diff --git a/src/resources/extensions/universal-config/discovery.ts b/src/resources/extensions/universal-config/discovery.ts
new file mode 100644
index 000000000..12768111b
--- /dev/null
+++ b/src/resources/extensions/universal-config/discovery.ts
@@ -0,0 +1,78 @@
+/**
+ * Universal Config Discovery — main discovery orchestrator
+ *
+ * Runs all tool scanners in parallel and aggregates results into a
+ * unified DiscoveryResult.
+ */
+
+import { homedir } from "node:os";
+import { TOOLS } from "./tools.js";
+import { SCANNERS } from "./scanners.js";
+import type { DiscoveryResult, DiscoveredItem, ToolDiscoveryResult } from "./types.js";
+
+/**
+ * Run universal config discovery across all supported AI coding tools.
+ *
+ * @param projectRoot - Absolute path to the project root (cwd)
+ * @param home - Home directory override (defaults to os.homedir())
+ * @returns Aggregated discovery result
+ */
+export async function discoverAllConfigs(
+  projectRoot: string,
+  home: string = homedir(),
+): Promise<DiscoveryResult> {
+  const start = Date.now();
+  const allWarnings: string[] = [];
+  const toolResults: ToolDiscoveryResult[] = [];
+
+  // Run all scanners in parallel
+  const results = await Promise.allSettled(
+    TOOLS.map(async (tool) => {
+      const scanner = SCANNERS[tool.id];
+      if (!scanner) return { tool, items: [] as DiscoveredItem[], warnings: [`No scanner for ${tool.id}`] };
+      try {
+        const { items, warnings } = await scanner(projectRoot, home, tool);
+        return { tool, items, warnings };
+      } catch (err) {
+        return {
+          tool,
+          items: [] as DiscoveredItem[],
+          warnings: [`Scanner error for ${tool.name}: ${err instanceof Error ? err.message : String(err)}`],
+        };
+      }
+    }),
+  );
+
+  for (const result of results) {
+    if (result.status === "fulfilled") {
+      toolResults.push(result.value);
+      allWarnings.push(...result.value.warnings);
+    } else {
+      allWarnings.push(`Scanner failed: ${result.reason}`);
+    }
+  }
+
+  const allItems = toolResults.flatMap((r) => r.items);
+
+  const mcpServers = allItems.filter((i) => i.type === "mcp-server").length;
+  const rules = allItems.filter((i) => i.type === "rule").length;
+  const contextFiles = allItems.filter((i) => i.type === "context-file").length;
+  const settings = allItems.filter((i) => i.type === "settings").length;
+  const toolsWithConfig = toolResults.filter((r) => r.items.length > 0).length;
+
+  return {
+    tools: toolResults,
+    allItems,
+    summary: {
+      mcpServers,
+      rules,
+      contextFiles,
+      settings,
+      totalItems: allItems.length,
+      toolsScanned: TOOLS.length,
+      toolsWithConfig,
+    },
+    warnings: allWarnings,
+    durationMs: Date.now() - start,
+  };
+}
diff --git a/src/resources/extensions/universal-config/format.ts b/src/resources/extensions/universal-config/format.ts
new file mode 100644
index 000000000..be6b69a54
--- /dev/null
+++ b/src/resources/extensions/universal-config/format.ts
@@ -0,0 +1,160 @@
+/**
+ * Universal Config Discovery — output formatting
+ *
+ * Formats DiscoveryResult into human-readable and LLM-readable output.
+ */
+
+import type { DiscoveryResult, DiscoveredItem, ToolDiscoveryResult } from "./types.js";
+
+/**
+ * Format discovery result as a compact text report for the LLM tool response.
+ */
+export function formatDiscoveryForTool(result: DiscoveryResult): string {
+  const lines: string[] = [];
+  const { summary } = result;
+
+  lines.push(`Universal Config Discovery — ${summary.toolsWithConfig}/${summary.toolsScanned} tools with config (${result.durationMs}ms)`);
+  lines.push("");
+
+  if (summary.totalItems === 0) {
+    lines.push("No configuration found from any AI coding tool.");
+    lines.push("");
+    lines.push("Scanned for: Claude Code, Cursor, Windsurf, Gemini CLI, Codex, Cline, GitHub Copilot, VS Code");
+    return lines.join("\n");
+  }
+
+  lines.push(`Found: ${summary.mcpServers} MCP server(s), ${summary.rules} rule(s), ${summary.contextFiles} context file(s), ${summary.settings} settings file(s)`);
+  lines.push("");
+
+  for (const toolResult of result.tools) {
+    if (toolResult.items.length === 0) continue;
+    lines.push(`## ${toolResult.tool.name}`);
+
+    const byType = groupByType(toolResult.items);
+
+    if (byType["mcp-server"]?.length) {
+      lines.push(`  MCP Servers (${byType["mcp-server"].length}):`);
+      for (const item of byType["mcp-server"]) {
+        if (item.type !== "mcp-server") continue;
+        const transport = item.transport ?? (item.url ? "http" : item.command ? "stdio" : "unknown");
+        const detail = item.command
+          ? `${item.command}${item.args?.length ? ` ${item.args.join(" ")}` : ""}`
+          : item.url ?? "no endpoint";
+        lines.push(`    - ${item.name} [${transport}] ${detail} (${item.source.level})`);
+      }
+    }
+
+    if (byType.rule?.length) {
+      lines.push(`  Rules (${byType.rule.length}):`);
+      for (const item of byType.rule) {
+        if (item.type !== "rule") continue;
+        const meta: string[] = [];
+        if (item.alwaysApply) meta.push("always");
+        if (item.globs?.length) meta.push(`globs: ${item.globs.join(", ")}`);
+        const suffix = meta.length ? ` [${meta.join(", ")}]` : "";
+        const preview = item.content.slice(0, 80).replace(/\n/g, " ").trim();
+        lines.push(`    - ${item.name}${suffix}: ${preview}${item.content.length > 80 ? "..." : ""}`);
+      }
+    }
+
+    if (byType["context-file"]?.length) {
+      lines.push(`  Context Files (${byType["context-file"].length}):`);
+      for (const item of byType["context-file"]) {
+        if (item.type !== "context-file") continue;
+        const size = item.content.length;
+        lines.push(`    - ${item.name} (${size} chars, ${item.source.level}) ${item.source.path}`);
+      }
+    }
+
+    if (byType.settings?.length) {
+      lines.push(`  Settings (${byType.settings.length}):`);
+      for (const item of byType.settings) {
+        if (item.type !== "settings") continue;
+        const keys = Object.keys(item.data).slice(0, 5);
+        const suffix = Object.keys(item.data).length > 5 ? ` +${Object.keys(item.data).length - 5} more` : "";
+        lines.push(`    - ${item.source.path} (${item.source.level}): keys: ${keys.join(", ")}${suffix}`);
+      }
+    }
+
+    lines.push("");
+  }
+
+  if (result.warnings.length > 0) {
+    lines.push("Warnings:");
+    for (const w of result.warnings) {
+      lines.push(`  - ${w}`);
+    }
+    lines.push("");
+  }
+
+  return lines.join("\n");
+}
+
+/**
+ * Format discovery result as a structured summary for /configs command output.
