diff --git a/README.md b/README.md
index ceba90c230fb1b034202284040e4ee936d4da82e..c81f142f730c2deaf4cf3b12aef84ebbfab9847b 100644
--- a/README.md
+++ b/README.md
@@ -1,92 +1,71 @@
-# TPTP server for technical site
+# TOTP server for technical site
 
+This is a simple back-end server meant to run in a secure enviromnent full with access to the database where users' TOTP secrets are stored.
+The server used HTTP to respond to GET queries. It azzepts two parameters
+- user - here you provide the user identifier as passed form eduTEAMS - this argument is mandatory
+- otp - the one-time time-based code entered by the user, this is optional
 
 
-## Getting started
 
-To make it easy for you to get started with GitLab, here's a list of recommended next steps.
+## Functions and return values
 
-Already a pro? Just edit this README.md and make it your own. Want to make it easy? [Use the template at the bottom](#editing-this-readme)!
+The server return a json-encoded integer:
+ *  -1 - user not found in the database (otp argument not required)
+ *   0 - user exists but there was a missmatch in the code (otp argument required)
+ *   1 - there was a success in verification of the code against the user secret (otp argument required)
+ *   2 - the code has not been provided -  the user has not been verified yet (otp argument not sent)
+ *   3 - the code has not been provided - just confirming that the user is verified (otp argument not sent)
+ *   4 - the code has been used for a second time (otp argument required)
 
-## Add your files
+When a code is verified, its value is written into the database as the "last_code" value to prevent reuse. Also the "verified" value
+is set to 1 (this is an ovekill as only needs to be done on the first succesful verification, but simplefies the code).
+The server reads the user's secret form the database, calculates the corresponding TOTP value and campares to the value provided.
 
-- [ ] [Create](https://docs.gitlab.com/ee/user/project/repository/web_editor.html#create-a-file) or [upload](https://docs.gitlab.com/ee/user/project/repository/web_editor.html#upload-a-file) files
-- [ ] [Add files using the command line](https://docs.gitlab.com/ee/gitlab-basics/add-file.html#add-a-file-using-the-command-line) or push an existing Git repository with the following command:
+The server may also be used to test if users exist in the database and whetehr they have ever successfully entered an TOPT code.
+This function is used by the login interface to determine if the registration needs to be perfored and the first confiramtion OTP
+code is required.
 
-```
-cd existing_repo
-git remote add origin https://gitlab.geant.org/edugain/tptp-server.git
-git branch -M main
-git push -uf origin main
-```
-
-## Integrate with your tools
-
-- [ ] [Set up project integrations](https://gitlab.geant.org/edugain/tptp-server/-/settings/integrations)
-
-## Collaborate with your team
-
-- [ ] [Invite team members and collaborators](https://docs.gitlab.com/ee/user/project/members/)
-- [ ] [Create a new merge request](https://docs.gitlab.com/ee/user/project/merge_requests/creating_merge_requests.html)
-- [ ] [Automatically close issues from merge requests](https://docs.gitlab.com/ee/user/project/issues/managing_issues.html#closing-issues-automatically)
-- [ ] [Enable merge request approvals](https://docs.gitlab.com/ee/user/project/merge_requests/approvals/)
-- [ ] [Automatically merge when pipeline succeeds](https://docs.gitlab.com/ee/user/project/merge_requests/merge_when_pipeline_succeeds.html)
-
-## Test and Deploy
-
-Use the built-in continuous integration in GitLab.
-
-- [ ] [Get started with GitLab CI/CD](https://docs.gitlab.com/ee/ci/quick_start/index.html)
-- [ ] [Analyze your code for known vulnerabilities with Static Application Security Testing(SAST)](https://docs.gitlab.com/ee/user/application_security/sast/)
-- [ ] [Deploy to Kubernetes, Amazon EC2, or Amazon ECS using Auto Deploy](https://docs.gitlab.com/ee/topics/autodevops/requirements.html)
-- [ ] [Use pull-based deployments for improved Kubernetes management](https://docs.gitlab.com/ee/user/clusters/agent/)
-- [ ] [Set up protected environments](https://docs.gitlab.com/ee/ci/environments/protected_environments.html)
-
-***
-
-# Editing this README
+## Installation
 
-When you're ready to make this README your own, just edit this file and use the handy template below (or feel free to structure it however you want - this is just a starting point!). Thank you to [makeareadme.com](https://www.makeareadme.com/) for this template.
+The server works with the **otp** database which is shared with the thechnical site installation.
+You must define user **otp** or whatever you decide to call it (and set in the otp_config.php).
 
-## Suggestions for a good README
-Every project is different, so consider which of these sections apply to yours. The sections used in the template are suggestions for most open source projects. Also keep in mind that while a README can be too long and detailed, too long is better than too short. If you think your README is too long, consider utilizing another form of documentation rather than cutting out information.
 
-## Name
-Choose a self-explaining name for your project.
+### Without Docker
 
-## Description
-Let people know what your project can do specifically. Provide context and add a link to any reference visitors might be unfamiliar with. A list of Features or a Background subsection can also be added here. If there are alternatives to your project, this is a good place to list differentiating factors.
+All you need is a https server with pho and mysql support. The server will need to make outside connections to the database host.
+If you run stuff within secure environment (as you should) you do not need https.
 
-## Badges
-On some READMEs, you may see small images that convey metadata, such as whether or not all the tests are passing for the project. You can use Shields to add some to your README. Many services also have instructions for adding a badge.
 
