dev-module-observer-list

List all Magento 2 module observers to identify event handlers and their configurations. Filter by specific events to analyze observer behavior and dependencies in your development environment.

Instructions

List all Magento 2 module observers

Input Schema

TableJSON Schema

Name	Required	Description	Default
`event`	No	Filter by specific event name
`format`	No	Output format	table

Implementation Reference

src/index.ts:452-481 (handler)

The handler function that constructs and executes the magerun2 dev:module:observer:list command, handles JSON parsing if needed, and returns formatted output or error.

async ({ format = "table", event }) => {
  let command = `magerun2 dev:module:observer:list --format=${format}`;

  if (event) {
    command += ` "${event}"`;
  }

  const result = await executeMagerun2Command(command, format === "json");

  if (!result.success) {
    return {
      content: [{
        type: "text",
        text: result.error
      }],
      isError: true
    };
  }

  const responseText = format === "json"
    ? `Observer list (${format} format):\n\n${JSON.stringify(result.data, null, 2)}`
    : `Observer list (${format} format):\n\n${result.data}`;

  return {
    content: [{
      type: "text",
      text: responseText
    }]
  };
}

src/index.ts:443-450 (schema)

Zod input schema for the tool, defining output format and optional event filter.

inputSchema: {
  format: z.enum(["table", "json", "csv"])
    .default("table")
    .describe("Output format"),
  event: z.string()
    .optional()
    .describe("Filter by specific event name")
}

src/index.ts:438-482 (registration)

MCP server tool registration call for 'dev-module-observer-list', including title, description, schema, and inline handler.

server.registerTool(
  "dev-module-observer-list",
  {
    title: "Module Observer List",
    description: "List all Magento 2 module observers",
    inputSchema: {
      format: z.enum(["table", "json", "csv"])
        .default("table")
        .describe("Output format"),
      event: z.string()
        .optional()
        .describe("Filter by specific event name")
    }
  },
  async ({ format = "table", event }) => {
    let command = `magerun2 dev:module:observer:list --format=${format}`;

    if (event) {
      command += ` "${event}"`;
    }

    const result = await executeMagerun2Command(command, format === "json");

    if (!result.success) {
      return {
        content: [{
          type: "text",
          text: result.error
        }],
        isError: true
      };
    }

    const responseText = format === "json"
      ? `Observer list (${format} format):\n\n${JSON.stringify(result.data, null, 2)}`
      : `Observer list (${format} format):\n\n${result.data}`;

    return {
      content: [{
        type: "text",
        text: responseText
      }]
    };
  }
);

src/index.ts:28-88 (helper)

Shared helper function for executing magerun2 CLI commands with timeout, JSON parsing option, Magento-specific error detection, and consistent response format.

async function executeMagerun2Command(command: string, parseJson: boolean = false): Promise<{
  success: true;
  data: any;
  rawOutput: string;
} | {
  success: false;
  error: string;
  isError: true;
}> {
  try {
    const { stdout, stderr } = await execAsync(command, {
      cwd: process.cwd(),
      timeout: 30000 // 30 second timeout
    });

    if (stderr && stderr.trim()) {
      console.error("magerun2 stderr:", stderr);
    }

    if (parseJson) {
      try {
        return { success: true, data: JSON.parse(stdout), rawOutput: stdout };
      } catch (parseError) {
        return {
          success: false,
          error: `Error parsing magerun2 JSON output: ${parseError}\n\nRaw output:\n${stdout}`,
          isError: true
        };
      }
    }

    return { success: true, data: stdout.trim(), rawOutput: stdout };

  } catch (error) {
    const errorMessage = error instanceof Error ? error.message : String(error);

    // Check if magerun2 is not found
    if (errorMessage.includes("command not found") || errorMessage.includes("not recognized")) {
      return {
        success: false,
        error: "Error: magerun2 command not found. Please ensure n98-magerun2 is installed and available in your PATH.\n\nInstallation instructions: https://github.com/netz98/n98-magerun2",
        isError: true
      };
    }

    // Check if not in Magento directory
    if (errorMessage.includes("not a Magento installation") || errorMessage.includes("app/etc/env.php")) {
      return {
        success: false,
        error: "Error: Current directory does not appear to be a Magento 2 installation. Please run this command from your Magento 2 root directory.",
        isError: true
      };
    }

    return {
      success: false,
      error: `Error executing magerun2 command: ${errorMessage}`,
      isError: true
    };
  }
}

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