style(mcp): Apply linter formatting

- Add type: ignore for aiohttp private _server.sockets access
- Add assert not None before accessing Optional refresh_token

autogpt_platform/backend/MCP_BLOCK_IMPLEMENTATION.md

@@ -0,0 +1,76 @@
+# MCP Block Implementation Plan
+
+## Overview
+
+Create a single **MCPBlock** that dynamically integrates with any MCP (Model Context Protocol)
+server. Users provide a server URL, the block discovers available tools, presents them as a
+dropdown, and dynamically adjusts input/output schema based on the selected tool — exactly like
+`AgentExecutorBlock` handles dynamic schemas.
+
+## Architecture
+
+```
+User provides MCP server URL + credentials
+         ↓
+MCPBlock fetches tools via MCP protocol (tools/list)
+         ↓
+User selects tool from dropdown (stored in constantInput)
+         ↓
+Input schema dynamically updates based on selected tool's inputSchema
+         ↓
+On execution: MCPBlock calls the tool via MCP protocol (tools/call)
+         ↓
+Result yielded as block output
+```
+
+## Design Decisions
+
+1. **Single block, not many blocks** — One `MCPBlock` handles all MCP servers/tools
+2. **Dynamic schema via AgentExecutorBlock pattern** — Override `get_input_schema()`,
+   `get_input_defaults()`, `get_missing_input()` on the Input class
+3. **Auth via API key or OAuth2 credentials** — Use existing `APIKeyCredentials` or
+   `OAuth2Credentials` with `ProviderName.MCP` provider. API keys are sent as Bearer tokens;
+   OAuth2 uses the access token.
+4. **HTTP-based MCP client** — Use `aiohttp` (already a dependency) to implement MCP Streamable
+   HTTP transport directly. No need for the `mcp` Python SDK — the protocol is simple JSON-RPC
+   over HTTP. Handles both JSON and SSE response formats.
+5. **No new DB tables** — Everything fits in existing `AgentBlock` + `AgentNode` tables
+
+## Implementation Files
+
+### New Files
+- `backend/blocks/mcp/` — MCP block package
+  - `__init__.py`
+  - `block.py` — MCPToolBlock implementation
+  - `client.py` — MCP HTTP client (list_tools, call_tool)
+  - `oauth.py` — MCP OAuth handler for dynamic endpoint discovery
+  - `test_mcp.py` — Unit tests
+  - `test_oauth.py` — OAuth handler tests
+  - `test_integration.py` — Integration tests with local test server
+  - `test_e2e.py` — E2E tests against real MCP servers
+
+### Modified Files
+- `backend/integrations/providers.py` — Add `MCP = "mcp"` to ProviderName
+
+## Dev Loop
+
+```bash
+cd autogpt_platform/backend
+poetry run pytest backend/blocks/mcp/test_mcp.py -xvs        # Unit tests
+poetry run pytest backend/blocks/mcp/test_oauth.py -xvs       # OAuth tests
+poetry run pytest backend/blocks/mcp/test_integration.py -xvs  # Integration tests
+poetry run pytest backend/blocks/mcp/ -xvs                     # All MCP tests
+```
+
+## Status
+
+- [x] Research & Design
+- [x] Add ProviderName.MCP
+- [x] Implement MCP client (client.py)
+- [x] Implement MCPToolBlock (block.py)
+- [x] Add OAuth2 support (oauth.py)
+- [x] Write unit tests
+- [x] Write integration tests
+- [x] Write E2E tests
+- [x] Run tests & fix issues
+- [x] Create PR

autogpt_platform/backend/backend/blocks/mcp/block.py

@@ -0,0 +1,265 @@
+"""
+MCP (Model Context Protocol) Tool Block.
+
+A single dynamic block that can connect to any MCP server, discover available tools,
+and execute them. Works like AgentExecutorBlock — the user selects a tool from a
+dropdown and the input/output schema adapts dynamically.
+"""
+
+import json
+import logging
+from typing import Any, Literal
+
+from pydantic import SecretStr
+
+from backend.blocks.mcp.client import MCPClient, MCPClientError
+from backend.data.block import (
+    Block,
+    BlockCategory,
+    BlockInput,
+    BlockOutput,
+    BlockSchemaInput,
+    BlockSchemaOutput,
+    BlockType,
+)
+from backend.data.model import (
+    APIKeyCredentials,
+    CredentialsField,
+    CredentialsMetaInput,
+    OAuth2Credentials,
+    SchemaField,
+)
+from backend.integrations.providers import ProviderName
+from backend.util.json import validate_with_jsonschema
+
+logger = logging.getLogger(__name__)
+
+MCPCredentials = APIKeyCredentials | OAuth2Credentials
+MCPCredentialsInput = CredentialsMetaInput[
+    Literal[ProviderName.MCP], Literal["api_key", "oauth2"]
+]
+
+TEST_CREDENTIALS = APIKeyCredentials(
+    id="01234567-89ab-cdef-0123-456789abcdef",
+    provider="mcp",
+    api_key=SecretStr("test-mcp-token"),
+    title="Mock MCP Credentials",
+)
+TEST_CREDENTIALS_INPUT = {
+    "provider": TEST_CREDENTIALS.provider,
+    "id": TEST_CREDENTIALS.id,
+    "type": TEST_CREDENTIALS.type,
+    "title": TEST_CREDENTIALS.title,
+}
+
+
+class MCPToolBlock(Block):
+    """
+    A block that connects to an MCP server, lets the user pick a tool,
+    and executes it with dynamic input/output schema.
+
+    The flow:
+    1. User provides an MCP server URL (and optional credentials)
+    2. Frontend calls the backend to get tool list from that URL
+    3. User selects a tool from a dropdown (available_tools)
+    4. The block's input schema updates to reflect the selected tool's parameters
+    5. On execution, the block calls the MCP server to run the tool
+    """
+
+    class Input(BlockSchemaInput):
+        # -- Static fields (always shown) --
+        credentials: MCPCredentialsInput = CredentialsField(
+            description="Credentials for the MCP server. Use an API key for Bearer "
+            "token auth, or OAuth2 for servers that support it. For public "
+            "servers, create a credential with any placeholder value.",
+        )
+        server_url: str = SchemaField(
+            description="URL of the MCP server (Streamable HTTP endpoint)",
+            placeholder="https://mcp.example.com/mcp",
+        )
+        available_tools: dict[str, Any] = SchemaField(
+            description="Available tools on the MCP server. "
+            "This is populated automatically when a server URL is provided.",
+            default={},
+            hidden=True,
+        )
+        selected_tool: str = SchemaField(
+            description="The MCP tool to execute",
+            placeholder="Select a tool",
+            default="",
+        )
+        tool_input_schema: dict[str, Any] = SchemaField(
+            description="JSON Schema for the selected tool's input parameters. "
+            "Populated automatically when a tool is selected.",
+            default={},
+            hidden=True,
+        )
+
+        # -- Dynamic field: actual arguments for the selected tool --
+        tool_arguments: dict[str, Any] = SchemaField(
+            description="Arguments to pass to the selected MCP tool. "
+            "The fields here are defined by the tool's input schema.",
+            default={},
+        )
+
+        @classmethod
+        def get_input_schema(cls, data: BlockInput) -> dict[str, Any]:
+            """Return the tool's input schema so the builder UI renders dynamic fields."""
+            return data.get("tool_input_schema", {})
+
+        @classmethod
+        def get_input_defaults(cls, data: BlockInput) -> BlockInput:
+            """Return the current tool_arguments as defaults for the dynamic fields."""
+            return data.get("tool_arguments", {})
+
+        @classmethod
+        def get_missing_input(cls, data: BlockInput) -> set[str]:
+            """Check which required tool arguments are missing."""
+            required_fields = cls.get_input_schema(data).get("required", [])
+            tool_arguments = data.get("tool_arguments", {})
+            return set(required_fields) - set(tool_arguments)
+
+        @classmethod
+        def get_mismatch_error(cls, data: BlockInput) -> str | None:
+            """Validate tool_arguments against the tool's input schema."""
+            tool_schema = cls.get_input_schema(data)
+            if not tool_schema:
+                return None
+            tool_arguments = data.get("tool_arguments", {})
+            return validate_with_jsonschema(tool_schema, tool_arguments)
+
+    class Output(BlockSchemaOutput):
+        result: Any = SchemaField(description="The result returned by the MCP tool")
+        error: str = SchemaField(description="Error message if the tool call failed")
+
+    def __init__(self):
+        super().__init__(
+            id="a0a4b1c2-d3e4-4f56-a7b8-c9d0e1f2a3b4",
+            description="Connect to any MCP server and execute its tools. "
+            "Provide a server URL, select a tool, and pass arguments dynamically.",
+            categories={BlockCategory.DEVELOPER_TOOLS},
+            input_schema=MCPToolBlock.Input,
+            output_schema=MCPToolBlock.Output,
+            block_type=BlockType.STANDARD,
+            test_input={
+                "server_url": "https://mcp.example.com/mcp",
+                "credentials": TEST_CREDENTIALS_INPUT,
+                "selected_tool": "get_weather",
+                "tool_input_schema": {
+                    "type": "object",
+                    "properties": {"city": {"type": "string"}},
+                    "required": ["city"],
+                },
+                "tool_arguments": {"city": "London"},
+            },
+            test_output=[
+                (
+                    "result",
+                    {"weather": "sunny", "temperature": 20},
+                ),
+            ],
+            test_mock={
+                "_call_mcp_tool": lambda *a, **kw: {
+                    "weather": "sunny",
+                    "temperature": 20,
+                },
+            },
+            test_credentials=TEST_CREDENTIALS,
+        )
+
+    async def _call_mcp_tool(
+        self,
+        server_url: str,
+        tool_name: str,
+        arguments: dict[str, Any],
+        auth_token: str | None = None,
+    ) -> Any:
+        """Call a tool on the MCP server. Extracted for easy mocking in tests."""
+        # Trust the user-configured server URL to allow internal/localhost servers
+        client = MCPClient(
+            server_url,
+            auth_token=auth_token,
+            trusted_origins=[server_url],
+        )
+        await client.initialize()
+        result = await client.call_tool(tool_name, arguments)
+
+        if result.is_error:
+            error_text = ""
+            for item in result.content:
+                if item.get("type") == "text":
+                    error_text += item.get("text", "")
+            raise MCPClientError(
+                f"MCP tool '{tool_name}' returned an error: "
+                f"{error_text or 'Unknown error'}"
+            )
+
+        # Extract text content from the result
+        output_parts = []
+        for item in result.content:
+            if item.get("type") == "text":
+                text = item.get("text", "")
+                # Try to parse as JSON for structured output
+                try:
+                    output_parts.append(json.loads(text))
+                except (json.JSONDecodeError, ValueError):
+                    output_parts.append(text)
+            elif item.get("type") == "image":
+                output_parts.append(
+                    {
+                        "type": "image",
+                        "data": item.get("data"),
+                        "mimeType": item.get("mimeType"),
+                    }
+                )
+            elif item.get("type") == "resource":
+                output_parts.append(item.get("resource", {}))
+
+        # If single result, unwrap
+        if len(output_parts) == 1:
+            return output_parts[0]
+        return output_parts if output_parts else None
+
+    @staticmethod
+    def _extract_auth_token(credentials: MCPCredentials) -> str | None:
+        """Extract a Bearer token from either API key or OAuth2 credentials."""
+        if isinstance(credentials, OAuth2Credentials):
+            return credentials.access_token.get_secret_value()
+
+        if isinstance(credentials, APIKeyCredentials) and credentials.api_key:
+            token_value = credentials.api_key.get_secret_value()
+            if token_value:
+                return token_value
+
+        return None
+
+    async def run(
+        self,
+        input_data: Input,
+        *,
+        credentials: MCPCredentials,
+        **kwargs,
+    ) -> BlockOutput:
+        if not input_data.server_url:
+            yield "error", "MCP server URL is required"
+            return
+
+        if not input_data.selected_tool:
+            yield "error", "No tool selected. Please select a tool from the dropdown."
+            return
+
+        auth_token = self._extract_auth_token(credentials)
+
+        try:
+            result = await self._call_mcp_tool(
+                server_url=input_data.server_url,
+                tool_name=input_data.selected_tool,
+                arguments=input_data.tool_arguments,
+                auth_token=auth_token,
+            )
+            yield "result", result
+        except MCPClientError as e:
+            yield "error", str(e)
+        except Exception as e:
+            logger.exception(f"MCP tool call failed: {e}")
+            yield "error", f"MCP tool call failed: {str(e)}"

