Add Freerouting autoroute integration

4 new MCP tools: autoroute (full DSN→Freerouting→SES pipeline),
export_dsn, import_ses, check_freerouting. Requires Java 11+ and
freerouting.jar. Includes 21 test cases and README usage examples.

src/server.ts

@@ -25,6 +25,7 @@ import { registerDatasheetTools } from "./tools/datasheet.js";
 import { registerFootprintTools } from "./tools/footprint.js";
 import { registerSymbolCreatorTools } from "./tools/symbol-creator.js";
 import { registerUITools } from "./tools/ui.js";
+import { registerFreeroutingTools } from "./tools/freerouting.js";
 import { registerRouterTools } from "./tools/router.js";
 
 // Import resource registration functions
@@ -251,6 +252,7 @@ export class KiCADMcpServer {
     registerFootprintTools(this.server, this.callKicadScript.bind(this));
     registerSymbolCreatorTools(this.server, this.callKicadScript.bind(this));
     registerUITools(this.server, this.callKicadScript.bind(this));
+    registerFreeroutingTools(this.server, this.callKicadScript.bind(this));
 
     // Register all resources
     registerProjectResources(this.server, this.callKicadScript.bind(this));

src/tools/freerouting.ts

@@ -0,0 +1,124 @@
+/**
+ * Freerouting autoroute tools for KiCAD MCP server
+ *
+ * Provides autorouting via Freerouting (Specctra DSN/SES workflow).
+ */
+
+import { McpServer } from "@modelcontextprotocol/sdk/server/mcp.js";
+import { z } from "zod";
+
+export function registerFreeroutingTools(
+  server: McpServer,
+  callKicadScript: Function,
+) {
+  // Full autoroute: export DSN -> run Freerouting -> import SES
+  server.tool(
+    "autoroute",
+    "Run Freerouting autorouter on the current PCB. Exports to Specctra DSN, runs Freerouting CLI, and imports the routed SES result. Requires Java 11+ and freerouting.jar (see check_freerouting).",
+    {
+      boardPath: z
+        .string()
+        .optional()
+        .describe("Path to .kicad_pcb file (default: current board)"),
+      freeroutingJar: z
+        .string()
+        .optional()
+        .describe(
+          "Path to freerouting.jar (default: ~/.kicad-mcp/freerouting.jar or FREEROUTING_JAR env)",
+        ),
+      maxPasses: z
+        .number()
+        .optional()
+        .describe("Maximum routing passes (default: 20)"),
+      timeout: z
+        .number()
+        .optional()
+        .describe("Timeout in seconds (default: 300)"),
+    },
+    async (args: any) => {
+      const result = await callKicadScript("autoroute", args);
+      return {
+        content: [
+          {
+            type: "text",
+            text: JSON.stringify(result, null, 2),
+          },
+        ],
+      };
+    },
+  );
+
+  // Export DSN only
+  server.tool(
+    "export_dsn",
+    "Export the current PCB to Specctra DSN format. Useful for manual Freerouting workflow or external autorouters.",
+    {
+      boardPath: z
+        .string()
+        .optional()
+        .describe("Path to .kicad_pcb file (default: current board)"),
+      outputPath: z
+        .string()
+        .optional()
+        .describe("Output DSN file path (default: same dir as board)"),
+    },
+    async (args: any) => {
+      const result = await callKicadScript("export_dsn", args);
+      return {
+        content: [
+          {
+            type: "text",
+            text: JSON.stringify(result, null, 2),
+          },
+        ],
+      };
+    },
+  );
+
+  // Import SES
+  server.tool(
+    "import_ses",
+    "Import a Specctra SES (session) file into the current PCB. Use after running Freerouting externally.",
+    {
+      sesPath: z.string().describe("Path to the .ses file to import"),
+      boardPath: z
+        .string()
+        .optional()
+        .describe("Path to .kicad_pcb file (default: current board)"),
+    },
+    async (args: any) => {
+      const result = await callKicadScript("import_ses", args);
+      return {
+        content: [
+          {
+            type: "text",
+            text: JSON.stringify(result, null, 2),
+          },
+        ],
+      };
+    },
+  );
+
+  // Check Freerouting dependencies
+  server.tool(
+    "check_freerouting",
+    "Check if Java and Freerouting JAR are available on the system. Run this before autoroute to verify prerequisites.",
+    {
+      freeroutingJar: z
+        .string()
+        .optional()
+        .describe("Path to freerouting.jar to check"),
+    },
+    async (args: any) => {
+      const result = await callKicadScript("check_freerouting", args);
+      return {
+        content: [
+          {
+            type: "text",
+            text: JSON.stringify(result, null, 2),
+          },
+        ],
+      };
+    },
+  );
+}

src/tools/index.ts

@@ -16,3 +16,4 @@ export { registerUITools } from "./ui.js";
 export { registerDatasheetTools } from "./datasheet.js";
 export { registerFootprintTools } from "./footprint.js";
 export { registerSymbolCreatorTools } from "./symbol-creator.js";
+export { registerFreeroutingTools } from "./freerouting.js";

src/tools/registry.ts

@@ -126,6 +126,16 @@ export const toolCategories: ToolCategory[] = [
       "add_via",
       "add_copper_pour"
     ]
+  },
+  {
+    name: "autoroute",
+    description: "Freerouting autorouter: automatic PCB routing via Specctra DSN/SES",
+    tools: [
+      "autoroute",
+      "export_dsn",
+      "import_ses",
+      "check_freerouting"
+    ]
   }
 ];