+ */
+export function formatDiscoveryForCommand(result: DiscoveryResult): string[] {
+  const lines: string[] = [];
+  const { summary } = result;
+
+  lines.push(`--- Universal Config Discovery ---`);
+  lines.push(`${summary.toolsWithConfig} of ${summary.toolsScanned} tools have configuration`);
+  lines.push(`${summary.totalItems} total items discovered in ${result.durationMs}ms`);
+  lines.push("");
+
+  if (summary.totalItems === 0) {
+    lines.push("No configuration found.");
+    return lines;
+  }
+
+  lines.push(`  MCP Servers: ${summary.mcpServers}`);
+  lines.push(`  Rules:       ${summary.rules}`);
+  lines.push(`  Context:     ${summary.contextFiles}`);
+  lines.push(`  Settings:    ${summary.settings}`);
+  lines.push("");
+
+  for (const toolResult of result.tools) {
+    if (toolResult.items.length === 0) continue;
+
+    const counts = countByType(toolResult.items);
+    const parts: string[] = [];
+    if (counts["mcp-server"]) parts.push(`${counts["mcp-server"]} MCP`);
+    if (counts.rule) parts.push(`${counts.rule} rules`);
+    if (counts["context-file"]) parts.push(`${counts["context-file"]} context`);
+    if (counts.settings) parts.push(`${counts.settings} settings`);
+
+    lines.push(`  ${toolResult.tool.name}: ${parts.join(", ")}`);
+
+    // Show MCP server names
+    const servers = toolResult.items.filter((i) => i.type === "mcp-server");
+    for (const server of servers) {
+      if (server.type !== "mcp-server") continue;
+      lines.push(`    MCP: ${server.name} (${server.source.level})`);
+    }
+  }
+
+  if (result.warnings.length > 0) {
+    lines.push("");
+    lines.push(`${result.warnings.length} warning(s) — run discover_configs tool for details`);
+  }
+
+  return lines;
+}
+
+// ── Helpers ───────────────────────────────────────────────────────────────────
+
+function groupByType(items: DiscoveredItem[]): Record<string, DiscoveredItem[]> {
+  const groups: Record<string, DiscoveredItem[]> = {};
+  for (const item of items) {
+    (groups[item.type] ??= []).push(item);
+  }
+  return groups;
+}
+
+function countByType(items: DiscoveredItem[]): Record<string, number> {
+  const counts: Record<string, number> = {};
+  for (const item of items) {
+    counts[item.type] = (counts[item.type] ?? 0) + 1;
+  }
+  return counts;
+}
diff --git a/src/resources/extensions/universal-config/index.ts b/src/resources/extensions/universal-config/index.ts
new file mode 100644
index 000000000..9201c5e88
--- /dev/null
+++ b/src/resources/extensions/universal-config/index.ts
@@ -0,0 +1,118 @@
+/**
+ * Universal Config Discovery Extension
+ *
+ * Auto-detects and displays configuration from 8 AI coding tools:
+ * Claude Code, Cursor, Windsurf, Gemini CLI, Codex, Cline,
+ * GitHub Copilot, and VS Code.
+ *
+ * Discovers: MCP servers, rules/instructions, context files, and settings.
+ *
+ * Read-only: never modifies other tools' config files.
+ *
+ * Provides:
+ *   - discover_configs tool (LLM-callable)
+ *   - /configs command (slash command)
+ */
+
+import type { ExtensionAPI, ExtensionCommandContext } from "@gsd/pi-coding-agent";
+import { Type } from "@sinclair/typebox";
+import { discoverAllConfigs } from "./discovery.js";
+import { formatDiscoveryForTool, formatDiscoveryForCommand } from "./format.js";
+import type { DiscoveryResult, ToolId } from "./types.js";
+
+// Cache discovery result within a session to avoid re-scanning
+let cachedResult: DiscoveryResult | null = null;
+
+export default function universalConfig(pi: ExtensionAPI) {
+  // ── Tool: discover_configs ──────────────────────────────────────────────
+
+  pi.registerTool({
+    name: "discover_configs",
+    label: "Discover Configs",
+    description:
+      "Scan for existing AI coding tool configurations in this project and the user's home directory. " +
+      "Discovers MCP servers, rules, context files, and settings from Claude Code, Cursor, Windsurf, " +
+      "Gemini CLI, Codex, Cline, GitHub Copilot, and VS Code. Read-only — never modifies config files.",
+    promptSnippet: "Discover existing AI tool configs (MCP servers, rules, context files) from 8 coding tools.",
+    promptGuidelines: [
+      "Use discover_configs when a user asks about their existing configuration, MCP servers, or when switching from another AI coding tool.",
+      "The tool scans both user-level (~/) and project-level (./) config directories.",
+      "Results include MCP servers that could be reused, rules/instructions that could be adapted, and context files from other tools.",
+    ],
+    parameters: Type.Object({
+      tool: Type.Optional(
+        Type.String({
+          description:
+            "Filter to a specific tool: claude, cursor, windsurf, gemini, codex, cline, github-copilot, vscode. Omit to scan all.",
+        }),
+      ),
+      refresh: Type.Optional(
+        Type.Boolean({
+          description: "Force re-scan even if cached results exist. Default: false.",
+        }),
+      ),
+    }),
+
+    async execute(_toolCallId, params, _signal, _onUpdate, ctx) {
+      if (params.refresh || !cachedResult) {
+        cachedResult = await discoverAllConfigs(ctx.cwd);
+      }
+
+      let result = cachedResult;
+
+      // Filter to specific tool if requested
+      if (params.tool) {
+        const toolId = params.tool as ToolId;
+        const filtered = result.tools.filter((t) => t.tool.id === toolId);
+        if (filtered.length === 0) {
+          return {
+            content: [{ type: "text", text: `No scanner found for tool "${params.tool}". Valid tools: claude, cursor, windsurf, gemini, codex, cline, github-copilot, vscode` }],
+            isError: true,
+            details: undefined as unknown,
+          };
+        }
+        // Rebuild result with filtered tools
+        const allItems = filtered.flatMap((t) => t.items);
+        result = {
+          ...result,
+          tools: filtered,
+          allItems,
+          summary: {
+            ...result.summary,
+            mcpServers: allItems.filter((i) => i.type === "mcp-server").length,
+            rules: allItems.filter((i) => i.type === "rule").length,
+            contextFiles: allItems.filter((i) => i.type === "context-file").length,
+            settings: allItems.filter((i) => i.type === "settings").length,
+            totalItems: allItems.length,
+            toolsWithConfig: filtered.filter((t) => t.items.length > 0).length,
+          },
+        };
+      }
+
+      const text = formatDiscoveryForTool(result);
+      return {
+        content: [{ type: "text", text }],
+        details: undefined as unknown,
+      };
+    },
+  });
+
+  // ── Command: /configs ───────────────────────────────────────────────────
+
+  pi.registerCommand("configs", {
+    description: "Show discovered AI tool configurations (MCP servers, rules, context files)",
+    async handler(_args: string, ctx: ExtensionCommandContext) {
+      // Always refresh on command invocation
+      cachedResult = await discoverAllConfigs(ctx.cwd);
+      const lines = formatDiscoveryForCommand(cachedResult);
+
+      ctx.ui.notify(lines.join("\n"), "info");
+    },
+  });
+
+  // ── Invalidate cache on session switch ──────────────────────────────────
+
+  pi.on("session_switch", () => {
+    cachedResult = null;
+  });
+}
diff --git a/src/resources/extensions/universal-config/package.json b/src/resources/extensions/universal-config/package.json
new file mode 100644
index 000000000..b88eb676f
--- /dev/null
+++ b/src/resources/extensions/universal-config/package.json
@@ -0,0 +1,11 @@
+{
+  "name": "pi-extension-universal-config",
+  "private": true,
+  "version": "1.0.0",
+  "type": "module",
+  "pi": {
+    "extensions": [
+      "./index.ts"
+    ]
+  }
+}
diff --git a/src/resources/extensions/universal-config/scanners.ts b/src/resources/extensions/universal-config/scanners.ts
new file mode 100644
index 000000000..874a7b0f4
--- /dev/null
+++ b/src/resources/extensions/universal-config/scanners.ts
@@ -0,0 +1,579 @@
+/**
+ * Universal Config Discovery — per-tool scanners
+ *
+ * Each scanner reads config files for a specific AI coding tool and
+ * normalizes them to DiscoveredItem[]. Read-only: never modifies files.
+ *
+ * Config path sources verified against Oh My Pi's discovery module.
+ */
+
+import { readFile, readdir, stat } from "node:fs/promises";
+import { join, basename, resolve } from "node:path";
+import { homedir } from "node:os";
+import type {
+  ConfigSource,
+  ConfigLevel,
+  DiscoveredItem,
+  DiscoveredMCPServer,
+  DiscoveredRule,
+  DiscoveredContextFile,
+  DiscoveredSettings,
+  ToolDiscoveryResult,
+  ToolId,
+  ToolInfo,
+} from "./types.js";
+
+// ── Helpers ───────────────────────────────────────────────────────────────────
+
+function source(tool: ToolInfo, path: string, level: ConfigLevel): ConfigSource {
+  return { tool: tool.id, toolName: tool.name, path, level };
+}
+
+async function readTextFile(path: string): Promise<string | null> {
+  try {
+    return await readFile(path, "utf8");
+  } catch {
+    return null;
+  }
+}
+
+function tryParseJson<T>(content: string): T | null {
+  try {
+    return JSON.parse(content) as T;
+  } catch {
+    return null;
+  }
+}
+
+async function fileExists(path: string): Promise<boolean> {
+  try {
+    await stat(path);
+    return true;
+  } catch {
+    return false;
+  }
+}
+
+async function isDirectory(path: string): Promise<boolean> {
+  try {
+    const s = await stat(path);
+    return s.isDirectory();
+  } catch {
+    return false;
+  }
+}
+
+async function readDirSafe(dir: string): Promise<string[]> {
+  try {
+    return await readdir(dir);
+  } catch {
+    return [];
+  }
+}
+
+/**
+ * Parse MDC/YAML frontmatter from a markdown file.
