refactor: move mcp sdk converters to wf_sources_mcp

src/wf_sources_mcp/sdk/__init__.py

@@ -1,9 +1,21 @@
 from __future__ import annotations
 
+from .converters import (
+    prompt_to_discovered,
+    resource_to_discovered,
+    tool_result_to_call_result,
+    tool_to_discovered,
+    workflow_output_schema_from_mcp_tool_schema,
+)
 from .protocols import BackendAdapter, ToolCallResult, ToolExecutor
 
 __all__ = [
     "BackendAdapter",
     "ToolCallResult",
     "ToolExecutor",
+    "prompt_to_discovered",
+    "resource_to_discovered",
+    "tool_result_to_call_result",
+    "tool_to_discovered",
+    "workflow_output_schema_from_mcp_tool_schema",
 ]

src/wf_sources_mcp/sdk/converters.py

@@ -0,0 +1,99 @@
+from __future__ import annotations
+
+from typing import Any
+
+from mcp.types import CallToolResult as McpCallToolResult
+from mcp.types import Prompt as McpPrompt
+from mcp.types import Resource as McpResource
+from mcp.types import Tool as McpTool
+
+from wf_sources_mcp.catalog import DiscoveredPrompt, DiscoveredResource, DiscoveredTool
+
+from .protocols import ToolCallResult
+
+
+def tool_to_discovered(tool: McpTool) -> DiscoveredTool:
+    """Convert an MCP SDK tool into the source discovery model."""
+    output_schema = workflow_output_schema_from_mcp_tool_schema(tool.outputSchema)
+    display_name = (
+        tool.annotations.title
+        if tool.annotations is not None and tool.annotations.title
+        else tool.title
+    )
+    return DiscoveredTool(
+        name=tool.name,
+        title=display_name,
+        description=tool.description,
+        input_schema=tool.inputSchema,
+        output_schema=output_schema,
+        outcomes=("ok", "error"),
+        metadata=tool.model_dump(by_alias=True, mode="json"),
+    )
+
+
+def workflow_output_schema_from_mcp_tool_schema(
+    schema: dict[str, Any] | None,
+) -> dict[str, Any]:
+    """Return the MCP tool output schema without inventing workflow fields.
+
+    MCP tools without structured output expose raw content blocks. Those blocks
+    can be text, images, resource links, or mixed results, so this layer must not
+    pretend there is a stable top-level ``text`` field. Workflow authors should
+    add an explicit wrapper/extraction node for the block shape they expect.
+    """
+    return schema or {
+        "type": "object",
+        "properties": {"content": {"type": "array"}},
+    }
+
+
+def resource_to_discovered(resource: McpResource) -> DiscoveredResource:
+    """Convert an MCP SDK resource into the source discovery model."""
+    local_name = resource.name or str(resource.uri)
+    return DiscoveredResource(
+        uri=str(resource.uri),
+        name=local_name,
+        title=resource.title,
+        description=resource.description,
+        mime_type=resource.mimeType,
+        metadata=resource.model_dump(by_alias=True, mode="json"),
+    )
+
+
+def prompt_to_discovered(prompt: McpPrompt) -> DiscoveredPrompt:
+    """Convert an MCP SDK prompt into the source discovery model."""
+    arguments = [
+        argument.model_dump(by_alias=True, mode="json")
+        for argument in prompt.arguments or []
+    ]
+    return DiscoveredPrompt(
+        name=prompt.name,
+        title=prompt.title,
+        description=prompt.description,
+        arguments=arguments,
+        metadata=prompt.model_dump(by_alias=True, mode="json"),
+    )
+
+
+def tool_result_to_call_result(result: McpCallToolResult) -> ToolCallResult:
+    """Convert an MCP SDK tool call result into the adapter result model."""
+    if result.structuredContent is not None:
+        output = result.structuredContent
+    else:
+        output: dict[str, Any] = {
+            "content": [item.model_dump(by_alias=True) for item in result.content]
+        }
+    return ToolCallResult(
+        outcome="error" if result.isError else "ok",
+        output=output,
+        meta=result.meta or {},
+    )
+
+
+__all__ = [
+    "prompt_to_discovered",
+    "resource_to_discovered",
+    "tool_result_to_call_result",
+    "tool_to_discovered",
+    "workflow_output_schema_from_mcp_tool_schema",
+]