autogpt_platform/backend/backend/blocks/mcp/client.py

@@ -0,0 +1,316 @@
+"""
+MCP (Model Context Protocol) HTTP client.
+
+Implements the MCP Streamable HTTP transport for listing tools and calling tools
+on remote MCP servers. Uses JSON-RPC 2.0 over HTTP POST.
+
+Handles both JSON and SSE (text/event-stream) response formats per the MCP spec.
+
+Reference: https://modelcontextprotocol.io/specification/2025-03-26/basic/transports
+"""
+
+import json
+import logging
+from dataclasses import dataclass, field
+from typing import Any
+
+from backend.util.request import Requests
+
+logger = logging.getLogger(__name__)
+
+
+@dataclass
+class MCPTool:
+    """Represents an MCP tool discovered from a server."""
+
+    name: str
+    description: str
+    input_schema: dict[str, Any]
+
+
+@dataclass
+class MCPCallResult:
+    """Result from calling an MCP tool."""
+
+    content: list[dict[str, Any]] = field(default_factory=list)
+    is_error: bool = False
+
+
+class MCPClientError(Exception):
+    """Raised when an MCP protocol error occurs."""
+
+    pass
+
+
+class MCPClient:
+    """
+    Async HTTP client for the MCP Streamable HTTP transport.
+
+    Communicates with MCP servers using JSON-RPC 2.0 over HTTP POST.
+    Supports optional Bearer token authentication.
+    """
+
+    def __init__(
+        self,
+        server_url: str,
+        auth_token: str | None = None,
+        trusted_origins: list[str] | None = None,
+    ):
+        self.server_url = server_url.rstrip("/")
+        self.auth_token = auth_token
+        self.trusted_origins = trusted_origins or []
+        self._request_id = 0
+
+    def _next_id(self) -> int:
+        self._request_id += 1
+        return self._request_id
+
+    def _build_headers(self) -> dict[str, str]:
+        headers = {
+            "Content-Type": "application/json",
+            "Accept": "application/json, text/event-stream",
+        }
+        if self.auth_token:
+            headers["Authorization"] = f"Bearer {self.auth_token}"
+        return headers
+
+    def _build_jsonrpc_request(
+        self, method: str, params: dict[str, Any] | None = None
+    ) -> dict[str, Any]:
+        req: dict[str, Any] = {
+            "jsonrpc": "2.0",
+            "method": method,
+            "id": self._next_id(),
+        }
+        if params is not None:
+            req["params"] = params
+        return req
+
+    @staticmethod
+    def _parse_sse_response(text: str) -> dict[str, Any]:
+        """Parse an SSE (text/event-stream) response body into JSON-RPC data.
+
+        MCP servers may return responses as SSE with format:
+            event: message
+            data: {"jsonrpc":"2.0","result":{...},"id":1}
+
+        We extract the last `data:` line that contains a JSON-RPC response
+        (i.e. has an "id" field), which is the reply to our request.
+        """
+        last_data: dict[str, Any] | None = None
+        for line in text.splitlines():
+            stripped = line.strip()
+            if stripped.startswith("data:"):
+                payload = stripped[len("data:") :].strip()
+                if not payload:
+                    continue
+                try:
+                    parsed = json.loads(payload)
+                    # Only keep JSON-RPC responses (have "id"), skip notifications
+                    if isinstance(parsed, dict) and "id" in parsed:
+                        last_data = parsed
+                except (json.JSONDecodeError, ValueError):
+                    continue
+        if last_data is None:
+            raise MCPClientError("No JSON-RPC response found in SSE stream")
+        return last_data
+
+    async def _send_request(
+        self, method: str, params: dict[str, Any] | None = None
+    ) -> Any:
+        """Send a JSON-RPC request to the MCP server and return the result.
+
+        Handles both ``application/json`` and ``text/event-stream`` responses
+        as required by the MCP Streamable HTTP transport specification.
+        """
+        payload = self._build_jsonrpc_request(method, params)
+        headers = self._build_headers()
+
+        requests = Requests(
+            raise_for_status=True,
+            extra_headers=headers,
+            trusted_origins=self.trusted_origins,
+        )
+        response = await requests.post(self.server_url, json=payload)
+
+        content_type = response.headers.get("content-type", "")
+        if "text/event-stream" in content_type:
+            body = self._parse_sse_response(response.text())
+        else:
+            try:
+                body = response.json()
+            except (ValueError, Exception) as e:
+                raise MCPClientError(
+                    f"MCP server returned non-JSON response: {e}"
+                ) from e
+
+        # Handle JSON-RPC error
+        if "error" in body:
+            error = body["error"]
+            if isinstance(error, dict):
+                raise MCPClientError(
+                    f"MCP server error [{error.get('code', '?')}]: "
+                    f"{error.get('message', 'Unknown error')}"
+                )
+            raise MCPClientError(f"MCP server error: {error}")
+
+        return body.get("result")
+
+    async def _send_notification(self, method: str) -> None:
+        """Send a JSON-RPC notification (no id, no response expected)."""
+        headers = self._build_headers()
+        notification = {"jsonrpc": "2.0", "method": method}
+        requests = Requests(
+            raise_for_status=False,
+            extra_headers=headers,
+            trusted_origins=self.trusted_origins,
+        )
+        await requests.post(self.server_url, json=notification)
+
+    async def discover_auth(self) -> dict[str, Any] | None:
+        """Probe the MCP server's OAuth metadata (RFC 9728 / MCP spec).
+
+        Returns ``None`` if the server doesn't require auth, otherwise returns
+        a dict with:
+          - ``authorization_servers``: list of authorization server URLs
+          - ``resource``: the resource indicator URL (usually the MCP endpoint)
+          - ``scopes_supported``: optional list of supported scopes
+
+        The caller can then fetch the authorization server metadata to get
+        ``authorization_endpoint``, ``token_endpoint``, etc.
+        """
+        from urllib.parse import urlparse
+
+        parsed = urlparse(self.server_url)
+        base = f"{parsed.scheme}://{parsed.netloc}"
+
+        # Build candidates for protected-resource metadata (per RFC 9728)
+        path = parsed.path.rstrip("/")
+        candidates = []
+        if path and path != "/":
+            candidates.append(f"{base}/.well-known/oauth-protected-resource{path}")
+        candidates.append(f"{base}/.well-known/oauth-protected-resource")
+
+        requests = Requests(
+            raise_for_status=False,
+            trusted_origins=self.trusted_origins,
+        )
+        for url in candidates:
+            try:
+                resp = await requests.get(url)
+                if resp.status == 200:
+                    data = resp.json()
+                    if isinstance(data, dict) and "authorization_servers" in data:
+                        return data
+            except Exception:
+                continue
+
+        return None
+
+    async def discover_auth_server_metadata(
+        self, auth_server_url: str
+    ) -> dict[str, Any] | None:
+        """Fetch the OAuth Authorization Server Metadata (RFC 8414).
+
+        Given an authorization server URL, returns a dict with:
+          - ``authorization_endpoint``
+          - ``token_endpoint``
+          - ``registration_endpoint`` (for dynamic client registration)
+          - ``scopes_supported``
+          - ``code_challenge_methods_supported``
+          - etc.
+        """
+        from urllib.parse import urlparse
+
+        parsed = urlparse(auth_server_url)
+        base = f"{parsed.scheme}://{parsed.netloc}"
+        path = parsed.path.rstrip("/")
+
+        # Try standard metadata endpoints (RFC 8414 and OpenID Connect)
+        candidates = []
+        if path and path != "/":
+            candidates.append(f"{base}/.well-known/oauth-authorization-server{path}")
+        candidates.append(f"{base}/.well-known/oauth-authorization-server")
+        candidates.append(f"{base}/.well-known/openid-configuration")
+
+        requests = Requests(
+            raise_for_status=False,
+            trusted_origins=self.trusted_origins,
+        )
+        for url in candidates:
+            try:
+                resp = await requests.get(url)
+                if resp.status == 200:
+                    data = resp.json()
+                    if isinstance(data, dict) and "authorization_endpoint" in data:
+                        return data
+            except Exception:
+                continue
+
+        return None
+
+    async def initialize(self) -> dict[str, Any]:
+        """
+        Send the MCP initialize request.
+
+        This is required by the MCP protocol before any other requests.
+        Returns the server's capabilities.
+        """
+        result = await self._send_request(
+            "initialize",
+            {
+                "protocolVersion": "2025-03-26",
+                "capabilities": {},
+                "clientInfo": {"name": "AutoGPT-Platform", "version": "1.0.0"},
+            },
+        )
+        # Send initialized notification (no response expected)
+        await self._send_notification("notifications/initialized")
+
+        return result or {}
+
+    async def list_tools(self) -> list[MCPTool]:
+        """
+        Discover available tools from the MCP server.
+
+        Returns a list of MCPTool objects with name, description, and input schema.
+        """
+        result = await self._send_request("tools/list")
+        if not result or "tools" not in result:
+            return []
+
+        tools = []
+        for tool_data in result["tools"]:
+            tools.append(
+                MCPTool(
+                    name=tool_data.get("name", ""),
+                    description=tool_data.get("description", ""),
+                    input_schema=tool_data.get("inputSchema", {}),
+                )
+            )
+        return tools
+
+    async def call_tool(
+        self, tool_name: str, arguments: dict[str, Any]
+    ) -> MCPCallResult:
+        """
+        Call a tool on the MCP server.
+
+        Args:
+            tool_name: The name of the tool to call.
+            arguments: The arguments to pass to the tool.
+
+        Returns:
+            MCPCallResult with the tool's response content.
+        """
+        result = await self._send_request(
+            "tools/call",
+            {"name": tool_name, "arguments": arguments},
+        )
+        if not result:
+            return MCPCallResult(is_error=True)
+
+        return MCPCallResult(
+            content=result.get("content", []),
+            is_error=result.get("isError", False),
+        )

