Implement proper client and bidi streaming

src/claude_code_sdk/query.py

@@ -0,0 +1,99 @@
+"""Query function for one-shot interactions with Claude Code."""
+
+import os
+from collections.abc import AsyncIterable, AsyncIterator
+
+from ._internal.client import InternalClient
+from .types import ClaudeCodeOptions, Message
+
+
+async def query(
+    *, prompt: str | AsyncIterable[dict], options: ClaudeCodeOptions | None = None
+) -> AsyncIterator[Message]:
+    """
+    Query Claude Code for one-shot or unidirectional streaming interactions.
+
+    This function is ideal for simple, stateless queries where you don't need
+    bidirectional communication or conversation management. For interactive,
+    stateful conversations, use ClaudeSDKClient instead.
+
+    Key differences from ClaudeSDKClient:
+    - **Unidirectional**: Send all messages upfront, receive all responses
+    - **Stateless**: Each query is independent, no conversation state
+    - **Simple**: Fire-and-forget style, no connection management
+    - **No interrupts**: Cannot interrupt or send follow-up messages
+
+    When to use query():
+    - Simple one-off questions ("What is 2+2?")
+    - Batch processing of independent prompts
+    - Code generation or analysis tasks
+    - Automated scripts and CI/CD pipelines
+    - When you know all inputs upfront
+
+    When to use ClaudeSDKClient:
+    - Interactive conversations with follow-ups
+    - Chat applications or REPL-like interfaces
+    - When you need to send messages based on responses
+    - When you need interrupt capabilities
+    - Long-running sessions with state
+
+    Args:
+        prompt: The prompt to send to Claude. Can be a string for single-shot queries
+                or an AsyncIterable[dict] for streaming mode with continuous interaction.
+                In streaming mode, each dict should have the structure:
+                {
+                    "type": "user",
+                    "message": {"role": "user", "content": "..."},
+                    "parent_tool_use_id": None,
+                    "session_id": "..."
+                }
+        options: Optional configuration (defaults to ClaudeCodeOptions() if None).
+                 Set options.permission_mode to control tool execution:
+                 - 'default': CLI prompts for dangerous tools
+                 - 'acceptEdits': Auto-accept file edits
+                 - 'bypassPermissions': Allow all tools (use with caution)
+                 Set options.cwd for working directory.
+
+    Yields:
+        Messages from the conversation
+
+    Example - Simple query:
+        ```python
+        # One-off question
+        async for message in query(prompt="What is the capital of France?"):
+            print(message)
+        ```
+
+    Example - With options:
+        ```python
+        # Code generation with specific settings
+        async for message in query(
+            prompt="Create a Python web server",
+            options=ClaudeCodeOptions(
+                system_prompt="You are an expert Python developer",
+                cwd="/home/user/project"
+            )
+        ):
+            print(message)
+        ```
+
+    Example - Streaming mode (still unidirectional):
+        ```python
+        async def prompts():
+            yield {"type": "user", "message": {"role": "user", "content": "Hello"}}
+            yield {"type": "user", "message": {"role": "user", "content": "How are you?"}}
+
+        # All prompts are sent, then all responses received
+        async for message in query(prompt=prompts()):
+            print(message)
+        ```
+    """
+    if options is None:
+        options = ClaudeCodeOptions()
+
+    os.environ["CLAUDE_CODE_ENTRYPOINT"] = "sdk-py"
+
+    client = InternalClient()
+
+    async for message in client.process_query(prompt=prompt, options=options):
+        yield message