extract parser.py and tool_runner.py from agent code

agents/fce.py

@@ -12,6 +12,7 @@ from datetime import datetime, timezone
 from typing import Any
 
 from agents.shared.mcp_client import MCPMultiClient
+from agents.shared.tool_runner import build_tool_caller
 
 
 async def run_fce(
@@ -65,40 +66,7 @@ async def run_fce(
     origin = flight_status.get("origin", "")
     destination = flight_status.get("destination", "")
 
-    async def _call(server, tool, args, is_live=False, timeout=15.0):
-        t = time.time()
-        ctx = lf.start_as_current_observation(
-            name=tool, as_type="tool", input=args,
-            metadata={"server": server, "is_live": is_live},
-        ) if lf else None
-        if ctx:
-            ctx.__enter__()
-        try:
-            result = await asyncio.wait_for(
-                mcp.call_tool(server, tool, args), timeout=timeout,
-            )
-            lat = int((time.time() - t) * 1000)
-            if ctx:
-                lf.update_current_span(output=result, metadata={"latency_ms": lat})
-                ctx.__exit__(None, None, None)
-            await emit("tool_call_end", tool=tool, latency_ms=lat, is_live=is_live)
-            return result
-        except asyncio.TimeoutError:
-            lat = int((time.time() - t) * 1000)
-            if ctx:
-                lf.update_current_span(output={"error": "timeout"}, level="ERROR")
-                ctx.__exit__(None, None, None)
-            await emit("tool_call_error", tool=tool, error="timeout", latency_ms=lat)
-            errors.append(f"{tool}: timeout after {timeout}s")
-            return None
-        except Exception as e:
-            lat = int((time.time() - t) * 1000)
-            if ctx:
-                lf.update_current_span(output={"error": str(e)}, level="ERROR")
-                ctx.__exit__(None, None, None)
-            await emit("tool_call_error", tool=tool, error=str(e), latency_ms=lat)
-            errors.append(f"{tool}: {e}")
-            return None
+    _call = build_tool_caller(mcp, emit=emit, errors=errors, lf=lf)
 
     # Fire all independent calls in parallel
     ops_data_task = asyncio.create_task(

agents/handover.py

@@ -11,6 +11,7 @@ from datetime import datetime, timezone
 from typing import Any
 
 from agents.shared.mcp_client import MCPMultiClient
+from agents.shared.tool_runner import build_tool_caller
 
 ALL_HUBS = ["ORD", "EWR", "IAH", "SFO", "DEN"]
 
@@ -43,40 +44,7 @@ async def run_handover(
 
     await emit("node_enter", node="gather_all")
 
-    async def _call(server, tool, args, is_live=False, timeout=15.0):
-        t = time.time()
-        ctx = lf.start_as_current_observation(
-            name=tool, as_type="tool", input=args,
-            metadata={"server": server, "is_live": is_live},
-        ) if lf else None
-        if ctx:
-            ctx.__enter__()
-        try:
-            result = await asyncio.wait_for(
-                mcp.call_tool(server, tool, args), timeout=timeout,
-            )
-            lat = int((time.time() - t) * 1000)
-            if ctx:
-                lf.update_current_span(output=result, metadata={"latency_ms": lat})
-                ctx.__exit__(None, None, None)
-            await emit("tool_call_end", tool=tool, latency_ms=lat, is_live=is_live)
-            return result
-        except asyncio.TimeoutError:
-            lat = int((time.time() - t) * 1000)
-            if ctx:
-                lf.update_current_span(output={"error": "timeout"}, level="ERROR")
-                ctx.__exit__(None, None, None)
-            await emit("tool_call_error", tool=tool, error="timeout", latency_ms=lat)
-            errors.append(f"{tool}: timeout after {timeout}s")
-            return None
-        except Exception as e:
-            lat = int((time.time() - t) * 1000)
-            if ctx:
-                lf.update_current_span(output={"error": str(e)}, level="ERROR")
-                ctx.__exit__(None, None, None)
-            await emit("tool_call_error", tool=tool, error=str(e), latency_ms=lat)
-            errors.append(f"{tool}: {e}")
-            return None
+    _call = build_tool_caller(mcp, emit=emit, errors=errors, lf=lf)
 
