diff --git a/ORACLE_LINUX_DEPLOYMENT.md b/ORACLE_LINUX_DEPLOYMENT.md
new file mode 100644
index 0000000..df83285
--- /dev/null
+++ b/ORACLE_LINUX_DEPLOYMENT.md
@@ -0,0 +1,721 @@
+# OracleQuant API Deployment Guide
+
+This guide explains how to run **OracleQuant API** on **Oracle Linux VirtualBox** and connect it to an **Oracle Database Free Docker container running on Windows**.
+
+This setup is for a **local development / training deployment**, not public production hosting.
+
+---
+
+## 1. Final Working Setup
+
+| Part | Machine | Value |
+|---|---|---|
+| Oracle Database | Windows Docker | `container-registry.oracle.com/database/free:latest` |
+| Oracle DB Container Name | Windows | `oracle-db` |
+| Oracle DB Port | Windows | `1521` |
+| Oracle DB Service Name | Docker Oracle DB | `FREEPDB1` |
+| Oracle DB Admin User | Docker Oracle DB | `SYSTEM` |
+| Oracle DB Admin Password | Docker Oracle DB | `OracleAdmin7191` |
+| App DB User | Oracle DB | `ORACLEQUANTAPI` |
+| App DB Password | Oracle DB | `StrongPassword123` |
+| Spring Boot JAR | Oracle Linux | `/home/sulaiman/oraclequantapi.jar` |
+| API Port | Oracle Linux | `8080` |
+| Windows IP | Windows Wi-Fi | `172.20.10.2` |
+| Oracle Linux IP | VirtualBox Bridged Adapter | `172.20.10.3` |
+| API Base URL | Browser/Postman | `http://172.20.10.3:8080` |
+
+> Important: Your IPs can change after restarting Wi-Fi, Windows hotspot, or the VM. Always check them again if something stops working.
+
+---
+
+## 2. Where to Run Each Command
+
+| Command Type | Run It In |
+|---|---|
+| `docker ps`, `docker exec`, `docker logs` | Windows CMD |
+| `netsh advfirewall ...` | Windows CMD as Administrator |
+| `java -jar ...` | Oracle Linux terminal |
+| `ip addr` | Oracle Linux terminal |
+| `timeout 5 bash -c ...` | Oracle Linux terminal |
+| SQL commands | Inside `SQL>` prompt |
+| API testing | Windows browser or Postman |
+
+---
+
+## 3. Start Oracle Database on Windows
+
+Open **Windows CMD**.
+
+Check Docker:
+
+```cmd
+docker ps
+```
+
+If the container already exists but is stopped, start it:
+
+```cmd
+docker start oracle-db
+```
+
+If the container does not exist, create it:
+
+```cmd
+docker run -d --name oracle-db -p 1521:1521 -e ORACLE_PWD=OracleAdmin7191 container-registry.oracle.com/database/free:latest
+```
+
+Check that it is running:
+
+```cmd
+docker ps
+```
+
+Expected:
+
+```text
+oracle-db
+0.0.0.0:1521->1521/tcp
+healthy
+```
+
+Check logs:
+
+```cmd
+docker logs -f oracle-db
+```
+
+Wait until the database is ready. When done, press:
+
+```text
+CTRL + C
+```
+
+This only stops viewing logs. It does not stop the database.
+
+---
+
+## 4. Test Oracle Database Inside Docker
+
+Run in **Windows CMD**:
+
+```cmd
+docker exec -it oracle-db sqlplus system/OracleAdmin7191@localhost:1521/FREEPDB1
+```
+
+If connected, you will see:
+
+```sql
+SQL>
+```
+
+Exit:
+
+```sql
+EXIT;
+```
+
+---
+
+## 5. Open Windows Firewall Port 1521
+
+Open **CMD as Administrator**.
+
+Run:
+
+```cmd
+netsh advfirewall firewall add rule name="Oracle DB 1521" dir=in action=allow protocol=TCP localport=1521
+```
+
+Expected:
+
+```text
+Ok.
+```
+
+This allows Oracle Linux to reach the Oracle Database running on Windows Docker.
+
+---
+
+## 6. Configure VirtualBox Network
+
+In **VirtualBox Manager**:
+
+1. Shut down Oracle Linux first:
+
+```bash
+sudo poweroff
+```
+
+2. Select your Oracle Linux VM.
+3. Go to:
+
+```text
+Settings -> Network
+```
+
+4. Adapter 1:
+
+```text
+Attached to: Bridged Adapter
+Name: Intel(R) Dual Band Wireless-AC 3165
+Cable Connected: checked
+```
+
+5. Click **OK**.
+6. Start Oracle Linux again.
+
+---
+
+## 7. Check Oracle Linux IP
+
+Run inside **Oracle Linux**:
+
+```bash
+ip addr
+```
+
+Look for `enp0s3`.
+
+Working example:
+
+```text
+inet 172.20.10.3/28
+```
+
+So your Linux API IP is:
+
+```text
+172.20.10.3
+```
+
+Your Windows IP from `ipconfig` is:
+
+```text
+172.20.10.2
+```
+
+Both must be on the same network:
+
+```text
+Windows:      172.20.10.2
+Oracle Linux: 172.20.10.3
+```
+
+---
+
+## 8. Test Windows Oracle DB Port From Oracle Linux
+
+Run this in **Oracle Linux**:
+
+```bash
+timeout 5 bash -c '</dev/tcp/172.20.10.2/1521' && echo "PORT OPEN" || echo "PORT CLOSED"
+```
+
+Expected:
+
+```text
+PORT OPEN
+```
+
+If it says `PORT CLOSED`, check:
+
+1. Docker container is running on Windows:
+
+```cmd
+docker ps
+```
+
+2. Windows firewall rule exists.
+3. VirtualBox network is set to Bridged Adapter.
+4. Windows IP is still `172.20.10.2`.