+ * Returns the frontmatter as key-value pairs and the body content.
+ */
+function parseFrontmatter(content: string): { frontmatter: Record<string, unknown>; body: string } {
+  const match = content.match(/^---\s*\n([\s\S]*?)\n---\s*\n([\s\S]*)$/);
+  if (!match) {
+    return { frontmatter: {}, body: content };
+  }
+
+  const rawFm = match[1] ?? "";
+  const body = match[2] ?? "";
+  const frontmatter: Record<string, unknown> = {};
+
+  for (const line of rawFm.split("\n")) {
+    const colonIdx = line.indexOf(":");
+    if (colonIdx === -1) continue;
+    const key = line.slice(0, colonIdx).trim();
+    let value: unknown = line.slice(colonIdx + 1).trim();
+
+    // Strip surrounding quotes from YAML string values
+    if (typeof value === "string" && /^["'].*["']$/.test(value)) {
+      value = value.slice(1, -1);
+    }
+
+    // Parse simple types
+    if (value === "true") value = true;
+    else if (value === "false") value = false;
+    else if (typeof value === "string" && /^\d+$/.test(value)) value = parseInt(value, 10);
+
+    frontmatter[key] = value;
+  }
+
+  return { frontmatter, body };
+}
+
+/**
+ * Parse MCP servers from a JSON object with `mcpServers` key.
+ * Common format used by Claude Code, Cursor, Windsurf, Gemini CLI.
+ */
+function parseMcpServersFromJson(
+  json: Record<string, unknown>,
+  filePath: string,
+  tool: ToolInfo,
+  level: ConfigLevel,
+): DiscoveredMCPServer[] {
+  const servers: DiscoveredMCPServer[] = [];
+  const mcpServers = json.mcpServers as Record<string, unknown> | undefined;
+  if (!mcpServers || typeof mcpServers !== "object") return servers;
+
+  for (const [name, config] of Object.entries(mcpServers)) {
+    if (!config || typeof config !== "object") continue;
+    const c = config as Record<string, unknown>;
+    servers.push({
+      type: "mcp-server",
+      name,
+      command: typeof c.command === "string" ? c.command : undefined,
+      args: Array.isArray(c.args) ? (c.args as string[]) : undefined,
+      env: c.env && typeof c.env === "object" ? (c.env as Record<string, string>) : undefined,
+      url: typeof c.url === "string" ? c.url : undefined,
+      transport: ["stdio", "sse", "http"].includes(c.type as string)
+        ? (c.type as "stdio" | "sse" | "http")
+        : undefined,
+      source: source(tool, filePath, level),
+    });
+  }
+  return servers;
+}
+
+// ── Per-tool scanners ─────────────────────────────────────────────────────────
+
+type Scanner = (projectRoot: string, home: string, tool: ToolInfo) => Promise<{ items: DiscoveredItem[]; warnings: string[] }>;
+
+// ---------- Claude Code ----------
+
+async function scanClaude(projectRoot: string, home: string, tool: ToolInfo): Promise<{ items: DiscoveredItem[]; warnings: string[] }> {
+  const items: DiscoveredItem[] = [];
+  const warnings: string[] = [];
+
+  // User-level MCP: ~/.claude.json or ~/.claude/mcp.json
+  for (const relPath of [".claude.json", ".claude/mcp.json"]) {
+    const fullPath = join(home, relPath);
+    const content = await readTextFile(fullPath);
+    if (content) {
+      const json = tryParseJson<Record<string, unknown>>(content);
+      if (json) {
+        const servers = parseMcpServersFromJson(json, fullPath, tool, "user");
+        if (servers.length > 0) {
+          items.push(...servers);
+          break; // First hit wins (matches Oh My Pi behavior)
+        }
+      }
+    }
+  }
+
+  // Project-level MCP: .claude/.mcp.json or .claude/mcp.json
+  for (const relPath of [".claude/.mcp.json", ".claude/mcp.json"]) {
+    const fullPath = join(projectRoot, relPath);
+    const content = await readTextFile(fullPath);
+    if (content) {
+      const json = tryParseJson<Record<string, unknown>>(content);
+      if (json) {
+        const servers = parseMcpServersFromJson(json, fullPath, tool, "project");
+        if (servers.length > 0) {
+          items.push(...servers);
+          break;
+        }
+      }
+    }
+  }
+
+  // User-level context: ~/.claude/CLAUDE.md
+  const userClaudeMd = join(home, ".claude/CLAUDE.md");
+  const userMdContent = await readTextFile(userClaudeMd);
+  if (userMdContent) {
+    items.push({
+      type: "context-file",
+      name: "CLAUDE.md (user)",
+      content: userMdContent,
+      source: source(tool, userClaudeMd, "user"),
+    });
+  }
+
+  // Project-level context: CLAUDE.md (root) and .claude/CLAUDE.md
+  for (const relPath of ["CLAUDE.md", ".claude/CLAUDE.md"]) {
+    const fullPath = join(projectRoot, relPath);
+    const content = await readTextFile(fullPath);
+    if (content) {
+      items.push({
+        type: "context-file",
+        name: `${relPath}`,
+        content,
+        source: source(tool, fullPath, "project"),
+      });
+    }
+  }
+
+  // User-level settings: ~/.claude/settings.json
+  const userSettings = join(home, ".claude/settings.json");
+  const settingsContent = await readTextFile(userSettings);
+  if (settingsContent) {
+    const json = tryParseJson<Record<string, unknown>>(settingsContent);
+    if (json) {
+      items.push({ type: "settings", data: json, source: source(tool, userSettings, "user") });
+    }
+  }
+
+  return { items, warnings };
+}
+
+// ---------- Cursor ----------
+
+async function scanCursor(projectRoot: string, home: string, tool: ToolInfo): Promise<{ items: DiscoveredItem[]; warnings: string[] }> {
+  const items: DiscoveredItem[] = [];
+  const warnings: string[] = [];
+
+  // MCP servers: ~/.cursor/mcp.json and .cursor/mcp.json
+  for (const { dir, level } of [
+    { dir: home, level: "user" as ConfigLevel },
+    { dir: projectRoot, level: "project" as ConfigLevel },
+  ]) {
+    const mcpPath = join(dir, ".cursor/mcp.json");
+    const content = await readTextFile(mcpPath);
+    if (content) {
+      const json = tryParseJson<Record<string, unknown>>(content);
+      if (json) items.push(...parseMcpServersFromJson(json, mcpPath, tool, level));
+    }
+  }
+
+  // Rules: .cursor/rules/*.mdc and .cursor/rules/*.md
+  const projectRulesDir = join(projectRoot, ".cursor/rules");
+  const ruleFiles = await readDirSafe(projectRulesDir);
+  for (const file of ruleFiles) {
+    if (!file.endsWith(".mdc") && !file.endsWith(".md")) continue;
+    const filePath = join(projectRulesDir, file);
+    const content = await readTextFile(filePath);
+    if (!content) continue;
+
+    const { frontmatter, body } = parseFrontmatter(content);
+    items.push({
+      type: "rule",
+      name: file.replace(/\.(mdc|md)$/, ""),
+      content: body,
+      globs: typeof frontmatter.globs === "string" ? [frontmatter.globs] : undefined,
+      alwaysApply: frontmatter.alwaysApply === true,
+      description: typeof frontmatter.description === "string" ? frontmatter.description : undefined,
+      source: source(tool, filePath, "project"),
+    });
+  }
+
+  // Legacy: .cursorrules (root-level file)
+  const legacyRulesPath = join(projectRoot, ".cursorrules");
+  const legacyContent = await readTextFile(legacyRulesPath);
+  if (legacyContent) {
+    items.push({
+      type: "rule",
+      name: "cursorrules (legacy)",
+      content: legacyContent,
+      alwaysApply: true,
+      source: source(tool, legacyRulesPath, "project"),
+    });
+  }
+
+  // Settings: .cursor/settings.json
+  const settingsPath = join(projectRoot, ".cursor/settings.json");
+  const settingsContent = await readTextFile(settingsPath);
+  if (settingsContent) {
+    const json = tryParseJson<Record<string, unknown>>(settingsContent);
+    if (json) items.push({ type: "settings", data: json, source: source(tool, settingsPath, "project") });
+  }
+
+  return { items, warnings };
+}
+
+// ---------- Windsurf ----------
+
+async function scanWindsurf(projectRoot: string, home: string, tool: ToolInfo): Promise<{ items: DiscoveredItem[]; warnings: string[] }> {
+  const items: DiscoveredItem[] = [];
+  const warnings: string[] = [];
+
+  // MCP servers: ~/.codeium/windsurf/mcp_config.json and .windsurf/mcp_config.json
+  for (const { path: mcpPath, level } of [
+    { path: join(home, ".codeium/windsurf/mcp_config.json"), level: "user" as ConfigLevel },
+    { path: join(projectRoot, ".windsurf/mcp_config.json"), level: "project" as ConfigLevel },
+  ]) {
+    const content = await readTextFile(mcpPath);
+    if (content) {
+      const json = tryParseJson<Record<string, unknown>>(content);
+      if (json) items.push(...parseMcpServersFromJson(json, mcpPath, tool, level));
+    }
+  }
+
+  // User rules: ~/.codeium/windsurf/memories/global_rules.md