autogpt_platform/backend/backend/blocks/mcp/conftest.py

@@ -0,0 +1,21 @@
+"""
+Conftest for MCP block tests.
+
+Override the session-scoped server and graph_cleanup fixtures from
+backend/conftest.py so that MCP integration tests don't spin up the
+full SpinTestServer infrastructure.
+"""
+
+import pytest
+
+
+@pytest.fixture(scope="session")
+def server():
+    """No-op override — MCP tests don't need the full platform server."""
+    yield None
+
+
+@pytest.fixture(scope="session", autouse=True)
+def graph_cleanup(server):
+    """No-op override — MCP tests don't create graphs."""
+    yield

autogpt_platform/backend/backend/blocks/mcp/oauth.py

@@ -0,0 +1,198 @@
+"""
+MCP OAuth handler for MCP servers that use OAuth 2.1 authorization.
+
+Unlike other OAuth handlers (GitHub, Google, etc.) where endpoints are fixed,
+MCP servers have dynamic endpoints discovered via RFC 9728 / RFC 8414 metadata.
+This handler accepts those endpoints at construction time.
+"""
+
+import logging
+import time
+import urllib.parse
+from typing import ClassVar, Optional
+
+from pydantic import SecretStr
+
+from backend.data.model import OAuth2Credentials
+from backend.integrations.oauth.base import BaseOAuthHandler
+from backend.integrations.providers import ProviderName
+from backend.util.request import Requests
+
+logger = logging.getLogger(__name__)
+
+
+class MCPOAuthHandler(BaseOAuthHandler):
+    """
+    OAuth handler for MCP servers with dynamically-discovered endpoints.
+
+    Construction requires the authorization and token endpoint URLs,
+    which are obtained via MCP OAuth metadata discovery
+    (``MCPClient.discover_auth`` + ``discover_auth_server_metadata``).
+    """
+
+    PROVIDER_NAME: ClassVar[ProviderName | str] = ProviderName.MCP
+    DEFAULT_SCOPES: ClassVar[list[str]] = []
+
+    def __init__(
+        self,
+        client_id: str,
+        client_secret: str,
+        redirect_uri: str,
+        *,
+        authorize_url: str,
+        token_url: str,
+        revoke_url: str | None = None,
+        resource_url: str | None = None,
+    ):
+        self.client_id = client_id
+        self.client_secret = client_secret
+        self.redirect_uri = redirect_uri
+        self.authorize_url = authorize_url
+        self.token_url = token_url
+        self.revoke_url = revoke_url
+        self.resource_url = resource_url
+
+    def get_login_url(
+        self,
+        scopes: list[str],
+        state: str,
+        code_challenge: Optional[str],
+    ) -> str:
+        scopes = self.handle_default_scopes(scopes)
+
+        params: dict[str, str] = {
+            "response_type": "code",
+            "client_id": self.client_id,
+            "redirect_uri": self.redirect_uri,
+            "state": state,
+        }
+        if scopes:
+            params["scope"] = " ".join(scopes)
+        # PKCE (S256) — included when the caller provides a code_challenge
+        if code_challenge:
+            params["code_challenge"] = code_challenge
+            params["code_challenge_method"] = "S256"
+        # MCP spec requires resource indicator (RFC 8707)
+        if self.resource_url:
+            params["resource"] = self.resource_url
+
+        return f"{self.authorize_url}?{urllib.parse.urlencode(params)}"
+
+    async def exchange_code_for_tokens(
+        self,
+        code: str,
+        scopes: list[str],
+        code_verifier: Optional[str],
+    ) -> OAuth2Credentials:
+        data: dict[str, str] = {
+            "grant_type": "authorization_code",
+            "code": code,
+            "redirect_uri": self.redirect_uri,
+            "client_id": self.client_id,
+        }
+        if self.client_secret:
+            data["client_secret"] = self.client_secret
+        if code_verifier:
+            data["code_verifier"] = code_verifier
+        if self.resource_url:
+            data["resource"] = self.resource_url
+
+        response = await Requests(raise_for_status=True).post(
+            self.token_url,
+            data=data,
+            headers={"Content-Type": "application/x-www-form-urlencoded"},
+        )
+        tokens = response.json()
+
+        if "error" in tokens:
+            raise RuntimeError(
+                f"Token exchange failed: {tokens.get('error_description', tokens['error'])}"
+            )
+
+        now = int(time.time())
+        expires_in = tokens.get("expires_in")
+
+        return OAuth2Credentials(
+            provider=str(self.PROVIDER_NAME),
+            title=None,
+            access_token=SecretStr(tokens["access_token"]),
+            refresh_token=(
+                SecretStr(tokens["refresh_token"])
+                if tokens.get("refresh_token")
+                else None
+            ),
+            access_token_expires_at=now + expires_in if expires_in else None,
+            refresh_token_expires_at=None,
+            scopes=scopes,
+            metadata={
+                "mcp_token_url": self.token_url,
+                "mcp_resource_url": self.resource_url,
+            },
+        )
+
+    async def _refresh_tokens(
+        self, credentials: OAuth2Credentials
+    ) -> OAuth2Credentials:
+        if not credentials.refresh_token:
+            raise ValueError("No refresh token available for MCP OAuth credentials")
+
+        data: dict[str, str] = {
+            "grant_type": "refresh_token",
+            "refresh_token": credentials.refresh_token.get_secret_value(),
+            "client_id": self.client_id,
+        }
+        if self.client_secret:
+            data["client_secret"] = self.client_secret
+        if self.resource_url:
+            data["resource"] = self.resource_url
+
+        response = await Requests(raise_for_status=True).post(
+            self.token_url,
+            data=data,
+            headers={"Content-Type": "application/x-www-form-urlencoded"},
+        )
+        tokens = response.json()
+
+        if "error" in tokens:
+            raise RuntimeError(
+                f"Token refresh failed: {tokens.get('error_description', tokens['error'])}"
+            )
+
+        now = int(time.time())
+        expires_in = tokens.get("expires_in")
+
+        return OAuth2Credentials(
+            id=credentials.id,
+            provider=str(self.PROVIDER_NAME),
+            title=credentials.title,
+            access_token=SecretStr(tokens["access_token"]),
+            refresh_token=(
+                SecretStr(str(tokens["refresh_token"]))
+                if tokens.get("refresh_token")
+                else credentials.refresh_token
+            ),
+            access_token_expires_at=now + expires_in if expires_in else None,
+            refresh_token_expires_at=credentials.refresh_token_expires_at,
+            scopes=credentials.scopes,
+            metadata=credentials.metadata,
+        )
+
+    async def revoke_tokens(self, credentials: OAuth2Credentials) -> bool:
+        if not self.revoke_url:
+            return False
+
+        try:
+            data = {
+                "token": credentials.access_token.get_secret_value(),
+                "token_type_hint": "access_token",
+                "client_id": self.client_id,
+            }
+            await Requests().post(
+                self.revoke_url,
+                data=data,
+                headers={"Content-Type": "application/x-www-form-urlencoded"},
+            )
+            return True
+        except Exception:
+            logger.warning("Failed to revoke MCP OAuth tokens", exc_info=True)
+            return False