+
+---
+
+## 9. Create Oracle App User
+
+Run this in **Windows CMD**:
+
+```cmd
+docker exec -it oracle-db sqlplus system/OracleAdmin7191@localhost:1521/FREEPDB1
+```
+
+Inside `SQL>` run:
+
+```sql
+CREATE USER ORACLEQUANTAPI IDENTIFIED BY "StrongPassword123";
+
+GRANT CREATE SESSION TO ORACLEQUANTAPI;
+GRANT CREATE TABLE TO ORACLEQUANTAPI;
+GRANT CREATE SEQUENCE TO ORACLEQUANTAPI;
+GRANT CREATE VIEW TO ORACLEQUANTAPI;
+GRANT UNLIMITED TABLESPACE TO ORACLEQUANTAPI;
+```
+
+If `CREATE USER` says the user already exists, continue with the grants.
+
+Exit:
+
+```sql
+EXIT;
+```
+
+---
+
+## 10. Create Application Table
+
+Connect as the app user:
+
+```cmd
+docker exec -it oracle-db sqlplus ORACLEQUANTAPI/StrongPassword123@localhost:1521/FREEPDB1
+```
+
+Create the table:
+
+```sql
+CREATE TABLE sequence_history (
+    id RAW(16) PRIMARY KEY,
+    timestamp TIMESTAMP,
+    input VARCHAR2(2000),
+    output VARCHAR2(2000)
+);
+```
+
+If it says table already exists, that is okay.
+
+Check the table:
+
+```sql
+SELECT table_name
+FROM user_tables
+WHERE table_name = 'SEQUENCE_HISTORY';
+```
+
+Expected:
+
+```text
+SEQUENCE_HISTORY
+```
+
+Exit:
+
+```sql
+EXIT;
+```
+
+---
+
+## 11. Copy JAR to Oracle Linux
+
+If the JAR is not already on Oracle Linux, copy it from **Windows CMD or PowerShell**:
+
+```cmd
+scp "C:\Users\Codeline\Documents\GitHub\oraclequantapi\target\oraclequantapi-0.0.1.jar" sulaiman@172.20.10.3:/home/sulaiman/oraclequantapi.jar
+```
+
+Check on Oracle Linux:
+
+```bash
+ls -lh /home/sulaiman/oraclequantapi.jar
+```
+
+---
+
+## 12. Check Java 17 on Oracle Linux
+
+Run:
+
+```bash
+java -version
+```
+
+If Java is missing:
+
+```bash
+sudo dnf install -y java-17-openjdk
+java -version
+```
+
+---
+
+## 13. Run Spring Boot API Manually
+
+Run this in **Oracle Linux**:
+
+```bash
+export SPRING_DATASOURCE_URL='jdbc:oracle:thin:@//172.20.10.2:1521/FREEPDB1'
+export SPRING_DATASOURCE_USERNAME='ORACLEQUANTAPI'
+export SPRING_DATASOURCE_PASSWORD='StrongPassword123'
+export SPRING_DATASOURCE_DRIVER_CLASS_NAME='oracle.jdbc.OracleDriver'
+export SPRING_JPA_HIBERNATE_DDL_AUTO='validate'
+export SPRING_JPA_OPEN_IN_VIEW='false'
+
+java -jar /home/sulaiman/oraclequantapi.jar --server.address=0.0.0.0 --server.port=8080
+```
+
+Successful startup should include something like:
+
+```text
+HikariPool-1 - Added connection
+Tomcat started on port 8080
+Started PackageMeasurementApiApplication
+```
+
+Keep this terminal open while testing.
+
+---
+
+## 14. Open Oracle Linux Firewall Port 8080
+
+In another Oracle Linux terminal:
+
+```bash
+sudo firewall-cmd --permanent --add-port=8080/tcp
+sudo firewall-cmd --reload
+sudo firewall-cmd --list-ports
+```
+
+---
+
+## 15. Test API From Windows
+
+Open browser or Postman on Windows.
+
+Base URL:
+
+```text
+http://172.20.10.3:8080
+```
+
+Test history:
+
+```text
+http://172.20.10.3:8080/history
+```
+
+Test conversion:
+
+```text
+http://172.20.10.3:8080/convert-measurements?input=1kg
+```
+
+---
+
+## 16. Check Saved Data in Oracle Database
+
+Run in **Windows CMD**:
+
+```cmd
+docker exec -it oracle-db sqlplus ORACLEQUANTAPI/StrongPassword123@localhost:1521/FREEPDB1
+```
+
+Inside `SQL>`:
+
+```sql
+SELECT * FROM sequence_history ORDER BY timestamp DESC;
+```
+
+Exit:
+
+```sql
+EXIT;
+```
+
+---
+
+## 17. Run API in Background Temporarily
+
+For quick background testing on Oracle Linux:
+
+```bash
+nohup java -jar /home/sulaiman/oraclequantapi.jar --server.address=0.0.0.0 --server.port=8080 > /home/sulaiman/oraclequantapi.log 2>&1 &
+```
+
+Check logs:
+
+```bash
+tail -f /home/sulaiman/oraclequantapi.log
+```
+
+Stop it:
+
+```bash
+pkill -f oraclequantapi.jar
+```
+
+---
+
+## 18. Run API as a systemd Service
+
+Create environment file:
+
+```bash
+sudo vi /etc/oraclequantapi.env
+```
+
+Paste:
+
+```bash
+SPRING_DATASOURCE_URL=jdbc:oracle:thin:@//172.20.10.2:1521/FREEPDB1
+SPRING_DATASOURCE_USERNAME=ORACLEQUANTAPI
+SPRING_DATASOURCE_PASSWORD=StrongPassword123
+SPRING_DATASOURCE_DRIVER_CLASS_NAME=oracle.jdbc.OracleDriver
+SPRING_JPA_HIBERNATE_DDL_AUTO=validate
+SPRING_JPA_OPEN_IN_VIEW=false
+```
+
+Protect it:
+
+```bash
+sudo chmod 600 /etc/oraclequantapi.env
+```
+
+Create service file:
+
+```bash
+sudo vi /etc/systemd/system/oraclequantapi.service
+```
+
+Paste:
+
+```ini
+[Unit]
+Description=Oracle Quant API
+After=network.target
+
+[Service]
+User=sulaiman
+WorkingDirectory=/home/sulaiman
+EnvironmentFile=/etc/oraclequantapi.env
+ExecStart=/usr/bin/java -jar /home/sulaiman/oraclequantapi.jar --server.address=0.0.0.0 --server.port=8080
+Restart=always
+RestartSec=10
+
+[Install]
+WantedBy=multi-user.target
+```
+
+Start service:
+
+```bash
+sudo systemctl daemon-reload
+sudo systemctl start oraclequantapi
+sudo systemctl enable oraclequantapi
+```
+
+Check status:
+
+```bash
+sudo systemctl status oraclequantapi
+```
+
+View logs:
+
+```bash
+journalctl -u oraclequantapi -f
+```
+
+Restart after replacing JAR:
+
+```bash
+sudo systemctl restart oraclequantapi
+```
+
+Stop service:
+
+```bash
+sudo systemctl stop oraclequantapi
+```
+
+---
+
+## 19. Daily Start Checklist
+
+### On Windows
+
+Start Docker Desktop.
