MCPX MCP Gateway

import { ExtensionDescription, ToolExtensions, } from "../src/model/config/tool-extensions.js"; import { buildConfig, getTestHarness, transportTypes } from "./utils.js"; describe.each(transportTypes)( "Tools Customization over %s Router", (transportType) => { const toolExtensions: ToolExtensions = { services: { "calculator-service": { add: { childTools: [ { name: "add_10", description: { action: "rewrite", text: "Adds 10 to the a number", }, overrideParams: { b: { value: 10 }, a: { description: { action: "rewrite", text: "This is a description for a", }, }, }, }, ], }, powerOfTwo: { childTools: [ { name: "powerOfTwo_for_2", description: { action: "append", text: "This tool will always return 4 since it's only parameter is hardcoded to 2", }, overrideParams: { base: { value: 2, description: { action: "append", text: "This is a description for base", }, }, }, }, ], }, }, }, }; const config = buildConfig({ toolExtensions }); const testHarness = getTestHarness({ config }); beforeAll(async () => { await testHarness.initialize(transportType); }); afterAll(async () => { await testHarness.shutdown(); }); it("overrides param when calling tool", async () => { const res = await testHarness.client.callTool({ name: "calculator-service__add_10", arguments: { a: 5, b: 2 }, }); const result = (res.content as [{ text: string }])[0]; expect(result.text).toEqual("Result: 15"); }); it("overrides only param when calling tool", async () => { const res = await testHarness.client.callTool({ name: "calculator-service__powerOfTwo_for_2", arguments: { base: 3 }, }); const result = (res.content as [{ text: string }])[0]; expect(result.text).toEqual("Result: 4"); }); it("rewrites tool's description", async () => { const tools = await testHarness.client.listTools(); const add10Tool = tools.tools.find( (t) => t.name === "calculator-service__add_10", ); expect(add10Tool).toBeDefined(); expect(add10Tool?.description).toEqual("Adds 10 to the a number"); }); it("rewrites param description", async () => { const tools = await testHarness.client.listTools(); const add10Tool = tools.tools.find( (t) => t.name === "calculator-service__add_10", ); expect(add10Tool).toBeDefined(); const properties = add10Tool?.inputSchema?.properties as { a: { type?: string; description?: ExtensionDescription }; b: { type?: string; description?: ExtensionDescription }; }; expect(properties.a.description).toBeDefined(); expect(properties.a.description).toEqual("This is a description for a"); }); it("appends to tool's description", async () => { const tools = await testHarness.client.listTools(); const powerOfTwoTool = tools.tools.find( (t) => t.name === "calculator-service__powerOfTwo_for_2", ); expect(powerOfTwoTool).toBeDefined(); expect(powerOfTwoTool?.description).toEqual( "Calculates the power of two for a given number. This tool will always return 4 since it's only parameter is hardcoded to 2", ); }); it("appends to param description", async () => { const tools = await testHarness.client.listTools(); const powerOfTwoTool = tools.tools.find( (t) => t.name === "calculator-service__powerOfTwo_for_2", ); expect(powerOfTwoTool?.inputSchema).toBeDefined(); expect(powerOfTwoTool).toBeDefined(); const properties = powerOfTwoTool?.inputSchema?.properties as { base: { type?: string; description?: ExtensionDescription }; }; expect(properties.base.description).toBeDefined(); expect(properties.base.description).toEqual( "This is a description for base. Note: This parameter is ignored - it is hardcoded to be 2. Pass an empty string for this parameter.", ); }); it("annotates overridden argument in inputSchema", async () => { const tools = await testHarness.client.listTools(); const add10Tool = tools.tools.find( (t) => t.name === "calculator-service__add_10", ); expect(add10Tool?.inputSchema).toBeDefined(); const properties = add10Tool?.inputSchema?.properties as { a: { type?: string; description?: ExtensionDescription }; b: { type?: string; description?: ExtensionDescription }; }; expect(properties.a.type).toEqual("number"); expect(properties.b.type).toEqual("number"); expect(properties.a.description).toBeDefined(); expect(properties.a.description).toEqual("This is a description for a"); expect(properties.b.description).toBeDefined(); expect(properties.b.description).toMatch( /Note: This parameter is ignored - it is hardcoded to be 10. Pass an empty string for this parameter.$/, ); }); }, );