-## Visuals
-Depending on what you are making, it can be a good idea to include screenshots or even a video (you'll frequently see GIFs rather than actual videos). Tools like ttygif can help, but check out Asciinema for a more sophisticated method.
+When you unpack the code form Git:
 
-## Installation
-Within a particular ecosystem, there may be a common way of installing things, such as using Yarn, NuGet, or Homebrew. However, consider the possibility that whoever is reading your README is a novice and would like more guidance. Listing specific steps helps remove ambiguity and gets people to using your project as quickly as possible. If it only runs in a specific context like a particular programming language version or operating system or has dependencies that have to be installed manually, also add a Requirements subsection.
+- Run composer to pull the TOTP PHP package.
+- Create a directory where you will place server config file and copy **otp_config-template.php** there
+  using a name of your choice; this file contains access details to the OTP database and it must be read by the server,
+  but should not be placed within the web-server directory, in case a problem with your PHP could lead to exposure.
+- In the config directory, copy **config-template.php** to **config.php** and put in the location of the otp_server config file.
+- Configure your httpd server to be able to execute otp_server.php
 
-## Usage
-Use examples liberally, and show the expected output if you can. It's helpful to have inline the smallest example of usage that you can demonstrate, while providing links to more sophisticated examples if they are too long to reasonably include in the README.
+### Using Docker
 
-## Support
-Tell people where they can go to for help. It can be any combination of an issue tracker, a chat room, an email address, etc.
+We suggest that you use **--network host** Docker run option which will allow address
+resolution based on the host machine and standard port 80 for connections.
 
-## Roadmap
-If you have ideas for releases in the future, it is a good idea to list them in the README.
+- You need docker instaled on your host machine
+- If you do not want to use **--network host** option then decide which port will be mapped to your Docker image (say 8080)
+- Download the code from git
+- As root run **aa-t otp_server:latest .**
+- As root run **docker run -d --name otp_server --network host --rm   otp_server:latest**
 
-## Contributing
-State if you are open to contributions and what your requirements are for accepting them.
+## Testing
 
-For people who want to make changes to your project, it's helpful to have some documentation on how to get started. Perhaps there is a script that they should run or some environment variables that they need to set. Make these steps explicit. These instructions could also be useful to your future self.
+From the main technical site run:
 
-You can also document commands to lint the code or run tests. These steps help to ensure high code quality and reduce the likelihood that the changes inadvertently break something. Having instructions for running tests is especially helpful if it requires external setup, such as starting a Selenium server for testing in a browser.
+wget -O otp.out http://otp_server_address/otp_server.php?user=xxx@example.com
 
-## Authors and acknowledgment
-Show your appreciation to those who have contributed to the project.
+or
 
-## License
-For open source projects, say how it is licensed.
+curl -o otp.out http://otp_server_address/otp_server.php?user=xxx@example.com
 
-## Project status
-If you have run out of energy or time for your project, put a note at the top of the README saying that development has slowed down or stopped completely. Someone may choose to fork your project or volunteer to step in as a maintainer or owner, allowing your project to keep going. You can also make an explicit request for maintainers.
+Your otp.out should contain value "-1" which means - the user not found. 
+If this works then you are ready to go.
diff --git a/config/config-template.php b/config/config-template.php
index 5927622f63586cc83212cecf3f7f1b416a915095..d563f976aeb944da4d0273237d8349635195f88a 100644
--- a/config/config-template.php
+++ b/config/config-template.php
@@ -1,4 +1,7 @@
 <?php
+// location of otp_config.php
+//current path corresponds to the settings in the Dockerfile
+// therefore you you are using Docker intall do not change this
 
-define('DB_CONFIG_LOCATION', 'location of otp_config.php');
+define('DB_CONFIG_LOCATION', '/var/otp_server_config/otp_config.php');
 
diff --git a/otp_server.php b/otp_server.php
index d593b2653bd3fb5ae407ee6ba4f569fb94882f4d..23839a9e46637817e4cef73b2095a9a04086792c 100644
--- a/otp_server.php
+++ b/otp_server.php
@@ -18,10 +18,12 @@ require_once('config/config.php');
 require_once(DB_CONFIG_LOCATION);
 use OTPHP\TOTP;
 
-$mysqli = new mysqli(DB_HOST, USER, PASSWORD, OTP_DATABASE);
-if ($mysqli->connect_error) {
-    die("Not connected");
+try {
+    $mysqli = new mysqli(DB_HOST, USER, PASSWORD, DB_DATABASE);
+} catch (Exception $e) {
+    die("Database connection problem\n");
 }
+
 $mysqli->set_charset('utf8');
 $mysqli->query("SET time_zone='+00:00'");
 
diff --git a/otp_server_config/otp_config-template.php b/otp_server_config/otp_config-template.php
index 685d80733fda9be864bd0463a9149b0143050354..99fe5aee0facfd30c5736075cd39f6c60cb9a96a 100644
--- a/otp_server_config/otp_config-template.php
+++ b/otp_server_config/otp_config-template.php
@@ -1,6 +1,14 @@
 <?php
+/*
+ * if you are using Docker then it may have problems with resolving the host name
+ * in this case just use an IP address of DB_HOST
+
+ * Remember that the database host and the database bust match those set in the 
+ * config of the technical site, however the database user must not be the same
+ * access provileges need to be different
+*/
 define('DB_HOST','edugain-db');
-define('DB_DATABASE','edugain');
+define('DB_DATABASE','otp');
 define('USER', 'otp');
 define('PASSWORD', 'xxxx');