+
+Check Oracle DB:
+
+```cmd
+docker ps
+```
+
+If stopped:
+
+```cmd
+docker start oracle-db
+```
+
+### On Oracle Linux
+
+Check IP:
+
+```bash
+ip addr
+```
+
+Test DB port:
+
+```bash
+timeout 5 bash -c '</dev/tcp/172.20.10.2/1521' && echo "PORT OPEN" || echo "PORT CLOSED"
+```
+
+Start API:
+
+```bash
+sudo systemctl start oraclequantapi
+```
+
+Check API:
+
+```text
+http://172.20.10.3:8080/history
+```
+
+---
+
+## 20. Common Errors and Fixes
+
+### Error: `No such container: oracle-db`
+
+You are running Docker command in Oracle Linux, but the container is on Windows.
+
+Run Docker commands from:
+
+```text
+C:\Users\Codeline>
+```
+
+Not from:
+
+```text
+[sulaiman@localhost ~]$
+```
+
+---
+
+### Error: `NoRouteToHostException`
+
+Linux cannot reach Windows DB port.
+
+Fix:
+
+1. Use Bridged Adapter in VirtualBox.
+2. Make sure Windows and Linux are on same network.
+3. Open Windows firewall port `1521`.
+4. Test:
+
+```bash
+timeout 5 bash -c '</dev/tcp/172.20.10.2/1521' && echo "PORT OPEN" || echo "PORT CLOSED"
+```
+
+---
+
+### Error: `Unknown host specified.: WINDOWS_IP`
+
+You copied the placeholder `WINDOWS_IP`.
+
+Wrong:
+
+```text
+jdbc:oracle:thin:@//WINDOWS_IP:1521/FREEPDB1
+```
+
+Correct:
+
+```text
+jdbc:oracle:thin:@//172.20.10.2:1521/FREEPDB1
+```
+
+---
+
+### Error: `Schema-validation: missing table [sequence_history]`
+
+The API connected to DB, but the table does not exist.
+
+Create it:
+
+```sql
+CREATE TABLE sequence_history (
+    id RAW(16) PRIMARY KEY,
+    timestamp TIMESTAMP,
+    input VARCHAR2(2000),
+    output VARCHAR2(2000)
+);
+```
+
+---
+
+### Error: `New-NetFirewallRule is not recognized`
+
+You ran a PowerShell command in CMD.
+
+Either open PowerShell as Administrator, or use CMD as Administrator:
+
+```cmd
+netsh advfirewall firewall add rule name="Oracle DB 1521" dir=in action=allow protocol=TCP localport=1521
+```
+
+---
+
+### Error: API not opening from Windows browser
+
+Check if app is listening:
+
+```bash
+sudo ss -lntp | grep 8080
+```
+
+Open Linux firewall:
+
+```bash
+sudo firewall-cmd --permanent --add-port=8080/tcp
+sudo firewall-cmd --reload
+```
+
+Make sure app is started with:
+
+```text
+--server.address=0.0.0.0
+```
+
+---
+
+## 21. Important Notes
+
+- This setup is local only.
+- Do not expose these passwords publicly.
+- For real production, change all passwords.
+- Windows IP or Linux IP may change after restart.
+- If IP changes, update:
+    - `SPRING_DATASOURCE_URL`
+    - API test URL
+    - `/etc/oraclequantapi.env` if using systemd
+
+---
+
+## 22. Final Working URLs
+
+API base:
+
+```text
+http://172.20.10.3:8080
+```
+
+History endpoint:
+
+```text
+http://172.20.10.3:8080/history
+```
+
+Convert endpoint:
+
+```text
+http://172.20.10.3:8080/convert-measurements?input=za
+```
+
+Oracle JDBC URL used by Spring Boot:
+
+```text
+jdbc:oracle:thin:@//172.20.10.2:1521/FREEPDB1
+```
diff --git a/README.md b/README.md
index b1cccfd..32b7b62 100644
--- a/README.md
+++ b/README.md
@@ -1,61 +1,356 @@
-## Submission Instructions
-
-To submit your Oracle JAVA Spring Boot Maven project as a solution, please follow these steps:
-
-### Step 1: Install git on your PC
-- Install "git" as shown in this tutorial: [How to install git](https://youtu.be/iYkLrXobBbA?si=_l0haibv_X9NpIjJ)
-- Open command prompt and run
-  ```bash
-  git version
-  ```
-- If you see the version, then git is successfully installed.
-
-### Step 2: Fork the Repository
-- Navigate to [this repository](https://github.com/CodelineAtyab/oraclequantapi) provided by Codeline.
-- Click on the "Fork" button at the top-right corner of the page to create a copy of the repository under your own GitHub account.
-
-### Step 3: Clone the Forked Repository
-- Open your terminal or command prompt.
-- Clone the forked repository to your local machine using the following command:
-  ```bash
-  git clone https://github.com/your-username/repo-name.git
-  ```
-
-### Step 4: Create a new branch
-- Navigate to the cloned repository directory
-  ```bash
-  cd repo-name
-  ```
-- Create a new branch for your code submissions (Replace your-name with your name in your-name-submission-branch):
-  ```bash
-  git checkout -b your-name-submission-branch
-  ```
-
-
-### Step 5: Add Your Code
-- Implement the API
-
-### Step 6: Commit your changes
-- Run the following commands in order to commit your changes:
-  ```bash
-  git add *
-  git commit -m "Meaningful commit message here"
-  ```
-
-### Step 7: Push Your Branch to GitHub
-- Run the following commands to upload the changes to the forked github repository (Replace your-name with your name in your-name-submission-branch):
-  ```bash
-  git push origin your-name-submission-branch
-  ```
-
-### Step 8: Create a Pull Request
-- Go to your forked repository on GitHub.
