fix: mypy errors silently dropped during CI (#832)

Resolves
https://linear.app/arcadedev/issue/TOO-788/mypy-failures-are-silently-dropped-during-arcade-mcp-ci

<!-- CURSOR_SUMMARY -->
---

> [!NOTE]
> **Low Risk**
> Low risk: primarily CI/Makefile behavior and type-annotation tweaks;
functional logic is unchanged aside from stricter failure propagation in
`make check`.
> 
> **Overview**
> **Stops CI from silently ignoring mypy failures.** The `make check`
target now runs `mypy` across `libs/arcade*/` and exits non-zero if any
package fails, reporting the failed libs.
> 
> Separately tightens typing to satisfy `mypy` (removing `type: ignore`
on OAuth helpers, adding `cast()`/`Any` annotations for JSON response
shapes and subprocess kwargs, and handling non-`str` `server_address`
hosts), and bumps patch versions for `arcade-mcp` and
`arcade-mcp-server`.
> 
> <sup>Reviewed by [Cursor Bugbot](https://cursor.com/bugbot) for commit
e79575b13a2d03adf3548104a0064c643f1e21b1. Bugbot is set up for automated
code reviews on this repo. Configure
[here](https://www.cursor.com/dashboard/bugbot).</sup>
<!-- /CURSOR_SUMMARY -->

Makefile

@@ -10,11 +10,15 @@ install: ## Install the uv environment and all packages with dependencies
 check: ## Run code quality tools.
 	@echo "🚀 Linting code: Running pre-commit"
 	@uv run pre-commit run -a
-		@echo "🚀 Static type checking: Running mypy on libs"
-	@for lib in libs/arcade*/ ; do \
-			echo "🔍 Type checking $$lib"; \
-			(cd $$lib && uv run mypy . --exclude tests || true); \
-		done
+	@echo "🚀 Static type checking: Running mypy on libs"
+	@failed_libs=""; for lib in libs/arcade*/ ; do \
+		echo "🔍 Type checking $$lib"; \
+		(cd $$lib && uv run mypy . --exclude tests) || failed_libs="$$failed_libs $$lib"; \
+	done; \
+	if [ -n "$$failed_libs" ]; then \
+		echo "❌ mypy failed in:$$failed_libs"; \
+		exit 1; \
+	fi
 
 .PHONY: check-libs
 check-libs: ## Run code quality tools for each lib package

libs/arcade-cli/arcade_cli/authn.py

@@ -75,7 +75,7 @@ def _get_default_oauth_timeout_seconds() -> int:
 DEFAULT_OAUTH_TIMEOUT_SECONDS = _get_default_oauth_timeout_seconds()
 
 
-def create_oauth_client(cli_config: CLIConfig) -> OAuth2Client:  # type: ignore[no-any-unimported]
+def create_oauth_client(cli_config: CLIConfig) -> OAuth2Client:
     """
     Create an authlib OAuth2Client configured for the CLI.
 
@@ -92,7 +92,7 @@ def create_oauth_client(cli_config: CLIConfig) -> OAuth2Client:  # type: ignore[
     )
 
 
-def generate_authorization_url(  # type: ignore[no-any-unimported]
+def generate_authorization_url(
     client: OAuth2Client,
     cli_config: CLIConfig,
     redirect_uri: str,
@@ -123,7 +123,7 @@ def generate_authorization_url(  # type: ignore[no-any-unimported]
     return url, code_verifier
 
 
-def exchange_code_for_tokens(  # type: ignore[no-any-unimported]
+def exchange_code_for_tokens(
     client: OAuth2Client,
     code: str,
     redirect_uri: str,
@@ -321,7 +321,7 @@ class _LoopbackHTTPServer(HTTPServer):
     def server_bind(self) -> None:
         socketserver.TCPServer.server_bind(self)
         host, port = self.server_address[:2]
-        self.server_name = host
+        self.server_name = host if isinstance(host, str) else host.decode()
         self.server_port = port
 