autogpt_platform/backend/backend/blocks/mcp/test_e2e.py

@@ -0,0 +1,104 @@
+"""
+End-to-end tests against a real public MCP server.
+
+These tests hit the OpenAI docs MCP server (https://developers.openai.com/mcp)
+which is publicly accessible without authentication and returns SSE responses.
+
+Mark: These are tagged with ``@pytest.mark.e2e`` so they can be run/skipped
+independently of the rest of the test suite (they require network access).
+"""
+
+import json
+
+import pytest
+
+from backend.blocks.mcp.client import MCPClient
+
+# Public MCP server that requires no authentication
+OPENAI_DOCS_MCP_URL = "https://developers.openai.com/mcp"
+
+
+@pytest.mark.e2e
+class TestRealMCPServer:
+    """Tests against the live OpenAI docs MCP server."""
+
+    @pytest.mark.asyncio
+    async def test_initialize(self):
+        """Verify we can complete the MCP handshake with a real server."""
+        client = MCPClient(OPENAI_DOCS_MCP_URL)
+        result = await client.initialize()
+
+        assert result["protocolVersion"] == "2025-03-26"
+        assert "serverInfo" in result
+        assert result["serverInfo"]["name"] == "openai-docs-mcp"
+        assert "tools" in result.get("capabilities", {})
+
+    @pytest.mark.asyncio
+    async def test_list_tools(self):
+        """Verify we can discover tools from a real MCP server."""
+        client = MCPClient(OPENAI_DOCS_MCP_URL)
+        await client.initialize()
+        tools = await client.list_tools()
+
+        assert len(tools) >= 3  # server has at least 5 tools as of writing
+
+        tool_names = {t.name for t in tools}
+        # These tools are documented and should be stable
+        assert "search_openai_docs" in tool_names
+        assert "list_openai_docs" in tool_names
+        assert "fetch_openai_doc" in tool_names
+
+        # Verify schema structure
+        search_tool = next(t for t in tools if t.name == "search_openai_docs")
+        assert "query" in search_tool.input_schema.get("properties", {})
+        assert "query" in search_tool.input_schema.get("required", [])
+
+    @pytest.mark.asyncio
+    async def test_call_tool_list_api_endpoints(self):
+        """Call the list_api_endpoints tool and verify we get real data."""
+        client = MCPClient(OPENAI_DOCS_MCP_URL)
+        await client.initialize()
+        result = await client.call_tool("list_api_endpoints", {})
+
+        assert not result.is_error
+        assert len(result.content) >= 1
+        assert result.content[0]["type"] == "text"
+
+        data = json.loads(result.content[0]["text"])
+        assert "paths" in data or "urls" in data
+        # The OpenAI API should have many endpoints
+        total = data.get("total", len(data.get("paths", [])))
+        assert total > 50
+
+    @pytest.mark.asyncio
+    async def test_call_tool_search(self):
+        """Search for docs and verify we get results."""
+        client = MCPClient(OPENAI_DOCS_MCP_URL)
+        await client.initialize()
+        result = await client.call_tool(
+            "search_openai_docs", {"query": "chat completions", "limit": 3}
+        )
+
+        assert not result.is_error
+        assert len(result.content) >= 1
+
+    @pytest.mark.asyncio
+    async def test_sse_response_handling(self):
+        """Verify the client correctly handles SSE responses from a real server.
+
+        This is the key test — our local test server returns JSON,
+        but real MCP servers typically return SSE. This proves the
+        SSE parsing works end-to-end.
+        """
+        client = MCPClient(OPENAI_DOCS_MCP_URL)
+        # initialize() internally calls _send_request which must parse SSE
+        result = await client.initialize()
+
+        # If we got here without error, SSE parsing works
+        assert isinstance(result, dict)
+        assert "protocolVersion" in result
+
+        # Also verify list_tools works (another SSE response)
+        tools = await client.list_tools()
+        assert len(tools) > 0
+        assert all(hasattr(t, "name") for t in tools)

autogpt_platform/backend/backend/blocks/mcp/test_integration.py

@@ -0,0 +1,367 @@
+"""
+Integration tests for MCP client and MCPToolBlock against a real HTTP server.
+
+These tests spin up a local MCP test server and run the full client/block flow
+against it — no mocking, real HTTP requests.
+"""
+
+import asyncio
+import json
+import threading
+
+import pytest
+from aiohttp import web
+from pydantic import SecretStr
+
+from backend.blocks.mcp.block import MCPToolBlock
+from backend.blocks.mcp.client import MCPClient
+from backend.blocks.mcp.test_server import create_test_mcp_app
+from backend.data.model import APIKeyCredentials
+
+
+class _MCPTestServer:
+    """
+    Run an MCP test server in a background thread with its own event loop.
+    This avoids event loop conflicts with pytest-asyncio.
+    """
+
+    def __init__(self, auth_token: str | None = None):
+        self.auth_token = auth_token
+        self.url: str = ""
+        self._runner: web.AppRunner | None = None
+        self._loop: asyncio.AbstractEventLoop | None = None
+        self._thread: threading.Thread | None = None
+        self._started = threading.Event()
+
+    def _run(self):
+        self._loop = asyncio.new_event_loop()
+        asyncio.set_event_loop(self._loop)
+        self._loop.run_until_complete(self._start())
+        self._started.set()
+        self._loop.run_forever()
+
+    async def _start(self):
+        app = create_test_mcp_app(auth_token=self.auth_token)
+        self._runner = web.AppRunner(app)
+        await self._runner.setup()
+        site = web.TCPSite(self._runner, "127.0.0.1", 0)
+        await site.start()
+        port = site._server.sockets[0].getsockname()[1]  # type: ignore[union-attr]
+        self.url = f"http://127.0.0.1:{port}/mcp"
+
+    def start(self):
+        self._thread = threading.Thread(target=self._run, daemon=True)
+        self._thread.start()
+        if not self._started.wait(timeout=5):
+            raise RuntimeError("MCP test server failed to start within 5 seconds")
+        return self
+
+    def stop(self):
+        if self._loop and self._runner:
+            asyncio.run_coroutine_threadsafe(self._runner.cleanup(), self._loop).result(
+                timeout=5
+            )
+            self._loop.call_soon_threadsafe(self._loop.stop)
+        if self._thread:
+            self._thread.join(timeout=5)
+
+
+@pytest.fixture(scope="module")
+def mcp_server():
+    """Start a local MCP test server in a background thread."""
+    server = _MCPTestServer()
+    server.start()
+    yield server.url
+    server.stop()
+
+
+@pytest.fixture(scope="module")
+def mcp_server_with_auth():
+    """Start a local MCP test server with auth in a background thread."""
+    server = _MCPTestServer(auth_token="test-secret-token")
+    server.start()
+    yield server.url, "test-secret-token"
+    server.stop()
+
+
+def _make_client(url: str, auth_token: str | None = None) -> MCPClient:
+    """Create an MCPClient with localhost trusted for integration tests."""
+    return MCPClient(url, auth_token=auth_token, trusted_origins=[url])
+
+
+def _make_fake_creds(api_key: str = "FAKE_API_KEY") -> APIKeyCredentials:
+    return APIKeyCredentials(
+        id="test-integration",
+        provider="mcp",
+        api_key=SecretStr(api_key),
+        title="test",
+    )
+
+
+# ── MCPClient integration tests ──────────────────────────────────────
+
+
+class TestMCPClientIntegration:
+    """Test MCPClient against a real local MCP server."""
+
+    @pytest.mark.asyncio
+    async def test_initialize(self, mcp_server):
+        client = _make_client(mcp_server)
+        result = await client.initialize()
+
+        assert result["protocolVersion"] == "2025-03-26"
+        assert result["serverInfo"]["name"] == "test-mcp-server"
+        assert "tools" in result["capabilities"]
+
+    @pytest.mark.asyncio
+    async def test_list_tools(self, mcp_server):
+        client = _make_client(mcp_server)
+        await client.initialize()
+        tools = await client.list_tools()
+
+        assert len(tools) == 3
+
+        tool_names = {t.name for t in tools}
+        assert tool_names == {"get_weather", "add_numbers", "echo"}
+
+        # Check get_weather schema
+        weather = next(t for t in tools if t.name == "get_weather")
+        assert weather.description == "Get current weather for a city"
+        assert "city" in weather.input_schema["properties"]
+        assert weather.input_schema["required"] == ["city"]
+
+        # Check add_numbers schema
+        add = next(t for t in tools if t.name == "add_numbers")
+        assert "a" in add.input_schema["properties"]
+        assert "b" in add.input_schema["properties"]
+
+    @pytest.mark.asyncio
+    async def test_call_tool_get_weather(self, mcp_server):
+        client = _make_client(mcp_server)
+        await client.initialize()
+        result = await client.call_tool("get_weather", {"city": "London"})
+
+        assert not result.is_error
+        assert len(result.content) == 1
+        assert result.content[0]["type"] == "text"
+
+        data = json.loads(result.content[0]["text"])
+        assert data["city"] == "London"
+        assert data["temperature"] == 22
+        assert data["condition"] == "sunny"
+
+    @pytest.mark.asyncio
+    async def test_call_tool_add_numbers(self, mcp_server):
+        client = _make_client(mcp_server)
+        await client.initialize()
+        result = await client.call_tool("add_numbers", {"a": 3, "b": 7})
+
+        assert not result.is_error
+        data = json.loads(result.content[0]["text"])
+        assert data["result"] == 10
+
+    @pytest.mark.asyncio
+    async def test_call_tool_echo(self, mcp_server):
+        client = _make_client(mcp_server)
+        await client.initialize()
+        result = await client.call_tool("echo", {"message": "Hello MCP!"})
+
+        assert not result.is_error
+        assert result.content[0]["text"] == "Hello MCP!"
+
+    @pytest.mark.asyncio
+    async def test_call_unknown_tool(self, mcp_server):
+        client = _make_client(mcp_server)
+        await client.initialize()
+        result = await client.call_tool("nonexistent_tool", {})
+
+        assert result.is_error
+        assert "Unknown tool" in result.content[0]["text"]
+
+    @pytest.mark.asyncio
+    async def test_auth_success(self, mcp_server_with_auth):
+        url, token = mcp_server_with_auth
+        client = _make_client(url, auth_token=token)
+        result = await client.initialize()
+
+        assert result["protocolVersion"] == "2025-03-26"
+
+        tools = await client.list_tools()
+        assert len(tools) == 3
+
+    @pytest.mark.asyncio
+    async def test_auth_failure(self, mcp_server_with_auth):
+        url, _ = mcp_server_with_auth
+        client = _make_client(url, auth_token="wrong-token")
+
+        with pytest.raises(Exception):
+            await client.initialize()
+
+    @pytest.mark.asyncio
+    async def test_auth_missing(self, mcp_server_with_auth):
+        url, _ = mcp_server_with_auth
+        client = _make_client(url)
+
+        with pytest.raises(Exception):
+            await client.initialize()
+
+
+# ── MCPToolBlock integration tests ───────────────────────────────────
+
+
+class TestMCPToolBlockIntegration:
+    """Test MCPToolBlock end-to-end against a real local MCP server."""
+
+    @pytest.mark.asyncio
+    async def test_full_flow_get_weather(self, mcp_server):
+        """Full flow: discover tools, select one, execute it."""
+        # Step 1: Discover tools (simulating what the frontend/API would do)
+        client = _make_client(mcp_server)
+        await client.initialize()
+        tools = await client.list_tools()
+        assert len(tools) == 3
+
+        # Step 2: User selects "get_weather" and we get its schema
+        weather_tool = next(t for t in tools if t.name == "get_weather")
+
+        # Step 3: Execute the block with the selected tool
+        block = MCPToolBlock()
+        input_data = MCPToolBlock.Input(
+            server_url=mcp_server,
+            selected_tool="get_weather",
+            tool_input_schema=weather_tool.input_schema,
+            tool_arguments={"city": "Paris"},
+            credentials={  # type: ignore
+                "provider": "mcp",
+                "id": "test",
+                "type": "api_key",
+                "title": "test",
+            },
+        )
+
+        outputs = []
+        async for name, data in block.run(input_data, credentials=_make_fake_creds()):
+            outputs.append((name, data))
+
+        assert len(outputs) == 1
+        assert outputs[0][0] == "result"
+        result = outputs[0][1]
+        assert result["city"] == "Paris"
+        assert result["temperature"] == 22
+        assert result["condition"] == "sunny"
+
+    @pytest.mark.asyncio
+    async def test_full_flow_add_numbers(self, mcp_server):
+        """Full flow for add_numbers tool."""
+        client = _make_client(mcp_server)
+        await client.initialize()
+        tools = await client.list_tools()
+        add_tool = next(t for t in tools if t.name == "add_numbers")
+
+        block = MCPToolBlock()
+        input_data = MCPToolBlock.Input(
+            server_url=mcp_server,
+            selected_tool="add_numbers",
+            tool_input_schema=add_tool.input_schema,
+            tool_arguments={"a": 42, "b": 58},
+            credentials={  # type: ignore
+                "provider": "mcp",
+                "id": "test",
+                "type": "api_key",
+                "title": "test",
+            },
+        )
+
+        outputs = []
+        async for name, data in block.run(input_data, credentials=_make_fake_creds()):
+            outputs.append((name, data))
+
+        assert len(outputs) == 1
+        assert outputs[0][0] == "result"
+        assert outputs[0][1]["result"] == 100
+
+    @pytest.mark.asyncio
+    async def test_full_flow_echo_plain_text(self, mcp_server):
+        """Verify plain text (non-JSON) responses work."""
+        block = MCPToolBlock()
+        input_data = MCPToolBlock.Input(
+            server_url=mcp_server,
+            selected_tool="echo",
+            tool_input_schema={
+                "type": "object",
+                "properties": {"message": {"type": "string"}},
+                "required": ["message"],
+            },
+            tool_arguments={"message": "Hello from AutoGPT!"},
+            credentials={  # type: ignore
+                "provider": "mcp",
+                "id": "test",
+                "type": "api_key",
+                "title": "test",
+            },
+        )
+
+        outputs = []
+        async for name, data in block.run(input_data, credentials=_make_fake_creds()):
+            outputs.append((name, data))
+
+        assert len(outputs) == 1
+        assert outputs[0][0] == "result"
+        assert outputs[0][1] == "Hello from AutoGPT!"
+
+    @pytest.mark.asyncio
+    async def test_full_flow_unknown_tool_yields_error(self, mcp_server):
+        """Calling an unknown tool should yield an error output."""
+        block = MCPToolBlock()
+        input_data = MCPToolBlock.Input(
+            server_url=mcp_server,
+            selected_tool="nonexistent_tool",
+            tool_arguments={},
+            credentials={  # type: ignore
+                "provider": "mcp",
+                "id": "test",
+                "type": "api_key",
+                "title": "test",
+            },
+        )
+
+        outputs = []
+        async for name, data in block.run(input_data, credentials=_make_fake_creds()):
+            outputs.append((name, data))
+
+        assert len(outputs) == 1
+        assert outputs[0][0] == "error"
+        assert "returned an error" in outputs[0][1]
+
+    @pytest.mark.asyncio
+    async def test_full_flow_with_auth(self, mcp_server_with_auth):
+        """Full flow with authentication."""
+        url, token = mcp_server_with_auth
+
+        block = MCPToolBlock()
+        input_data = MCPToolBlock.Input(
+            server_url=url,
+            selected_tool="echo",
+            tool_input_schema={
+                "type": "object",
+                "properties": {"message": {"type": "string"}},
+                "required": ["message"],
+            },
+            tool_arguments={"message": "Authenticated!"},
+            credentials={  # type: ignore
+                "provider": "mcp",
+                "id": "test",
+                "type": "api_key",
+                "title": "test",
+            },
+        )
+
+        outputs = []
+        async for name, data in block.run(
+            input_data, credentials=_make_fake_creds(api_key=token)
+        ):
+            outputs.append((name, data))
+
+        assert len(outputs) == 1
+        assert outputs[0][0] == "result"
+        assert outputs[0][1] == "Authenticated!"