-- You should see a prompt to create a pull request. Click on "Compare & pull request".
-- Provide a title and description for your pull request, then click "Create pull request".
-
-### Step 9: Notify Codeline
-- Notify on slack that you have created a PR for your solution.
-
-## Note: If you face any issues in the process above, Please do the following:
-- Watch [this youtube tutorial](https://www.youtube.com/watch?v=a_FLqX3vGR4)
-- Contact Ikhlas or Atyab.
+# OracleQuant ERP - Package Measurement Conversion API
+
+Spring Boot API for converting encoded package measurement strings into total measured inflows per package.
+
+## Requirements
+
+- Oracle OpenJDK 17
+- Maven wrapper included in this repository
+- Oracle XE Database for production/runtime persistence
+
+## Build And Test
+
+```powershell
+.\mvnw.cmd test
+.\mvnw.cmd package
+```
+
+The runnable artifact is created at:
+
+```text
+target/pkc-api.jar
+```
+
+## Oracle XE Configuration
+
+The application reads database settings from environment variables:
+
+```bash
+export PKC_DB_URL="jdbc:oracle:thin:@localhost:1521/XEPDB1"
+export PKC_DB_USERNAME="pkc_user"
+export PKC_DB_PASSWORD="pkc_password"
+export PKC_JPA_DDL_AUTO="update"
+```
+
+Create the Oracle user before running the application:
+
+```sql
+CREATE USER pkc_user IDENTIFIED BY pkc_password;
+GRANT CONNECT, RESOURCE TO pkc_user;
+ALTER USER pkc_user QUOTA UNLIMITED ON USERS;
+```
+
+## Run Locally
+
+For quick local Postman testing without Oracle XE, run the application with the `local` profile. This uses an in-memory H2 database:
+
+```powershell
+.\mvnw.cmd spring-boot:run "-Dspring-boot.run.profiles=local"
+```
+
+Or run the packaged jar with the local profile:
+
+```powershell
+.\mvnw.cmd package
+java -jar target/pkc-api.jar --spring.profiles.active=local
+```
+
+Use the default profile when Oracle XE is running and you want history persisted in Oracle:
+
+```powershell
+$env:PKC_DB_URL="jdbc:oracle:thin:@localhost:1521/XEPDB1"
+$env:PKC_DB_USERNAME="pkc_user"
+$env:PKC_DB_PASSWORD="pkc_password"
+.\mvnw.cmd spring-boot:run
+```
+
+Or run the packaged jar with Oracle:
+
+```bash
+java -jar target/pkc-api.jar
+```
+
+The API listens on `http://localhost:8080` by default. Override with `SERVER_PORT`.
+
+## Conversion API
+
+`GET /convert-measurements?input={encoded-input}`
+
+Examples:
+
+```bash
+curl "http://localhost:8080/convert-measurements?input=aa"
+# [1]
+
+curl "http://localhost:8080/convert-measurements?input=abbcc"
+# [2,6]
+
+curl "http://localhost:8080/convert-measurements?input=dz_a_aazzaaa"
+# [28,53,1]
+```
+
+Encoding rules:
+
+- `a` through `z` represent `1` through `26`.
+- Numbers higher than `26` start with one or more `z` characters and end at the first non-`z` character.
+- Non-letter characters such as `_` contribute `0` and can terminate a multi-character number.
+- Each package starts with a count, followed by that many measured values. The response contains the sum for each package.
+
+## Postman Test Cases
+
+Start the application first. If Oracle XE is not running locally, use:
+
+```powershell
+.\mvnw.cmd spring-boot:run "-Dspring-boot.run.profiles=local"
+```
+
+Create a Postman environment variable:
+
+```text
+base_url = http://localhost:8080
+```
+
+Before testing history, clear old records:
+
+```text
+DELETE {{base_url}}/history
+```
+
+### Conversion Tests
+
+For each row, create a `GET` request and verify the response body exactly matches the expected JSON array.
+
+| Case | Method | URL | Expected status | Expected body |
+| --- | --- | --- | --- | --- |
+| 1 | GET | `{{base_url}}/convert-measurements?input=aa` | `200 OK` | `[1]` |
+| 2 | GET | `{{base_url}}/convert-measurements?input=abbcc` | `200 OK` | `[2,6]` |
+| 3 | GET | `{{base_url}}/convert-measurements?input=dz_a_aazzaaa` | `200 OK` | `[28,53,1]` |
+| 4 | GET | `{{base_url}}/convert-measurements?input=a_` | `200 OK` | `[0]` |
+| 5 | GET | `{{base_url}}/convert-measurements?input=abcdabcdab` | `200 OK` | `[2,7,7]` |
+| 6 | GET | `{{base_url}}/convert-measurements?input=abcdabcdab_` | `200 OK` | `[2,7,7,0]` |
+| 7 | GET | `{{base_url}}/convert-measurements?input=zdaaaaaaaabaaaaaaaabaaaaaaaabbaa` | `200 OK` | `[34]` |
+| 8 | GET | `{{base_url}}/convert-measurements?input=za_a_a_a_a_a_a_a_a_a_a_a_a_azaaa` | `200 OK` | `[40,1]` |
+
+Use this Postman `Tests` script for each conversion request. Change `expected` for each case:
+
+```javascript
+const expected = [1];
+
+pm.test("status is 200", function () {
+    pm.response.to.have.status(200);
+});
+
+pm.test("response is expected JSON array", function () {
+    pm.expect(pm.response.json()).to.eql(expected);
+});
+```
+
+Example for case 3:
+
+```javascript
+const expected = [28, 53, 1];
+
+pm.test("status is 200", function () {
+    pm.response.to.have.status(200);
+});
+
+pm.test("response is expected JSON array", function () {
+    pm.expect(pm.response.json()).to.eql(expected);
+});
+```
+
+### History Tests In Postman
+
+After running any conversion request, the API saves a history record.
