AWS Cognito MCP Server

Implementation Reference

• index.ts:548-621 (handler)

  The handler function for the 'refresh_session' tool. It retrieves the current Cognito user, gets the current session to extract the refresh token, and calls cognitoUser.refreshSession to obtain new access and ID tokens.

  async ({}) => {
      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;
              }
  
              const refreshToken = _session.getRefreshToken();
              cognitoUser.refreshSession(refreshToken, (err, result) => {
                  if (err) {
                      reject({
                          content: [
                              {
                                  type: "text" as const,
                                  text: `Failed to refresh session: ${err.message}`,
                              },
                              {
                                  type: "text" as const,
                                  text: `Error code: ${(err as any).code || 'Unknown'}`,
                              }
                          ]
                      });
                      return;
                  }
  
                  resolve({
                      content: [
                          {
                              type: "text" as const,
                              text: "Session refreshed successfully",
                          },
                          {
                              type: "text" as const,
                              text: `New Access Token: ${result.getAccessToken().getJwtToken()}`,
                          },
                          {
                              type: "text" as const,
                              text: `New ID Token: ${result.getIdToken().getJwtToken()}`,
                          },
                          {
                              type: "text" as const,
                              text: `Token Expiration: ${new Date(result.getAccessToken().getExpiration() * 1000).toISOString()}`,
                          },
                          {
                              type: "text" as const,
                              text: `Time: ${new Date().toISOString()}`,
                          }
                      ]
                  });
              });
          });
      });
  }

• index.ts:544-622 (registration)

  Registration of the 'refresh_session' tool using server.tool(name, inputSchema, handler).

  server.tool(
      "refresh_session",
      {
      },
      async ({}) => {
          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;
                  }
  
                  const refreshToken = _session.getRefreshToken();
                  cognitoUser.refreshSession(refreshToken, (err, result) => {
                      if (err) {
                          reject({
                              content: [
                                  {
                                      type: "text" as const,
                                      text: `Failed to refresh session: ${err.message}`,
                                  },
                                  {
                                      type: "text" as const,
                                      text: `Error code: ${(err as any).code || 'Unknown'}`,
                                  }
                              ]
                          });
                          return;
                      }
  
                      resolve({
                          content: [
                              {
                                  type: "text" as const,
                                  text: "Session refreshed successfully",
                              },
                              {
                                  type: "text" as const,
                                  text: `New Access Token: ${result.getAccessToken().getJwtToken()}`,
                              },
                              {
                                  type: "text" as const,
                                  text: `New ID Token: ${result.getIdToken().getJwtToken()}`,
                              },
                              {
                                  type: "text" as const,
                                  text: `Token Expiration: ${new Date(result.getAccessToken().getExpiration() * 1000).toISOString()}`,
                              },
                              {
                                  type: "text" as const,
                                  text: `Time: ${new Date().toISOString()}`,
                              }
                          ]
                      });
                  });
              });
          });
      }
  )

• index.ts:546-547 (schema)

  Empty input schema indicating the tool requires no parameters.

  {
  },