--- auto_validation: true time: 15 author_name: Daniel Wroblewski author_profile: https://github.com/thecodester tags: [ tutorial>beginner, topic>cloud ] primary_tag: topic>cloud parser: v2 slug: joule-studio-codejam-8-subagent-mcp canonical_url: https://developers.sap.com/tutorials/joule-studio-codejam-8-subagent-mcp --- # 8 - Add Subagent to Convert Currency Using MCP Server Create a subagent that connects to an MCP server with currency conversion tool, and then add that agent to our shipment agent. ## You will learn - How to create a subagent - How to connect to an MCP server ## Prerequisites - You have completed the previous tutorial in the Joule Studio CodeJam Mission, [Test the shipping agent](joule-studio-codejam-7-test-agent). ## Intro In this tutorial we will explore two additional features of agents: - You can create **subagents** to be called from another agent, so you can better structure your projects. A subagent is built the same way as any other agent, just that it is added as a tool in another agent. For now, once an agent is used as a tool in another agent, it cannot be called directly. - You can connect your agent to an **MCP server** and use its tools as part of that agent. You will create an agent that uses an MCP server for converting currencies, and then use that agent within your logistics agent. >We probably could have just added the MCP server to the first agent, but we wanted to show the subagent feature as well 😊. ### Create empty agent 1. Select the **Overview** tab. 2. Click **Create**, and choose **Joule Agent**. ![New agent](https://raw.githubusercontent.com/sap-tutorials/developer-advocates/main/tutorials/joule-studio-codejam-8-subagent-mcp/1-empty-1.png) 3. In the **Create Joule Agent** dialog, enter the following details: | Field | Value | |---------------|-------------------------------------------| | **Name** | `Agent for Converting Currencies` | | **Description** | `An agent for converting currencies and show the value of one currency in another currency` | Click **Create**. ![Name agent](https://raw.githubusercontent.com/sap-tutorials/developer-advocates/main/tutorials/joule-studio-codejam-8-subagent-mcp/1-empty-2.png) Once the Joule skill is created, you are taken to the skill builder. ### Add expertise, instructions and context 1. In the agent builder, enter the following for the **Expertise** section: ```Text Converts currency amount to a different currency, and takes precedence over any other way to convert currencies ``` 2. Enter the following for the **Instructions** section: ```Text When asked to convert currency, use the get_latest_base_currency skill from the MCP server ``` 3. Enter the following for the **Additional Context** section: ```Text Please show the currency conversion in a table, with the column headers with the currency abbreviations and the row values the currency amounts. ``` ![Agent instructions](https://raw.githubusercontent.com/sap-tutorials/developer-advocates/main/tutorials/joule-studio-codejam-8-subagent-mcp/1-empty-3.png) ### Add MCP server We have created an MCP server for converting currencies, and created a destination so the MCP server is available to Joule Studio and to be added to agents. 1. In your agent, click **Add MCP Server**. ![Add MCP Server](https://raw.githubusercontent.com/sap-tutorials/developer-advocates/main/tutorials/joule-studio-codejam-8-subagent-mcp/3-mcp-1.png) 2. In the **Add MCP Server** dialog, enter the following details: | Field | Value | |---------------|-------------------------------------------| | **Name** | `Currency Conversions` | | **Description for Agent** | `Use this MCP server for converting currencies` | | **Destination** | Select **cap-mcp-convert-currency** | ![Configure MCP server](https://raw.githubusercontent.com/sap-tutorials/developer-advocates/main/tutorials/joule-studio-codejam-8-subagent-mcp/3-mcp-2.png) Once you select the destination, scroll down and you should see a list of tools in that MCP server. ![New tools](https://raw.githubusercontent.com/sap-tutorials/developer-advocates/main/tutorials/joule-studio-codejam-8-subagent-mcp/3-mcp-3.png) Click **Add Server**. You will see the MCP server added, plus an indication of how many tools are exposed through that server. ![Server added](https://raw.githubusercontent.com/sap-tutorials/developer-advocates/main/tutorials/joule-studio-codejam-8-subagent-mcp/3-mcp-4.png) 3. Click **Save** (upper right). ### Add currency agent as subagent 1. Open your **Agent for Logistics** agent. ![Open agent](https://raw.githubusercontent.com/sap-tutorials/developer-advocates/main/tutorials/joule-studio-codejam-8-subagent-mcp/4-subagent-1.png) 2. Click **Add Tool > Joule Agent**. ![Add