from __future__ import annotations import json import sys import tempfile import unittest from pathlib import Path from unittest.mock import patch from src.agent_runtime import LocalCodingAgent from src.agent_tools import build_tool_context, default_tool_registry, execute_tool from src.agent_types import AgentRuntimeConfig, ModelConfig from src.mcp_runtime import MCPRuntime class FakeHTTPResponse: def __init__(self, payload: dict[str, object]) -> None: self.payload = payload def read(self) -> bytes: return json.dumps(self.payload).encode('utf-8') def __enter__(self) -> 'FakeHTTPResponse': return self def __exit__(self, exc_type, exc, tb) -> None: return None def make_urlopen_side_effect(responses: list[dict[str, object]]): queued = [FakeHTTPResponse(payload) for payload in responses] def _fake_urlopen(request_obj, timeout=None): # noqa: ANN001 return queued.pop(0) return _fake_urlopen class MCPRuntimeTests(unittest.TestCase): def _write_fake_stdio_server(self, workspace: Path) -> Path: server_path = workspace / 'fake_mcp_server.py' server_path.write_text( ( 'import json, sys\n' 'RESOURCES = [{"uri": "mcp://remote/notes", "name": "Remote Notes", "mimeType": "text/plain"}]\n' 'TOOLS = [{"name": "echo", "description": "Echo text", "inputSchema": {"type": "object", "properties": {"text": {"type": "string"}}}}]\n' 'for raw in sys.stdin:\n' ' raw = raw.strip()\n' ' if not raw:\n' ' continue\n' ' message = json.loads(raw)\n' ' method = message.get("method")\n' ' if method == "initialize":\n' ' response = {"jsonrpc": "2.0", "id": message.get("id"), "result": {"protocolVersion": "2025-11-25", "capabilities": {"resources": {}, "tools": {}}, "serverInfo": {"name": "fake-remote", "version": "1.0.0"}}}\n' ' print(json.dumps(response), flush=True)\n' ' continue\n' ' if method == "notifications/initialized":\n' ' continue\n' ' if method == "resources/list":\n' ' response = {"jsonrpc": "2.0", "id": message.get("id"), "result": {"resources": RESOURCES}}\n' ' print(json.dumps(response), flush=True)\n' ' continue\n' ' if method == "resources/read":\n' ' uri = message.get("params", {}).get("uri")\n' ' text = "remote notes via stdio" if uri == "mcp://remote/notes" else "unknown resource"\n' ' response = {"jsonrpc": "2.0", "id": message.get("id"), "result": {"contents": [{"uri": uri, "mimeType": "text/plain", "text": text}]}}\n' ' print(json.dumps(response), flush=True)\n' ' continue\n' ' if method == "tools/list":\n' ' response = {"jsonrpc": "2.0", "id": message.get("id"), "result": {"tools": TOOLS}}\n' ' print(json.dumps(response), flush=True)\n' ' continue\n' ' if method == "tools/call":\n' ' params = message.get("params", {})\n' ' text = params.get("arguments", {}).get("text", "")\n' ' response = {"jsonrpc": "2.0", "id": message.get("id"), "result": {"content": [{"type": "text", "text": "echo:" + text}], "isError": False}}\n' ' print(json.dumps(response), flush=True)\n' ' continue\n' ' response = {"jsonrpc": "2.0", "id": message.get("id"), "error": {"code": -32601, "message": "Method not found"}}\n' ' print(json.dumps(response), flush=True)\n' ), encoding='utf-8', ) return server_path def test_runtime_discovers_and_reads_local_resources(self) -> None: with tempfile.TemporaryDirectory() as tmp_dir: workspace = Path(tmp_dir) (workspace / 'notes.txt').write_text('mcp notes\n', encoding='utf-8') (workspace / '.claw-mcp.json').write_text( ( '{"servers":[{"name":"workspace","resources":[' '{"uri":"mcp://workspace/notes","name":"Notes","path":"notes.txt"},' '{"uri":"mcp://workspace/inline","name":"Inline","text":"inline body"}' ']}]}' ), encoding='utf-8', ) runtime = MCPRuntime.from_workspace(workspace) self.assertEqual(len(runtime.resources), 2) self.assertIn('Local MCP resources: 2', runtime.render_summary()) self.assertEqual(runtime.read_resource('mcp://workspace/inline'), 'inline body') self.assertIn('mcp notes', runtime.read_resource('mcp://workspace/notes')) def test_runtime_discovers_stdio_server_and_remote_resources_and_tools(self) -> None: with tempfile.TemporaryDirectory() as tmp_dir: workspace = Path(tmp_dir) server_path = self._write_fake_stdio_server(workspace) (workspace / '.claw-mcp.json').write_text( json.dumps( { 'mcpServers': { 'remote': { 'command': sys.executable, 'args': ['-u', str(server_path)], } } } ), encoding='utf-8', ) runtime = MCPRuntime.from_workspace(workspace) resources = runtime.list_resources() tools = runtime.list_tools() self.assertEqual(len(runtime.servers), 1) self.assertTrue(runtime.has_transport_servers()) self.assertIn('Configured MCP servers: 1', runtime.render_summary()) self.assertEqual(len(resources), 1) self.assertEqual(resources[0].uri, 'mcp://remote/notes') self.assertIn('remote notes via stdio', runtime.read_resource('mcp://remote/notes')) self.assertEqual(len(tools), 1) self.assertEqual(tools[0].name, 'echo') rendered, metadata = runtime.call_tool('echo', arguments={'text': 'hello'}) self.assertIn('echo:hello', rendered) self.assertEqual(metadata.get('server_name'), 'remote') def test_mcp_tools_execute_against_runtime(self) -> None: with tempfile.TemporaryDirectory() as tmp_dir: workspace = Path(tmp_dir) (workspace / 'notes.txt').write_text('mcp notes\n', encoding='utf-8') (workspace / '.claw-mcp.json').write_text( ( '{"servers":[{"name":"workspace","resources":[' '{"uri":"mcp://workspace/notes","name":"Notes","path":"notes.txt"}' ']}]}' ), encoding='utf-8', ) runtime = MCPRuntime.from_workspace(workspace) context = build_tool_context( AgentRuntimeConfig(cwd=workspace), mcp_runtime=runtime, ) list_result = execute_tool( default_tool_registry(), 'mcp_list_resources', {}, context, ) read_result = execute_tool( default_tool_registry(), 'mcp_read_resource', {'uri': 'mcp://workspace/notes'}, context, ) self.assertTrue(list_result.ok) self.assertIn('mcp://workspace/notes', list_result.content) self.assertTrue(read_result.ok) self.assertIn('mcp notes', read_result.content) def test_mcp_transport_tools_execute_against_runtime(self) -> None: with tempfile.TemporaryDirectory() as tmp_dir: workspace = Path(tmp_dir) server_path = self._write_fake_stdio_server(workspace) (workspace / '.claw-mcp.json').write_text( json.dumps( { 'mcpServers': { 'remote': { 'command': sys.executable, 'args': ['-u', str(server_path)], } } } ), encoding='utf-8', ) runtime = MCPRuntime.from_workspace(workspace) context = build_tool_context( AgentRuntimeConfig(cwd=workspace), mcp_runtime=runtime, ) list_result = execute_tool( default_tool_registry(), 'mcp_list_tools', {}, context, ) call_result = execute_tool( default_tool_registry(), 'mcp_call_tool', {'tool_name': 'echo', 'arguments': {'text': 