     # Per-hub calls
     hub_tasks = {}

agents/shared/mcp_client.py

@@ -4,42 +4,17 @@ Composes the three domain-scoped MCP servers into namespaced configurations
 that agents connect to as a single client.
 """
 
-import json
+import os
 from contextlib import asynccontextmanager
 from typing import Any
 
 from fastmcp import Client
 
-
-def _env() -> dict:
-    """Forward LLM-related env vars and active scenario to MCP server subprocesses."""
-    import os
-    from mcp_servers.data.scenarios.manager import scenario_manager
-
-    env = {}
-    for key in (
-        "LLM_PROVIDER", "GROQ_API_KEY", "GROQ_MODEL",
-        "ANTHROPIC_API_KEY", "ANTHROPIC_MODEL",
-        "OPENAI_API_KEY", "OPENAI_BASE_URL", "OPENAI_MODEL",
-        "AWS_ACCESS_KEY_ID", "AWS_SECRET_ACCESS_KEY", "AWS_DEFAULT_REGION",
-        "BEDROCK_MODEL_ID", "USE_BEDROCK",
-        "PATH",
-    ):
-        val = os.getenv(key)
-        if val:
-            env[key] = val
-    env["ACTIVE_SCENARIO"] = scenario_manager.active_id
-    return env
-
-
-def _server_config(module: str) -> dict:
-    """Build server config with current env vars (called at connect time, not import time)."""
-    return {
-        "command": "uv",
-        "args": ["run", "python", "-m", module],
-        "env": _env(),
-    }
-
+from agents.shared.parser import (
+    parse_prompt_result,
+    parse_resource_result,
+    parse_tool_result,
+)
 
 SERVER_MODULES = {
     "shared": "mcp_servers.shared",
@@ -47,12 +22,33 @@ SERVER_MODULES = {
     "passenger": "mcp_servers.passenger",
 }
 
-# Agent profiles — which servers each agent connects to
 AGENT_PROFILES = {
     "fce": ["shared", "ops", "passenger"],
     "handover": ["shared", "ops"],
 }
 
+_FORWARDED_ENV_KEYS = (
+    "LLM_PROVIDER", "GROQ_API_KEY", "GROQ_MODEL",
+    "ANTHROPIC_API_KEY", "ANTHROPIC_MODEL",
+    "OPENAI_API_KEY", "OPENAI_BASE_URL", "OPENAI_MODEL",
+    "AWS_ACCESS_KEY_ID", "AWS_SECRET_ACCESS_KEY", "AWS_DEFAULT_REGION",
+    "BEDROCK_MODEL_ID", "USE_BEDROCK",
+    "PATH",
+)
+
+
+def _subprocess_env() -> dict:
+    """Env vars forwarded to MCP server subprocesses (LLM config + active scenario)."""
+    from mcp_servers.data.scenarios.manager import scenario_manager
+
+    env = {k: os.environ[k] for k in _FORWARDED_ENV_KEYS if k in os.environ}
+    env["ACTIVE_SCENARIO"] = scenario_manager.active_id
+    return env
+
+
+def _server_config(module: str) -> dict:
+    return {"command": "uv", "args": ["run", "python", "-m", module], "env": _subprocess_env()}
+
 
 class MCPMultiClient:
     """Manages connections to multiple MCP servers via fastmcp Client."""
@@ -61,7 +57,6 @@ class MCPMultiClient:
         self._clients: dict[str, Client] = {}
 
     async def connect(self, server_names: list[str]) -> None:
-        """Connect to the specified MCP servers."""
         for name in server_names:
             if name not in SERVER_MODULES:
                 raise ValueError(f"Unknown server: {name}. Available: {list(SERVER_MODULES.keys())}")
@@ -71,7 +66,6 @@ class MCPMultiClient:
             self._clients[name] = client
 
     async def close(self) -> None:
-        """Close all server connections."""
         for client in self._clients.values():
             try:
                 await client.__aexit__(None, None, None)
@@ -79,71 +73,23 @@ class MCPMultiClient:
                 pass
         self._clients.clear()
 
