feat: ModelRouter — unified OpenAI-compatible multi-source LLM gateway

- Lua adapters per upstream (transform_request/response/stream_chunk, build_headers signing hooks) - AUTO priority routing with per-model kind (chat/image), explicit source/model routing - Per-source concurrency caps with queueing, exponential backoff, AUTO failover - OpenAI-compatible API: chat completions, SSE streaming, image generations, models - Gateway key auth, web UI for adapter/source management, runtime persistence - e2e test running the real binary against mocked upstreams
2026-09-20 08:57:57 +00:00 · 2026-08-05 15:24:51 +08:00
parent 8631b08253
commit f7f76e097d
32 changed files with 4382 additions and 2 deletions
--- a/internal/types/types.go
+++ b/internal/types/types.go
@ -0,0 +1,120 @@
+// Package types defines the unified (OpenAI-compatible) wire format that the
+// gateway exposes to its clients, plus the unified internal representation.
+package types
+
+import (
+	"encoding/json"
+	"time"
+)
+
+// ---- OpenAI wire request (gateway input) ----
+
+type ChatRequest struct {
+	Model            string             `json:"model"`
+	Messages         []ChatMessage      `json:"messages"`
+	Temperature      *float64           `json:"temperature,omitempty"`
+	MaxTokens        int                `json:"max_tokens,omitempty"`
+	Stream           bool               `json:"stream,omitempty"`
+	Tools            []interface{}      `json:"tools,omitempty"`
+	ToolChoice       interface{}        `json:"tool_choice,omitempty"`
+	DisableThinking  bool               `json:"disable_thinking"`
+	ExtraBody        map[string]interface{} `json:"-"`
+}
+
+func (r *ChatRequest) MarshalJSON() ([]byte, error) {
+	type Alias ChatRequest
+	data, err := json.Marshal((*Alias)(r))
+	if err != nil {
+		return nil, err
+	}
+	if len(r.ExtraBody) == 0 {
+		return data, nil
+	}
+	var raw map[string]interface{}
+	if err := json.Unmarshal(data, &raw); err != nil {
+		return nil, err
+	}
+	for k, v := range r.ExtraBody {
+		raw[k] = v
+	}
+	return json.Marshal(raw)
+}
+
+// ChatMessage supports both plain string content and multimodal arrays
+// (RawMessage preserves whatever the client sent for the adapter to process).
+type ChatMessage struct {
+	Role             string          `json:"role"`
+	Content          json.RawMessage `json:"content,omitempty"`
+	ReasoningContent string          `json:"reasoning_content,omitempty"`
+	ToolCallID       string          `json:"tool_call_id,omitempty"`
+	ToolCalls        []ToolCall      `json:"tool_calls,omitempty"`
+}
+
+func StringContent(s string) json.RawMessage { b, _ := json.Marshal(s); return b }
+
+type ToolCall struct {
+	ID        string                 `json:"id"`
+	Type      string                 `json:"type"`
+	Name      string                 `json:"name"`
+	Arguments map[string]interface{} `json:"arguments"`
+}
+
+// ---- Unified internal representation (what adapters produce) ----
+
+type UnifiedResponse struct {
+	Content          string     `json:"content"`
+	ReasoningContent string     `json:"reasoning_content,omitempty"`
+	FinishReason     string     `json:"finish_reason,omitempty"`
+	TokenUsage       TokenUsage `json:"token_usage"`
+	ToolCalls        []ToolCall `json:"tool_calls,omitempty"`
+	// ImageData used by image-generation adapters.
+	ImageData []ImageData `json:"image_data,omitempty"`
+}
+
+type TokenUsage struct {
+	Prompt     int `json:"prompt"`
+	Completion int `json:"completion"`
+	Total      int `json:"total"`
+}
+
+type ImageData struct {
+	B64JSON string `json:"b64_json,omitempty"`
+	URL     string `json:"url,omitempty"`
+	Revised string `json:"revised_prompt,omitempty"`
+}
+
+// ---- Image generation (OpenAI /v1/images/generations wire) ----
+
+type ImageGenRequest struct {
+	Model          string `json:"model"`
+	Prompt         string `json:"prompt"`
+	N              int    `json:"n,omitempty"`
+	Size           string `json:"size,omitempty"`
+	ResponseFormat string `json:"response_format,omitempty"`
+}
+
+type ImageGenResponse struct {
+	Created int64       `json:"created"`
+	Data    []ImageData `json:"data"`
+}
+
+// ---- Unified streaming chunk produced by adapters ----
+
+type UnifiedChunk struct {
+	Content          string     `json:"content"`
+	Done             bool       `json:"done"`
+	ToolCalls        []ToolCall `json:"tool_calls,omitempty"`
+	ReasoningContent string     `json:"reasoning_content,omitempty"`
+}
+
+// Meta passed to Lua build_headers hook
+type BuildMeta struct {
+	URL       string                 `json:"url"`
+	Method    string                 `json:"method"`
+	Body      string                 `json:"body"`
+	APIKey    string                 `json:"api_key"`
+	Timestamp int64                  `json:"timestamp"`
+	Source    map[string]interface{} `json:"source"`
+}
+
+func Now() int64 { return time.Now().Unix() }