autogpt_platform/backend/backend/blocks/mcp/test_mcp.py

@@ -0,0 +1,667 @@
+"""
+Tests for MCP client and MCPToolBlock.
+"""
+
+import json
+from unittest.mock import AsyncMock, patch
+
+import pytest
+from pydantic import SecretStr
+
+from backend.blocks.mcp.block import (
+    TEST_CREDENTIALS,
+    TEST_CREDENTIALS_INPUT,
+    MCPToolBlock,
+)
+from backend.blocks.mcp.client import MCPCallResult, MCPClient, MCPClientError
+from backend.data.model import APIKeyCredentials, OAuth2Credentials
+from backend.util.test import execute_block_test
+
+# ── SSE parsing unit tests ───────────────────────────────────────────
+
+
+class TestSSEParsing:
+    """Tests for SSE (text/event-stream) response parsing."""
+
+    def test_parse_sse_simple(self):
+        sse = (
+            "event: message\n"
+            'data: {"jsonrpc":"2.0","result":{"tools":[]},"id":1}\n'
+            "\n"
+        )
+        body = MCPClient._parse_sse_response(sse)
+        assert body["result"] == {"tools": []}
+        assert body["id"] == 1
+
+    def test_parse_sse_with_notifications(self):
+        """SSE streams can contain notifications (no id) before the response."""
+        sse = (
+            "event: message\n"
+            'data: {"jsonrpc":"2.0","method":"some/notification"}\n'
+            "\n"
+            "event: message\n"
+            'data: {"jsonrpc":"2.0","result":{"ok":true},"id":2}\n'
+            "\n"
+        )
+        body = MCPClient._parse_sse_response(sse)
+        assert body["result"] == {"ok": True}
+        assert body["id"] == 2
+
+    def test_parse_sse_error_response(self):
+        sse = (
+            "event: message\n"
+            'data: {"jsonrpc":"2.0","error":{"code":-32600,"message":"Bad Request"},"id":1}\n'
+        )
+        body = MCPClient._parse_sse_response(sse)
+        assert "error" in body
+        assert body["error"]["code"] == -32600
+
+    def test_parse_sse_no_data_raises(self):
+        with pytest.raises(MCPClientError, match="No JSON-RPC response found"):
+            MCPClient._parse_sse_response("event: message\n\n")
+
+    def test_parse_sse_empty_raises(self):
+        with pytest.raises(MCPClientError, match="No JSON-RPC response found"):
+            MCPClient._parse_sse_response("")
+
+    def test_parse_sse_ignores_non_data_lines(self):
+        sse = (
+            ": comment line\n"
+            "event: message\n"
+            "id: 123\n"
+            'data: {"jsonrpc":"2.0","result":"ok","id":1}\n'
+            "\n"
+        )
+        body = MCPClient._parse_sse_response(sse)
+        assert body["result"] == "ok"
+
+    def test_parse_sse_uses_last_response(self):
+        """If multiple responses exist, use the last one."""
+        sse = (
+            'data: {"jsonrpc":"2.0","result":"first","id":1}\n'
+            "\n"
+            'data: {"jsonrpc":"2.0","result":"second","id":2}\n'
+            "\n"
+        )
+        body = MCPClient._parse_sse_response(sse)
+        assert body["result"] == "second"
+
+
+# ── MCPClient unit tests ─────────────────────────────────────────────
+
+
+class TestMCPClient:
+    """Tests for the MCP HTTP client."""
+
+    def test_build_headers_without_auth(self):
+        client = MCPClient("https://mcp.example.com")
+        headers = client._build_headers()
+        assert "Authorization" not in headers
+        assert headers["Content-Type"] == "application/json"
+
+    def test_build_headers_with_auth(self):
+        client = MCPClient("https://mcp.example.com", auth_token="my-token")
+        headers = client._build_headers()
+        assert headers["Authorization"] == "Bearer my-token"
+
+    def test_build_jsonrpc_request(self):
+        client = MCPClient("https://mcp.example.com")
+        req = client._build_jsonrpc_request("tools/list")
+        assert req["jsonrpc"] == "2.0"
+        assert req["method"] == "tools/list"
+        assert "id" in req
+        assert "params" not in req
+
+    def test_build_jsonrpc_request_with_params(self):
+        client = MCPClient("https://mcp.example.com")
+        req = client._build_jsonrpc_request(
+            "tools/call", {"name": "test", "arguments": {"x": 1}}
+        )
+        assert req["params"] == {"name": "test", "arguments": {"x": 1}}
+
+    def test_request_id_increments(self):
+        client = MCPClient("https://mcp.example.com")
+        req1 = client._build_jsonrpc_request("tools/list")
+        req2 = client._build_jsonrpc_request("tools/list")
+        assert req2["id"] > req1["id"]
+
+    def test_server_url_trailing_slash_stripped(self):
+        client = MCPClient("https://mcp.example.com/mcp/")
+        assert client.server_url == "https://mcp.example.com/mcp"
+
+    @pytest.mark.asyncio
+    async def test_send_request_success(self):
+        client = MCPClient("https://mcp.example.com")
+
+        mock_response = AsyncMock()
+        mock_response.json.return_value = {
+            "jsonrpc": "2.0",
+            "result": {"tools": []},
+            "id": 1,
+        }
+
+        with patch.object(client, "_send_request", return_value={"tools": []}):
+            result = await client._send_request("tools/list")
+            assert result == {"tools": []}
+
+    @pytest.mark.asyncio
+    async def test_send_request_error(self):
+        client = MCPClient("https://mcp.example.com")
+
+        async def mock_send(*args, **kwargs):
+            raise MCPClientError("MCP server error [-32600]: Invalid Request")
+
+        with patch.object(client, "_send_request", side_effect=mock_send):
+            with pytest.raises(MCPClientError, match="Invalid Request"):
+                await client._send_request("tools/list")
+
+    @pytest.mark.asyncio
+    async def test_list_tools(self):
+        client = MCPClient("https://mcp.example.com")
+
+        mock_result = {
+            "tools": [
+                {
+                    "name": "get_weather",
+                    "description": "Get current weather for a city",
+                    "inputSchema": {
+                        "type": "object",
+                        "properties": {"city": {"type": "string"}},
+                        "required": ["city"],
+                    },
+                },
+                {
+                    "name": "search",
+                    "description": "Search the web",
+                    "inputSchema": {
+                        "type": "object",
+                        "properties": {"query": {"type": "string"}},
+                        "required": ["query"],
+                    },
+                },
+            ]
+        }
+
+        with patch.object(client, "_send_request", return_value=mock_result):
+            tools = await client.list_tools()
+
+        assert len(tools) == 2
+        assert tools[0].name == "get_weather"
+        assert tools[0].description == "Get current weather for a city"
+        assert tools[0].input_schema["properties"]["city"]["type"] == "string"
+        assert tools[1].name == "search"
+
+    @pytest.mark.asyncio
+    async def test_list_tools_empty(self):
+        client = MCPClient("https://mcp.example.com")
+
+        with patch.object(client, "_send_request", return_value={"tools": []}):
+            tools = await client.list_tools()
+
+        assert tools == []
+
+    @pytest.mark.asyncio
+    async def test_list_tools_none_result(self):
+        client = MCPClient("https://mcp.example.com")
+
+        with patch.object(client, "_send_request", return_value=None):
+            tools = await client.list_tools()
+
+        assert tools == []
+
+    @pytest.mark.asyncio
+    async def test_call_tool_success(self):
+        client = MCPClient("https://mcp.example.com")
+
+        mock_result = {
+            "content": [
+                {"type": "text", "text": json.dumps({"temp": 20, "city": "London"})}
+            ],
+            "isError": False,
+        }
+
+        with patch.object(client, "_send_request", return_value=mock_result):
+            result = await client.call_tool("get_weather", {"city": "London"})
+
+        assert not result.is_error
+        assert len(result.content) == 1
+        assert result.content[0]["type"] == "text"
+
+    @pytest.mark.asyncio
+    async def test_call_tool_error(self):
+        client = MCPClient("https://mcp.example.com")
+
+        mock_result = {
+            "content": [{"type": "text", "text": "City not found"}],
+            "isError": True,
+        }
+
+        with patch.object(client, "_send_request", return_value=mock_result):
+            result = await client.call_tool("get_weather", {"city": "???"})
+
+        assert result.is_error
+
+    @pytest.mark.asyncio
+    async def test_call_tool_none_result(self):
+        client = MCPClient("https://mcp.example.com")
+
+        with patch.object(client, "_send_request", return_value=None):
+            result = await client.call_tool("get_weather", {"city": "London"})
+
+        assert result.is_error
+
+    @pytest.mark.asyncio
+    async def test_initialize(self):
+        client = MCPClient("https://mcp.example.com")
+
+        mock_result = {
+            "protocolVersion": "2025-03-26",
+            "capabilities": {"tools": {}},
+            "serverInfo": {"name": "test-server", "version": "1.0.0"},
+        }
+
+        with (
+            patch.object(client, "_send_request", return_value=mock_result) as mock_req,
+            patch.object(client, "_send_notification") as mock_notif,
+        ):
+            result = await client.initialize()
+
+        mock_req.assert_called_once()
+        mock_notif.assert_called_once_with("notifications/initialized")
+        assert result["protocolVersion"] == "2025-03-26"
+
+
+# ── MCPToolBlock unit tests ──────────────────────────────────────────
+
+
+class TestMCPToolBlock:
+    """Tests for the MCPToolBlock."""
+
+    def test_block_instantiation(self):
+        block = MCPToolBlock()
+        assert block.id == "a0a4b1c2-d3e4-4f56-a7b8-c9d0e1f2a3b4"
+        assert block.name == "MCPToolBlock"
+
+    def test_input_schema_has_required_fields(self):
+        block = MCPToolBlock()
+        schema = block.input_schema.jsonschema()
+        props = schema.get("properties", {})
+        assert "server_url" in props
+        assert "selected_tool" in props
+        assert "tool_arguments" in props
+        assert "credentials" in props
+
+    def test_output_schema(self):
+        block = MCPToolBlock()
+        schema = block.output_schema.jsonschema()
+        props = schema.get("properties", {})
+        assert "result" in props
+        assert "error" in props
+
+    def test_get_input_schema_with_tool_schema(self):
+        tool_schema = {
+            "type": "object",
+            "properties": {"query": {"type": "string"}},
+            "required": ["query"],
+        }
+        data = {"tool_input_schema": tool_schema}
+        result = MCPToolBlock.Input.get_input_schema(data)
+        assert result == tool_schema
+
+    def test_get_input_schema_without_tool_schema(self):
+        result = MCPToolBlock.Input.get_input_schema({})
+        assert result == {}
+
+    def test_get_input_defaults(self):
+        data = {"tool_arguments": {"city": "London"}}
+        result = MCPToolBlock.Input.get_input_defaults(data)
