MCP Connected System

The MCP connected system connects AI agents to external MCP servers so they can use tools hosted outside of Appian. Use this page to learn how to create, authenticate, and manage an MCP connected system.

What is an MCP connected system?

The Model Context Protocol (MCP) connected system lets AI agents connect to external MCP servers and use their tools. MCP is an open protocol for connecting AI applications to external tools and services. With an MCP connected system, you can give AI agents access to external tools without writing custom code. For example, your AI agent could query a Snowflake database, manage files in Google Drive, or work with GitHub repositories.

Appian acts as an MCP client. It connects to any remote MCP server hosted externally, discovers the tools that server offers, and lets AI agents call those tools at runtime. You set up the connection once in the connected system, then choose which tools to use in each AI agent.

For information that applies to all connected systems, see Connected System Object. To learn how to add MCP tools to an AI agent, see MCP Tools for AI Agents.

When to use an MCP connected system

Use an MCP connected system when you need to:

• Connect an AI agent to an external system that offers an MCP server.
• Give an AI agent access to external tools without building custom integration objects.
• Use the MCP protocol to standardize how AI agents interact with third-party services.

If the external system does not offer an MCP server, use an HTTP Connected System or OpenAPI Connected System with a process model tool.

Verified MCP servers

Appian has verified that these MCP servers work correctly:

• Snowflake
• Zapier
• Tavily
• Stripe
• Kapa
• Box
• Google Drive
• GitHub

You can connect to any MCP-compliant server. Appian uses generic protocol support, not server-specific code. Any server that follows the MCP spec should work.

Create an MCP connected system

To create an MCP connected system:

1. In Appian Designer, go to the Build view.
2. Click NEW > Connected System.
3. Select MCP as the connected system type.
4. Configure the properties described in the following section.
5. Click SAVE.

Properties

Each MCP connected system has the following properties:

Field	Description
Name	The name of the connected system. Use a name that identifies the external MCP server.
Description	Extra information about the connected system. This text shows in object grids and when you select the connected system while setting up the AI agent.
System Logo	An image to represent the external MCP server. If you do not select one, a default logo is used.
Authentication	The type of authentication to use when connecting to the MCP server. See Authentication.
Server URL	The URL of the MCP server. This value is included in import customization files so you can set a different value for each environment.
Tags	Keywords to help organize and find the connected system in Appian Designer.

Authentication

The MCP connected system supports the following authentication methods:

• API Key: Use an API key to connect to the MCP server. Some MCP servers accept personal access tokens (PATs) through this method.
• OAuth 2.0 Client Credentials Grant: Use client credentials to connect to the MCP server. This method works for server-to-server calls where no user context is needed.

For details on configuring these authentication types, see Authentication Types.

API key properties

Field	Description
API Key	The key or token value used to authenticate requests to the MCP server.
Header Name	The HTTP header used to send the API key. Default is Authorization.
Header Prefix	The prefix added before the API key value in the header, such as Bearer or ApiKey. Leave empty for no prefix.

OAuth 2.0 client credentials properties

Field	Description
Client ID	The client ID from the MCP server's auth provider.
Client Secret	The client secret from the MCP server's auth provider.
Token URL	The URL used to get an access token.

Security

Connected system security controls which developers can use the MCP server in their AI agents. Only developers with Viewer permissions or above on the connected system can select it when setting up an AI agent.

To configure security for an MCP connected system:

1. Open the connected system in Appian Designer.
2. Click the Security icon.
3. Add users or groups and assign role permissions.
4. Click SAVE.

For details on configuring object security, see Connected System Object.

Deployment

MCP connected system settings are included in application packages for import and export. Use import customization files to set different server URLs and credentials for each environment.

The following properties are available for import customization:

Authentication Type	Available Properties
API Key	serverUrl, apiKeyValue, headerName, headerPrefix
OAuth 2.0: Client Credentials Grant	serverUrl, clientId, clientSecret, tokenUrl

Limitations

The MCP connected system has the following limitations:

• MCP client only. Appian connects to external MCP servers as a client. You cannot host or create MCP servers in Appian.
• Tools primitive only. MCP defines three primitives: tools, resources, and prompts. Appian supports the tools primitive only.
• No automatic tool migration. If an MCP server changes or removes a tool, you must update the AI agents that use it. Appian does not update agent configurations when tool schemas change on the server.
• Server-side rate limits apply. Appian does not limit MCP tool calls. The external MCP server may have its own limits. Check the vendor docs for your MCP server and design your agent to handle limits.
• Authentication methods. Only API key and OAuth 2.0 Client Credentials Grant are supported.

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