'tool-run'}}, context, ) self.assertTrue(list_result.ok) self.assertIn('echo', list_result.content) self.assertTrue(call_result.ok) self.assertIn('echo:tool-run', call_result.content) self.assertEqual(call_result.metadata.get('action'), 'mcp_call_tool') def test_agent_can_use_mcp_tools_in_model_loop(self) -> None: responses = [ { 'choices': [ { 'message': { 'role': 'assistant', 'content': 'I will inspect the MCP resource.', 'tool_calls': [ { 'id': 'call_1', 'type': 'function', 'function': { 'name': 'mcp_read_resource', 'arguments': '{"uri": "mcp://workspace/notes"}', }, } ], }, 'finish_reason': 'tool_calls', } ], 'usage': {'prompt_tokens': 8, 'completion_tokens': 3}, }, { 'choices': [ { 'message': { 'role': 'assistant', 'content': 'The MCP resource says mcp notes.', }, 'finish_reason': 'stop', } ], 'usage': {'prompt_tokens': 6, 'completion_tokens': 3}, }, ] with tempfile.TemporaryDirectory() as tmp_dir: workspace = Path(tmp_dir) (workspace / 'notes.txt').write_text('mcp notes\n', encoding='utf-8') (workspace / '.claw-mcp.json').write_text( ( '{"servers":[{"name":"workspace","resources":[' '{"uri":"mcp://workspace/notes","name":"Notes","path":"notes.txt"}' ']}]}' ), encoding='utf-8', ) with patch('src.openai_compat.request.urlopen', side_effect=make_urlopen_side_effect(responses)): agent = LocalCodingAgent( model_config=ModelConfig( model='Qwen/Qwen3-Coder-30B-A3B-Instruct', base_url='http://127.0.0.1:8000/v1', ), runtime_config=AgentRuntimeConfig(cwd=workspace), ) result = agent.run('Read the MCP notes resource') self.assertEqual(result.final_output, 'The MCP resource says mcp notes.') self.assertEqual(result.tool_calls, 1) tool_message = next( message for message in result.transcript if message.get('role') == 'tool' ) self.assertIn('mcp notes', tool_message.get('content', '')) def test_agent_can_use_transport_backed_mcp_call_tool_in_model_loop(self) -> None: responses = [ { 'choices': [ { 'message': { 'role': 'assistant', 'content': 'I will call the remote MCP tool.', 'tool_calls': [ { 'id': 'call_1', 'type': 'function', 'function': { 'name': 'mcp_call_tool', 'arguments': '{"tool_name": "echo", "server": "remote", "arguments": {"text": "agent-call"}}', }, } ], }, 'finish_reason': 'tool_calls', } ], 'usage': {'prompt_tokens': 8, 'completion_tokens': 3}, }, { 'choices': [ { 'message': { 'role': 'assistant', 'content': 'The remote MCP tool replied with echo:agent-call.', }, 'finish_reason': 'stop', } ], 'usage': {'prompt_tokens': 6, 'completion_tokens': 3}, }, ] with tempfile.TemporaryDirectory() as tmp_dir: workspace = Path(tmp_dir) server_path = self._write_fake_stdio_server(workspace) (workspace / '.claw-mcp.json').write_text( json.dumps( { 'mcpServers': { 'remote': { 'command': sys.executable, 'args': ['-u', str(server_path)], } } } ), encoding='utf-8', ) with patch('src.openai_compat.request.urlopen', side_effect=make_urlopen_side_effect(responses)): agent = LocalCodingAgent( model_config=ModelConfig( model='Qwen/Qwen3-Coder-30B-A3B-Instruct', base_url='http://127.0.0.1:8000/v1', ), runtime_config=AgentRuntimeConfig(cwd=workspace), ) result = agent.run('Call the remote MCP echo tool') self.assertEqual(result.final_output, 'The remote MCP tool replied with echo:agent-call.') self.assertEqual(result.tool_calls, 1) tool_message = next( message for message in result.transcript if message.get('role') == 'tool' ) self.assertIn('echo:agent-call', tool_message.get('content', ''))