diff --git a/.gitignore b/.gitignore
index acb9124..487180a 100644
--- a/.gitignore
+++ b/.gitignore
@@ -16,7 +16,7 @@
 go.sum
 
 # build binary
-leadercraft-s
+leadercraft-c
 
 # sqlite default db
 test.sqlite
diff --git a/main.go b/main.go
new file mode 100644
index 0000000..d7fb31e
--- /dev/null
+++ b/main.go
@@ -0,0 +1,226 @@
+// NGnius 2020-02-27
+
+package main
+
+import (
+	"bytes"
+	"encoding/json"
+	"flag"
+	"fmt"
+	"io/ioutil"
+	"net/http"
+	"os"
+	"os/signal"
+	"path/filepath"
+	"strconv"
+)
+
+const (
+	defaultPassword     = ""
+	defaultEntryURL     = "http://localhost:1337/record"
+	defaultPort         = "9000"
+	defaultDir          = "criterias"
+	defaultCriteriaJson = "criteria.json"
+)
+
+var (
+	// cli params
+	password string
+	entryURL string
+	port     string
+	dir      string
+	// internal
+	handler           http.Handler
+	server            *http.Server
+	client            *http.Client
+	isClosing         bool
+	referenceCriteria map[string]Criteria
+)
+
+// json structs
+
+// NewEntryJSON a new entry to be saved to a leaderboard
+type NewEntryJSON struct { // from leadercraft-s
+	Score    int64
+	PlayerID int64
+	BoardID  int64
+	Password string
+}
+
+// Criteria a set of values that must be met
+type Criteria struct {
+	Location    [2][3]float64 // (min coords (x,y,z), max coords (x,y,z))
+	Time        int64         // time since start of game (seconds)
+	GameID      int64         // game/board id in leadercraft-s and in Gamecraft (workshop ID?)
+	PlayerID    int64         // player id in leadercraft-s and in Gamecraft (steam ID)
+	Coefficient float64       // coefficient for calculating the score
+	Complete    bool          // game has been completed
+	Points      int64         // points scored in game
+	ScoreMode   string        // score calculation mode
+}
+
+func (c *Criteria) Meets(c2 *Criteria) bool {
+	meets := false
+	if c2.Location[0][0] != 0.0 && c2.Location[0][1] != 0.0 && c2.Location[0][2] != 0.0 &&
+		c2.Location[1][0] != 0.0 && c2.Location[1][1] != 0.0 && c2.Location[1][2] != 0.0 {
+		// criteria is location-based
+		meets = c.Location[0][0] >= c2.Location[0][0] && c.Location[0][1] >= c2.Location[0][1] && c.Location[0][2] >= c2.Location[0][2]
+		meets = meets && c.Location[1][0] <= c2.Location[1][0] && c.Location[1][1] <= c2.Location[1][1] && c.Location[1][2] <= c2.Location[1][2]
+		return meets
+	}
+	if c2.Complete {
+		return c.Complete && (c.Points >= c2.Points)
+	}
+	return meets
+}
+
+func (c *Criteria) Score(c2 *Criteria) int64 {
+	if c2.ScoreMode == "time" {
+		return int64(c2.Coefficient / float64(c.Time))
+	}
+	if c2.ScoreMode == "points" {
+		return int64(c2.Coefficient * float64(c.Points))
+	}
+	return 0
+}
+
+func init() {
+	flag.StringVar(&password, "entry-pwd", defaultPassword, "Password for new entry POST requests")
+	flag.StringVar(&entryURL, "url", defaultEntryURL, "URL for new entry POST requests")
+	flag.StringVar(&port, "port", defaultPort, "Port to listen on")
+	flag.StringVar(&dir, "dir", defaultDir, "Working directory")
+}
+
+func main() {
+	flag.Parse()
+	serverMux := http.NewServeMux()
+	serverMux.HandleFunc("/criteria", criteriaHandler)
+	signalChan := make(chan os.Signal)
+	signal.Notify(signalChan, os.Interrupt)
+	go func() {
+		s := <-signalChan
+		fmt.Println("Received terminate signal " + s.String())
+		isClosing = true
