1 files changed, 91 insertions, 141 deletions

diff --git a/internal/appconfig/config.go b/internal/appconfig/config.go
index 47abaaf..63d0437 100644
--- a/internal/appconfig/config.go
+++ b/internal/appconfig/config.go
@@ -13,6 +13,13 @@ import (
 	"github.com/pelletier/go-toml/v2"
 )
 
+// SurfaceConfig describes a provider/model pairing (with optional temperature).
+type SurfaceConfig struct {
+	Provider    string
+	Model       string
+	Temperature *float64
+}
+
 // App holds user-configurable settings read from ~/.config/hexai/config.toml.
 type App struct {
 	MaxTokens          int    `json:"max_tokens" toml:"max_tokens"`
@@ -58,19 +65,11 @@ type App struct {
 	// Default temperature for Copilot requests (nil means use provider default)
 	CopilotTemperature *float64 `json:"copilot_temperature" toml:"copilot_temperature"`
 
-	// Per-surface model overrides (fall back to provider defaults when unset)
-	CompletionModel       string   `json:"completion_model" toml:"completion_model"`
-	CompletionTemperature *float64 `json:"completion_temperature" toml:"completion_temperature"`
-	CompletionProvider    string   `json:"completion_provider" toml:"completion_provider"`
-	CodeActionModel       string   `json:"code_action_model" toml:"code_action_model"`
-	CodeActionTemperature *float64 `json:"code_action_temperature" toml:"code_action_temperature"`
-	CodeActionProvider    string   `json:"code_action_provider" toml:"code_action_provider"`
-	ChatModel             string   `json:"chat_model" toml:"chat_model"`
-	ChatTemperature       *float64 `json:"chat_temperature" toml:"chat_temperature"`
-	ChatProvider          string   `json:"chat_provider" toml:"chat_provider"`
-	CLIModel              string   `json:"cli_model" toml:"cli_model"`
-	CLITemperature        *float64 `json:"cli_temperature" toml:"cli_temperature"`
-	CLIProvider           string   `json:"cli_provider" toml:"cli_provider"`
+	// Per-surface provider/model configurations (ordered; first entry is primary)
+	CompletionConfigs []SurfaceConfig `json:"-" toml:"-"`
+	CodeActionConfigs []SurfaceConfig `json:"-" toml:"-"`
+	ChatConfigs       []SurfaceConfig `json:"-" toml:"-"`
+	CLIConfigs        []SurfaceConfig `json:"-" toml:"-"`
 
 	// Prompt templates (configured only via file; no env overrides)
 	// Completion/chat/code action/CLI prompt strings. See config.toml.example for placeholders.
@@ -662,72 +661,66 @@ func parseSurfaceModels(raw map[string]any, logger *log.Logger) *App {
 		return nil
 	}
 	var out App
-	var any bool
-	if model, provider, temp, ok := decodeModelEntry(table["completion"], "models.completion", logger); ok {
-		if model != "" {
-			out.CompletionModel = model
-		}
-		if provider != "" {
-			out.CompletionProvider = provider
-		}
-		if temp != nil {
-			out.CompletionTemperature = temp
-		}
-		any = true
-	}
-	if model, provider, temp, ok := decodeModelEntry(table["code_action"], "models.code_action", logger); ok {
-		if model != "" {
-			out.CodeActionModel = model
-		}
-		if provider != "" {
-			out.CodeActionProvider = provider
-		}
-		if temp != nil {
-			out.CodeActionTemperature = temp
-		}
-		any = true
-	}
-	if model, provider, temp, ok := decodeModelEntry(table["chat"], "models.chat", logger); ok {
-		if model != "" {
-			out.ChatModel = model
-		}
-		if provider != "" {
-			out.ChatProvider = provider
-		}
-		if temp != nil {
-			out.ChatTemperature = temp
-		}
-		any = true
+	appendEntries := func(dest *[]SurfaceConfig, key string, val any) bool {
+		entries, ok := parseSurfaceEntries(val, key, logger)
+		if !ok || len(entries) == 0 {
+			return false
+		}
+		*dest = append(*dest, entries...)
+		return true
+	}
+	any := appendEntries(&out.CompletionConfigs, "models.completion", table["completion"])
+	any = appendEntries(&out.CodeActionConfigs, "models.code_action", table["code_action"]) || any
+	any = appendEntries(&out.ChatConfigs, "models.chat", table["chat"]) || any
+	any = appendEntries(&out.CLIConfigs, "models.cli", table["cli"]) || any
+	if !any {
+		return nil
 	}
-	if model, provider, temp, ok := decodeModelEntry(table["cli"], "models.cli", logger); ok {
-		if model != "" {
-			out.CLIModel = model
-		}
-		if provider != "" {
-			out.CLIProvider = provider
+	return &out
+}
+
+func parseSurfaceEntries(raw any, path string, logger *log.Logger) ([]SurfaceConfig, bool) {
+	switch v := raw.(type) {
+	case nil:
+		return nil, false
+	case []any:
+		var out []SurfaceConfig
+		for i, entry := range v {
+			cfg, ok := decodeModelEntry(entry, fmt.Sprintf("%s[%d]", path, i), logger)
+			if !ok || cfg == nil {
+				continue
+			}
+			out = append(out, *cfg)
 		}
-		if temp != nil {
-			out.CLITemperature = temp
+		return out, len(out) > 0
+	default:
+		if cfg, ok := decodeModelEntry(v, path, logger); ok && cfg != nil {
+			return []SurfaceConfig{*cfg}, true
 		}
-		any = true
+		return nil, false
 	}
-	if !any {
+}
+
+func cloneSurfaceConfigs(src []SurfaceConfig) []SurfaceConfig {
+	if len(src) == 0 {
 		return nil
 	}
-	return &out
+	out := make([]SurfaceConfig, len(src))
+	copy(out, src)
+	return out
 }
 