+  const globalRulesPath = join(home, ".codeium/windsurf/memories/global_rules.md");
+  const globalRules = await readTextFile(globalRulesPath);
+  if (globalRules) {
+    items.push({
+      type: "rule",
+      name: "global_rules",
+      content: globalRules,
+      alwaysApply: true,
+      source: source(tool, globalRulesPath, "user"),
+    });
+  }
+
+  // Project rules: .windsurf/rules/*.md
+  const rulesDir = join(projectRoot, ".windsurf/rules");
+  const ruleFiles = await readDirSafe(rulesDir);
+  for (const file of ruleFiles) {
+    if (!file.endsWith(".md")) continue;
+    const filePath = join(rulesDir, file);
+    const content = await readTextFile(filePath);
+    if (!content) continue;
+    const { frontmatter, body } = parseFrontmatter(content);
+    items.push({
+      type: "rule",
+      name: file.replace(/\.md$/, ""),
+      content: body,
+      description: typeof frontmatter.description === "string" ? frontmatter.description : undefined,
+      source: source(tool, filePath, "project"),
+    });
+  }
+
+  // Legacy: .windsurfrules
+  const legacyPath = join(projectRoot, ".windsurfrules");
+  const legacyContent = await readTextFile(legacyPath);
+  if (legacyContent) {
+    items.push({
+      type: "rule",
+      name: "windsurfrules (legacy)",
+      content: legacyContent,
+      alwaysApply: true,
+      source: source(tool, legacyPath, "project"),
+    });
+  }
+
+  return { items, warnings };
+}
+
+// ---------- Gemini CLI ----------
+
+async function scanGemini(projectRoot: string, home: string, tool: ToolInfo): Promise<{ items: DiscoveredItem[]; warnings: string[] }> {
+  const items: DiscoveredItem[] = [];
+  const warnings: string[] = [];
+
+  // MCP servers: ~/.gemini/settings.json and .gemini/settings.json
+  for (const { path: settingsPath, level } of [
+    { path: join(home, ".gemini/settings.json"), level: "user" as ConfigLevel },
+    { path: join(projectRoot, ".gemini/settings.json"), level: "project" as ConfigLevel },
+  ]) {
+    const content = await readTextFile(settingsPath);
+    if (content) {
+      const json = tryParseJson<Record<string, unknown>>(content);
+      if (json) {
+        items.push(...parseMcpServersFromJson(json, settingsPath, tool, level));
+        items.push({ type: "settings", data: json, source: source(tool, settingsPath, level) });
+      }
+    }
+  }
+
+  // Context files: ~/.gemini/GEMINI.md and .gemini/GEMINI.md
+  for (const { path: mdPath, level } of [
+    { path: join(home, ".gemini/GEMINI.md"), level: "user" as ConfigLevel },
+    { path: join(projectRoot, ".gemini/GEMINI.md"), level: "project" as ConfigLevel },
+  ]) {
+    const content = await readTextFile(mdPath);
+    if (content) {
+      items.push({
+        type: "context-file",
+        name: `GEMINI.md (${level})`,
+        content,
+        source: source(tool, mdPath, level),
+      });
+    }
+  }
+
+  return { items, warnings };
+}
+
+// ---------- Codex ----------
+
+async function scanCodex(projectRoot: string, home: string, tool: ToolInfo): Promise<{ items: DiscoveredItem[]; warnings: string[] }> {
+  const items: DiscoveredItem[] = [];
+  const warnings: string[] = [];
+
+  // Context file: ~/.codex/AGENTS.md
+  const agentsMdPath = join(home, ".codex/AGENTS.md");
+  const agentsMd = await readTextFile(agentsMdPath);
+  if (agentsMd) {
+    items.push({
+      type: "context-file",
+      name: "AGENTS.md (user)",
+      content: agentsMd,
+      source: source(tool, agentsMdPath, "user"),
+    });
+  }
+
+  // Project-level: AGENTS.md at root (Codex convention)
+  const projectAgentsMd = join(projectRoot, "AGENTS.md");
+  const projectContent = await readTextFile(projectAgentsMd);
+  if (projectContent) {
+    items.push({
+      type: "context-file",
+      name: "AGENTS.md (project)",
+      content: projectContent,
+      source: source(tool, projectAgentsMd, "project"),
+    });
+  }
+
+  // Codex uses TOML for MCP config — we parse only the JSON subset
+  // (TOML parsing would require a dependency; skip for now, log warning)
+  for (const { path: tomlPath, level } of [
+    { path: join(home, ".codex/config.toml"), level: "user" as ConfigLevel },
+    { path: join(projectRoot, ".codex/config.toml"), level: "project" as ConfigLevel },
+  ]) {
+    if (await fileExists(tomlPath)) {
+      warnings.push(`Found ${tomlPath} (TOML config) — MCP server parsing from TOML not yet supported`);
+    }
+  }
+
+  return { items, warnings };
+}
+
+// ---------- Cline ----------
+
+async function scanCline(projectRoot: string, _home: string, tool: ToolInfo): Promise<{ items: DiscoveredItem[]; warnings: string[] }> {
+  const items: DiscoveredItem[] = [];
+  const warnings: string[] = [];
+
+  const clinerulesPath = join(projectRoot, ".clinerules");
+
+  if (await isDirectory(clinerulesPath)) {
+    // Directory format: .clinerules/*.md
+    const files = await readDirSafe(clinerulesPath);
+    for (const file of files) {
+      if (!file.endsWith(".md")) continue;
+      const filePath = join(clinerulesPath, file);
+      const content = await readTextFile(filePath);
+      if (!content) continue;
+      const { body } = parseFrontmatter(content);
+      items.push({
+        type: "rule",
+        name: file.replace(/\.md$/, ""),
+        content: body,
+        alwaysApply: true,
+        source: source(tool, filePath, "project"),
+      });
+    }
+  } else {
+    // Single file format
+    const content = await readTextFile(clinerulesPath);
+    if (content) {
+      items.push({
+        type: "rule",
+        name: "clinerules",
+        content,
+        alwaysApply: true,
+        source: source(tool, clinerulesPath, "project"),
+      });
+    }
+  }
+
+  // Cline MCP: .cline/mcp_settings.json (VS Code extension stores MCP here)
+  const clineMcpPath = join(projectRoot, ".cline/mcp_settings.json");
+  const clineMcpContent = await readTextFile(clineMcpPath);
+  if (clineMcpContent) {
+    const json = tryParseJson<Record<string, unknown>>(clineMcpContent);
+    if (json) items.push(...parseMcpServersFromJson(json, clineMcpPath, tool, "project"));
+  }
+
+  return { items, warnings };
+}
+
+// ---------- GitHub Copilot ----------
+
+async function scanGithubCopilot(projectRoot: string, _home: string, tool: ToolInfo): Promise<{ items: DiscoveredItem[]; warnings: string[] }> {
+  const items: DiscoveredItem[] = [];
+  const warnings: string[] = [];
+
+  // Context file: .github/copilot-instructions.md
+  const instructionsPath = join(projectRoot, ".github/copilot-instructions.md");
+  const instructions = await readTextFile(instructionsPath);
+  if (instructions) {
+    items.push({
+      type: "context-file",
+      name: "copilot-instructions.md",
+      content: instructions,
+      source: source(tool, instructionsPath, "project"),
+    });
+  }
+
+  // Instructions: .github/instructions/*.instructions.md
+  const instructionsDir = join(projectRoot, ".github/instructions");
+  const instrFiles = await readDirSafe(instructionsDir);
+  for (const file of instrFiles) {
+    if (!file.endsWith(".instructions.md")) continue;
+    const filePath = join(instructionsDir, file);
+    const content = await readTextFile(filePath);
+    if (!content) continue;
+    const { frontmatter, body } = parseFrontmatter(content);
+    const applyTo = typeof frontmatter.applyTo === "string" ? frontmatter.applyTo : undefined;
+    items.push({
+      type: "rule",
+      name: file.replace(".instructions.md", ""),
+      content: body,
+      globs: applyTo ? [applyTo] : undefined,
+      description: `GitHub Copilot instruction${applyTo ? ` (applies to: ${applyTo})` : ""}`,
+      source: source(tool, filePath, "project"),
+    });
+  }
+
+  return { items, warnings };
+}
+
+// ---------- VS Code ----------
+
+async function scanVSCode(projectRoot: string, _home: string, tool: ToolInfo): Promise<{ items: DiscoveredItem[]; warnings: string[] }> {
+  const items: DiscoveredItem[] = [];
+  const warnings: string[] = [];
+
+  // Settings: .vscode/settings.json (may contain MCP servers and AI settings)
+  const settingsPath = join(projectRoot, ".vscode/settings.json");
+  const settingsContent = await readTextFile(settingsPath);
+  if (settingsContent) {
+    const json = tryParseJson<Record<string, unknown>>(settingsContent);
+    if (json) {
+      items.push({ type: "settings", data: json, source: source(tool, settingsPath, "project") });
+
+      // VS Code MCP servers: look for mcp-related keys
+      // Format varies: "mcp.servers", "mcpServers", etc.