-    async def call_tool(self, server: str, tool_name: str, arguments: dict) -> Any:
-        """Call a tool on a specific server. Returns parsed result."""
+    def _client(self, server: str) -> Client:
         client = self._clients.get(server)
         if not client:
             raise ValueError(f"Not connected to server: {server}")
+        return client
 
-        result = await client.call_tool(tool_name, arguments)
-
-        # Parse the result content
-        if isinstance(result, list):
-            texts = [c.text for c in result if hasattr(c, "text")]
-        elif hasattr(result, "content"):
-            texts = [c.text for c in result.content if hasattr(c, "text")]
-        else:
-            return result
-
-        if len(texts) == 1:
-            try:
-                return json.loads(texts[0])
-            except (json.JSONDecodeError, TypeError):
-                return texts[0]
-        elif len(texts) > 1:
-            parsed = []
-            for t in texts:
-                try:
-                    parsed.append(json.loads(t))
-                except (json.JSONDecodeError, TypeError):
-                    parsed.append(t)
-            return parsed
-        return None
+    async def call_tool(self, server: str, tool_name: str, arguments: dict) -> Any:
+        result = await self._client(server).call_tool(tool_name, arguments)
+        return parse_tool_result(result)
 
     async def read_resource(self, server: str, uri: str) -> Any:
-        """Read a resource from a specific server."""
-        client = self._clients.get(server)
-        if not client:
-            raise ValueError(f"Not connected to server: {server}")
-
-        result = await client.read_resource(uri)
-        if isinstance(result, str):
-            try:
-                return json.loads(result)
-            except (json.JSONDecodeError, TypeError):
-                return result
-        return result
+        result = await self._client(server).read_resource(uri)
+        return parse_resource_result(result)
 
     async def get_prompt(self, server: str, prompt_name: str, arguments: dict) -> str:
-        """Get a rendered prompt from a specific server."""
-        client = self._clients.get(server)
-        if not client:
-            raise ValueError(f"Not connected to server: {server}")
-
-        result = await client.get_prompt(prompt_name, arguments)
-        if isinstance(result, str):
-            return result
-        # Handle structured prompt response
-        texts = []
-        if hasattr(result, "messages"):
-            for msg in result.messages:
-                if hasattr(msg.content, "text"):
-                    texts.append(msg.content.text)
-                elif isinstance(msg.content, list):
-                    for c in msg.content:
-                        if hasattr(c, "text"):
-                            texts.append(c.text)
-        return "\n".join(texts) if texts else str(result)
+        result = await self._client(server).get_prompt(prompt_name, arguments)
+        return parse_prompt_result(result)
 
