1 files changed, 171 insertions, 0 deletions
diff --git a/packages/cli/src/services/FileCommandLoader.ts b/packages/cli/src/services/FileCommandLoader.ts
new file mode 100644
index 00000000..1b96cb35
--- /dev/null
+++ b/packages/cli/src/services/FileCommandLoader.ts
@@ -0,0 +1,171 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ * SPDX-License-Identifier: Apache-2.0
+ */
+
+import { promises as fs } from 'fs';
+import path from 'path';
+import toml from '@iarna/toml';
+import { glob } from 'glob';
+import { z } from 'zod';
+import {
+  Config,
+  getProjectCommandsDir,
+  getUserCommandsDir,
+} from '@google/gemini-cli-core';
+import { ICommandLoader } from './types.js';
+import { CommandKind, SlashCommand } from '../ui/commands/types.js';
+
+/**
+ * Defines the Zod schema for a command definition file. This serves as the
+ * single source of truth for both validation and type inference.
+ */
+const TomlCommandDefSchema = z.object({
+  prompt: z.string({
+    required_error: "The 'prompt' field is required.",
+    invalid_type_error: "The 'prompt' field must be a string.",
+  }),
+  description: z.string().optional(),
+});
+
+/**
+ * Discovers and loads custom slash commands from .toml files in both the
+ * user's global config directory and the current project's directory.
+ *
+ * This loader is responsible for:
+ * - Recursively scanning command directories.
+ * - Parsing and validating TOML files.
+ * - Adapting valid definitions into executable SlashCommand objects.
+ * - Handling file system errors and malformed files gracefully.
+ */
+export class FileCommandLoader implements ICommandLoader {
+  private readonly projectRoot: string;
+
+  constructor(private readonly config: Config | null) {
+    this.projectRoot = config?.getProjectRoot() || process.cwd();
+  }
+
+  /**
+   * Loads all commands, applying the precedence rule where project-level
+   * commands override user-level commands with the same name.
+   * @param signal An AbortSignal to cancel the loading process.
+   * @returns A promise that resolves to an array of loaded SlashCommands.
+   */
+  async loadCommands(signal: AbortSignal): Promise<SlashCommand[]> {
+    const commandMap = new Map<string, SlashCommand>();
+    const globOptions = {
+      nodir: true,
+      dot: true,
+      signal,
+    };
+
+    try {
+      // User Commands
+      const userDir = getUserCommandsDir();
+      const userFiles = await glob('**/*.toml', {
+        ...globOptions,
+        cwd: userDir,
+      });
+      const userCommandPromises = userFiles.map((file) =>
+        this.parseAndAdaptFile(path.join(userDir, file), userDir),
+      );
+      const userCommands = (await Promise.all(userCommandPromises)).filter(
+        (cmd): cmd is SlashCommand => cmd !== null,
+      );
+      for (const cmd of userCommands) {
+        commandMap.set(cmd.name, cmd);
+      }
+
+      // Project Commands (these intentionally override user commands)
+      const projectDir = getProjectCommandsDir(this.projectRoot);
+      const projectFiles = await glob('**/*.toml', {
+        ...globOptions,
+        cwd: projectDir,
+      });
+      const projectCommandPromises = projectFiles.map((file) =>
+        this.parseAndAdaptFile(path.join(projectDir, file), projectDir),
+      );
+      const projectCommands = (
+        await Promise.all(projectCommandPromises)
+      ).filter((cmd): cmd is SlashCommand => cmd !== null);
+      for (const cmd of projectCommands) {
+        commandMap.set(cmd.name, cmd);
+      }
+    } catch (error) {
+      console.error(`[FileCommandLoader] Error during file search:`, error);
+    }
+
+    return Array.from(commandMap.values());
+  }
+
+  /**
+   * Parses a single .toml file and transforms it into a SlashCommand object.
+   * @param filePath The absolute path to the .toml file.
+   * @param baseDir The root command directory for name calculation.
+   * @returns A promise resolving to a SlashCommand, or null if the file is invalid.
+   */
+  private async parseAndAdaptFile(
+    filePath: string,
+    baseDir: string,
+  ): Promise<SlashCommand | null> {
+    let fileContent: string;
+    try {
+      fileContent = await fs.readFile(filePath, 'utf-8');
+    } catch (error: unknown) {
+      console.error(
+        `[FileCommandLoader] Failed to read file ${filePath}:`,
+        error instanceof Error ? error.message : String(error),
+      );
+      return null;
+    }
+
+    let parsed: unknown;
+    try {
+      parsed = toml.parse(fileContent);
+    } catch (error: unknown) {
+      console.error(
+        `[FileCommandLoader] Failed to parse TOML file ${filePath}:`,
+        error instanceof Error ? error.message : String(error),
+      );
+      return null;
+    }
+
+    const validationResult = TomlCommandDefSchema.safeParse(parsed);
+
+    if (!validationResult.success) {
+      console.error(
+        `[FileCommandLoader] Skipping invalid command file: ${filePath}. Validation errors:`,
+        validationResult.error.flatten(),
+      );
+      return null;
+    }
+
+    const validDef = validationResult.data;
+
+    const relativePathWithExt = path.relative(baseDir, filePath);
+    const relativePath = relativePathWithExt.substring(
+      0,
+      relativePathWithExt.length - 5, // length of '.toml'
+    );
+    const commandName = relativePath
+      .split(path.sep)
+      // Sanitize each path segment to prevent ambiguity. Since ':' is our
+      // namespace separator, we replace any literal colons in filenames
+      // with underscores to avoid naming conflicts.
+      .map((segment) => segment.replaceAll(':', '_'))
+      .join(':');
+
+    return {
+      name: commandName,
+      description:
+        validDef.description ||
+        `Custom command from ${path.basename(filePath)}`,
+      kind: CommandKind.FILE,
+      action: async () => ({
+        type: 'submit_prompt',
+        content: validDef.prompt,
+      }),
+    };
+  }
+}