+
+#### Get All History
+
+```text
+GET {{base_url}}/history
+```
+
+Expected:
+
+```json
+[
+  {
+    "id": "550e8400-e29b-41d4-a716-446655440000",
+    "timestamp": "2026-05-20T11:00:00.000000",
+    "input": "aa",
+    "output": "[1]"
+  }
+]
+```
+
+Postman `Tests` script:
+
+```javascript
+pm.test("status is 200", function () {
+    pm.response.to.have.status(200);
+});
+
+pm.test("history contains required fields", function () {
+    const records = pm.response.json();
+    pm.expect(records.length).to.be.above(0);
+
+    const record = records[0];
+    pm.expect(record).to.have.property("id");
+    pm.expect(record).to.have.property("timestamp");
+    pm.expect(record).to.have.property("input");
+    pm.expect(record).to.have.property("output");
+
+    pm.collectionVariables.set("history_id", record.id);
+});
+```
+
+#### Get One History Record
+
+```text
+GET {{base_url}}/history/{{history_id}}
+```
+
+Postman `Tests` script:
+
+```javascript
+pm.test("status is 200", function () {
+    pm.response.to.have.status(200);
+});
+
+pm.test("history record id matches", function () {
+    const record = pm.response.json();
+    pm.expect(record.id).to.eql(pm.collectionVariables.get("history_id"));
+});
+```
+
+#### Update History Record
+
+```text
+PATCH {{base_url}}/history/{{history_id}}
+Content-Type: application/json
+```
+
+Body:
+
+```json
+{
+  "input": "a_",
+  "output": "[0]"
+}
+```
+
+Postman `Tests` script:
+
+```javascript
+pm.test("status is 200", function () {
+    pm.response.to.have.status(200);
+});
+
+pm.test("history record was updated", function () {
+    const record = pm.response.json();
+    pm.expect(record.input).to.eql("a_");
+    pm.expect(record.output).to.eql("[0]");
+});
+```
+
+#### Clear History
+
+```text
+DELETE {{base_url}}/history
+```
+
+Postman `Tests` script:
+
+```javascript
+pm.test("status is 200", function () {
+    pm.response.to.have.status(200);
+});
+```
+
+Then confirm history is empty:
+
+```text
+GET {{base_url}}/history
+```
+
+Expected body:
+
+```json
+[]
+```
+
+## History API
+
+History records contain `id`, `timestamp`, `input`, and `output`.
+
+```bash
+curl "http://localhost:8080/history"
+curl "http://localhost:8080/history/550e8400-e29b-41d4-a716-446655440000"
+
+curl -X PATCH "http://localhost:8080/history/550e8400-e29b-41d4-a716-446655440000" \
+  -H "Content-Type: application/json" \
+  -d '{"input":"a_","output":"[0]"}'
+
+curl -X PUT "http://localhost:8080/history/550e8400-e29b-41d4-a716-446655440000" \
+  -H "Content-Type: application/json" \
+  -d '{"input":"aa","output":"[1]"}'
+
+curl -X DELETE "http://localhost:8080/history"
+```
+
+## Logging
+
+Logs are written to the console and to rolling files under `logs/`.
+The application keeps seven days of compressed log files.
+
+## Deploy On Oracle Linux Via SSH
+
+Build the jar locally:
+
+```powershell
+.\mvnw.cmd package
+```
+
+Copy it to the Oracle Linux host:
+
+```bash
+scp target/pkc-api.jar opc@YOUR_HOST:/home/opc/pkc-api.jar
+```
+
+SSH into the host and run it:
+
+```bash
+ssh opc@YOUR_HOST
+export PKC_DB_URL="jdbc:oracle:thin:@localhost:1521/XEPDB1"
+export PKC_DB_USERNAME="pkc_user"
+export PKC_DB_PASSWORD="pkc_password"
+java -jar /home/opc/pkc-api.jar
+```
+
+For a long-running service, create `/etc/systemd/system/pkc-api.service`:
+
+```ini
+[Unit]
+Description=OracleQuant Package Measurement Conversion API
+After=network.target
+
+[Service]
+User=opc
+Environment=PKC_DB_URL=jdbc:oracle:thin:@localhost:1521/XEPDB1
+Environment=PKC_DB_USERNAME=pkc_user
+Environment=PKC_DB_PASSWORD=pkc_password
+ExecStart=/usr/bin/java -jar /home/opc/pkc-api.jar
+Restart=always
+RestartSec=5
+
+[Install]
+WantedBy=multi-user.target
+```
+
+Enable and start:
+
+```bash
+sudo systemctl daemon-reload
+sudo systemctl enable pkc-api
+sudo systemctl start pkc-api
+sudo systemctl status pkc-api
+```
diff --git a/pom.xml b/pom.xml
index 20909d2..426ecb6 100644
--- a/pom.xml
+++ b/pom.xml
@@ -10,7 +10,7 @@
 	</parent>
 	<groupId>com.oraclequantapi</groupId>
 	<artifactId>oraclequantapi</artifactId>
-	<version>0.0.1-SNAPSHOT</version>
+	<version>0.0.1</version>
 	<name/>
 	<description/>
 	<url/>
@@ -35,6 +35,23 @@
 			<artifactId>spring-boot-starter-web</artifactId>
 		</dependency>
 
+		<dependency>
+			<groupId>org.springframework.boot</groupId>
+			<artifactId>spring-boot-starter-data-jpa</artifactId>
+		</dependency>
+
+		<dependency>
+			<groupId>com.h2database</groupId>
+			<artifactId>h2</artifactId>
+			<scope>runtime</scope>
+		</dependency>
+
+		<dependency>
+			<groupId>com.oracle.database.jdbc</groupId>
+			<artifactId>ojdbc11</artifactId>
+			<scope>runtime</scope>
+		</dependency>
+
 		<dependency>
 			<groupId>org.springframework.boot</groupId>
 			<artifactId>spring-boot-starter-test</artifactId>
diff --git a/src/main/java/com/example/pkc_api/PackageMeasurementApiApplication.java b/src/main/java/com/example/pkc_api/PackageMeasurementApiApplication.java
new file mode 100644
index 0000000..acc1c39
--- /dev/null
+++ b/src/main/java/com/example/pkc_api/PackageMeasurementApiApplication.java
@@ -0,0 +1,12 @@
+package com.example.pkc_api;
+
+import org.springframework.boot.SpringApplication;
+import org.springframework.boot.autoconfigure.SpringBootApplication;
+
+@SpringBootApplication
+public class PackageMeasurementApiApplication {
+
+    public static void main(String[] args) {
+        SpringApplication.run(PackageMeasurementApiApplication.class, args);
+    }
+}
diff --git a/src/main/java/com/example/pkc_api/config/CorsConfig.java b/src/main/java/com/example/pkc_api/config/CorsConfig.java
new file mode 100644
index 0000000..c98cfb0
--- /dev/null
+++ b/src/main/java/com/example/pkc_api/config/CorsConfig.java
@@ -0,0 +1,17 @@
+package com.example.pkc_api.config;
+
+import org.springframework.context.annotation.Configuration;
+import org.springframework.web.servlet.config.annotation.CorsRegistry;
+import org.springframework.web.servlet.config.annotation.WebMvcConfigurer;
+
+@Configuration
+public class CorsConfig implements WebMvcConfigurer {
+
+    @Override
+    public void addCorsMappings(CorsRegistry registry) {
+        registry.addMapping("/**")
+                .allowedOrigins("*") // TODO: Restrict this for production.
