
 
     monkeypatch.setattr("agentfield.harness.providers.opencode.run_cli", fake_run_cli)
 
-    provider = OpenCodeProvider(server_url="http://127.0.0.1:9999")
+    provider = OpenCodeProvider()
     raw = await provider.execute("hello", {})
 
     # No model → estimate_cli_cost gets empty string → returns None
     assert raw.metrics.total_cost_usd is None
+
+
+@pytest.mark.asyncio
+async def test_opencode_command_does_not_use_attach_pattern(
+    monkeypatch: pytest.MonkeyPatch,
+):
+    """Verify the provider uses direct CLI pattern, NOT serve+attach workaround."""
+    captured_cmd = None
+
+    async def capture_cmd(cmd, *, env=None, cwd=None, timeout=None):
+        nonlocal captured_cmd
+        captured_cmd = cmd
+        return "result", "", 0
+
+    monkeypatch.setattr("agentfield.harness.providers.opencode.run_cli", capture_cmd)
+
+    provider = OpenCodeProvider(bin_path="opencode")
+    await provider.execute("test prompt", {"model": "gpt-4"})
+
+    cmd_str = " ".join(captured_cmd)
+    assert "--attach" not in cmd_str
+    assert "http://" not in cmd_str
+    assert "127.0.0.1" not in cmd_str
+    assert "localhost" not in cmd_str
+    assert "opencode run" in cmd_str