-func decodeModelEntry(raw any, path string, logger *log.Logger) (string, string, *float64, bool) {
+func decodeModelEntry(raw any, path string, logger *log.Logger) (*SurfaceConfig, bool) {
 	if raw == nil {
-		return "", "", nil, false
+		return nil, false
 	}
 	switch v := raw.(type) {
 	case string:
 		model := strings.TrimSpace(v)
 		if model == "" {
-			return "", "", nil, false
+			return nil, false
 		}
-		return model, "", nil, true
+		return &SurfaceConfig{Model: model}, true
 	case map[string]any:
 		model := ""
 		provider := ""
@@ -737,7 +730,7 @@ func decodeModelEntry(raw any, path string, logger *log.Logger) (string, string,
 				if logger != nil {
 					logger.Printf("config: %s.model must be a string", path)
 				}
-				return "", "", nil, false
+				return nil, false
 			}
 			model = strings.TrimSpace(s)
 		}
@@ -747,7 +740,7 @@ func decodeModelEntry(raw any, path string, logger *log.Logger) (string, string,
 				if logger != nil {
 					logger.Printf("config: %s.provider must be a string", path)
 				}
-				return "", "", nil, false
+				return nil, false
 			}
 			provider = strings.TrimSpace(ps)
 		}
@@ -755,19 +748,19 @@ func decodeModelEntry(raw any, path string, logger *log.Logger) (string, string,
 		if tRaw, ok := v["temperature"]; ok {
 			parsed, ok := parseTemperatureValue(tRaw, path, logger)
 			if !ok {
-				return "", "", nil, false
+				return nil, false
 			}
 			tempPtr = parsed
 		}
 		if model == "" && tempPtr == nil && provider == "" {
-			return "", "", nil, false
+			return nil, false
 		}
-		return model, provider, tempPtr, true
+		return &SurfaceConfig{Provider: provider, Model: model, Temperature: tempPtr}, true
 	default:
 		if logger != nil {
 			logger.Printf("config: %s must be a string or table, got %T", path, raw)
 		}
-		return "", "", nil, false
+		return nil, false
 	}
 }
 