+        assert result == {"city": "London"}
+
+    def test_get_missing_input(self):
+        data = {
+            "tool_input_schema": {
+                "type": "object",
+                "properties": {
+                    "city": {"type": "string"},
+                    "units": {"type": "string"},
+                },
+                "required": ["city", "units"],
+            },
+            "tool_arguments": {"city": "London"},
+        }
+        missing = MCPToolBlock.Input.get_missing_input(data)
+        assert missing == {"units"}
+
+    def test_get_missing_input_all_present(self):
+        data = {
+            "tool_input_schema": {
+                "type": "object",
+                "properties": {"city": {"type": "string"}},
+                "required": ["city"],
+            },
+            "tool_arguments": {"city": "London"},
+        }
+        missing = MCPToolBlock.Input.get_missing_input(data)
+        assert missing == set()
+
+    @pytest.mark.asyncio
+    async def test_run_with_mock(self):
+        """Test the block using the built-in test infrastructure."""
+        block = MCPToolBlock()
+        await execute_block_test(block)
+
+    @pytest.mark.asyncio
+    async def test_run_missing_server_url(self):
+        block = MCPToolBlock()
+        input_data = MCPToolBlock.Input(
+            server_url="",
+            selected_tool="test",
+            credentials=TEST_CREDENTIALS_INPUT,  # type: ignore
+        )
+        outputs = []
+        async for name, data in block.run(input_data, credentials=TEST_CREDENTIALS):
+            outputs.append((name, data))
+        assert outputs == [("error", "MCP server URL is required")]
+
+    @pytest.mark.asyncio
+    async def test_run_missing_tool(self):
+        block = MCPToolBlock()
+        input_data = MCPToolBlock.Input(
+            server_url="https://mcp.example.com/mcp",
+            selected_tool="",
+            credentials=TEST_CREDENTIALS_INPUT,  # type: ignore
+        )
+        outputs = []
+        async for name, data in block.run(input_data, credentials=TEST_CREDENTIALS):
+            outputs.append((name, data))
+        assert outputs == [
+            ("error", "No tool selected. Please select a tool from the dropdown.")
+        ]
+
+    @pytest.mark.asyncio
+    async def test_run_success(self):
+        block = MCPToolBlock()
+        input_data = MCPToolBlock.Input(
+            server_url="https://mcp.example.com/mcp",
+            selected_tool="get_weather",
+            tool_input_schema={
+                "type": "object",
+                "properties": {"city": {"type": "string"}},
+            },
+            tool_arguments={"city": "London"},
+            credentials=TEST_CREDENTIALS_INPUT,  # type: ignore
+        )
+
+        async def mock_call(*args, **kwargs):
+            return {"temp": 20, "city": "London"}
+
+        block._call_mcp_tool = mock_call  # type: ignore
+
+        outputs = []
+        async for name, data in block.run(input_data, credentials=TEST_CREDENTIALS):
+            outputs.append((name, data))
+
+        assert len(outputs) == 1
+        assert outputs[0][0] == "result"
+        assert outputs[0][1] == {"temp": 20, "city": "London"}
+
+    @pytest.mark.asyncio
+    async def test_run_mcp_error(self):
+        block = MCPToolBlock()
+        input_data = MCPToolBlock.Input(
+            server_url="https://mcp.example.com/mcp",
+            selected_tool="bad_tool",
+            credentials=TEST_CREDENTIALS_INPUT,  # type: ignore
+        )
+
+        async def mock_call(*args, **kwargs):
+            raise MCPClientError("Tool not found")
+
+        block._call_mcp_tool = mock_call  # type: ignore
+
+        outputs = []
+        async for name, data in block.run(input_data, credentials=TEST_CREDENTIALS):
+            outputs.append((name, data))
+
+        assert outputs[0][0] == "error"
+        assert "Tool not found" in outputs[0][1]
+
+    @pytest.mark.asyncio
+    async def test_call_mcp_tool_parses_json_text(self):
+        block = MCPToolBlock()
+
+        mock_result = MCPCallResult(
+            content=[
+                {"type": "text", "text": '{"temp": 20}'},
+            ],
+            is_error=False,
+        )
+
+        async def mock_init(self):
+            return {}
+
+        async def mock_call(self, name, args):
+            return mock_result
+
+        with (
+            patch.object(MCPClient, "initialize", mock_init),
+            patch.object(MCPClient, "call_tool", mock_call),
+        ):
+            result = await block._call_mcp_tool(
+                "https://mcp.example.com", "test_tool", {}
+            )
+
+        assert result == {"temp": 20}
+
+    @pytest.mark.asyncio
+    async def test_call_mcp_tool_plain_text(self):
+        block = MCPToolBlock()
+
+        mock_result = MCPCallResult(
+            content=[
+                {"type": "text", "text": "Hello, world!"},
+            ],
+            is_error=False,
+        )
+
+        async def mock_init(self):
+            return {}
+
+        async def mock_call(self, name, args):
+            return mock_result
+
+        with (
+            patch.object(MCPClient, "initialize", mock_init),
+            patch.object(MCPClient, "call_tool", mock_call),
+        ):
+            result = await block._call_mcp_tool(
+                "https://mcp.example.com", "test_tool", {}
+            )
+
+        assert result == "Hello, world!"
+
+    @pytest.mark.asyncio
+    async def test_call_mcp_tool_multiple_content(self):
+        block = MCPToolBlock()
+
+        mock_result = MCPCallResult(
+            content=[
+                {"type": "text", "text": "Part 1"},
+                {"type": "text", "text": '{"part": 2}'},
+            ],
+            is_error=False,
+        )
+
+        async def mock_init(self):
+            return {}
+
+        async def mock_call(self, name, args):
+            return mock_result
+
+        with (
+            patch.object(MCPClient, "initialize", mock_init),
+            patch.object(MCPClient, "call_tool", mock_call),
+        ):
+            result = await block._call_mcp_tool(
+                "https://mcp.example.com", "test_tool", {}
+            )
+
+        assert result == ["Part 1", {"part": 2}]
+
+    @pytest.mark.asyncio
+    async def test_call_mcp_tool_error_result(self):
+        block = MCPToolBlock()
+
+        mock_result = MCPCallResult(
+            content=[{"type": "text", "text": "Something went wrong"}],
+            is_error=True,
+        )
+
+        async def mock_init(self):
+            return {}
+
+        async def mock_call(self, name, args):
+            return mock_result
+
+        with (
+            patch.object(MCPClient, "initialize", mock_init),
+            patch.object(MCPClient, "call_tool", mock_call),
+        ):
+            with pytest.raises(MCPClientError, match="returned an error"):
+                await block._call_mcp_tool("https://mcp.example.com", "test_tool", {})
+
+    @pytest.mark.asyncio
+    async def test_call_mcp_tool_image_content(self):
+        block = MCPToolBlock()
+
+        mock_result = MCPCallResult(
+            content=[
+                {
+                    "type": "image",
+                    "data": "base64data==",
+                    "mimeType": "image/png",
+                }
+            ],
+            is_error=False,
+        )
+
+        async def mock_init(self):
+            return {}
+
+        async def mock_call(self, name, args):
+            return mock_result
+
+        with (
+            patch.object(MCPClient, "initialize", mock_init),
+            patch.object(MCPClient, "call_tool", mock_call),
+        ):
+            result = await block._call_mcp_tool(
+                "https://mcp.example.com", "test_tool", {}
+            )
+
+        assert result == {
+            "type": "image",
+            "data": "base64data==",
+            "mimeType": "image/png",
+        }
+
+    @pytest.mark.asyncio
+    async def test_run_sends_api_key_credentials(self):
+        """Ensure non-empty API keys are sent to the MCP server."""
+        block = MCPToolBlock()
+        input_data = MCPToolBlock.Input(
+            server_url="https://mcp.example.com/mcp",
+            selected_tool="test_tool",
+            credentials=TEST_CREDENTIALS_INPUT,  # type: ignore
+        )
+
+        creds = APIKeyCredentials(
+            id="test-id",
+            provider="mcp",
+            api_key=SecretStr("real-api-key"),
+            title="Real",
+        )
+
+        captured_tokens = []
+
+        async def mock_call(server_url, tool_name, arguments, auth_token=None):
+            captured_tokens.append(auth_token)
+            return "ok"
+
+        block._call_mcp_tool = mock_call  # type: ignore
+
+        async for _ in block.run(input_data, credentials=creds):
+            pass
+
+        assert captured_tokens == ["real-api-key"]
+
+
+# ── OAuth2 credential support tests ─────────────────────────────────
+
+
+class TestMCPOAuth2Support:
+    """Tests for OAuth2 credential support in MCPToolBlock."""
+
+    def test_extract_auth_token_from_api_key(self):
+        creds = APIKeyCredentials(
+            id="test",
+            provider="mcp",
+            api_key=SecretStr("my-api-key"),
+            title="test",
+        )
+        token = MCPToolBlock._extract_auth_token(creds)
+        assert token == "my-api-key"
+
+    def test_extract_auth_token_from_oauth2(self):
+        creds = OAuth2Credentials(
+            id="test",
+            provider="mcp",
+            access_token=SecretStr("oauth2-access-token"),
+            scopes=["read"],
+            title="test",
+        )
+        token = MCPToolBlock._extract_auth_token(creds)
+        assert token == "oauth2-access-token"
+
+    def test_extract_auth_token_empty_skipped(self):
+        creds = APIKeyCredentials(
+            id="test",
+            provider="mcp",
+            api_key=SecretStr(""),
+            title="test",
+        )
+        token = MCPToolBlock._extract_auth_token(creds)
+        assert token is None
+
+    @pytest.mark.asyncio
+    async def test_run_with_oauth2_credentials(self):
+        """Verify the block can run with OAuth2 credentials."""
+        block = MCPToolBlock()
+        input_data = MCPToolBlock.Input(
+            server_url="https://mcp.example.com/mcp",
+            selected_tool="test_tool",
+            credentials=TEST_CREDENTIALS_INPUT,  # type: ignore
+        )
+
+        oauth2_creds = OAuth2Credentials(
+            id="test-id",
+            provider="mcp",
+            access_token=SecretStr("real-oauth2-token"),
+            scopes=["read", "write"],
+            title="MCP OAuth",
+        )
+
+        captured_tokens = []
+
+        async def mock_call(server_url, tool_name, arguments, auth_token=None):
+            captured_tokens.append(auth_token)
+            return {"status": "ok"}
+
+        block._call_mcp_tool = mock_call  # type: ignore
+
+        outputs = []
+        async for name, data in block.run(input_data, credentials=oauth2_creds):
+            outputs.append((name, data))
+
+        assert captured_tokens == ["real-oauth2-token"]
+        assert outputs == [("result", {"status": "ok"})]

