Changeset 0.5.0 (#35)

server/providers/openrouter.go

@@ -0,0 +1,160 @@
+package providers
+
+import (
+	"context"
+	"encoding/json"
+	"fmt"
+	"io"
+	"net/http"
+	"strconv"
+	"strings"
+)
+
+// OpenRouterProvider handles the OpenRouter unified API.
+// OpenRouter is OpenAI-compatible with 300+ models, per-model pricing,
+// and architecture metadata. Requires HTTP-Referer and X-Title headers.
+//
+// Ported from ai-editor js/providers/openrouter.js
+type OpenRouterProvider struct{}
+
+func (p *OpenRouterProvider) ID() string { return "openrouter" }
+
+// ── Chat Completion ─────────────────────────
+// Delegates to OpenAI provider — OpenRouter is fully OAI-compatible.
+
+func (p *OpenRouterProvider) ChatCompletion(ctx context.Context, cfg ProviderConfig, req CompletionRequest) (*CompletionResponse, error) {
+	oai := &OpenAIProvider{}
+	return oai.ChatCompletion(ctx, cfg, req)
+}
+
+func (p *OpenRouterProvider) StreamCompletion(ctx context.Context, cfg ProviderConfig, req CompletionRequest) (<-chan StreamEvent, error) {
+	oai := &OpenAIProvider{}
+	return oai.StreamCompletion(ctx, cfg, req)
+}
+
+// ── List Models ─────────────────────────────
+// OpenRouter /v1/models returns architecture, pricing, context_length.
+
+func (p *OpenRouterProvider) ListModels(ctx context.Context, cfg ProviderConfig) ([]Model, error) {
+	endpoint := strings.TrimSuffix(cfg.Endpoint, "/") + "/models"
+
+	httpReq, err := http.NewRequestWithContext(ctx, "GET", endpoint, nil)
+	if err != nil {
+		return nil, err
+	}
+	if cfg.APIKey != "" {
+		httpReq.Header.Set("Authorization", "Bearer "+cfg.APIKey)
+	}
+	for k, v := range cfg.CustomHeaders {
+		httpReq.Header.Set(k, v)
+	}
+
+	resp, err := http.DefaultClient.Do(httpReq)
+	if err != nil {
+		return nil, fmt.Errorf("openrouter list models: %w", err)
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		b, _ := io.ReadAll(resp.Body)
+		return nil, fmt.Errorf("openrouter list models: HTTP %d: %s", resp.StatusCode, string(b))
+	}
+
+	var result orModelsResponse
+	if err := json.NewDecoder(resp.Body).Decode(&result); err != nil {
+		return nil, fmt.Errorf("openrouter decode models: %w", err)
+	}
+
+	models := make([]Model, 0, len(result.Data))
+	for _, m := range result.Data {
+		// Start with known table, fall back to heuristic
+		caps, found := LookupKnownModel(m.ID)
+		if !found {
+			caps = InferCapabilities(m.ID)
+		}
+
+		// Overlay context length from OpenRouter metadata
+		if m.ContextLength > 0 && caps.MaxContext == 0 {
+			caps.MaxContext = m.ContextLength
+		}
+
+		// Overlay max output from OpenRouter if available
+		if m.TopProvider.MaxCompletionTokens > 0 && caps.MaxOutputTokens == 0 {
+			caps.MaxOutputTokens = m.TopProvider.MaxCompletionTokens
+		}
+
+		// Vision from architecture modality
+		arch := m.Architecture
+		if arch.Modality == "multimodal" {
+			caps.Vision = true
+		}
+
+		// Streaming is universal on OpenRouter
+		caps.Streaming = true
+
+		// Parse pricing (OpenRouter uses per-token strings, convert to per-1M)
+		var pricing *ModelPricing
+		if m.Pricing.Prompt != "" {
+			inputPerToken, _ := strconv.ParseFloat(m.Pricing.Prompt, 64)
+			outputPerToken, _ := strconv.ParseFloat(m.Pricing.Completion, 64)
+			if inputPerToken > 0 || outputPerToken > 0 {
+				pricing = &ModelPricing{
+					InputPerM:  inputPerToken * 1_000_000,
+					OutputPerM: outputPerToken * 1_000_000,
+				}
+			}
+		}
+
+		// Owner from model ID prefix (e.g. "anthropic/claude-3-opus" → "anthropic")
+		ownedBy := ""
+		if idx := strings.Index(m.ID, "/"); idx >= 0 {
+			ownedBy = m.ID[:idx]
+		}
+
+		name := m.Name
+		if name == "" {
+			name = m.ID
+		}
+
+		models = append(models, Model{
+			ID:           m.ID,
+			Name:         name,
+			OwnedBy:      ownedBy,
+			Capabilities: caps,
+			Pricing:      pricing,
+		})
+	}
+	return models, nil
+}
+
+// ── OpenRouter Wire Types ───────────────────
+
+type orModelsResponse struct {
+	Data []orModel `json:"data"`
+}
+
+type orModel struct {
+	ID            string        `json:"id"`
+	Name          string        `json:"name"`
+	Description   string        `json:"description"`
+	ContextLength int           `json:"context_length"`
+	Architecture  orArch        `json:"architecture"`
+	Pricing       orPricing     `json:"pricing"`
+	TopProvider   orTopProvider `json:"top_provider"`
+}
+
+type orArch struct {
+	Modality       string `json:"modality"`
+	Tokenizer      string `json:"tokenizer"`
+	InstructType   string `json:"instruct_type"`
+}
+
+type orPricing struct {
+	Prompt     string `json:"prompt"`     // per-token cost as string
+	Completion string `json:"completion"` // per-token cost as string
+}
+
+type orTopProvider struct {
+	MaxCompletionTokens int  `json:"max_completion_tokens"`
+	IsModerated         bool `json:"is_moderated"`
+}