@@ -861,41 +854,17 @@ func (a *App) mergeBasics(other *App) {
 
 // mergeSurfaceModels copies per-surface model and temperature overrides.
 func (a *App) mergeSurfaceModels(other *App) {
-	if s := strings.TrimSpace(other.CompletionModel); s != "" {
-		a.CompletionModel = s
-	}
-	if other.CompletionTemperature != nil {
-		a.CompletionTemperature = other.CompletionTemperature
-	}
-	if s := strings.TrimSpace(other.CompletionProvider); s != "" {
-		a.CompletionProvider = s
+	if len(other.CompletionConfigs) > 0 {
+		a.CompletionConfigs = cloneSurfaceConfigs(other.CompletionConfigs)
 	}
-	if s := strings.TrimSpace(other.CodeActionModel); s != "" {
-		a.CodeActionModel = s
+	if len(other.CodeActionConfigs) > 0 {
+		a.CodeActionConfigs = cloneSurfaceConfigs(other.CodeActionConfigs)
 	}
-	if other.CodeActionTemperature != nil {
-		a.CodeActionTemperature = other.CodeActionTemperature
+	if len(other.ChatConfigs) > 0 {
+		a.ChatConfigs = cloneSurfaceConfigs(other.ChatConfigs)
 	}
-	if s := strings.TrimSpace(other.CodeActionProvider); s != "" {
-		a.CodeActionProvider = s
-	}
-	if s := strings.TrimSpace(other.ChatModel); s != "" {
-		a.ChatModel = s
-	}
-	if other.ChatTemperature != nil {
-		a.ChatTemperature = other.ChatTemperature
-	}
-	if s := strings.TrimSpace(other.ChatProvider); s != "" {
-		a.ChatProvider = s
-	}
-	if s := strings.TrimSpace(other.CLIModel); s != "" {
-		a.CLIModel = s
-	}
-	if other.CLITemperature != nil {
-		a.CLITemperature = other.CLITemperature
-	}
-	if s := strings.TrimSpace(other.CLIProvider); s != "" {
-		a.CLIProvider = s
+	if len(other.CLIConfigs) > 0 {
+		a.CLIConfigs = cloneSurfaceConfigs(other.CLIConfigs)
 	}
 }
 
@@ -1263,52 +1232,33 @@ func loadFromEnv(logger *log.Logger) *App {
 	}
 
 	// Per-surface overrides
-	if s := getenv("HEXAI_MODEL_COMPLETION"); s != "" {
-		out.CompletionModel = s
-		any = true
-	}
-	if f, ok := parseFloatPtr("HEXAI_TEMPERATURE_COMPLETION"); ok {
-		out.CompletionTemperature = f
-		any = true
-	}
-	if s := getenv("HEXAI_PROVIDER_COMPLETION"); s != "" {
-		out.CompletionProvider = s
-		any = true
-	}
-	if s := getenv("HEXAI_MODEL_CODE_ACTION"); s != "" {
-		out.CodeActionModel = s
-		any = true
-	}
-	if f, ok := parseFloatPtr("HEXAI_TEMPERATURE_CODE_ACTION"); ok {
-		out.CodeActionTemperature = f
-		any = true
-	}
-	if s := getenv("HEXAI_PROVIDER_CODE_ACTION"); s != "" {
-		out.CodeActionProvider = s
-		any = true
-	}
-	if s := getenv("HEXAI_MODEL_CHAT"); s != "" {
-		out.ChatModel = s
-		any = true
-	}
-	if f, ok := parseFloatPtr("HEXAI_TEMPERATURE_CHAT"); ok {
-		out.ChatTemperature = f
-		any = true
+	buildEntry := func(modelKey, tempKey, providerKey string) ([]SurfaceConfig, bool) {
+		model := getenv(modelKey)
+		tempPtr, tempSet := parseFloatPtr(tempKey)
+		provider := getenv(providerKey)
+		if model == "" && provider == "" && !tempSet {
+			return nil, false
+		}
+		entry := SurfaceConfig{Provider: provider, Model: model}
+		if tempSet {
+			entry.Temperature = tempPtr
+		}
+		return []SurfaceConfig{entry}, true
 	}
-	if s := getenv("HEXAI_PROVIDER_CHAT"); s != "" {
-		out.ChatProvider = s
+	if entries, ok := buildEntry("HEXAI_MODEL_COMPLETION", "HEXAI_TEMPERATURE_COMPLETION", "HEXAI_PROVIDER_COMPLETION"); ok {
+		out.CompletionConfigs = entries
 		any = true
 	}
-	if s := getenv("HEXAI_MODEL_CLI"); s != "" {
-		out.CLIModel = s
+	if entries, ok := buildEntry("HEXAI_MODEL_CODE_ACTION", "HEXAI_TEMPERATURE_CODE_ACTION", "HEXAI_PROVIDER_CODE_ACTION"); ok {
+		out.CodeActionConfigs = entries
 		any = true
 	}
-	if f, ok := parseFloatPtr("HEXAI_TEMPERATURE_CLI"); ok {
-		out.CLITemperature = f
+	if entries, ok := buildEntry("HEXAI_MODEL_CHAT", "HEXAI_TEMPERATURE_CHAT", "HEXAI_PROVIDER_CHAT"); ok {
+		out.ChatConfigs = entries
 		any = true
 	}
-	if s := getenv("HEXAI_PROVIDER_CLI"); s != "" {
-		out.CLIProvider = s
+	if entries, ok := buildEntry("HEXAI_MODEL_CLI", "HEXAI_TEMPERATURE_CLI", "HEXAI_PROVIDER_CLI"); ok {
+		out.CLIConfigs = entries
 		any = true
 	}