Delta Air Lines MCP Server

Instructions

Implementation Reference

• src/browser.ts:1227-1299 (handler)

  The main checkIn function that executes the tool logic - navigates to Delta's check-in page, fills in confirmation number and last name, submits the form, and returns the check-in result.

  export async function checkIn(params: {
    confirmationNumber: string;
    lastName: string;
  }): Promise<CheckInResult> {
    const { page } = await initBrowser();
  
    await page.goto(`${DELTA_BASE_URL}/us/en/check-in/overview`, {
      waitUntil: "domcontentloaded",
      timeout: DEFAULT_TIMEOUT,
    });
    await randomDelay(1500, 3000);
  
    try {
      // Fill in confirmation number
      await page.fill(
        'input[name*="confirmation"], input[id*="confirmation"], [data-testid*="confirmation"]',
        params.confirmationNumber,
        { timeout: 10000 }
      );
      await randomDelay(300, 600);
  
      // Fill in last name
      await page.fill(
        'input[name*="lastName"], input[name*="last-name"], input[id*="lastName"], [data-testid*="last-name"]',
        params.lastName,
        { timeout: 5000 }
      );
      await randomDelay(300, 600);
  
      // Submit
      await page.click(
        'button:has-text("Check In"), button[type="submit"], [data-testid*="check-in-btn"]',
        { timeout: 5000 }
      );
      await randomDelay(3000, 6000);
  
      // Check for success
      const success = await page.evaluate(() => {
        const body = document.body.innerText;
        return (
          body.includes("Check-in Complete") ||
          body.includes("Boarding Pass") ||
          body.includes("You're checked in")
        );
      });
  
      if (success) {
        return {
          success: true,
          message: "Check-in successful! Use get_boarding_pass to retrieve your boarding pass.",
          confirmationNumber: params.confirmationNumber,
        };
      }
  
      const errorMsg = await page.evaluate(() => {
        const errorEl = document.querySelector(
          '[class*="error"], [role="alert"], [class*="alert"]'
        );
        return errorEl?.textContent?.trim();
      });
  
      return {
        success: false,
        message: errorMsg || "Check-in could not be completed. Please try again or check in at the airport.",
      };
    } catch (error) {
      const msg = error instanceof Error ? error.message : String(error);
      return {
        success: false,
        message: `Check-in failed: ${msg}. Please try check-in at delta.com or at the airport kiosk.`,
      };
    }
  }

• src/browser.ts:145-150 (schema)

  CheckInResult interface defining the output schema for the check_in tool with success status, message, boarding passes, and confirmation number.

  export interface CheckInResult {
    success: boolean;
    message: string;
    boardingPasses?: BoardingPass[];
    confirmationNumber?: string;
  }

• src/index.ts:279-296 (registration)

  Tool registration defining 'check_in' with its name, description, and inputSchema specifying confirmationNumber and lastName as required parameters.

  {
    name: "check_in",
    description:
      "Complete online check-in for an upcoming Delta flight. Check-in opens 24 hours before departure. Returns boarding pass info on success.",
    inputSchema: {
      type: "object",
      properties: {
        confirmationNumber: {
          type: "string",
          description: "Delta booking confirmation number",
        },
        lastName: {
          type: "string",
          description: "Passenger last name (as it appears on the ticket)",
        },
      },
      required: ["confirmationNumber", "lastName"],
    },

• src/index.ts:722-749 (handler)

  Case handler for 'check_in' tool that extracts confirmationNumber and lastName from args, calls the checkIn function from browser.ts, and returns formatted JSON response.

  case "check_in": {
    const { confirmationNumber, lastName } = args as {
      confirmationNumber: string;
      lastName: string;
    };
  
    const result = await checkIn({ confirmationNumber, lastName });
  
    return {
      content: [
        {
          type: "text",
          text: JSON.stringify(
            {
              success: result.success,
              message: result.message,
              boardingPasses: result.boardingPasses,
              note: result.success
                ? "Check-in complete. Use get_boarding_pass to retrieve your digital boarding pass."
                : undefined,
            },
            null,
            2
          ),
        },
      ],
    };
  }