feat: model selection for Claude, Codex, and Copilot

cmd/nightshift/commands/helpers.go

@@ -40,9 +40,13 @@ func newClaudeAgentFromConfig(cfg *config.Config) *agents.ClaudeAgent {
 	if cfg == nil {
 		return agents.NewClaudeAgent()
 	}
-	return agents.NewClaudeAgent(
+	opts := []agents.ClaudeOption{
 		agents.WithDangerouslySkipPermissions(cfg.Providers.Claude.DangerouslySkipPermissions),
-	)
+	}
+	if cfg.Providers.Claude.Model != "" {
+		opts = append(opts, agents.WithModel(cfg.Providers.Claude.Model))
+	}
+	return agents.NewClaudeAgent(opts...)
 }
 
 func newCodexAgentFromConfig(cfg *config.Config) *agents.CodexAgent {
@@ -65,6 +69,9 @@ func newCodexAgentFromConfig(cfg *config.Config) *agents.CodexAgent {
 	if cfg.Providers.Codex.DangerouslyBypassApprovalsAndSandbox {
 		opts = append(opts, agents.WithDangerouslyBypassApprovalsAndSandbox(true))
 	}
+	if cfg.Providers.Codex.Model != "" {
+		opts = append(opts, agents.WithCodexModel(cfg.Providers.Codex.Model))
+	}
 	return agents.NewCodexAgent(opts...)
 }
 
@@ -91,5 +98,8 @@ func newCopilotAgentFromConfig(cfg *config.Config, binaryPath ...string) *agents
 		agents.WithCopilotBinaryPath(binary),
 		agents.WithCopilotDangerouslySkipPermissions(cfg.Providers.Copilot.DangerouslySkipPermissions),
 	}
+	if cfg.Providers.Copilot.Model != "" {
+		opts = append(opts, agents.WithCopilotModel(cfg.Providers.Copilot.Model))
+	}
 	return agents.NewCopilotAgent(opts...)
 }

cmd/nightshift/commands/preview.go

@@ -410,6 +410,7 @@ func buildPreviewResult(cfg *config.Config, database *db.DB, projects []string,
 
 type providerBudgetSummary struct {
 	name      string
+	model     string
 	allowance *budget.AllowanceResult
 	err       error
 }
@@ -420,6 +421,7 @@ func collectProviderBudgets(cfg *config.Config, budgetMgr *budget.Manager) []pro
 		allowance, err := budgetMgr.CalculateAllowance("claude")
 		summaries = append(summaries, providerBudgetSummary{
 			name:      "claude",
+			model:     cfg.Providers.Claude.Model,
 			allowance: allowance,
 			err:       err,
 		})
@@ -428,6 +430,7 @@ func collectProviderBudgets(cfg *config.Config, budgetMgr *budget.Manager) []pro
 		allowance, err := budgetMgr.CalculateAllowance("codex")
 		summaries = append(summaries, providerBudgetSummary{
 			name:      "codex",
+			model:     cfg.Providers.Codex.Model,
 			allowance: allowance,
 			err:       err,
 		})
@@ -436,6 +439,7 @@ func collectProviderBudgets(cfg *config.Config, budgetMgr *budget.Manager) []pro
 		allowance, err := budgetMgr.CalculateAllowance("copilot")
 		summaries = append(summaries, providerBudgetSummary{
 			name:      "copilot",
+			model:     cfg.Providers.Copilot.Model,
 			allowance: allowance,
 			err:       err,
 		})

cmd/nightshift/commands/preview_output.go

@@ -71,12 +71,17 @@ func renderPreviewText(result *previewResult, opts previewTextOptions) string {
 				fmt.Fprintf(b, "    - %s: budget error: %v\n", summary.name, summary.err)
 				continue
 			}
-			line := fmt.Sprintf("    - %s: %s available (%.1f%% used, weekly=%s, source=%s)",
+			model := summary.model
+			if model == "" {
+				model = "default"
+			}
+			line := fmt.Sprintf("    - %s: %s available (%.1f%% used, weekly=%s, source=%s, model=%s)",
 				summary.name,
 				formatTokens64(summary.allowance.Allowance),
 				summary.allowance.UsedPercent,
 				formatTokens64(summary.allowance.WeeklyBudget),
-				summary.allowance.BudgetSource)
+				summary.allowance.BudgetSource,
+				model)
 			if summary.allowance.Allowance == 0 && summary.allowance.PredictedUsage > 0 {
 				line += fmt.Sprintf(" [daytime reserve: %s]", formatTokens64(summary.allowance.PredictedUsage))
 			}

cmd/nightshift/commands/setup.go

@@ -58,6 +58,7 @@ const (
 	stepProjects
 	stepBudget
 	stepSafety
+	stepModel
 	stepTaskPreset
 	stepTaskSelect
 	stepSchedule
@@ -73,6 +74,62 @@ const (
 	nightshiftPlanIgnoreComment = "# Nightshift plan artifacts (keep out of version control)"
 )
 
