# Add cost-proxy token guidance

```go
import (
	"context"
	"encoding/json"
	"errors"
	"fmt"
	"io"
	"strconv"
)

func newCheckpointTokensCmd() *cobra.Command {
	var jsonFlag bool
	var compareFlag string
	var agentBriefFlag bool

cmd := &cobra.Command{
		Use:   "tokens <checkpoint-id>",
		...
	}

cmd.Flags().BoolVar(&jsonFlag, "json", false, "Output as JSON")
	cmd.Flags().StringVar(&compareFlag, "compare", "", "Compare against a baseline checkpoint ID")
	cmd.Flags().BoolVar(&agentBriefFlag, "agent-brief", false, "Output compact next-step guidance for agents")
	return cmd
}

func runCheckpointTokens(ctx context.Context, cmd *cobra.Command, checkpointIDPrefix string, jsonOutput bool, comparePrefix string) error {
	report, lookup, err := loadCheckpointTokensReport(ctx, cmd, checkpointIDPrefix)
	if lookup != nil {
		defer lookup.Close()
	}
	...
}

func writeCheckpointTokensAgentBrief(w io.Writer, report checkpointTokensReport) {
	fmt.Fprintln(w, "Checkpoint token brief")
	fmt.Fprintf(w, "Checkpoint: %s\n", report.CheckpointID)
	...
}

func checkpointAgentBriefNextAction(report checkpointTokensReport) string {
	...
}

func formatTokenClassList(classes []string) string {
	switch len(classes) {
	case 0:
		return ""
	case 1:
		return classes[0]
	case 2:
		return classes[0] + " and " + classes[1]
	default:
		return strings.Join(classes[:len(classes)-1], ", ") + ", and " + classes[len(classes)-1]
	}
}

func buildCheckpointMetricDelta(baseline, current int) *checkpointTokensMetricDelta {
	delta := &checkpointTokensMetricDelta{
		Baseline:  baseline,
		Current:   current,
		...
	}
	return delta
}

```

## Changes

- cmd/entire/cli
  - Mcheckpoint_tokens.go+90/-2
  - Msession_tokens.go+62/-9
  - Msessions_test.go+352/-16

```go
func TestRecommendationRules_CacheWritePressure(t *testing.T) {
	t.Parallel()

recs := recommendationRules(tokenRecommendationSignals{
		Tokens: &sessionTokensUsage{
			Total:      50_000,
			CacheWrite: 6_000,
		},
	})

if !recommendationsIncludeID(recs, "cache-write-pressure") {
		t.Fatalf("expected cache-write-pressure recommendation, got %+v", recs)
	}
}

func recommendationsIncludeID(recs []sessionTokensRecommendation, id string) bool {
	for _, rec := range recs {
		if rec.ID == id {
			return true
		}
	}
	return false
}

```