autogpt_platform/backend/backend/blocks/mcp/test_oauth.py

@@ -0,0 +1,242 @@
+"""
+Tests for MCP OAuth handler.
+"""
+
+from unittest.mock import AsyncMock, MagicMock, patch
+
+import pytest
+from pydantic import SecretStr
+
+from backend.blocks.mcp.client import MCPClient
+from backend.blocks.mcp.oauth import MCPOAuthHandler
+from backend.data.model import OAuth2Credentials
+
+
+def _mock_response(json_data: dict, status: int = 200) -> MagicMock:
+    """Create a mock Response with synchronous json() (matching Requests.Response)."""
+    resp = MagicMock()
+    resp.status = status
+    resp.ok = 200 <= status < 300
+    resp.json.return_value = json_data
+    return resp
+
+
+class TestMCPOAuthHandler:
+    """Tests for the MCPOAuthHandler."""
+
+    def _make_handler(self, **overrides) -> MCPOAuthHandler:
+        defaults = {
+            "client_id": "test-client-id",
+            "client_secret": "test-client-secret",
+            "redirect_uri": "https://app.example.com/callback",
+            "authorize_url": "https://auth.example.com/authorize",
+            "token_url": "https://auth.example.com/token",
+        }
+        defaults.update(overrides)
+        return MCPOAuthHandler(**defaults)
+
+    def test_get_login_url_basic(self):
+        handler = self._make_handler()
+        url = handler.get_login_url(
+            scopes=["read", "write"],
+            state="random-state-token",
+            code_challenge="S256-challenge-value",
+        )
+
+        assert "https://auth.example.com/authorize?" in url
+        assert "response_type=code" in url
+        assert "client_id=test-client-id" in url
+        assert "state=random-state-token" in url
+        assert "code_challenge=S256-challenge-value" in url
+        assert "code_challenge_method=S256" in url
+        assert "scope=read+write" in url
+
+    def test_get_login_url_with_resource(self):
+        handler = self._make_handler(resource_url="https://mcp.example.com/mcp")
+        url = handler.get_login_url(
+            scopes=[], state="state", code_challenge="challenge"
+        )
+
+        assert "resource=https" in url
+
+    def test_get_login_url_without_pkce(self):
+        handler = self._make_handler()
+        url = handler.get_login_url(scopes=["read"], state="state", code_challenge=None)
+
+        assert "code_challenge" not in url
+        assert "code_challenge_method" not in url
+
+    @pytest.mark.asyncio
+    async def test_exchange_code_for_tokens(self):
+        handler = self._make_handler()
+
+        resp = _mock_response(
+            {
+                "access_token": "new-access-token",
+                "refresh_token": "new-refresh-token",
+                "expires_in": 3600,
+                "token_type": "Bearer",
+            }
+        )
+
+        with patch("backend.blocks.mcp.oauth.Requests") as MockRequests:
+            instance = MockRequests.return_value
+            instance.post = AsyncMock(return_value=resp)
+
+            creds = await handler.exchange_code_for_tokens(
+                code="auth-code",
+                scopes=["read"],
+                code_verifier="pkce-verifier",
+            )
+
+        assert isinstance(creds, OAuth2Credentials)
+        assert creds.access_token.get_secret_value() == "new-access-token"
+        assert creds.refresh_token is not None
+        assert creds.refresh_token.get_secret_value() == "new-refresh-token"
+        assert creds.scopes == ["read"]
+        assert creds.access_token_expires_at is not None
+
+    @pytest.mark.asyncio
+    async def test_refresh_tokens(self):
+        handler = self._make_handler()
+
+        existing_creds = OAuth2Credentials(
+            id="existing-id",
+            provider="mcp",
+            access_token=SecretStr("old-token"),
+            refresh_token=SecretStr("old-refresh"),
+            scopes=["read"],
+            title="test",
+        )
+
+        resp = _mock_response(
+            {
+                "access_token": "refreshed-token",
+                "refresh_token": "new-refresh",
+                "expires_in": 3600,
+            }
+        )
+
+        with patch("backend.blocks.mcp.oauth.Requests") as MockRequests:
+            instance = MockRequests.return_value
+            instance.post = AsyncMock(return_value=resp)
+
+            refreshed = await handler._refresh_tokens(existing_creds)
+
+        assert refreshed.id == "existing-id"
+        assert refreshed.access_token.get_secret_value() == "refreshed-token"
+        assert refreshed.refresh_token is not None
+        assert refreshed.refresh_token.get_secret_value() == "new-refresh"
+
+    @pytest.mark.asyncio
+    async def test_refresh_tokens_no_refresh_token(self):
+        handler = self._make_handler()
+
+        creds = OAuth2Credentials(
+            provider="mcp",
+            access_token=SecretStr("token"),
+            scopes=["read"],
+            title="test",
+        )
+
+        with pytest.raises(ValueError, match="No refresh token"):
+            await handler._refresh_tokens(creds)
+
+    @pytest.mark.asyncio
+    async def test_revoke_tokens_no_url(self):
+        handler = self._make_handler(revoke_url=None)
+
+        creds = OAuth2Credentials(
+            provider="mcp",
+            access_token=SecretStr("token"),
+            scopes=[],
+            title="test",
+        )
+
+        result = await handler.revoke_tokens(creds)
+        assert result is False
+
+    @pytest.mark.asyncio
+    async def test_revoke_tokens_with_url(self):
+        handler = self._make_handler(revoke_url="https://auth.example.com/revoke")
+
+        creds = OAuth2Credentials(
+            provider="mcp",
+            access_token=SecretStr("token"),
+            scopes=[],
+            title="test",
+        )
+
+        resp = _mock_response({}, status=200)
+
+        with patch("backend.blocks.mcp.oauth.Requests") as MockRequests:
+            instance = MockRequests.return_value
+            instance.post = AsyncMock(return_value=resp)
+
+            result = await handler.revoke_tokens(creds)
+
+        assert result is True
+
+
+class TestMCPClientDiscovery:
+    """Tests for MCPClient OAuth metadata discovery."""
+
+    @pytest.mark.asyncio
+    async def test_discover_auth_found(self):
+        client = MCPClient("https://mcp.example.com/mcp")
+
+        metadata = {
+            "authorization_servers": ["https://auth.example.com"],
+            "resource": "https://mcp.example.com/mcp",
+        }
+
+        resp = _mock_response(metadata, status=200)
+
+        with patch("backend.blocks.mcp.client.Requests") as MockRequests:
+            instance = MockRequests.return_value
+            instance.get = AsyncMock(return_value=resp)
+
+            result = await client.discover_auth()
+
+        assert result is not None
+        assert result["authorization_servers"] == ["https://auth.example.com"]
+
+    @pytest.mark.asyncio
+    async def test_discover_auth_not_found(self):
+        client = MCPClient("https://mcp.example.com/mcp")
+
+        resp = _mock_response({}, status=404)
+
+        with patch("backend.blocks.mcp.client.Requests") as MockRequests:
+            instance = MockRequests.return_value
+            instance.get = AsyncMock(return_value=resp)
+
+            result = await client.discover_auth()
+
+        assert result is None
+
+    @pytest.mark.asyncio
+    async def test_discover_auth_server_metadata(self):
+        client = MCPClient("https://mcp.example.com/mcp")
+
+        server_metadata = {
+            "issuer": "https://auth.example.com",
+            "authorization_endpoint": "https://auth.example.com/authorize",
+            "token_endpoint": "https://auth.example.com/token",
+            "registration_endpoint": "https://auth.example.com/register",
+            "code_challenge_methods_supported": ["S256"],
+        }
+
+        resp = _mock_response(server_metadata, status=200)
+
+        with patch("backend.blocks.mcp.client.Requests") as MockRequests:
+            instance = MockRequests.return_value
+            instance.get = AsyncMock(return_value=resp)
+
+            result = await client.discover_auth_server_metadata(
+                "https://auth.example.com"
+            )
+
+        assert result is not None
+        assert result["authorization_endpoint"] == "https://auth.example.com/authorize"
+        assert result["token_endpoint"] == "https://auth.example.com/token"