+                .allowedMethods("GET", "POST", "PUT", "PATCH", "DELETE", "OPTIONS")
+                .allowedHeaders("*");
+    }
+}
diff --git a/src/main/java/com/example/pkc_api/controller/HistoryController.java b/src/main/java/com/example/pkc_api/controller/HistoryController.java
new file mode 100644
index 0000000..bd202f8
--- /dev/null
+++ b/src/main/java/com/example/pkc_api/controller/HistoryController.java
@@ -0,0 +1,53 @@
+package com.example.pkc_api.controller;
+
+
+import com.example.pkc_api.dto.UpdateHistoryRequest;
+import com.example.pkc_api.entity.SequenceHistory;
+import com.example.pkc_api.service.HistoryService;
+import org.springframework.web.bind.annotation.*;
+
+import java.util.List;
+import java.util.UUID;
+
+@RestController
+@RequestMapping("/history")
+public class HistoryController {
+
+    private final HistoryService historyService;
+
+    public HistoryController(HistoryService historyService) {
+        this.historyService = historyService;
+    }
+
+    @GetMapping
+    public List<SequenceHistory> getAllHistory() {
+        return historyService.getAllHistory();
+    }
+
+    @GetMapping("/{id}")
+    public SequenceHistory getHistoryById(@PathVariable UUID id) {
+        return historyService.getHistoryById(id);
+    }
+
+    @PatchMapping("/{id}")
+    public SequenceHistory updateHistory(
+            @PathVariable UUID id,
+            @RequestBody UpdateHistoryRequest request
+    ) {
+        return historyService.updateHistory(id, request);
+    }
+
+    @PutMapping("/{id}")
+    public SequenceHistory replaceHistory(
+            @PathVariable UUID id,
+            @RequestBody UpdateHistoryRequest request
+    ) {
+        return historyService.updateHistory(id, request);
+    }
+
+    @DeleteMapping
+    public String clearHistory() {
+        historyService.clearHistory();
+        return "History cleared successfully.";
+    }
+}
diff --git a/src/main/java/com/example/pkc_api/controller/MeasurementController.java b/src/main/java/com/example/pkc_api/controller/MeasurementController.java
new file mode 100644
index 0000000..fce1af6
--- /dev/null
+++ b/src/main/java/com/example/pkc_api/controller/MeasurementController.java
@@ -0,0 +1,38 @@
+package com.example.pkc_api.controller;
+
+
+import com.example.pkc_api.service.HistoryService;
+import com.example.pkc_api.service.MeasurementConverter;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.RestController;
+
+import java.util.List;
+
+@RestController
+public class MeasurementController {
+
+    private static final Logger log = LoggerFactory.getLogger(MeasurementController.class);
+
+    private final MeasurementConverter measurementConverter;
+    private final HistoryService historyService;
+
+    public MeasurementController(MeasurementConverter measurementConverter, HistoryService historyService) {
+        this.measurementConverter = measurementConverter;
+        this.historyService = historyService;
+    }
+
+    @GetMapping("/convert-measurements")
+    public List<Integer> convertMeasurements(
+            @RequestParam String input
+    ) {
+        List<Integer> output = measurementConverter.convertMeasurements(input);
+
+        historyService.saveHistory(input, output.toString());
+        log.info("Converted measurement inputLength={} output={}", input.length(), output);
+
+        return output;
+    }
+}
diff --git a/src/main/java/com/example/pkc_api/dto/UpdateHistoryRequest.java b/src/main/java/com/example/pkc_api/dto/UpdateHistoryRequest.java
new file mode 100644
index 0000000..b9f4c51
--- /dev/null
+++ b/src/main/java/com/example/pkc_api/dto/UpdateHistoryRequest.java
@@ -0,0 +1,23 @@
+package com.example.pkc_api.dto;
+
+public class UpdateHistoryRequest {
+
+    private String input;
+    private String output;
+
+    public String getInput() {
+        return input;
+    }
+
+    public String getOutput() {
+        return output;
+    }
+
+    public void setInput(String input) {
+        this.input = input;
+    }
+
+    public void setOutput(String output) {
+        this.output = output;
+    }
+}
diff --git a/src/main/java/com/example/pkc_api/entity/SequenceHistory.java b/src/main/java/com/example/pkc_api/entity/SequenceHistory.java
new file mode 100644
index 0000000..014735b
--- /dev/null
+++ b/src/main/java/com/example/pkc_api/entity/SequenceHistory.java
@@ -0,0 +1,65 @@
+package com.example.pkc_api.entity;
+
+
+import jakarta.persistence.Column;
+import jakarta.persistence.Entity;
+import jakarta.persistence.Id;
+import jakarta.persistence.Table;
+
+import java.time.LocalDateTime;
+import java.util.UUID;
+
+@Entity
+@Table(name = "sequence_history")
+@SuppressWarnings("unused")
+public class SequenceHistory {
+
+    @Id
+    @Column(nullable = false, updatable = false)
+    private UUID id = UUID.randomUUID();
+
+    private LocalDateTime timestamp;
+
+    @Column(length = 2000)
+    private String input;
+
+    @Column(length = 2000)
+    private String output;
+
+    public SequenceHistory() {
+    }
+
+    public SequenceHistory(LocalDateTime timestamp, String input, String output) {
+        this.timestamp = timestamp;
+        this.input = input;
+        this.output = output;
+    }
+
+    public UUID getId() {
+        return id;
+    }
+
+    public LocalDateTime getTimestamp() {
+        return timestamp;
+    }
+
+    public String getInput() {
