Phase 1 MVP — echo bot factory

config.go

@@ -0,0 +1,43 @@
+package main
+
+import (
+	"fmt"
+	"os"
+	"strings"
+
+	"gopkg.in/yaml.v3"
+)
+
+type Config struct {
+	Bots map[string]BotConfig `yaml:"bots"`
+}
+
+type BotConfig struct {
+	Handler string `yaml:"handler"`
+	Token   string `yaml:"-"`
+	Secret  string `yaml:"-"`
+}
+
+// LoadConfig reads the YAML routing config and merges per-bot secrets pulled
+// from the process environment. Per-bot env keys are derived from the bot
+// slug uppercased: BOT_<UPPER_SLUG>_TOKEN, BOT_<UPPER_SLUG>_SECRET.
+func LoadConfig(path string) (*Config, error) {
+	raw, err := os.ReadFile(path)
+	if err != nil {
+		return nil, fmt.Errorf("read config %s: %w", path, err)
+	}
+	var cfg Config
+	if err := yaml.Unmarshal(raw, &cfg); err != nil {
+		return nil, fmt.Errorf("parse yaml: %w", err)
+	}
+	if len(cfg.Bots) == 0 {
+		return nil, fmt.Errorf("no bots in %s", path)
+	}
+	for slug, b := range cfg.Bots {
+		envSlug := strings.ToUpper(strings.ReplaceAll(slug, "-", "_"))
+		b.Token = os.Getenv("BOT_" + envSlug + "_TOKEN")
+		b.Secret = os.Getenv("BOT_" + envSlug + "_SECRET")
+		cfg.Bots[slug] = b
+	}
+	return &cfg, nil
+}