⚙️ FEATURE-#36: Share MCP servers with pycodeloop's native saved: registry

src/features/settings/settings.controller.ts

@@ -5,6 +5,7 @@ import { API_KEY_SECRET, providerKeySecret } from "../../services/credentials.se
 import { PostMessage, ResolveSetting } from "../chat/chat.types";
 import { PROVIDER_CATALOG, findProviderDef } from "./providerCatalog";
 import { ADD_MCP_SERVER_LABEL, addServer, parseServerLabel, removeServer, toQuickPickLabels } from "./mcpServerList";
+import { McpServerNameTakenError, saveMcpServer, splitCommand } from "../../services/mcpRegistry.service";
 
 export class SettingsController {
   constructor(
@@ -343,6 +344,60 @@ export class SettingsController {
     this.reload();
   }
 
+  private async maybeSaveToRegistry(command: string): Promise<string> {
+    const choice = await vscode.window.showQuickPick(["Just this workspace", "Save for reuse in the CLI too"], {
+      title: "Save this MCP server for pycodeloop CLI reuse?",
+    });
+    if (choice !== "Save for reuse in the CLI too") {
+      return command;
+    }
+
+    const { command: cmd, args } = splitCommand(command);
+    const defaultName = path.basename(cmd).replace(/\.[^.]+$/, "") || "server";
+    const name = await vscode.window.showInputBox({
+      title: "Name for this saved MCP server",
+      value: defaultName,
+      ignoreFocusOut: true,
+    });
+    if (!name) {
+      return command;
+    }
+
+    let overwrite = false;
+    try {
+      await saveMcpServer(name, { command: cmd, args });
+    } catch (err) {
+      if (!(err instanceof McpServerNameTakenError)) {
+        vscode.window.showErrorMessage(
+          `Couldn't save "${name}" to the pycodeloop registry: ${(err as Error).message}`
+        );
+        return command;
+      }
+      const action = await vscode.window.showWarningMessage(
+        `"${name}" already exists in the pycodeloop registry. Overwrite it?`,
+        "Overwrite",
+        "Cancel"
+      );
+      if (action !== "Overwrite") {
+        return command;
+      }
+      overwrite = true;
+    }
+
+    if (overwrite) {
+      try {
+        await saveMcpServer(name, { command: cmd, args }, { overwrite: true });
+      } catch (err) {
+        vscode.window.showErrorMessage(
+          `Couldn't save "${name}" to the pycodeloop registry: ${(err as Error).message}`
+        );
+        return command;
+      }
+    }
+
+    return `saved:${name}`;
+  }
+
   async toggleWorkspace(next: boolean): Promise<void> {
     await updateSetting("workspace", next);
     await this.postSettings();
@@ -370,7 +425,9 @@ export class SettingsController {
       if (!command) {
         return;
       }
-      await updateSetting("mcpServers", addServer(servers, command));
+
+      const entry = await this.maybeSaveToRegistry(command);
+      await updateSetting("mcpServers", addServer(servers, entry));
     } else {
       const removed = parseServerLabel(picked);
       if (!removed) {

src/services/mcpRegistry.service.ts

@@ -0,0 +1,71 @@
+import * as fs from "fs";
+import * as os from "os";
+import * as path from "path";
+
+const CONFIG_PATH = path.join(os.homedir(), ".pycodeloop", "config.json");
+const SECTION = "mcp_servers";
+
+export interface SavedMcpServer {
+  command: string;
+  args: string[];
+  env?: Record<string, string>;
+}
+
+export class McpServerNameTakenError extends Error {
+  constructor(readonly name: string) {
+    super(`A server named "${name}" already exists in the registry.`);
+  }
+}
+
+async function readConfig(): Promise<Record<string, unknown>> {
+  try {
+    return JSON.parse(await fs.promises.readFile(CONFIG_PATH, "utf8"));
+  } catch {
+    return {};
+  }
+}
+
+async function writeConfig(data: Record<string, unknown>): Promise<void> {
+  await fs.promises.mkdir(path.dirname(CONFIG_PATH), { recursive: true });
+  await fs.promises.writeFile(CONFIG_PATH, JSON.stringify(data, null, 2));
+}
+
+// Mirrors shlex.split() on the pycodeloop side (cli/flow.py's _load_mcp_tools).
+export function splitCommand(command: string): { command: string; args: string[] } {
+  const tokens = command.match(/"[^"]*"|'[^']*'|\S+/g) ?? [];
+  const unquoted = tokens.map((t) =>
+    (t.startsWith('"') && t.endsWith('"')) || (t.startsWith("'") && t.endsWith("'"))
+      ? t.slice(1, -1)
+      : t
+  );
+  const [head, ...rest] = unquoted;
+  return { command: head ?? "", args: rest };
+}
+
+export async function listSavedMcpServers(): Promise<Record<string, SavedMcpServer>> {
+  const data = await readConfig();
+  return (data[SECTION] as Record<string, SavedMcpServer>) ?? {};
+}
+
+export async function saveMcpServer(
+  name: string,
+  server: SavedMcpServer,
+  { overwrite = false }: { overwrite?: boolean } = {}
+): Promise<void> {
+  const data = await readConfig();
+  const servers = (data[SECTION] as Record<string, SavedMcpServer>) ?? {};
+  if (servers[name] && !overwrite) {
+    throw new McpServerNameTakenError(name);
+  }
+  servers[name] = server;
+  data[SECTION] = servers;
+  await writeConfig(data);
+}
+
+export async function deleteSavedMcpServer(name: string): Promise<void> {
+  const data = await readConfig();
+  const servers = (data[SECTION] as Record<string, SavedMcpServer>) ?? {};
+  delete servers[name];
+  data[SECTION] = servers;
+  await writeConfig(data);
+}

test/mcpRegistry.service.test.ts

@@ -0,0 +1,35 @@
+import assert from "node:assert/strict";
+import { test } from "node:test";
+import { splitCommand } from "../src/services/mcpRegistry.service";
+
+test("splitCommand splits a bare command with no args", () => {
+  assert.deepEqual(splitCommand("npx"), { command: "npx", args: [] });
+});
+
+test("splitCommand splits command and positional args", () => {
+  assert.deepEqual(splitCommand("npx -y @modelcontextprotocol/server-filesystem ."), {
+    command: "npx",
+    args: ["-y", "@modelcontextprotocol/server-filesystem", "."],
+  });
+});
+
+test("splitCommand keeps a double-quoted argument as one token", () => {
+  assert.deepEqual(splitCommand('node server.js "a path/with spaces"'), {
+    command: "node",
+    args: ["server.js", "a path/with spaces"],
+  });
+});
+
+test("splitCommand keeps a single-quoted argument as one token", () => {
+  assert.deepEqual(splitCommand("node server.js 'a path/with spaces'"), {
+    command: "node",
+    args: ["server.js", "a path/with spaces"],
+  });
+});
+
+test("splitCommand collapses extra whitespace between tokens", () => {
+  assert.deepEqual(splitCommand("npx   -y   server"), {
+    command: "npx",
+    args: ["-y", "server"],
+  });
+});