+        return input;
+    }
+
+    public String getOutput() {
+        return output;
+    }
+
+    public void setTimestamp(LocalDateTime timestamp) {
+        this.timestamp = timestamp;
+    }
+
+    public void setInput(String input) {
+        this.input = input;
+    }
+
+    public void setOutput(String output) {
+        this.output = output;
+    }
+}
diff --git a/src/main/java/com/example/pkc_api/exception/HistoryRecordNotFoundException.java b/src/main/java/com/example/pkc_api/exception/HistoryRecordNotFoundException.java
new file mode 100644
index 0000000..899dbbe
--- /dev/null
+++ b/src/main/java/com/example/pkc_api/exception/HistoryRecordNotFoundException.java
@@ -0,0 +1,14 @@
+package com.example.pkc_api.exception;
+
+import org.springframework.http.HttpStatus;
+import org.springframework.web.bind.annotation.ResponseStatus;
+
+import java.util.UUID;
+
+@ResponseStatus(HttpStatus.NOT_FOUND)
+public class HistoryRecordNotFoundException extends RuntimeException {
+
+    public HistoryRecordNotFoundException(UUID id) {
+        super("History record not found with id: " + id);
+    }
+}
diff --git a/src/main/java/com/example/pkc_api/parser/EncodedNumberParser.java b/src/main/java/com/example/pkc_api/parser/EncodedNumberParser.java
new file mode 100644
index 0000000..f3ffbf8
--- /dev/null
+++ b/src/main/java/com/example/pkc_api/parser/EncodedNumberParser.java
@@ -0,0 +1,53 @@
+package com.example.pkc_api.parser;
+
+import org.springframework.stereotype.Component;
+
+@Component
+public class EncodedNumberParser implements NumberParser {
+
+    @Override
+    public ParsedNumber parse(String input, int startIndex) {
+        if (input == null || startIndex >= input.length()) {
+            return new ParsedNumber(0, startIndex);
+        }
+
+        char current = input.charAt(startIndex);
+
+        if (isContinuationCharacter(current)) {
+            return parseMultiCharacterNumber(input, startIndex);
+        }
+
+        int value = getCharacterValue(current);
+        return new ParsedNumber(value, startIndex + 1);
+    }
+
+    private ParsedNumber parseMultiCharacterNumber(String input, int index) {
+        int total = 0;
+
+        while (index < input.length() && isContinuationCharacter(input.charAt(index))) {
+            total += 26;
+            index++;
+        }
+
+        if (index < input.length()) {
+            total += getCharacterValue(input.charAt(index));
+            index++;
+        }
+
+        return new ParsedNumber(total, index);
+    }
+
+    private int getCharacterValue(char character) {
+        character = Character.toLowerCase(character);
+
+        if (character >= 'a' && character <= 'z') {
+            return character - 'a' + 1;
+        }
+
+        return 0;
+    }
+
+    private boolean isContinuationCharacter(char character) {
+        return Character.toLowerCase(character) == 'z';
+    }
+}
diff --git a/src/main/java/com/example/pkc_api/parser/NumberParser.java b/src/main/java/com/example/pkc_api/parser/NumberParser.java
new file mode 100644
index 0000000..451a6e0
--- /dev/null
+++ b/src/main/java/com/example/pkc_api/parser/NumberParser.java
@@ -0,0 +1,6 @@
+package com.example.pkc_api.parser;
+
+public interface NumberParser {
+
+    ParsedNumber parse(String input, int startIndex);
+}
diff --git a/src/main/java/com/example/pkc_api/parser/ParsedNumber.java b/src/main/java/com/example/pkc_api/parser/ParsedNumber.java
new file mode 100644
index 0000000..75e96a1
--- /dev/null
+++ b/src/main/java/com/example/pkc_api/parser/ParsedNumber.java
@@ -0,0 +1,20 @@
+package com.example.pkc_api.parser;
+
+public class ParsedNumber {
+
+    private final int value;
+    private final int nextIndex;
+
+    public ParsedNumber(int value, int nextIndex) {
+        this.value = value;
+        this.nextIndex = nextIndex;
+    }
+
+    public int getValue() {
+        return value;
+    }
+
+    public int getNextIndex() {
+        return nextIndex;
+    }
+}
\ No newline at end of file
diff --git a/src/main/java/com/example/pkc_api/repository/SequenceHistoryRepository.java b/src/main/java/com/example/pkc_api/repository/SequenceHistoryRepository.java
new file mode 100644
index 0000000..11292b0
--- /dev/null
+++ b/src/main/java/com/example/pkc_api/repository/SequenceHistoryRepository.java
@@ -0,0 +1,10 @@
+package com.example.pkc_api.repository;
+
+
+import com.example.pkc_api.entity.SequenceHistory;
+import org.springframework.data.jpa.repository.JpaRepository;
+
+import java.util.UUID;
+
+public interface SequenceHistoryRepository extends JpaRepository<SequenceHistory, UUID> {
+}
diff --git a/src/main/java/com/example/pkc_api/service/HistoryService.java b/src/main/java/com/example/pkc_api/service/HistoryService.java
new file mode 100644
index 0000000..f1a0a68
--- /dev/null
+++ b/src/main/java/com/example/pkc_api/service/HistoryService.java
@@ -0,0 +1,69 @@
+package com.example.pkc_api.service;
+
+
+import com.example.pkc_api.dto.UpdateHistoryRequest;
+import com.example.pkc_api.entity.SequenceHistory;
+import com.example.pkc_api.exception.HistoryRecordNotFoundException;
+import com.example.pkc_api.repository.SequenceHistoryRepository;
+import org.slf4j.Logger;
+import org.slf4j.LoggerFactory;
+import org.springframework.data.domain.Sort;
+import org.springframework.stereotype.Service;
+
+import java.time.LocalDateTime;
+import java.util.List;