+		server.Close()
+	}()
+	server = &http.Server{
+		Addr:    ":" + port,
+		Handler: handler,
+	}
+	client = &http.Client{}
+	fmt.Println("Starting on " + server.Addr)
+	err := server.ListenAndServe()
+	if err != nil && !isClosing {
+		fmt.Println(err)
+	}
+}
+
+// criteria POST request handler
+// this also sends a new entry to leadercraft-s when the criteria is met
+func criteriaHandler(w http.ResponseWriter, r *http.Request) {
+	// TODO
+	if r.Method != "POST" {
+		w.WriteHeader(405)
+		return
+	}
+	authHeader := r.Header.Get("Authorization")
+	w.Header().Add("Content-Type", "application/json")
+	//w.Header().Add("Access-Control-Allow-Origin", "*")
+	data, readErr := ioutil.ReadAll(r.Body)
+	if readErr != nil {
+		// body could not be read properly
+		w.WriteHeader(500)
+		return
+	}
+	reqCriteria := &Criteria{}
+	unmarshErr := json.Unmarshal(data, reqCriteria)
+	if unmarshErr != nil {
+		// body could not be interpreted as json
+		w.WriteHeader(400)
+		return
+	}
+	// TODO load criteria for game id
+	criteriaFilename := filepath.Join(dir, fmt.Sprintf("%d", reqCriteria.GameID)+".json")
+	realCriteria := &Criteria{}
+	realCriteriaF, openErr := os.Open(criteriaFilename)
+	if openErr != nil {
+		w.WriteHeader(404)
+		return
+	}
+	realCritData, realCritReadErr := ioutil.ReadAll(realCriteriaF)
+	if realCritReadErr != nil {
+		w.WriteHeader(404)
+		return
+	}
+	unmarshCritErr := json.Unmarshal(realCritData, realCriteria)
+	if unmarshCritErr != nil {
+		// criteria file is invalid json
+		w.WriteHeader(404)
+		return
+	}
+	if reqCriteria.GameID > 1 {
+		f, fileErr := os.Open(filepath.Join(dir, "criteria-"+strconv.Itoa(int(reqCriteria.GameID))+".json"))
+		if fileErr != nil {
+			// file not found
+			w.WriteHeader(404)
+			return
+		}
+		data, readErr = ioutil.ReadAll(f)
+		if readErr != nil {
+			// file could not be read properly (file doesn't exist?)
+			w.WriteHeader(404)
+			return
+		}
+		unmarshErr = json.Unmarshal(data, &realCriteria)
+		if unmarshErr != nil {
+			// data could not be interpreted as json
+			w.WriteHeader(500)
+			return
+		}
+	} else {
+		// Game ID cannot exist
+		w.WriteHeader(404)
+		return
+	}
+	// TODO check if criteria matches
+	if !realCriteria.Meets(reqCriteria) {
+		// if criteria does not match, stop
+		w.WriteHeader(400)
+		return
+	}
+	// if criteria matches, send new entry to leadercraft-s
+	entry := NewEntryJSON{
+		Score:    realCriteria.Score(reqCriteria),
+		PlayerID: reqCriteria.PlayerID,
+		BoardID:  realCriteria.GameID,
+		Password: password,
+	}
+	echoData, marshErr := json.Marshal(entry)
+	if marshErr != nil {
+		w.WriteHeader(500)
+		return
+	}
+	echoBody := bytes.NewReader(echoData)
+	entryReq, reqErr := http.NewRequest("POST", entryURL, echoBody)
+	if reqErr != nil {
+		// malformed request parameters
+		w.WriteHeader(500)
+		return
+	}
+	entryReq.Header.Add("Authorization", authHeader)
+	entryReq.Header.Add("Content-Type", "application/json")
+	echoResp, postErr := client.Do(entryReq)
+	if postErr != nil {
+		// bad communication or malformed request
+		w.WriteHeader(500)
+		return
+	}
+	// echo new entry request response to original sender
+	w.WriteHeader(echoResp.StatusCode)
+	echoRespData, echoReadErr := ioutil.ReadAll(echoResp.Body)
+	if echoReadErr != nil {
+		// body read error (should never occur)
+		return
+	}
+	w.Write(echoRespData)
+}