feat(routing): router dispatch wrapper

Composes Fetcher + Policy + Logger + CompleteFunc into a single Run method. Falls open to Claude on local-model errors; defaults to local when brain is unreachable. Skill packages will receive Router.Run as their CompleteFunc. Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-05-04 22:51:01 +02:00
parent 2a5a74f7c0
commit 9a258ca32a
2 changed files with 216 additions and 0 deletions
--- a/internal/routing/router.go
+++ b/internal/routing/router.go
@@ -0,0 +1,80 @@
+package routing
+
+import (
+	"context"
+	"fmt"
+	"log/slog"
+)
+
+// CompleteFunc matches the signature used by every skill package's Config.
+type CompleteFunc func(ctx context.Context, model, system, user string) (string, int64, error)
+
+// RunInput captures the per-call inputs the dispatch wrapper needs.
+type RunInput struct {
+	Skill       string
+	System      string
+	User        string
+	SessionID   string
+	ProjectRoot string
+}
+
+// Router composes a pass-rate fetcher, a decision policy, a session logger,
+// and a LiteLLM client. Skill packages receive Router.Run as their CompleteFunc.
+type Router struct {
+	Fetcher     *Fetcher
+	Logger      *Logger
+	Policy      Policy
+	LocalModel  string
+	ClaudeModel string
+	Complete    CompleteFunc
+}
+
+// Run executes one skill call: decides local vs claude, calls LiteLLM, logs the
+// decision. On local-side error, falls open by retrying once on the Claude model.
+func (r *Router) Run(ctx context.Context, in RunInput) (string, int64, error) {
+	pr, ferr := r.Fetcher.Get(ctx, in.Skill)
+	if ferr != nil {
+		slog.Warn("router: pass-rate unreachable, defaulting to local", "skill", in.Skill, "err", ferr)
+		pr = nil
+	}
+	hash := CanonicalHash(in.System, in.User)
+	decision := r.Policy.Decide(pr, hash)
+
+	model := r.ClaudeModel
+	if decision == DecideLocal {
+		model = r.LocalModel
+	}
+
+	out, ms, err := r.Complete(ctx, model, in.System, in.User)
+	_ = r.Logger.LogDecision(ctx, LogEntry{
+		SessionID:   in.SessionID,
+		Skill:       in.Skill,
+		Decision:    decision.String(),
+		Message:     fmt.Sprintf("model=%s, pass_rate=%s", model, formatPassRate(pr)),
+		ProjectRoot: in.ProjectRoot,
+		DurationMs:  ms,
+		Failed:      err != nil,
+	})
+
+	if err != nil && decision == DecideLocal {
+		slog.Warn("router: local failed, falling open to claude", "skill", in.Skill, "err", err)
+		out, ms, err = r.Complete(ctx, r.ClaudeModel, in.System, in.User)
+		_ = r.Logger.LogDecision(ctx, LogEntry{
+			SessionID:   in.SessionID,
+			Skill:       in.Skill,
+			Decision:    "claude_fallback",
+			Message:     fmt.Sprintf("model=%s, after-local-error", r.ClaudeModel),
+			ProjectRoot: in.ProjectRoot,
+			DurationMs:  ms,
+			Failed:      err != nil,
+		})
+	}
+	return out, ms, err
+}
+
+func formatPassRate(pr *float64) string {
+	if pr == nil {
+		return "null"
+	}
+	return fmt.Sprintf("%.2f", *pr)
+}