+import java.util.UUID;
+
+@Service
+public class HistoryService {
+
+    private static final Logger log = LoggerFactory.getLogger(HistoryService.class);
+
+    private final SequenceHistoryRepository historyRepository;
+
+    public HistoryService(SequenceHistoryRepository historyRepository) {
+        this.historyRepository = historyRepository;
+    }
+
+    public SequenceHistory saveHistory(String input, String output) {
+        SequenceHistory history = new SequenceHistory(
+                LocalDateTime.now(),
+                input,
+                output
+        );
+
+        SequenceHistory savedHistory = historyRepository.save(history);
+        log.info("Saved history record id={}", savedHistory.getId());
+        return savedHistory;
+    }
+
+    public List<SequenceHistory> getAllHistory() {
+        return historyRepository.findAll(Sort.by(Sort.Direction.ASC, "id"));
+    }
+
+    public SequenceHistory getHistoryById(UUID id) {
+        return historyRepository.findById(id)
+                .orElseThrow(() -> new HistoryRecordNotFoundException(id));
+    }
+
+    public SequenceHistory updateHistory(UUID id, UpdateHistoryRequest request) {
+        SequenceHistory history = getHistoryById(id);
+
+        if (request.getInput() != null) {
+            history.setInput(request.getInput());
+        }
+
+        if (request.getOutput() != null) {
+            history.setOutput(request.getOutput());
+        }
+
+        SequenceHistory savedHistory = historyRepository.save(history);
+        log.info("Updated history record id={}", id);
+        return savedHistory;
+    }
+
+    public void clearHistory() {
+        historyRepository.deleteAll();
+        log.info("Cleared all history records");
+    }
+}
diff --git a/src/main/java/com/example/pkc_api/service/MeasurementConverter.java b/src/main/java/com/example/pkc_api/service/MeasurementConverter.java
new file mode 100644
index 0000000..1a0f37b
--- /dev/null
+++ b/src/main/java/com/example/pkc_api/service/MeasurementConverter.java
@@ -0,0 +1,8 @@
+package com.example.pkc_api.service;
+
+import java.util.List;
+
+public interface MeasurementConverter {
+
+    List<Integer> convertMeasurements(String input);
+}
diff --git a/src/main/java/com/example/pkc_api/service/SequenceService.java b/src/main/java/com/example/pkc_api/service/SequenceService.java
new file mode 100644
index 0000000..74f3657
--- /dev/null
+++ b/src/main/java/com/example/pkc_api/service/SequenceService.java
@@ -0,0 +1,54 @@
+package com.example.pkc_api.service;
+
+
+import com.example.pkc_api.parser.NumberParser;
+import com.example.pkc_api.parser.ParsedNumber;
+import org.springframework.stereotype.Service;
+
+import java.util.ArrayList;
+import java.util.List;
+
+@Service
+public class SequenceService implements MeasurementConverter {
+
+    private final NumberParser numberParser;
+
+    public SequenceService(NumberParser numberParser) {
+        this.numberParser = numberParser;
+    }
+
+    @Override
+    public List<Integer> convertMeasurements(String input) {
+        List<Integer> result = new ArrayList<>();
+
+        if (input == null || input.isEmpty()) {
+            return result;
+        }
+
+        int index = 0;
+
+        while (index < input.length()) {
+            ParsedNumber countNumber = numberParser.parse(input, index);
+
+            int count = countNumber.getValue();
+            index = countNumber.getNextIndex();
+
+            int packageTotal = 0;
+
+            for (int i = 0; i < count; i++) {
+                if (index >= input.length()) {
+                    break;
+                }
+
+                ParsedNumber measurementNumber = numberParser.parse(input, index);
+
+                packageTotal += measurementNumber.getValue();
+                index = measurementNumber.getNextIndex();
+            }
+
+            result.add(packageTotal);
+        }
+
+        return result;
+    }
+}
diff --git a/src/main/java/com/oraclequantapi/oraclequantapi/OraclequantapiApplication.java b/src/main/java/com/oraclequantapi/oraclequantapi/OraclequantapiApplication.java
deleted file mode 100644
index 5e28689..0000000
--- a/src/main/java/com/oraclequantapi/oraclequantapi/OraclequantapiApplication.java
+++ /dev/null
@@ -1,13 +0,0 @@
-package com.oraclequantapi.oraclequantapi;
-
-import org.springframework.boot.SpringApplication;
-import org.springframework.boot.autoconfigure.SpringBootApplication;
-
-@SpringBootApplication
-public class OraclequantapiApplication {
-
-	public static void main(String[] args) {
-		SpringApplication.run(OraclequantapiApplication.class, args);
-	}
-
-}
diff --git a/src/test/java/com/oraclequantapi/oraclequantapi/OraclequantapiApplicationTests.java b/src/test/java/com/example/pkc_api/OraclequantapiApplicationTests.java
similarity index 81%
rename from src/test/java/com/oraclequantapi/oraclequantapi/OraclequantapiApplicationTests.java
rename to src/test/java/com/example/pkc_api/OraclequantapiApplicationTests.java
index 2de285b..a991606 100644
--- a/src/test/java/com/oraclequantapi/oraclequantapi/OraclequantapiApplicationTests.java
+++ b/src/test/java/com/example/pkc_api/OraclequantapiApplicationTests.java
@@ -1,4 +1,4 @@
-package com.oraclequantapi.oraclequantapi;
+package com.example.pkc_api;
 
 import org.junit.jupiter.api.Test;
 import org.springframework.boot.test.context.SpringBootTest;