+      const mcpServers = (json["mcp.servers"] ?? json.mcpServers ?? (json.mcp as Record<string, unknown>)?.servers) as Record<string, unknown> | undefined;
+      if (mcpServers && typeof mcpServers === "object") {
+        items.push(...parseMcpServersFromJson({ mcpServers }, settingsPath, tool, "project"));
+      }
+    }
+  }
+
+  // VS Code MCP config: .vscode/mcp.json
+  const mcpPath = join(projectRoot, ".vscode/mcp.json");
+  const mcpContent = await readTextFile(mcpPath);
+  if (mcpContent) {
+    const json = tryParseJson<Record<string, unknown>>(mcpContent);
+    if (json) {
+      // VS Code uses { servers: { ... } } or { mcpServers: { ... } }
+      const servers = (json.servers ?? json.mcpServers) as Record<string, unknown> | undefined;
+      if (servers && typeof servers === "object") {
+        items.push(...parseMcpServersFromJson({ mcpServers: servers }, mcpPath, tool, "project"));
+      }
+    }
+  }
+
+  return { items, warnings };
+}
+
+// ── Scanner registry ──────────────────────────────────────────────────────────
+
+export const SCANNERS: Record<ToolId, Scanner> = {
+  claude: scanClaude,
+  cursor: scanCursor,
+  windsurf: scanWindsurf,
+  gemini: scanGemini,
+  codex: scanCodex,
+  cline: scanCline,
+  "github-copilot": scanGithubCopilot,
+  vscode: scanVSCode,
+};
diff --git a/src/resources/extensions/universal-config/tests/discovery.test.ts b/src/resources/extensions/universal-config/tests/discovery.test.ts
new file mode 100644
index 000000000..7d3706881
--- /dev/null
+++ b/src/resources/extensions/universal-config/tests/discovery.test.ts
@@ -0,0 +1,111 @@
+/**
+ * Tests for the discovery orchestrator.
+ * Runs with: node --experimental-strip-types --test
+ */
+
+import { describe, test } from "node:test";
+import { strict as assert } from "node:assert";
+import { mkdirSync, writeFileSync, rmSync } from "node:fs";
+import { join } from "node:path";
+import { tmpdir } from "node:os";
+import { discoverAllConfigs } from "../discovery.ts";
+
+function mkdirp(path: string) {
+  mkdirSync(path, { recursive: true });
+}
+
+function writeJson(path: string, data: unknown) {
+  mkdirp(join(path, ".."));
+  writeFileSync(path, JSON.stringify(data, null, 2), "utf8");
+}
+
+function writeText(path: string, content: string) {
+  mkdirp(join(path, ".."));
+  writeFileSync(path, content, "utf8");
+}
+
+function makeTempDirs() {
+  const base = join(tmpdir(), `ucd-disc-${Date.now()}-${Math.random().toString(36).slice(2, 8)}`);
+  const testRoot = join(base, "project");
+  const testHome = join(base, "home");
+  mkdirp(testRoot);
+  mkdirp(testHome);
+  return { testRoot, testHome, cleanup: () => rmSync(base, { recursive: true, force: true }) };
+}
+
+describe("discoverAllConfigs", () => {
+  test("returns empty result for clean directories", async () => {
+    const { testRoot, testHome, cleanup } = makeTempDirs();
+    try {
+      const result = await discoverAllConfigs(testRoot, testHome);
+      assert.equal(result.summary.totalItems, 0);
+      assert.equal(result.summary.toolsScanned, 8);
+      assert.equal(result.summary.toolsWithConfig, 0);
+      assert.ok(result.durationMs >= 0);
+    } finally {
+      cleanup();
+    }
+  });
+
+  test("discovers config from multiple tools", async () => {
+    const { testRoot, testHome, cleanup } = makeTempDirs();
+    try {
+      writeJson(join(testHome, ".claude.json"), {
+        mcpServers: { "claude-mcp": { command: "node", args: ["server.js"] } },
+      });
+      writeText(join(testRoot, ".cursorrules"), "Use semicolons.");
+      writeText(join(testRoot, ".github/copilot-instructions.md"), "Be helpful.");
+
+      const result = await discoverAllConfigs(testRoot, testHome);
+      assert.equal(result.summary.toolsWithConfig, 3);
+      assert.equal(result.summary.mcpServers, 1);
+      assert.equal(result.summary.rules, 1);
+      assert.equal(result.summary.contextFiles, 1);
+      assert.equal(result.allItems.length, 3);
+    } finally {
+      cleanup();
+    }
+  });
+
+  test("handles nonexistent paths gracefully", async () => {
+    const result = await discoverAllConfigs("/nonexistent/path", "/nonexistent/home");
+    assert.equal(result.summary.totalItems, 0);
+    assert.ok(result.warnings.length >= 0);
+  });
+
+  test("groups items by tool", async () => {
+    const { testRoot, testHome, cleanup } = makeTempDirs();
+    try {
+      writeJson(join(testRoot, ".cursor/mcp.json"), {
+        mcpServers: { s1: { command: "a" }, s2: { command: "b" } },
+      });
+
+      const result = await discoverAllConfigs(testRoot, testHome);
+      const cursorResult = result.tools.find((t) => t.tool.id === "cursor");
+      assert.ok(cursorResult);
+      assert.equal(cursorResult!.items.length, 2);
+    } finally {
+      cleanup();
+    }
+  });
+
+  test("summary counts are accurate", async () => {
+    const { testRoot, testHome, cleanup } = makeTempDirs();
+    try {
+      writeJson(join(testRoot, ".cursor/mcp.json"), { mcpServers: { s1: { command: "a" } } });
+      writeText(join(testRoot, ".cursorrules"), "Rule 1");
+      writeText(join(testRoot, ".clinerules"), "Rule 2");
+      writeText(join(testRoot, ".github/copilot-instructions.md"), "Instructions");
+      writeJson(join(testRoot, ".vscode/settings.json"), { "editor.tabSize": 2 });
+
+      const result = await discoverAllConfigs(testRoot, testHome);
+      assert.equal(result.summary.mcpServers, 1);
+      assert.equal(result.summary.rules, 2);
+      assert.equal(result.summary.contextFiles, 1);
+      assert.equal(result.summary.settings, 1);
+      assert.equal(result.summary.totalItems, 5);
+    } finally {
+      cleanup();
+    }
+  });
+});
diff --git a/src/resources/extensions/universal-config/tests/format.test.ts b/src/resources/extensions/universal-config/tests/format.test.ts
new file mode 100644
index 000000000..0d0f48370
--- /dev/null
+++ b/src/resources/extensions/universal-config/tests/format.test.ts
@@ -0,0 +1,111 @@
+/**
+ * Tests for output formatting.