+type modelOption struct {
+	label string
+	value string // empty = use CLI default
+}
+
+// modelProviderLists holds the model option slice for each provider in cursor order
+// (claude=0, codex=1, copilot=2). Used to bound modelCursor in handleModelInput.
+var modelProviderLists = []*[]modelOption{&claudeModels, &codexModels, &copilotModels}
+
+// claudeModels lists available Claude models.
+// Source: https://platform.claude.com/docs/en/about-claude/models/overview (Claude API aliases)
+var claudeModels = []modelOption{
+	{label: "default", value: ""},
+	{label: "claude-opus-4-6", value: "claude-opus-4-6"},
+	{label: "claude-sonnet-4-6", value: "claude-sonnet-4-6"},
+	{label: "claude-haiku-4-5", value: "claude-haiku-4-5"},
+}
+
+// codexModels lists available Codex models.
+// Source: https://developers.openai.com/codex/models/
+var codexModels = []modelOption{
+	{label: "default", value: ""},
+	{label: "gpt-5.3-codex", value: "gpt-5.3-codex"},
+	{label: "gpt-5.3-codex-spark", value: "gpt-5.3-codex-spark"},
+	{label: "gpt-5.2-codex", value: "gpt-5.2-codex"},
+	{label: "gpt-5.2", value: "gpt-5.2"},
+	{label: "gpt-5.1-codex-max", value: "gpt-5.1-codex-max"},
+	{label: "gpt-5.1-codex", value: "gpt-5.1-codex"},
+	{label: "gpt-5.1", value: "gpt-5.1"},
+	{label: "gpt-5-codex", value: "gpt-5-codex"},
+	{label: "gpt-5", value: "gpt-5"},
+}
+
+// copilotModels lists available Copilot models.
+// Source: `copilot --help`, see the --model flag description for the full list.
+var copilotModels = []modelOption{
+	{label: "default", value: ""},
+	{label: "claude-sonnet-4.6", value: "claude-sonnet-4.6"},
+	{label: "claude-sonnet-4.5", value: "claude-sonnet-4.5"},
+	{label: "claude-haiku-4.5", value: "claude-haiku-4.5"},
+	{label: "claude-opus-4.6", value: "claude-opus-4.6"},
+	{label: "claude-opus-4.6-fast", value: "claude-opus-4.6-fast"},
+	{label: "claude-opus-4.5", value: "claude-opus-4.5"},
+	{label: "claude-sonnet-4", value: "claude-sonnet-4"},
+	{label: "gemini-3-pro-preview", value: "gemini-3-pro-preview"},
+	{label: "gpt-5.3-codex", value: "gpt-5.3-codex"},
+	{label: "gpt-5.2-codex", value: "gpt-5.2-codex"},
+	{label: "gpt-5.2", value: "gpt-5.2"},
+	{label: "gpt-5.1-codex-max", value: "gpt-5.1-codex-max"},
+	{label: "gpt-5.1-codex", value: "gpt-5.1-codex"},
+	{label: "gpt-5.1", value: "gpt-5.1"},
+	{label: "gpt-5.1-codex-mini", value: "gpt-5.1-codex-mini"},
+	{label: "gpt-5-mini", value: "gpt-5-mini"},
+	{label: "gpt-4.1", value: "gpt-4.1"},
+}
+
 type setupModel struct {
 	step setupStep
 
@@ -97,6 +154,11 @@ type setupModel struct {
 
 	safetyCursor int
 
+	modelCursor      int
+	claudeModelIdx   int
+	codexModelIdx    int
+	copilotModelIdx  int
+
 	taskPresetCursor int
 	taskCursor       int
 	taskItems        []taskItem
@@ -246,6 +308,9 @@ func newSetupModel() (*setupModel, error) {
 		scheduleInput:    scheduleInput,
 		spinner:          spin,
 		nightshiftInPath: nightshiftInPath,
+		claudeModelIdx:   modelIndex(claudeModels, cfg.Providers.Claude.Model),
+		codexModelIdx:    modelIndex(codexModels, cfg.Providers.Codex.Model),
+		copilotModelIdx:  modelIndex(copilotModels, cfg.Providers.Copilot.Model),
 	}
 
