model_router.go RawHistoryFolder

1package provider
2
3import (
4	"context"
5	"fmt"
6)
7
8const (
9	// APIAnthropicMessages identifies the Anthropic Messages wire API.
10	APIAnthropicMessages = "anthropic-messages"
11	// APICompletions identifies the OpenAI Chat Completions wire API.
12	APICompletions = "openai-completions"
13	// APIResponses identifies the OpenAI Responses wire API.
14	APIResponses = "openai-responses"
15)
16
17// modelRouter dispatches each request according to the selected model's API.
18// This lets one provider expose models that use different wire protocols while
19// remaining reusable across model switches.
20type modelRouter struct {
21	name     string
22	fallback Client
23	byAPI    map[string]Client
24}
25
26// NewModelRouter creates a client that dispatches requests using Model.API.
27// Models with no API override, and models absent from the catalog, use fallback.
28func NewModelRouter(name string, fallback Client, byAPI map[string]Client) Client {
29	return &modelRouter{name: name, fallback: fallback, byAPI: byAPI}
30}
31
32func (c *modelRouter) Name() string { return c.name }
33
34func (c *modelRouter) Stream(ctx context.Context, req Request) (<-chan Event, error) {
35	client := c.fallback
36	if model, err := FindModel(c.name, req.Model); err == nil && model.API != "" {
37		routed := c.byAPI[model.API]
38		if routed == nil {
39			return nil, fmt.Errorf("provider %q has no client for model API %q", c.name, model.API)
40		}
41		client = routed
42	}
43	return client.Stream(ctx, req)
44}