+ * Runs with: node --experimental-strip-types --test
+ */
+
+import { describe, test } from "node:test";
+import { strict as assert } from "node:assert";
+import { formatDiscoveryForTool, formatDiscoveryForCommand } from "../format.ts";
+import type { DiscoveryResult } from "../types.ts";
+
+const emptyResult: DiscoveryResult = {
+  tools: [],
+  allItems: [],
+  summary: {
+    mcpServers: 0,
+    rules: 0,
+    contextFiles: 0,
+    settings: 0,
+    totalItems: 0,
+    toolsScanned: 8,
+    toolsWithConfig: 0,
+  },
+  warnings: [],
+  durationMs: 42,
+};
+
+const populatedResult: DiscoveryResult = {
+  tools: [
+    {
+      tool: { id: "cursor", name: "Cursor", userDir: ".cursor", projectDir: ".cursor" },
+      items: [
+        {
+          type: "mcp-server",
+          name: "test-mcp",
+          command: "node",
+          args: ["server.js"],
+          transport: "stdio",
+          source: { tool: "cursor", toolName: "Cursor", path: "/project/.cursor/mcp.json", level: "project" },
+        },
+        {
+          type: "rule",
+          name: "style",
+          content: "Use semicolons and strict TypeScript.",
+          alwaysApply: true,
+          source: { tool: "cursor", toolName: "Cursor", path: "/project/.cursor/rules/style.mdc", level: "project" },
+        },
+      ],
+      warnings: [],
+    },
+    {
+      tool: { id: "github-copilot", name: "GitHub Copilot", userDir: null, projectDir: ".github" },
+      items: [
+        {
+          type: "context-file",
+          name: "copilot-instructions.md",
+          content: "Be helpful.",
+          source: { tool: "github-copilot", toolName: "GitHub Copilot", path: "/project/.github/copilot-instructions.md", level: "project" },
+        },
+      ],
+      warnings: [],
+    },
+  ],
+  allItems: [],
+  summary: {
+    mcpServers: 1,
+    rules: 1,
+    contextFiles: 1,
+    settings: 0,
+    totalItems: 3,
+    toolsScanned: 8,
+    toolsWithConfig: 2,
+  },
+  warnings: [],
+  durationMs: 15,
+};
+populatedResult.allItems = populatedResult.tools.flatMap((t) => t.items);
+
+describe("formatDiscoveryForTool", () => {
+  test("formats empty result", () => {
+    const text = formatDiscoveryForTool(emptyResult);
+    assert.ok(text.includes("0/8 tools with config"));
+    assert.ok(text.includes("No configuration found"));
+  });
+
+  test("formats populated result with sections", () => {
+    const text = formatDiscoveryForTool(populatedResult);
+    assert.ok(text.includes("2/8 tools with config"));
+    assert.ok(text.includes("1 MCP server(s)"));
+    assert.ok(text.includes("Cursor"));
+    assert.ok(text.includes("test-mcp"));
+    assert.ok(text.includes("GitHub Copilot"));
+    assert.ok(text.includes("copilot-instructions.md"));
+  });
+});
+
+describe("formatDiscoveryForCommand", () => {
+  test("formats empty result", () => {
+    const lines = formatDiscoveryForCommand(emptyResult);
+    const text = lines.join("\n");
+    assert.ok(text.includes("0 of 8"));
+    assert.ok(text.includes("No configuration found"));
+  });
+
+  test("formats populated result as summary", () => {
+    const lines = formatDiscoveryForCommand(populatedResult);
+    const text = lines.join("\n");
+    assert.ok(text.includes("2 of 8"));
+    assert.ok(text.includes("Cursor"));
+    assert.ok(text.includes("MCP: test-mcp"));
+  });
+});
diff --git a/src/resources/extensions/universal-config/tests/scanners.test.ts b/src/resources/extensions/universal-config/tests/scanners.test.ts
new file mode 100644
index 000000000..f31c8452a
--- /dev/null
+++ b/src/resources/extensions/universal-config/tests/scanners.test.ts
@@ -0,0 +1,438 @@
+/**
+ * Tests for universal config discovery scanners.
+ *
+ * Uses temporary directories to simulate config layouts from each tool.
+ * Runs with: node --experimental-strip-types --test
+ */
+
+import { describe, test } from "node:test";
+import { strict as assert } from "node:assert";
+import { mkdirSync, writeFileSync, rmSync } from "node:fs";
+import { join } from "node:path";
+import { tmpdir } from "node:os";
+import { SCANNERS } from "../scanners.ts";
+import { TOOLS } from "../tools.ts";
+import type { ToolInfo, DiscoveredItem } from "../types.ts";
+
+// ── Helpers ───────────────────────────────────────────────────────────────────
+
+function getTool(id: string): ToolInfo {
+  const tool = TOOLS.find((t) => t.id === id);
+  if (!tool) throw new Error(`Unknown tool: ${id}`);
+  return tool;
+}
+
+function mkdirp(path: string) {
+  mkdirSync(path, { recursive: true });
+}
+
+function writeJson(path: string, data: unknown) {
+  mkdirp(join(path, ".."));
+  writeFileSync(path, JSON.stringify(data, null, 2), "utf8");
+}
+
+function writeText(path: string, content: string) {
+  mkdirp(join(path, ".."));
+  writeFileSync(path, content, "utf8");
+}
+
+function makeTempDirs(): { testRoot: string; testHome: string; cleanup: () => void } {
+  const base = join(tmpdir(), `ucd-test-${Date.now()}-${Math.random().toString(36).slice(2, 8)}`);
+  const testRoot = join(base, "project");
+  const testHome = join(base, "home");
+  mkdirp(testRoot);
+  mkdirp(testHome);
+  return {
+    testRoot,
+    testHome,
+    cleanup: () => rmSync(base, { recursive: true, force: true }),
+  };
+}
+
+// ── Claude Code ───────────────────────────────────────────────────────────────
+
+describe("Claude Code scanner", () => {
+  test("discovers MCP servers from ~/.claude.json", async () => {
+    const { testRoot, testHome, cleanup } = makeTempDirs();
+    try {
+      writeJson(join(testHome, ".claude.json"), {
+        mcpServers: {
+          "test-server": { command: "npx", args: ["-y", "test-mcp"], type: "stdio" },
+        },
+      });
+
+      const { items } = await SCANNERS.claude(testRoot, testHome, getTool("claude"));
+      const servers = items.filter((i) => i.type === "mcp-server");
+      assert.equal(servers.length, 1);
+      assert.equal(servers[0]!.type, "mcp-server");
+      if (servers[0]!.type === "mcp-server") {
+        assert.equal(servers[0]!.name, "test-server");
+        assert.equal(servers[0]!.command, "npx");
+        assert.equal(servers[0]!.transport, "stdio");
+        assert.equal(servers[0]!.source.level, "user");
+      }
+    } finally {
+      cleanup();
+    }
+  });
+
+  test("discovers project MCP from .claude/.mcp.json", async () => {
+    const { testRoot, testHome, cleanup } = makeTempDirs();
+    try {
+      writeJson(join(testRoot, ".claude/.mcp.json"), {
+        mcpServers: { "project-server": { command: "node", args: ["server.js"] } },
+      });
+
+      const { items } = await SCANNERS.claude(testRoot, testHome, getTool("claude"));
+      const servers = items.filter((i) => i.type === "mcp-server");
+      assert.equal(servers.length, 1);
+      assert.equal(servers[0]!.source.level, "project");
+    } finally {
+      cleanup();
+    }
+  });
+
+  test("discovers CLAUDE.md context files", async () => {
+    const { testRoot, testHome, cleanup } = makeTempDirs();
+    try {
+      writeText(join(testHome, ".claude/CLAUDE.md"), "# User instructions");
+      writeText(join(testRoot, "CLAUDE.md"), "# Project root instructions");
+      writeText(join(testRoot, ".claude/CLAUDE.md"), "# Project .claude instructions");
+
+      const { items } = await SCANNERS.claude(testRoot, testHome, getTool("claude"));
+      const contexts = items.filter((i) => i.type === "context-file");
+      assert.equal(contexts.length, 3);
+    } finally {
+      cleanup();
+    }
+  });
+
+  test("discovers settings.json", async () => {
+    const { testRoot, testHome, cleanup } = makeTempDirs();
+    try {
+      writeJson(join(testHome, ".claude/settings.json"), { theme: "dark" });
+
+      const { items } = await SCANNERS.claude(testRoot, testHome, getTool("claude"));
+      const settings = items.filter((i) => i.type === "settings");
+      assert.equal(settings.length, 1);
+    } finally {
+      cleanup();
+    }
+  });