autogpt_platform/backend/backend/blocks/mcp/test_server.py

@@ -0,0 +1,162 @@
+"""
+Minimal MCP server for integration testing.
+
+Implements the MCP Streamable HTTP transport (JSON-RPC 2.0 over HTTP POST)
+with a few sample tools. Runs on localhost with a random available port.
+"""
+
+import json
+import logging
+
+from aiohttp import web
+
+logger = logging.getLogger(__name__)
+
+# Sample tools this test server exposes
+TEST_TOOLS = [
+    {
+        "name": "get_weather",
+        "description": "Get current weather for a city",
+        "inputSchema": {
+            "type": "object",
+            "properties": {
+                "city": {
+                    "type": "string",
+                    "description": "City name",
+                },
+            },
+            "required": ["city"],
+        },
+    },
+    {
+        "name": "add_numbers",
+        "description": "Add two numbers together",
+        "inputSchema": {
+            "type": "object",
+            "properties": {
+                "a": {"type": "number", "description": "First number"},
+                "b": {"type": "number", "description": "Second number"},
+            },
+            "required": ["a", "b"],
+        },
+    },
+    {
+        "name": "echo",
+        "description": "Echo back the input message",
+        "inputSchema": {
+            "type": "object",
+            "properties": {
+                "message": {"type": "string", "description": "Message to echo"},
+            },
+            "required": ["message"],
+        },
+    },
+]
+
+
+def _handle_initialize(params: dict) -> dict:
+    return {
+        "protocolVersion": "2025-03-26",
+        "capabilities": {"tools": {"listChanged": False}},
+        "serverInfo": {"name": "test-mcp-server", "version": "1.0.0"},
+    }
+
+
+def _handle_tools_list(params: dict) -> dict:
+    return {"tools": TEST_TOOLS}
+
+
+def _handle_tools_call(params: dict) -> dict:
+    tool_name = params.get("name", "")
+    arguments = params.get("arguments", {})
+
+    if tool_name == "get_weather":
+        city = arguments.get("city", "Unknown")
+        return {
+            "content": [
+                {
+                    "type": "text",
+                    "text": json.dumps(
+                        {"city": city, "temperature": 22, "condition": "sunny"}
+                    ),
+                }
+            ],
+        }
+
+    elif tool_name == "add_numbers":
+        a = arguments.get("a", 0)
+        b = arguments.get("b", 0)
+        return {
+            "content": [{"type": "text", "text": json.dumps({"result": a + b})}],
+        }
+
+    elif tool_name == "echo":
+        message = arguments.get("message", "")
+        return {
+            "content": [{"type": "text", "text": message}],
+        }
+
+    else:
+        return {
+            "content": [{"type": "text", "text": f"Unknown tool: {tool_name}"}],
+            "isError": True,
+        }
+
+
+HANDLERS = {
+    "initialize": _handle_initialize,
+    "tools/list": _handle_tools_list,
+    "tools/call": _handle_tools_call,
+}
+
+
+async def handle_mcp_request(request: web.Request) -> web.Response:
+    """Handle incoming MCP JSON-RPC 2.0 requests."""
+    # Check auth if configured
+    expected_token = request.app.get("auth_token")
+    if expected_token:
+        auth_header = request.headers.get("Authorization", "")
+        if auth_header != f"Bearer {expected_token}":
+            return web.json_response(
+                {
+                    "jsonrpc": "2.0",
+                    "error": {"code": -32001, "message": "Unauthorized"},
+                    "id": None,
+                },
+                status=401,
+            )
+
+    body = await request.json()
+
+    # Handle notifications (no id field) — just acknowledge
+    if "id" not in body:
+        return web.Response(status=202)
+
+    method = body.get("method", "")
+    params = body.get("params", {})
+    request_id = body.get("id")
+
+    handler = HANDLERS.get(method)
+    if not handler:
+        return web.json_response(
+            {
+                "jsonrpc": "2.0",
+                "error": {
+                    "code": -32601,
+                    "message": f"Method not found: {method}",
+                },
+                "id": request_id,
+            }
+        )
+
+    result = handler(params)
+    return web.json_response({"jsonrpc": "2.0", "result": result, "id": request_id})
+
+
+def create_test_mcp_app(auth_token: str | None = None) -> web.Application:
+    """Create an aiohttp app that acts as an MCP server."""
+    app = web.Application()
+    app.router.add_post("/mcp", handle_mcp_request)
+    if auth_token:
+        app["auth_token"] = auth_token
+    return app

autogpt_platform/backend/backend/integrations/providers.py

@@ -30,6 +30,7 @@ class ProviderName(str, Enum):
     IDEOGRAM = "ideogram"
     JINA = "jina"
     LLAMA_API = "llama_api"
+    MCP = "mcp"
     MEDIUM = "medium"
     MEM0 = "mem0"
     NOTION = "notion"

docs/integrations/README.md

@@ -467,6 +467,7 @@ Below is a comprehensive list of all available blocks, categorized by their prim
 | [Github Update Comment](block-integrations/github/issues.md#github-update-comment) | A block that updates an existing comment on a GitHub issue or pull request |
 | [Github Update File](block-integrations/github/repo.md#github-update-file) | This block updates an existing file in a GitHub repository |
 | [Instantiate Code Sandbox](block-integrations/misc.md#instantiate-code-sandbox) | Instantiate a sandbox environment with internet access in which you can execute code with the Execute Code Step block |
+| [MCP Tool](block-integrations/mcp/block.md#mcp-tool) | Connect to any MCP server and execute its tools |
 | [Slant3D Order Webhook](block-integrations/slant3d/webhook.md#slant3d-order-webhook) | This block triggers on Slant3D order status updates and outputs the event details, including tracking information when orders are shipped |
 
 ## Media Generation

docs/integrations/SUMMARY.md

@@ -84,6 +84,7 @@
 * [Linear Projects](block-integrations/linear/projects.md)
 * [LLM](block-integrations/llm.md)
 * [Logic](block-integrations/logic.md)
+* [Mcp Block](block-integrations/mcp/block.md)
 * [Misc](block-integrations/misc.md)
 * [Notion Create Page](block-integrations/notion/create_page.md)
 * [Notion Read Database](block-integrations/notion/read_database.md)

docs/integrations/block-integrations/mcp/block.md

@@ -0,0 +1,36 @@
+# Mcp Block
+<!-- MANUAL: file_description -->
+_Add a description of this category of blocks._
+<!-- END MANUAL -->
+
+## MCP Tool
+
+### What it is
+Connect to any MCP server and execute its tools. Provide a server URL, select a tool, and pass arguments dynamically.
+
+### How it works
+<!-- MANUAL: how_it_works -->
+_Add technical explanation here._
+<!-- END MANUAL -->
+
+### Inputs
+
+| Input | Description | Type | Required |
+|-------|-------------|------|----------|
+| server_url | URL of the MCP server (Streamable HTTP endpoint) | str | Yes |
+| selected_tool | The MCP tool to execute | str | No |
+| tool_arguments | Arguments to pass to the selected MCP tool. The fields here are defined by the tool's input schema. | Dict[str, Any] | No |
+
+### Outputs
+
+| Output | Description | Type |
+|--------|-------------|------|
+| error | Error message if the tool call failed | str |
+| result | The result returned by the MCP tool | Result |
+
+### Possible use case
+<!-- MANUAL: use_case -->
+_Add practical use case examples here._
+<!-- END MANUAL -->
+
+---