 	return model, nil
@@ -283,6 +348,8 @@ func (m *setupModel) Update(msg tea.Msg) (tea.Model, tea.Cmd) {
 			return m.handleBudgetInput(msg)
 		case stepSafety:
 			return m.handleSafetyInput(msg)
+		case stepModel:
+			return m.handleModelInput(msg)
 		case stepTaskPreset:
 			return m.handlePresetInput(msg)
 		case stepTaskSelect:
@@ -405,6 +472,12 @@ func (m *setupModel) View() string {
 		b.WriteString("Use ↑/↓ to select, space to toggle.\n\n")
 		renderSafetyFields(&b, m)
 		b.WriteString("\nPress Enter to continue.\n")
+	case stepModel:
+		b.WriteString(styleAccent.Render("Model selection"))
+		b.WriteString("\n")
+		b.WriteString("Choose the model for each provider. Use ↑/↓ to select a row, ←/→ to cycle models.\n\n")
+		renderModelFields(&b, m)
+		b.WriteString("\nPress Enter to continue.\n")
 	case stepTaskPreset:
 		b.WriteString(styleAccent.Render("Task presets (derived from registry)"))
 		b.WriteString("\n")
@@ -813,7 +886,7 @@ func (m *setupModel) handleSafetyInput(msg tea.KeyMsg) (tea.Model, tea.Cmd) {
 			m.cfg.Providers.Copilot.DangerouslySkipPermissions = !m.cfg.Providers.Copilot.DangerouslySkipPermissions
 		}
 	case "enter":
-		return m, m.setStep(stepTaskPreset)
+		return m, m.setStep(stepModel)
 	}
 	return m, nil
 }
@@ -1592,6 +1665,92 @@ func renderSafetyFields(b *strings.Builder, m *setupModel) {
 	b.WriteString("\n")
 }
 