 
 @asynccontextmanager

agents/shared/parser.py

@@ -0,0 +1,56 @@
+"""Parsers for MCP response content (tools, resources, prompts)."""
+
+import json
+from typing import Any
+
+
+def _extract_texts(result: Any) -> list[str]:
+    """Pull text fields out of an MCP response, handling list/content/str shapes."""
+    if isinstance(result, list):
+        return [c.text for c in result if hasattr(c, "text")]
+    if hasattr(result, "content"):
+        return [c.text for c in result.content if hasattr(c, "text")]
+    return []
+
+
+def _maybe_json(text: str) -> Any:
+    """Parse JSON if possible; fall back to raw text."""
+    try:
+        return json.loads(text)
+    except (json.JSONDecodeError, TypeError):
+        return text
+
+
+def parse_tool_result(result: Any) -> Any:
+    """Parse `client.call_tool()` result into native Python structure."""
+    texts = _extract_texts(result)
+    if not texts:
+        return result
+    if len(texts) == 1:
+        return _maybe_json(texts[0])
+    return [_maybe_json(t) for t in texts]
+
+
+def parse_resource_result(result: Any) -> Any:
+    """Parse `client.read_resource()` result — often a JSON-encoded string."""
+    if isinstance(result, str):
+        return _maybe_json(result)
+    return result
+
+
+def parse_prompt_result(result: Any) -> str:
+    """Flatten a prompt response into a single string."""
+    if isinstance(result, str):
+        return result
+    if not hasattr(result, "messages"):
+        return str(result)
+
+    texts: list[str] = []
+    for msg in result.messages:
+        if hasattr(msg.content, "text"):
+            texts.append(msg.content.text)
+        elif isinstance(msg.content, list):
+            for c in msg.content:
+                if hasattr(c, "text"):
+                    texts.append(c.text)
+    return "\n".join(texts) if texts else str(result)

agents/shared/tool_runner.py

@@ -0,0 +1,73 @@
+"""Shared tool-call helper: timeout, tracing, event emission, error collection.
+
+Every agent invokes MCP tools through this so the three concerns
+(observability, resilience, error state) stay in one place.
+"""
+
+import asyncio
+import time
+from typing import Any, Awaitable, Callable
+
+
+EmitFn = Callable[..., Awaitable[None]]
+
+
+def build_tool_caller(
+    mcp,
+    *,
+    emit: EmitFn,
+    errors: list[str],
+    lf: Any = None,
+    timeout: float = 15.0,
+):
+    """Return an async `_call(server, tool, args, is_live=False)` closure.
+
+    On each invocation:
+      - opens a Langfuse span (if `lf` is provided)
+      - runs `mcp.call_tool` with an `asyncio.wait_for` timeout
+      - emits `tool_call_end` / `tool_call_error` events
+      - appends to `errors` on failure, returns `None`
+      - closes the Langfuse span with output or error level
+    """
+
+    async def _call(server: str, tool: str, args: dict, is_live: bool = False) -> Any:
+        t0 = time.time()
+        span_ctx = lf.start_as_current_observation(
+            name=tool, as_type="tool", input=args,
+            metadata={"server": server, "is_live": is_live},
+        ) if lf else None
+        if span_ctx:
+            span_ctx.__enter__()
+
+        def _close_span(output: Any, level: str | None = None):
+            if not span_ctx:
+                return
+            kwargs: dict[str, Any] = {"output": output}
+            if level:
+                kwargs["level"] = level
+            else:
+                kwargs["metadata"] = {"latency_ms": int((time.time() - t0) * 1000)}
+            lf.update_current_span(**kwargs)
+            span_ctx.__exit__(None, None, None)
+
+        try:
+            result = await asyncio.wait_for(mcp.call_tool(server, tool, args), timeout=timeout)
+        except asyncio.TimeoutError:
+            latency = int((time.time() - t0) * 1000)
+            _close_span({"error": "timeout"}, level="ERROR")
+            await emit("tool_call_error", tool=tool, error="timeout", latency_ms=latency)
+            errors.append(f"{tool}: timeout after {timeout}s")
+            return None
+        except Exception as e:
+            latency = int((time.time() - t0) * 1000)
+            _close_span({"error": str(e)}, level="ERROR")
+            await emit("tool_call_error", tool=tool, error=str(e), latency_ms=latency)
+            errors.append(f"{tool}: {e}")
+            return None
+
+        latency = int((time.time() - t0) * 1000)
+        _close_span(result)
+        await emit("tool_call_end", tool=tool, latency_ms=latency, is_live=is_live)
+        return result
+
+    return _call