Index: bots/main.go
===================================================================
--- bots/main.go	(revision b715712c7d5d3ee27c932a8a9d8e0a2bc6e85127)
+++ bots/main.go	(revision b715712c7d5d3ee27c932a8a9d8e0a2bc6e85127)
@@ -0,0 +1,168 @@
+// EduBerza market simulation bot.
+//
+// Walks a small price for every active market, inserts rows into
+// market_trades once per tick, and upserts the current 1m candle.
+//
+// Run from the repo root so the relative .env path resolves:
+//
+//	go run ./bots/...
+package main
+
+import (
+	"bufio"
+	"database/sql"
+	"flag"
+	"fmt"
+	"log"
+	"math/rand"
+	"os"
+	"strings"
+	"time"
+
+	_ "github.com/lib/pq"
+)
+
+type market struct {
+	id     string
+	symbol string
+	price  float64
+}
+
+func main() {
+	interval := flag.Duration("interval", 3*time.Second, "seconds between price ticks")
+	flag.Parse()
+
+	loadEnv(".env")
+	dsn := fmt.Sprintf(
+		"host=%s port=%s user=%s password=%s dbname=%s sslmode=disable options='--search_path=project,public'",
+		env("DBHOST", "localhost"),
+		env("DBPORT", "5432"),
+		env("DBUSER", "postgres"),
+		env("DBPASSWORD", ""),
+		env("DBNAME", "postgres"),
+	)
+	db, err := sql.Open("postgres", dsn)
+	if err != nil {
+		log.Fatalf("open db: %v", err)
+	}
+	defer db.Close()
+	if err := db.Ping(); err != nil {
+		log.Fatalf("ping: %v", err)
+	}
+
+	markets, err := loadMarkets(db)
+	if err != nil {
+		log.Fatalf("load markets: %v", err)
+	}
+	if len(markets) == 0 {
+		log.Fatal("no active markets found - run `go run ./server -init` first")
+	}
+
+	log.Printf("bot started. simulating %d markets every %s", len(markets), *interval)
+	rnd := rand.New(rand.NewSource(time.Now().UnixNano()))
+
+	for {
+		for i := range markets {
+			m := &markets[i]
+			// random walk: ±0.3% per tick
+			drift := (rnd.Float64() - 0.5) * 0.006
+			m.price = m.price * (1 + drift)
+			if m.price <= 0 {
+				m.price = 0.000001
+			}
+			qty := rnd.Float64()*0.5 + 0.01
+
+			side := "buy"
+			if rnd.Float64() < 0.5 {
+				side = "sell"
+			}
+
+			if err := insertTick(db, m.id, m.price, qty, side); err != nil {
+				log.Printf("insert tick %s: %v", m.symbol, err)
+				continue
+			}
+			log.Printf("  %-8s  %.6f  qty=%.4f  side=%s", m.symbol, m.price, qty, side)
+		}
+		time.Sleep(*interval)
+	}
+}
+
+func loadMarkets(db *sql.DB) ([]market, error) {
+	rows, err := db.Query(`
+		SELECT m.id, c.symbol, COALESCE(lp.price, 100)
+		  FROM markets m
+		  JOIN crypto  c  ON c.id = m.crypto_id
+		  LEFT JOIN v_latest_prices lp ON lp.market_id = m.id
+		 WHERE m.is_active = true
+		 ORDER BY c.symbol`)
+	if err != nil {
+		return nil, err
+	}
+	defer rows.Close()
+	var out []market
+	for rows.Next() {
+		var m market
+		if err := rows.Scan(&m.id, &m.symbol, &m.price); err != nil {
+			return nil, err
+		}
+		out = append(out, m)
+	}
+	return out, nil
+}
+
+func insertTick(db *sql.DB, marketID string, price, qty float64, side string) error {
+	tx, err := db.Begin()
+	if err != nil {
+		return err
+	}
+	defer tx.Rollback()
+
+	if _, err := tx.Exec(
+		`INSERT INTO market_trades (market_id, executed_at, price, quantity, side, source)
+		 VALUES ($1, now(), $2, $3, $4, 'simulation')`,
+		marketID, price, qty, side,
+	); err != nil {
+		return err
+	}
+
+	// upsert the current 1m candle
+	if _, err := tx.Exec(`
+		INSERT INTO market_candles (market_id, timeframe, open, high, low, close, volume, candle_time)
+		VALUES ($1, '1m', $2, $2, $2, $2, $3, date_trunc('minute', now()))
+		ON CONFLICT (market_id, timeframe, candle_time) DO UPDATE
+		   SET high   = GREATEST(market_candles.high, EXCLUDED.close),
+		       low    = LEAST(   market_candles.low,  EXCLUDED.close),
+		       close  = EXCLUDED.close,
+		       volume = market_candles.volume + EXCLUDED.volume`,
+		marketID, price, qty,
+	); err != nil {
+		return err
+	}
+	return tx.Commit()
+}
+
+func loadEnv(path string) {
+	f, err := os.Open(path)
+	if err != nil {
+		return
+	}
+	defer f.Close()
+	s := bufio.NewScanner(f)
+	for s.Scan() {
+		line := strings.TrimSpace(s.Text())
+		if line == "" || strings.HasPrefix(line, "#") {
+			continue
+		}
+		parts := strings.SplitN(line, "=", 2)
+		if len(parts) == 2 {
+			os.Setenv(strings.TrimSpace(parts[0]), strings.TrimSpace(parts[1]))
+		}
+	}
+}
+
+func env(k, def string) string {
+	if v := os.Getenv(k); v != "" {
+		return v
+	}
+	return def
+}