+func renderModelFields(b *strings.Builder, m *setupModel) {
+	rows := []struct {
+		label     string
+		models    []modelOption
+		idx       int
+		available bool
+	}{
+		{"Claude ", claudeModels, m.claudeModelIdx, m.cfg.Providers.Claude.Enabled},
+		{"Codex  ", codexModels, m.codexModelIdx, m.cfg.Providers.Codex.Enabled},
+		{"Copilot", copilotModels, m.copilotModelIdx, m.cfg.Providers.Copilot.Enabled},
+	}
+	for i, row := range rows {
+		cursor := " "
+		if i == m.modelCursor {
+			cursor = ">"
+		}
+		selected := row.models[row.idx].label
+		avail := ""
+		if !row.available {
+			avail = " (provider disabled)"
+		}
+		fmt.Fprintf(b, " %s %s  ← %s →%s\n", cursor, row.label, selected, avail)
+	}
+	b.WriteString(styleNote.Render("Tip: 'default' lets the CLI pick its built-in model."))
+	b.WriteString("\n")
+}
+
+func (m *setupModel) handleModelInput(msg tea.KeyMsg) (tea.Model, tea.Cmd) {
+	switch msg.String() {
+	case "up", "k":
+		if m.modelCursor > 0 {
+			m.modelCursor--
+		}
+	case "down", "j":
+		if m.modelCursor < len(modelProviderLists)-1 {
+			m.modelCursor++
+		}
+	case "left", "h":
+		switch m.modelCursor {
+		case 0:
+			if m.claudeModelIdx > 0 {
+				m.claudeModelIdx--
+			}
+		case 1:
+			if m.codexModelIdx > 0 {
+				m.codexModelIdx--
+			}
+		case 2:
+			if m.copilotModelIdx > 0 {
+				m.copilotModelIdx--
+			}
+		}
+	case "right", "l":
+		switch m.modelCursor {
+		case 0:
+			if m.claudeModelIdx < len(claudeModels)-1 {
+				m.claudeModelIdx++
+			}
+		case 1:
+			if m.codexModelIdx < len(codexModels)-1 {
+				m.codexModelIdx++
+			}
+		case 2:
+			if m.copilotModelIdx < len(copilotModels)-1 {
+				m.copilotModelIdx++
+			}
+		}
+	case "enter":
+		m.cfg.Providers.Claude.Model = claudeModels[m.claudeModelIdx].value
+		m.cfg.Providers.Codex.Model = codexModels[m.codexModelIdx].value
+		m.cfg.Providers.Copilot.Model = copilotModels[m.copilotModelIdx].value
+		return m, m.setStep(stepTaskPreset)
+	}
+	return m, nil
+}
+
+// modelIndex returns the index of the given model value in a model list, defaulting to 0.
+func modelIndex(models []modelOption, value string) int {
+	for i, m := range models {
+		if m.value == value {
+			return i
+		}
+	}
+	return 0
+}
+
 func renderScheduleFields(b *strings.Builder, m *setupModel) {
 	fields := []string{
 		fmt.Sprintf("Start time: %s", m.scheduleStart),
@@ -1783,6 +1942,7 @@ func setupSteps(includePathStep bool) []setupStepInfo {
 		{step: stepProjects, label: "Projects"},
 		{step: stepBudget, label: "Budget"},
 		{step: stepSafety, label: "Safety"},
+		{step: stepModel, label: "Models"},
 		{step: stepTaskPreset, label: "Task presets"},
 		{step: stepTaskSelect, label: "Task selection"},
 		{step: stepSchedule, label: "Schedule"},
@@ -1949,14 +2109,17 @@ func writeGlobalConfigToPath(cfg *config.Config, configPath string) error {
 	// Providers: set fields individually to match mapstructure tag names (fixes #20)
 	v.Set("providers.claude.enabled", cfg.Providers.Claude.Enabled)
 	v.Set("providers.claude.data_path", cfg.Providers.Claude.DataPath)
+	v.Set("providers.claude.model", cfg.Providers.Claude.Model)
 	v.Set("providers.claude.dangerously_skip_permissions", cfg.Providers.Claude.DangerouslySkipPermissions)
 	v.Set("providers.claude.dangerously_bypass_approvals_and_sandbox", cfg.Providers.Claude.DangerouslyBypassApprovalsAndSandbox)
 	v.Set("providers.codex.enabled", cfg.Providers.Codex.Enabled)
 	v.Set("providers.codex.data_path", cfg.Providers.Codex.DataPath)
+	v.Set("providers.codex.model", cfg.Providers.Codex.Model)
 	v.Set("providers.codex.dangerously_skip_permissions", cfg.Providers.Codex.DangerouslySkipPermissions)
 	v.Set("providers.codex.dangerously_bypass_approvals_and_sandbox", cfg.Providers.Codex.DangerouslyBypassApprovalsAndSandbox)
 	v.Set("providers.copilot.enabled", cfg.Providers.Copilot.Enabled)
 	v.Set("providers.copilot.data_path", cfg.Providers.Copilot.DataPath)
+	v.Set("providers.copilot.model", cfg.Providers.Copilot.Model)
 	v.Set("providers.copilot.dangerously_skip_permissions", cfg.Providers.Copilot.DangerouslySkipPermissions)
 	v.Set("providers.copilot.dangerously_bypass_approvals_and_sandbox", cfg.Providers.Copilot.DangerouslyBypassApprovalsAndSandbox)
 	v.Set("providers.preference", cfg.Providers.Preference)

internal/agents/agent.go

@@ -25,6 +25,7 @@ type ExecuteOptions struct {
 	WorkDir string        // Working directory for execution
 	Files   []string      // Optional file paths to include as context
 	Timeout time.Duration // Execution timeout (0 = default)
+	Model   string        // Model to use (optional, uses agent default if empty)
 }
 
 // ExecuteResult holds the outcome of an agent execution.

internal/agents/claude.go

@@ -61,6 +61,7 @@ type ClaudeAgent struct {
 	timeout    time.Duration // Default timeout
 	runner     CommandRunner // Command executor (for testing)
 	skipPerms  bool          // Pass --dangerously-skip-permissions
+	model      string        // Default model to use
 }
 
 // ClaudeOption configures a ClaudeAgent.
@@ -87,6 +88,13 @@ func WithDangerouslySkipPermissions(enabled bool) ClaudeOption {
 	}
 }
 
+// WithModel sets the default model to use.
+func WithModel(model string) ClaudeOption {
+	return func(a *ClaudeAgent) {
+		a.model = model
+	}
+}
+
 // WithRunner sets a custom command runner (for testing).
 func WithRunner(r CommandRunner) ClaudeOption {
 	return func(a *ClaudeAgent) {
@@ -133,6 +141,15 @@ func (a *ClaudeAgent) Execute(ctx context.Context, opts ExecuteOptions) (*Execut
 		args = append(args, "--dangerously-skip-permissions")
 	}
 
+	// Add model if specified
+	model := opts.Model
+	if model == "" {
+		model = a.model
+	}
+	if model != "" {
+		args = append(args, "--model", model)
+	}
+
 	// Add prompt directly as argument
 	if opts.Prompt != "" {
 		args = append(args, opts.Prompt)