fix(mcp): Fix CI failures and credential validation issues

- Fix pyright errors in graph_test.py by properly typing frozenset[CredentialsType]
- Fix executor validation crash when credentials is empty {} by nullifying
  the field before JSON schema validation
- Exclude MCP Tool block from e2e block discovery test (requires dialog)
- Normalize provider string in CredentialsMetaResponse to handle Python 3.13
  str(Enum) bug for stored credentials
- Fix get_host() to match MCP provider regardless of enum string format

autogpt_platform/backend/backend/api/features/integrations/router.py

@@ -1,7 +1,7 @@
 import asyncio
 import logging
 from datetime import datetime, timedelta, timezone
-from typing import TYPE_CHECKING, Annotated, List, Literal
+from typing import TYPE_CHECKING, Annotated, Any, List, Literal
 
 from autogpt_libs.auth import get_user_id
 from fastapi import (
@@ -14,7 +14,7 @@ from fastapi import (
     Security,
     status,
 )
-from pydantic import BaseModel, Field, SecretStr
+from pydantic import BaseModel, Field, SecretStr, model_validator
 from starlette.status import HTTP_500_INTERNAL_SERVER_ERROR, HTTP_502_BAD_GATEWAY
 
 from backend.api.features.library.db import set_preset_webhook, update_preset
@@ -106,12 +106,30 @@ class CredentialsMetaResponse(BaseModel):
         description="Host pattern for host-scoped or MCP server URL for MCP credentials",
     )
 
+    @model_validator(mode="before")
+    @classmethod
+    def _normalize_provider(cls, data: Any) -> Any:
+        """Fix ``ProviderName.X`` format from Python 3.13 ``str(Enum)`` bug."""
+        if isinstance(data, dict):
+            prov = data.get("provider", "")
+            if isinstance(prov, str) and prov.startswith("ProviderName."):
+                member = prov.removeprefix("ProviderName.")
+                try:
+                    data = {**data, "provider": ProviderName[member].value}
+                except KeyError:
+                    pass
+        return data
+
     @staticmethod
     def get_host(cred: Credentials) -> str | None:
         """Extract host from credential: HostScoped host or MCP server URL."""
         if isinstance(cred, HostScopedCredentials):
             return cred.host
-        if isinstance(cred, OAuth2Credentials) and cred.provider == ProviderName.MCP:
+        if isinstance(cred, OAuth2Credentials) and cred.provider in (
+            ProviderName.MCP,
+            ProviderName.MCP.value,
+            "ProviderName.MCP",
+        ):
             return (cred.metadata or {}).get("mcp_server_url")
         return None
 

autogpt_platform/backend/backend/data/graph_test.py

@@ -473,19 +473,21 @@ def test_node_credentials_optional_with_other_metadata():
 def test_mcp_credential_combine_different_servers():
     """Two MCP credential fields with different server URLs should produce
     separate entries when combined (not merged into one)."""
-    from backend.data.model import CredentialsFieldInfo
+    from backend.data.model import CredentialsFieldInfo, CredentialsType
     from backend.integrations.providers import ProviderName
 
+    oauth2_types: frozenset[CredentialsType] = frozenset(["oauth2"])
+
     field_sentry = CredentialsFieldInfo(
         credentials_provider=frozenset([ProviderName.MCP]),
-        credentials_types=frozenset(["oauth2"]),
+        credentials_types=oauth2_types,
         credentials_scopes=None,
         discriminator="server_url",
         discriminator_values={"https://mcp.sentry.dev/mcp"},
     )
     field_linear = CredentialsFieldInfo(
         credentials_provider=frozenset([ProviderName.MCP]),
-        credentials_types=frozenset(["oauth2"]),
+        credentials_types=oauth2_types,
         credentials_scopes=None,
         discriminator="server_url",
         discriminator_values={"https://mcp.linear.app/mcp"},
@@ -515,19 +517,21 @@ def test_mcp_credential_combine_different_servers():
 def test_mcp_credential_combine_same_server():
     """Two MCP credential fields with the same server URL should be combined
     into one credential entry."""
-    from backend.data.model import CredentialsFieldInfo
+    from backend.data.model import CredentialsFieldInfo, CredentialsType
     from backend.integrations.providers import ProviderName
 
+    oauth2_types: frozenset[CredentialsType] = frozenset(["oauth2"])
+
     field_a = CredentialsFieldInfo(
         credentials_provider=frozenset([ProviderName.MCP]),
-        credentials_types=frozenset(["oauth2"]),
+        credentials_types=oauth2_types,
         credentials_scopes=None,
         discriminator="server_url",
         discriminator_values={"https://mcp.sentry.dev/mcp"},
     )
     field_b = CredentialsFieldInfo(
         credentials_provider=frozenset([ProviderName.MCP]),
-        credentials_types=frozenset(["oauth2"]),
+        credentials_types=oauth2_types,
         credentials_scopes=None,
         discriminator="server_url",
         discriminator_values={"https://mcp.sentry.dev/mcp"},
@@ -548,18 +552,20 @@ def test_mcp_credential_combine_same_server():
 def test_mcp_credential_combine_no_discriminator_values():
     """MCP credential fields without discriminator_values should be merged
     into a single entry (backwards compat for blocks without server_url set)."""
-    from backend.data.model import CredentialsFieldInfo
+    from backend.data.model import CredentialsFieldInfo, CredentialsType
     from backend.integrations.providers import ProviderName
 
+    oauth2_types: frozenset[CredentialsType] = frozenset(["oauth2"])
+
     field_a = CredentialsFieldInfo(
         credentials_provider=frozenset([ProviderName.MCP]),
-        credentials_types=frozenset(["oauth2"]),
+        credentials_types=oauth2_types,
         credentials_scopes=None,
         discriminator="server_url",
     )
     field_b = CredentialsFieldInfo(
         credentials_provider=frozenset([ProviderName.MCP]),
-        credentials_types=frozenset(["oauth2"]),
+        credentials_types=oauth2_types,
         credentials_scopes=None,
         discriminator="server_url",
     )

autogpt_platform/backend/backend/executor/manager.py

@@ -274,7 +274,10 @@ async def execute_node(
         if not field_value or (
             isinstance(field_value, dict) and not field_value.get("id")
         ):
-            continue  # No credentials configured — block runs without
+            # No credentials configured — nullify so JSON schema validation
+            # doesn't choke on the empty default `{}`.
+            input_data[field_name] = None
+            continue  # Block runs without credentials
 
         credentials_meta = input_type(**field_value)
         # Write normalized values back so JSON schema validation also passes

autogpt_platform/frontend/src/tests/pages/build.page.ts

@@ -520,6 +520,9 @@ export class BuildPage extends BasePage {
   async getBlocksToSkip(): Promise<string[]> {
     return [
       (await this.getGithubTriggerBlockDetails()).map((b) => b.id),
+      // MCP Tool block requires an interactive dialog (server URL + OAuth) before
+      // it can be placed, so it can't be tested via the standard "add block" flow.
+      "a0a4b1c2-d3e4-4f56-a7b8-c9d0e1f2a3b4",
     ].flat();
   }