2 files changed, 94 insertions, 0 deletions
diff --git a/internal/provider/provider.go b/internal/provider/provider.go
new file mode 100644
index 0000000..6239ecf
--- /dev/null
+++ b/internal/provider/provider.go
@@ -0,0 +1,72 @@
+// Package provider defines capability-specific AI provider interfaces and shared
+// provider naming helpers. The concrete Gemini implementations will satisfy
+// these interfaces once the comic pipeline is wired up.
+package provider
+
+import (
+	"context"
+	"errors"
+	"strings"
+)
+
+const (
+	// Gemini is the canonical provider name for Google's Gemini backend.
+	Gemini = "gemini"
+
+	// OpenAI is the canonical provider name for OpenAI backends.
+	OpenAI = "openai"
+)
+
+// TextProvider generates text from prompts.
+type TextProvider interface {
+	Name() string
+	IsAvailable() error
+	GenerateText(ctx context.Context, prompt string) (string, error)
+}
+
+// ImageProvider generates images from prompts.
+type ImageProvider interface {
+	Name() string
+	IsAvailable() error
+	GenerateImage(ctx context.Context, prompt string, outputFile string) error
+}
+
+// TTSProvider generates audio from text.
+type TTSProvider interface {
+	Name() string
+	IsAvailable() error
+	GenerateAudio(ctx context.Context, text string, outputFile string) error
+}
+
+// TextConfig exposes the configured text provider name.
+type TextConfig interface {
+	TextProviderName() string
+}
+
+// ImageConfig exposes the configured image provider name.
+type ImageConfig interface {
+	ImageProviderName() string
+}
+
+// TTSConfig exposes the configured TTS provider name.
+type TTSConfig interface {
+	TTSProviderName() string
+}
+
+// NormalizeName returns a canonical lower-case provider name.
+func NormalizeName(name string) string {
+	return strings.ToLower(strings.TrimSpace(name))
+}
+
+// IsKnownName reports whether the name matches a supported provider family.
+func IsKnownName(name string) bool {
+	switch NormalizeName(name) {
+	case Gemini, OpenAI:
+		return true
+	default:
+		return false
+	}
+}
+
+// ErrUnknownProvider indicates that a provider name does not map to a known backend.
+var ErrUnknownProvider = errors.New("unknown provider")
diff --git a/internal/provider/provider_test.go b/internal/provider/provider_test.go
new file mode 100644
index 0000000..46931d1
--- /dev/null
+++ b/internal/provider/provider_test.go
@@ -0,0 +1,22 @@
+package provider
+
+import "testing"
+
+func TestNormalizeName(t *testing.T) {
+	t.Parallel()
+
+	if got, want := NormalizeName(" Gemini "), Gemini; got != want {
+		t.Fatalf("NormalizeName() = %q, want %q", got, want)
+	}
+}
+
+func TestIsKnownName(t *testing.T) {
+	t.Parallel()
+
+	if !IsKnownName("gemini") {
+		t.Fatal("expected gemini to be recognized")
+	}
+	if IsKnownName("bogus") {
+		t.Fatal("expected bogus provider to be rejected")
+	}
+}