+
+  test("handles missing files gracefully", async () => {
+    const { testRoot, testHome, cleanup } = makeTempDirs();
+    try {
+      const { items, warnings } = await SCANNERS.claude(testRoot, testHome, getTool("claude"));
+      assert.equal(items.length, 0);
+      assert.equal(warnings.length, 0);
+    } finally {
+      cleanup();
+    }
+  });
+});
+
+// ── Cursor ────────────────────────────────────────────────────────────────────
+
+describe("Cursor scanner", () => {
+  test("discovers MCP servers from .cursor/mcp.json", async () => {
+    const { testRoot, testHome, cleanup } = makeTempDirs();
+    try {
+      writeJson(join(testRoot, ".cursor/mcp.json"), {
+        mcpServers: { "cursor-mcp": { command: "python", args: ["mcp.py"], type: "stdio" } },
+      });
+
+      const { items } = await SCANNERS.cursor(testRoot, testHome, getTool("cursor"));
+      const servers = items.filter((i) => i.type === "mcp-server");
+      assert.equal(servers.length, 1);
+      if (servers[0]!.type === "mcp-server") {
+        assert.equal(servers[0]!.name, "cursor-mcp");
+        assert.equal(servers[0]!.command, "python");
+      }
+    } finally {
+      cleanup();
+    }
+  });
+
+  test("discovers rules from .cursor/rules/*.mdc", async () => {
+    const { testRoot, testHome, cleanup } = makeTempDirs();
+    try {
+      writeText(
+        join(testRoot, ".cursor/rules/coding-style.mdc"),
+        "---\ndescription: Coding style rules\nalwaysApply: true\n---\nUse TypeScript strict mode.",
+      );
+
+      const { items } = await SCANNERS.cursor(testRoot, testHome, getTool("cursor"));
+      const rules = items.filter((i) => i.type === "rule");
+      assert.equal(rules.length, 1);
+      if (rules[0]!.type === "rule") {
+        assert.equal(rules[0]!.name, "coding-style");
+        assert.equal(rules[0]!.alwaysApply, true);
+        assert.equal(rules[0]!.description, "Coding style rules");
+      }
+    } finally {
+      cleanup();
+    }
+  });
+
+  test("discovers legacy .cursorrules", async () => {
+    const { testRoot, testHome, cleanup } = makeTempDirs();
+    try {
+      writeText(join(testRoot, ".cursorrules"), "Always use semicolons.");
+
+      const { items } = await SCANNERS.cursor(testRoot, testHome, getTool("cursor"));
+      const rules = items.filter((i) => i.type === "rule");
+      assert.equal(rules.length, 1);
+      if (rules[0]!.type === "rule") {
+        assert.equal(rules[0]!.content, "Always use semicolons.");
+      }
+    } finally {
+      cleanup();
+    }
+  });
+});
+
+// ── Windsurf ──────────────────────────────────────────────────────────────────
+
+describe("Windsurf scanner", () => {
+  test("discovers MCP servers from mcp_config.json", async () => {
+    const { testRoot, testHome, cleanup } = makeTempDirs();
+    try {
+      writeJson(join(testRoot, ".windsurf/mcp_config.json"), {
+        mcpServers: { "ws-server": { command: "node", args: ["ws.js"] } },
+      });
+
+      const { items } = await SCANNERS.windsurf(testRoot, testHome, getTool("windsurf"));
+      const servers = items.filter((i) => i.type === "mcp-server");
+      assert.equal(servers.length, 1);
+    } finally {
+      cleanup();
+    }
+  });
+
+  test("discovers global rules from user dir", async () => {
+    const { testRoot, testHome, cleanup } = makeTempDirs();
+    try {
+      writeText(join(testHome, ".codeium/windsurf/memories/global_rules.md"), "Be concise.");
+
+      const { items } = await SCANNERS.windsurf(testRoot, testHome, getTool("windsurf"));
+      const rules = items.filter((i) => i.type === "rule");
+      assert.equal(rules.length, 1);
+      if (rules[0]!.type === "rule") {
+        assert.equal(rules[0]!.name, "global_rules");
+        assert.equal(rules[0]!.alwaysApply, true);
+      }
+    } finally {
+      cleanup();
+    }
+  });
+});
+
+// ── Gemini CLI ────────────────────────────────────────────────────────────────
+
+describe("Gemini CLI scanner", () => {
+  test("discovers MCP servers from settings.json", async () => {
+    const { testRoot, testHome, cleanup } = makeTempDirs();
+    try {
+      writeJson(join(testRoot, ".gemini/settings.json"), {
+        mcpServers: { "gemini-mcp": { command: "deno", args: ["run", "mcp.ts"] } },
+      });
+
+      const { items } = await SCANNERS.gemini(testRoot, testHome, getTool("gemini"));
+      const servers = items.filter((i) => i.type === "mcp-server");
+      assert.equal(servers.length, 1);
+    } finally {
+      cleanup();
+    }
+  });
+
+  test("discovers GEMINI.md context files", async () => {
+    const { testRoot, testHome, cleanup } = makeTempDirs();
+    try {
+      writeText(join(testHome, ".gemini/GEMINI.md"), "User gemini instructions");
+      writeText(join(testRoot, ".gemini/GEMINI.md"), "Project gemini instructions");
+
+      const { items } = await SCANNERS.gemini(testRoot, testHome, getTool("gemini"));
+      const contexts = items.filter((i) => i.type === "context-file");
+      assert.equal(contexts.length, 2);
+    } finally {
+      cleanup();
+    }
+  });
+});
+
+// ── Codex ─────────────────────────────────────────────────────────────────────
+
+describe("Codex scanner", () => {
+  test("discovers AGENTS.md from user dir", async () => {
+    const { testRoot, testHome, cleanup } = makeTempDirs();
+    try {
+      writeText(join(testHome, ".codex/AGENTS.md"), "Codex user instructions");
+
+      const { items } = await SCANNERS.codex(testRoot, testHome, getTool("codex"));
+      const contexts = items.filter((i) => i.type === "context-file");
+      assert.equal(contexts.length, 1);
+      if (contexts[0]!.type === "context-file") {
+        assert.equal(contexts[0]!.name, "AGENTS.md (user)");
+      }
+    } finally {
+      cleanup();
+    }
+  });
+
+  test("warns about TOML config", async () => {
+    const { testRoot, testHome, cleanup } = makeTempDirs();
+    try {
+      writeText(join(testHome, ".codex/config.toml"), "[mcp_servers.test]\ncommand = 'node'");
+
+      const { warnings } = await SCANNERS.codex(testRoot, testHome, getTool("codex"));
+      assert.ok(warnings.length > 0);
+      assert.ok(warnings[0]!.includes("TOML"));
+    } finally {
+      cleanup();
+    }
+  });
+});
+
+// ── Cline ─────────────────────────────────────────────────────────────────────
+
+describe("Cline scanner", () => {
+  test("discovers .clinerules as single file", async () => {
+    const { testRoot, testHome, cleanup } = makeTempDirs();
+    try {
+      writeText(join(testRoot, ".clinerules"), "Follow TDD.");
+
+      const { items } = await SCANNERS.cline(testRoot, testHome, getTool("cline"));
+      const rules = items.filter((i) => i.type === "rule");
+      assert.equal(rules.length, 1);
+      if (rules[0]!.type === "rule") {
+        assert.equal(rules[0]!.name, "clinerules");
+        assert.equal(rules[0]!.alwaysApply, true);
+      }
+    } finally {
+      cleanup();
+    }
+  });
+
+  test("discovers .clinerules as directory", async () => {
+    const { testRoot, testHome, cleanup } = makeTempDirs();
+    try {
+      mkdirp(join(testRoot, ".clinerules"));
+      writeText(join(testRoot, ".clinerules/style.md"), "Use 2-space indent.");
+      writeText(join(testRoot, ".clinerules/testing.md"), "Write tests first.");
+
+      const { items } = await SCANNERS.cline(testRoot, testHome, getTool("cline"));
+      const rules = items.filter((i) => i.type === "rule");
+      assert.equal(rules.length, 2);
+    } finally {
+      cleanup();
+    }
+  });
+
+  test("handles missing .clinerules", async () => {
+    const { testRoot, testHome, cleanup } = makeTempDirs();
+    try {
+      const { items } = await SCANNERS.cline(testRoot, testHome, getTool("cline"));
+      assert.equal(items.length, 0);
+    } finally {
+      cleanup();
+    }
+  });
+});
+
+// ── GitHub Copilot ────────────────────────────────────────────────────────────
+
+describe("GitHub Copilot scanner", () => {
