Add custom backend configuration

internal/config/config.go

@@ -7,6 +7,7 @@ import (
 	"io"
 	"os"
 	"path/filepath"
+	"sort"
 	"strings"
 
 	"gitea.maximumdirect.net/eric/scriptorium/internal/defaults"
@@ -32,11 +33,29 @@ var (
 
 // Config is the on-disk YAML shape for application-level settings.
 type Config struct {
-	PromptDir  string         `yaml:"prompt_dir"`
-	ProfileDir string         `yaml:"profile_dir"`
-	SchemaDir  string         `yaml:"schema_dir"`
-	Server     ServerConfig   `yaml:"server"`
-	Defaults   DefaultsConfig `yaml:"defaults"`
+	PromptDir  string                   `yaml:"prompt_dir"`
+	ProfileDir string                   `yaml:"profile_dir"`
+	SchemaDir  string                   `yaml:"schema_dir"`
+	Server     ServerConfig             `yaml:"server"`
+	Defaults   DefaultsConfig           `yaml:"defaults"`
+	Backends   map[string]BackendConfig `yaml:"backends"`
+}
+
+type BackendConfig struct {
+	Endpoint         string         `yaml:"endpoint"`
+	APIKeyEnv        string         `yaml:"api_key_env"`
+	ExtraParams      map[string]any `yaml:"extra_params"`
+	ConcurrencyLimit int            `yaml:"concurrency_limit"`
+	QueueCapacity    *int           `yaml:"queue_capacity"`
+}
+
+type BackendSettings struct {
+	ID               string
+	Endpoint         string
+	APIKeyEnv        string
+	ExtraParams      map[string]any
+	ConcurrencyLimit int
+	QueueCapacity    *int
 }
 
 type ServerConfig struct {
@@ -62,6 +81,7 @@ type AppSettings struct {
 	MaxArtifactBytes    int64
 	MaxResponseBytes    int64
 	DefaultRenderFormat renderformat.PreparedRunOutputFormat
+	Backends            []BackendSettings
 }
 
 // CLIOverrides can be applied after config load to enforce precedence.
@@ -245,6 +265,25 @@ func applyConfig(base AppSettings, cfg Config) (AppSettings, error) {
 		}
 		out.DefaultRenderFormat = parsed
 	}
+	if len(cfg.Backends) > 0 {
+		ids := make([]string, 0, len(cfg.Backends))
+		for id := range cfg.Backends {
+			ids = append(ids, id)
+		}
+		sort.Strings(ids)
+		out.Backends = make([]BackendSettings, 0, len(ids))
+		for _, id := range ids {
+			backend := cfg.Backends[id]
+			out.Backends = append(out.Backends, BackendSettings{
+				ID:               id,
+				Endpoint:         backend.Endpoint,
+				APIKeyEnv:        backend.APIKeyEnv,
+				ExtraParams:      backend.ExtraParams,
+				ConcurrencyLimit: backend.ConcurrencyLimit,
+				QueueCapacity:    backend.QueueCapacity,
+			})
+		}
+	}
 
 	return out, nil
 }