agent](https://raw.githubusercontent.com/sap-tutorials/developer-advocates/main/tutorials/joule-studio-codejam-8-subagent-mcp/4-subagent-2.png) Select **Agent for Converting Currencies** agent. Click **Add**. ![Select agent](https://raw.githubusercontent.com/sap-tutorials/developer-advocates/main/tutorials/joule-studio-codejam-8-subagent-mcp/4-subagent-3.png) 3. Click **Save** (upper right). ### Change instructions Now we have to instuct the agent to use the tool when someone asks for currency conversion. In the instructions of the **Agent for Logistics** agent, replace the first paragraph under **Suggest Carrier Options** with this one. ![Replace instructions](https://raw.githubusercontent.com/sap-tutorials/developer-advocates/main/tutorials/joule-studio-codejam-8-subagent-mcp/5-instructions-1.png) ```Text If the user asks for carrier suggestions, use the document “Carrier Selection Guide.docx” to present all available carrier options. Display the list of carriers for the user to view as a simple table, displaying only the name of the carrier and the price. If the user asks for the prices in a currency not USD, use the "Convert currencies" agent tool to get the currency conversions and show 2 columns, one for USD and one for the converted currency. ``` ![New instructions](https://raw.githubusercontent.com/sap-tutorials/developer-advocates/main/tutorials/joule-studio-codejam-8-subagent-mcp/5-instructions-2.png) Click **Save** (upper right). ### Test agent 1. Click **Test**. ![Start test](https://raw.githubusercontent.com/sap-tutorials/developer-advocates/main/tutorials/joule-studio-codejam-8-subagent-mcp/6-test-1.png) In the **Test Project** dialog, enter the following: | Field | Value | |---------------|-------------------------------------------| | **Environment** | Select the private environment for your user's email address | | **PostToGTT** | Select **gttwriteservice** | | **GetFromGTT** | Select **gttGetService** | Click **Continue**. ![Test variables](https://raw.githubusercontent.com/sap-tutorials/developer-advocates/main/tutorials/joule-studio-codejam-8-subagent-mcp/6-test-2.png) A test Joule interface will open up, letting you talk with your skills and agents in the project. 2. Ask Joule for suggested carriers and prices by entering the following: ```Prompt Suggest the best carriers from SFO to NYC, and show prices in euros ``` **Result**: Joule proposes the carriers based on the carrier rates document from our document grounding, and converts the prices to euros. ![Results](https://raw.githubusercontent.com/sap-tutorials/developer-advocates/main/tutorials/joule-studio-codejam-8-subagent-mcp/6-test-3.png) If you click on UPS, you will see the details and the price, in euros converted to up-to-date exchange rate returned by the MCP server. ![Results euros](https://raw.githubusercontent.com/sap-tutorials/developer-advocates/main/tutorials/joule-studio-codejam-8-subagent-mcp/6-test-4.png) >Feel free to check the current exchange rate, to make sure the value is live, and not old and taken from the LLM's memory. > >Here's a link to exchange rate for euro on [Yahoo Finance](https://finance.yahoo.com/quote/EUR=X/). > >![Euro to USD](https://raw.githubusercontent.com/sap-tutorials/developer-advocates/main/tutorials/joule-studio-codejam-8-subagent-mcp/6-test-yahoo.png) 3. Explore the logs. First find **Joule list message** and expand the node. Here you will find information on how Joule and the agent responded to your prompt. Click **Joule selected a scenario to execute**, and on the right you will see that it selected the agent to respond with. ![Logs](https://raw.githubusercontent.com/sap-tutorials/developer-advocates/main/tutorials/joule-studio-codejam-8-subagent-mcp/6-test-5.png) Open the **Agent** node, and click **Plan** and you can see that it figured out to check document grounding for carriers and then to use convert currencies agent to convert the currencies. ![Logs 2](https://raw.githubusercontent.com/sap-tutorials/developer-advocates/main/tutorials/joule-studio-codejam-8-subagent-mcp/6-test-6.png) If you scroll down and click **MCP Server**, you will see on the right that the MCP server was called and returned currency conversions for today. ![Logs 3](https://raw.githubusercontent.com/sap-tutorials/developer-advocates/main/tutorials/joule-studio-codejam-8-subagent-mcp/6-test-7.png) 4. Click **Stop Testing**. ![Stop Testing](https://raw.githubusercontent.com/sap-tutorials/developer-advocates/main/tutorials/joule-studio-codejam-8-subagent-mcp/6-test-8.png) ### Questions to ponder - What is the advantage of subagents? - What is the disadvantage of subagents the way they currently are designed? That is, what can I not do with subagents? - Did we need a subagent in this use case? Why or why not?