+  test("discovers copilot-instructions.md", async () => {
+    const { testRoot, testHome, cleanup } = makeTempDirs();
+    try {
+      writeText(join(testRoot, ".github/copilot-instructions.md"), "Use TypeScript.");
+
+      const { items } = await SCANNERS["github-copilot"](testRoot, testHome, getTool("github-copilot"));
+      const contexts = items.filter((i) => i.type === "context-file");
+      assert.equal(contexts.length, 1);
+      if (contexts[0]!.type === "context-file") {
+        assert.equal(contexts[0]!.name, "copilot-instructions.md");
+      }
+    } finally {
+      cleanup();
+    }
+  });
+
+  test("discovers .instructions.md files with frontmatter", async () => {
+    const { testRoot, testHome, cleanup } = makeTempDirs();
+    try {
+      writeText(
+        join(testRoot, ".github/instructions/react.instructions.md"),
+        '---\napplyTo: "**/*.tsx"\n---\nUse React functional components.',
+      );
+
+      const { items } = await SCANNERS["github-copilot"](testRoot, testHome, getTool("github-copilot"));
+      const rules = items.filter((i) => i.type === "rule");
+      assert.equal(rules.length, 1);
+      if (rules[0]!.type === "rule") {
+        assert.equal(rules[0]!.name, "react");
+        assert.deepEqual(rules[0]!.globs, ["**/*.tsx"]);
+      }
+    } finally {
+      cleanup();
+    }
+  });
+});
+
+// ── VS Code ───────────────────────────────────────────────────────────────────
+
+describe("VS Code scanner", () => {
+  test("discovers settings.json", async () => {
+    const { testRoot, testHome, cleanup } = makeTempDirs();
+    try {
+      writeJson(join(testRoot, ".vscode/settings.json"), {
+        "editor.fontSize": 14,
+      });
+
+      const { items } = await SCANNERS.vscode(testRoot, testHome, getTool("vscode"));
+      const settings = items.filter((i) => i.type === "settings");
+      assert.equal(settings.length, 1);
+    } finally {
+      cleanup();
+    }
+  });
+
+  test("discovers MCP servers from .vscode/mcp.json", async () => {
+    const { testRoot, testHome, cleanup } = makeTempDirs();
+    try {
+      writeJson(join(testRoot, ".vscode/mcp.json"), {
+        servers: { "vscode-mcp": { command: "node", args: ["mcp.js"] } },
+      });
+
+      const { items } = await SCANNERS.vscode(testRoot, testHome, getTool("vscode"));
+      const servers = items.filter((i) => i.type === "mcp-server");
+      assert.equal(servers.length, 1);
+      if (servers[0]!.type === "mcp-server") {
+        assert.equal(servers[0]!.name, "vscode-mcp");
+      }
+    } finally {
+      cleanup();
+    }
+  });
+
+  test("discovers MCP servers embedded in settings.json", async () => {
+    const { testRoot, testHome, cleanup } = makeTempDirs();
+    try {
+      writeJson(join(testRoot, ".vscode/settings.json"), {
+        "mcp.servers": {
+          "embedded-mcp": { command: "python", args: ["-m", "mcp_server"] },
+        },
+      });
+
+      const { items } = await SCANNERS.vscode(testRoot, testHome, getTool("vscode"));
+      const servers = items.filter((i) => i.type === "mcp-server");
+      assert.equal(servers.length, 1);
+      if (servers[0]!.type === "mcp-server") {
+        assert.equal(servers[0]!.name, "embedded-mcp");
+      }
+    } finally {
+      cleanup();
+    }
+  });
+});
diff --git a/src/resources/extensions/universal-config/tools.ts b/src/resources/extensions/universal-config/tools.ts
new file mode 100644
index 000000000..c59f4e19e
--- /dev/null
+++ b/src/resources/extensions/universal-config/tools.ts
@@ -0,0 +1,60 @@
+/**
+ * Universal Config Discovery — tool registry
+ *
+ * Known AI coding tools with their config directory locations.
+ * Based on research of Oh My Pi's discovery system and direct config
+ * file inspection of each tool.
+ */
+
+import type { ToolInfo } from "./types.js";
+
+export const TOOLS: ToolInfo[] = [
+  {
+    id: "claude",
+    name: "Claude Code",
+    userDir: ".claude",
+    projectDir: ".claude",
+  },
+  {
+    id: "cursor",
+    name: "Cursor",
+    userDir: ".cursor",
+    projectDir: ".cursor",
+  },
+  {
+    id: "windsurf",
+    name: "Windsurf",
+    userDir: ".codeium/windsurf",
+    projectDir: ".windsurf",
+  },
+  {
+    id: "gemini",
+    name: "Gemini CLI",
+    userDir: ".gemini",
+    projectDir: ".gemini",
+  },
+  {
+    id: "codex",
+    name: "OpenAI Codex",
+    userDir: ".codex",
+    projectDir: ".codex",
+  },
+  {
+    id: "cline",
+    name: "Cline",
+    userDir: null,
+    projectDir: null, // Uses root-level .clinerules (handled specially)
+  },
+  {
+    id: "github-copilot",
+    name: "GitHub Copilot",
+    userDir: null,
+    projectDir: ".github",
+  },
+  {
+    id: "vscode",
+    name: "VS Code",
+    userDir: null,
+    projectDir: ".vscode",
+  },
+];
diff --git a/src/resources/extensions/universal-config/types.ts b/src/resources/extensions/universal-config/types.ts
new file mode 100644
index 000000000..3f3eeae37
--- /dev/null
+++ b/src/resources/extensions/universal-config/types.ts
@@ -0,0 +1,116 @@
+/**
+ * Universal Config Discovery — shared types
+ *
+ * Normalized schema for discovered configuration items from all supported
+ * AI coding tools: Claude Code, Cursor, Windsurf, Gemini CLI, Codex,
+ * Cline, GitHub Copilot, VS Code.
+ */
+
+// ── Source metadata ───────────────────────────────────────────────────────────
+
+export type ConfigLevel = "user" | "project";
+
+export interface ConfigSource {
+  /** Which tool this config came from */
+  tool: ToolId;
+  /** Display name of the tool */
+  toolName: string;
+  /** Absolute path to the config file */
+  path: string;
+  /** User-level (~/) or project-level (./) */
+  level: ConfigLevel;
+}
+
+// ── Tool identifiers ──────────────────────────────────────────────────────────
+
+export type ToolId =
+  | "claude"
+  | "cursor"
+  | "windsurf"
+  | "gemini"
+  | "codex"
+  | "cline"
+  | "github-copilot"
+  | "vscode";
+
+export interface ToolInfo {
+  id: ToolId;
+  name: string;
+  /** User-level config base directory relative to $HOME (null = no user config) */
+  userDir: string | null;
+  /** Project-level config directory name relative to project root (null = no project config) */
+  projectDir: string | null;
+}
+
+// ── Discovered config items ───────────────────────────────────────────────────
+
+export interface DiscoveredMCPServer {
+  type: "mcp-server";
+  name: string;
+  command?: string;
+  args?: string[];
+  env?: Record<string, string>;
+  url?: string;
+  transport?: "stdio" | "sse" | "http";
+  source: ConfigSource;
+}
+
+export interface DiscoveredRule {
+  type: "rule";
+  name: string;
+  content: string;
+  /** Glob patterns this rule applies to */
+  globs?: string[];
+  /** Whether the rule applies to all files */
+  alwaysApply?: boolean;
+  description?: string;
+  source: ConfigSource;
+}
+
+export interface DiscoveredContextFile {
+  type: "context-file";
+  name: string;
+  content: string;
+  source: ConfigSource;
+}
+
+export interface DiscoveredSettings {
+  type: "settings";
+  data: Record<string, unknown>;
+  source: ConfigSource;
+}
+
+export type DiscoveredItem =
+  | DiscoveredMCPServer
+  | DiscoveredRule
+  | DiscoveredContextFile
+  | DiscoveredSettings;
+
+// ── Discovery result ──────────────────────────────────────────────────────────
+
+export interface ToolDiscoveryResult {
+  tool: ToolInfo;
+  items: DiscoveredItem[];
+  warnings: string[];
+}
+
+export interface DiscoveryResult {
+  /** All discovered items grouped by tool */
+  tools: ToolDiscoveryResult[];
+  /** Flat list of all discovered items */
+  allItems: DiscoveredItem[];
+  /** Summary counts by category */
+  summary: {
+    mcpServers: number;
+    rules: number;
+    contextFiles: number;
+    settings: number;
+    totalItems: number;
+    toolsScanned: number;
+    toolsWithConfig: number;
+  };
+  /** Warnings from scanners */
+  warnings: string[];
+  /** Duration in milliseconds */
+  durationMs: number;
+}