AWS Cognito MCP Server

Implementation Reference

• index.ts:464-542 (registration)

  Registers the change_password tool with McpServer, defining input schema and inline handler function that uses AWS Cognito to change the current user's password.

      "change_password",
      {
          oldPassword: z.string(),
          newPassword: z.string(),
      },
      async ({ oldPassword, newPassword }) => {
          return new Promise((resolve, reject) => {
              const cognitoUser = userPool.getCurrentUser();
              if (!cognitoUser) {
                  resolve({
                      content: [
                          {
                              type: "text" as const,
                              text: "No user currently signed in",
                          }
                      ]
                  });
                  return;
              }
  
              cognitoUser.getSession((err: Error | null, _session: CognitoUserSession) => {
                  if (err) {
                      reject({
                          content: [
                              {
                                  type: "text" as const,
                                  text: `Error getting session: ${err.message}`,
                              }
                          ]
                      });
                      return;
                  }
  
                  cognitoUser.changePassword(oldPassword, newPassword, (err, result) => {
                      if (err) {
                          reject({
                              content: [
                                  {
                                      type: "text" as const,
                                      text: `Failed to change password: ${err.message}`,
                                  },
                                  {
                                      type: "text" as const,
                                      text: `Error code: ${(err as any).code || 'Unknown'}`,
                                  },
                                  {
                                      type: "text" as const,
                                      text: `Time: ${new Date().toISOString()}`,
                                  }
                              ]
                          });
                          return;
                      }
  
                      resolve({
                          content: [
                              {
                                  type: "text" as const,
                                  text: "Password changed successfully",
                              },
                              {
                                  type: "text" as const,
                                  text: `Username: ${cognitoUser.getUsername()}`,
                              },
                              {
                                  type: "text" as const,
                                  text: `Result: ${result}`,
                              },
                              {
                                  type: "text" as const,
                                  text: `Time: ${new Date().toISOString()}`,
                              }
                          ]
                      });
                  });
              });
          });
      }
  )

• index.ts:469-541 (handler)

  The core handler logic for the change_password tool. It retrieves the current Cognito user, verifies the session, and invokes changePassword with old and new passwords, handling success and error responses.

  async ({ oldPassword, newPassword }) => {
      return new Promise((resolve, reject) => {
          const cognitoUser = userPool.getCurrentUser();
          if (!cognitoUser) {
              resolve({
                  content: [
                      {
                          type: "text" as const,
                          text: "No user currently signed in",
                      }
                  ]
              });
              return;
          }
  
          cognitoUser.getSession((err: Error | null, _session: CognitoUserSession) => {
              if (err) {
                  reject({
                      content: [
                          {
                              type: "text" as const,
                              text: `Error getting session: ${err.message}`,
                          }
                      ]
                  });
                  return;
              }
  
              cognitoUser.changePassword(oldPassword, newPassword, (err, result) => {
                  if (err) {
                      reject({
                          content: [
                              {
                                  type: "text" as const,
                                  text: `Failed to change password: ${err.message}`,
                              },
                              {
                                  type: "text" as const,
                                  text: `Error code: ${(err as any).code || 'Unknown'}`,
                              },
                              {
                                  type: "text" as const,
                                  text: `Time: ${new Date().toISOString()}`,
                              }
                          ]
                      });
                      return;
                  }
  
                  resolve({
                      content: [
                          {
                              type: "text" as const,
                              text: "Password changed successfully",
                          },
                          {
                              type: "text" as const,
                              text: `Username: ${cognitoUser.getUsername()}`,
                          },
                          {
                              type: "text" as const,
                              text: `Result: ${result}`,
                          },
                          {
                              type: "text" as const,
                              text: `Time: ${new Date().toISOString()}`,
                          }
                      ]
                  });
              });
          });
      });
  }

• index.ts:466-468 (schema)

  Zod schema defining input parameters for the change_password tool: oldPassword and newPassword as strings.

      oldPassword: z.string(),
      newPassword: z.string(),
  },