 

libs/arcade-cli/arcade_cli/connect.py

@@ -6,6 +6,7 @@ import json as _json
 import logging
 import time
 from pathlib import Path
+from typing import Any, cast
 
 import httpx
 from arcade_core.constants import PROD_COORDINATOR_HOST, PROD_ENGINE_HOST
@@ -55,7 +56,7 @@ def _read_cache(debug: bool = False) -> dict[str, list[str]] | None:
             return None
         if debug:
             console.print(f"  [dim]Using cached tool catalog ({age:.0f}s old)[/dim]")
-        return data.get("toolkits", {})
+        return cast("dict[str, list[str]]", data.get("toolkits", {}))
     except Exception:
         return None
 
@@ -318,7 +319,7 @@ def list_gateways(
         return []
 
     data = resp.json()
-    return data.get("items", [])
+    return cast("list[dict[Any, Any]]", data.get("items", []))
 
 
 def find_matching_gateway(
@@ -401,13 +402,13 @@ def create_gateway(
     if resp.status_code not in (200, 201):
         raise RuntimeError(f"Failed to create gateway ({resp.status_code}): {resp.text}")
 
-    data = resp.json()
+    data: dict[Any, Any] = resp.json()
 
     # The API may return the gateway directly or wrapped in a list/items envelope
     if "slug" in data:
         return data
     if data.get("items"):
-        return data["items"][0]
+        return cast("dict[Any, Any]", data["items"][0])
     if "id" in data:
         return data
 
@@ -695,13 +696,13 @@ def _resolve_gateway_slug(
         if gw.get("slug", "").lower() == input_lower:
             if debug:
                 console.print(f"  [dim]Matched by slug: {gw['slug']}[/dim]")
-            return gw["slug"]
+            return cast("str", gw["slug"])
     for gw in gateways:
         if gw.get("name", "").lower() == input_lower:
             slug = gw["slug"]
             if debug:
                 console.print(f"  [dim]Matched by name '{gw['name']}' -> slug: {slug}[/dim]")
-            return slug
+            return cast("str", slug)
     if debug:
         available = [f"{g.get('name')} ({g.get('slug')})" for g in gateways]
         console.print(f"  [dim]No match for '{user_input}', available: {available}[/dim]")

libs/arcade-cli/arcade_cli/main.py

@@ -4,7 +4,7 @@ import os
 import subprocess
 import sys
 from pathlib import Path
-from typing import Optional
+from typing import Any, Optional
 
 import click
 import typer
@@ -334,7 +334,7 @@ def mcp(
         # window from appearing (e.g. when an MCP client spawns this
         # command without an attached console).  The child process still
         # inherits stdin/stdout/stderr for stdio transport communication.
-        run_kwargs: dict[str, object] = {"check": False}
+        run_kwargs: dict[str, Any] = {"check": False}
         creation_flags = get_windows_no_window_creationflags()
         if creation_flags:
             run_kwargs["creationflags"] = creation_flags

libs/arcade-mcp-server/arcade_mcp_server/convert.py

@@ -184,7 +184,9 @@ def build_input_schema_from_definition(definition: ToolDefinition) -> dict[str,
     if getattr(definition, "input", None) and getattr(definition.input, "parameters", None):
         for param in definition.input.parameters:
             val_schema = getattr(param, "value_schema", None)
-            schema = _value_schema_to_json_schema(val_schema) if val_schema else {"type": "string"}
+            schema: dict[str, Any] = (
+                _value_schema_to_json_schema(val_schema) if val_schema else {"type": "string"}
+            )
 
             if getattr(param, "description", None):
                 schema["description"] = param.description

libs/arcade-mcp-server/pyproject.toml

@@ -4,7 +4,7 @@ build-backend = "hatchling.build"
 
 [project]
 name = "arcade-mcp-server"
-version = "1.21.0"
+version = "1.21.1"
 description = "Model Context Protocol (MCP) server framework for Arcade.dev"
 readme = "README.md"
 authors = [{ name = "Arcade.dev" }]

pyproject.toml

@@ -1,6 +1,6 @@
 [project]
 name = "arcade-mcp"
-version = "1.14.0"
+version = "1.14.1"
 description = "Arcade.dev - Tool Calling platform for Agents"
 readme = "README.md"
 license = { file = "LICENSE" }