api: add tax behavior

api/api.go

@@ -249,10 +249,10 @@ func (h *Handler) serveSubscribe(w http.ResponseWriter, r *http.Request) error {
 				return err
 			}
 			phases = append(phases, control.Phase{
-				Trial:        p.Trial,
-				Effective:    p.Effective,
-				Features:     fs,
-				AutomaticTax: sr.Tax.Automatic,
+				Trial:     p.Trial,
+				Effective: p.Effective,
+				Features:  fs,
+				Tax:       sr.Tax,
 			})
 		}
 	}
@@ -342,9 +342,7 @@ func (h *Handler) servePhase(w http.ResponseWriter, r *http.Request) error {
 				Plans:     p.Plans,
 				Fragments: p.Fragments(),
 				Trial:     p.Trial,
-				Tax: apitypes.Taxation{
-					Automatic: p.AutomaticTax,
-				},
+				Tax:       p.Tax,
 			})
 		}
 	}

api/api_test.go

@@ -18,6 +18,7 @@ import (
 	"tier.run/refs"
 	"tier.run/stripe"
 	"tier.run/stripe/stroke"
+	"tier.run/types/tax"
 	"tier.run/types/they"
 )
 
@@ -319,7 +320,7 @@ func TestScheduleAutomaticTax(t *testing.T) {
 		}
 	})
 	_, err := tc.Schedule(ctx, "org:test", &tier.ScheduleParams{
-		Tax: tier.Taxation{Automatic: true},
+		Tax: tax.Applied{Automatically: true},
 		Phases: []apitypes.Phase{
 			{
 				Features: []string{"plan:test@0"},

api/apitypes/apitypes.go

@@ -7,6 +7,7 @@ import (
 
 	"tier.run/refs"
 	"tier.run/types/payment"
+	"tier.run/types/tax"
 )
 
 type Error struct {
@@ -26,18 +27,14 @@ type Phase struct {
 	Features  []string  `json:"features,omitempty"`
 }
 
-type Taxation struct {
-	Automatic bool `json:"automatic,omitempty"`
-}
-
 type PhaseResponse struct {
 	Effective time.Time          `json:"effective,omitempty"`
 	End       time.Time          `json:"end,omitempty"`
 	Features  []refs.FeaturePlan `json:"features,omitempty"`
 	Plans     []refs.Plan        `json:"plans,omitempty"`
 	Fragments []refs.FeaturePlan `json:"fragments,omitempty"`
 	Trial     bool               `json:"trial,omitempty"`
-	Tax       Taxation           `json:"tax,omitempty"`
+	Tax       tax.Applied        `json:"tax"`
 }
 
 func (pr PhaseResponse) MarshalJSON() ([]byte, error) {
@@ -91,11 +88,11 @@ type CheckoutRequest struct {
 }
 
 type ScheduleRequest struct {
-	Org             string   `json:"org"`
-	PaymentMethodID string   `json:"payment_method_id"`
-	Info            *OrgInfo `json:"info"`
-	Phases          []Phase  `json:"phases"`
-	Tax             Taxation `json:"tax"`
+	Org             string      `json:"org"`
+	PaymentMethodID string      `json:"payment_method_id"`
+	Info            *OrgInfo    `json:"info"`
+	Phases          []Phase     `json:"phases"`
+	Tax             tax.Applied `json:"tax"`
 }
 
 // ScheduleResponse is the expected response from a schedule request. It is

api/apitypes/model.go

@@ -4,6 +4,7 @@ import (
 	"encoding/json"
 
 	"tier.run/refs"
+	"tier.run/types/tax"
 	"tier.run/values"
 )
 
@@ -53,12 +54,47 @@ type Divide struct {
 }
 
 type Feature struct {
-	Title     string  `json:"title,omitempty"`
-	Base      float64 `json:"base,omitempty"`
-	Mode      string  `json:"mode,omitempty"`
-	Aggregate string  `json:"aggregate,omitempty"`
-	Tiers     []Tier  `json:"tiers,omitempty"`
-	Divide    *Divide `json:"divide,omitempty"`
+	Title     string       `json:"title,omitempty"`
+	Base      float64      `json:"base,omitempty"`
+	Mode      string       `json:"mode,omitempty"`
+	Aggregate string       `json:"aggregate,omitempty"`
+	Tiers     []Tier       `json:"tiers,omitempty"`
+	Divide    Divide       `json:"divide"`
+	Tax       tax.Settings `json:"tax"`
+}
+
+func (v Feature) MarshalJSON() ([]byte, error) {
+	return json.Marshal(struct {
+		Title     string        `json:"title,omitempty"`
+		Base      float64       `json:"base,omitempty"`
+		Mode      string        `json:"mode,omitempty"`
+		Aggregate string        `json:"aggregate,omitempty"`
+		Tiers     []Tier        `json:"tiers,omitempty"`
+		Divide    *Divide       `json:"divide,omitempty"`
+		Tax       *tax.Settings `json:"tax,omitempty"`
+	}{
+		Title:     v.Title,
+		Base:      v.Base,
+		Mode:      v.Mode,
+		Aggregate: v.Aggregate,
+		Tiers:     v.Tiers,
+		Divide:    zeroAsNil(v.Divide),
+		Tax:       zeroAsNil(v.Tax),
+	})
+}
+
+// zeroAsNil returns a pointer to v if v is not the zero value for its type.
+// If v implements IsZero, it is used to determine if v is the zero value.
+func zeroAsNil[T comparable](v T) *T {
+	z, ok := any(v).(interface{ IsZero() bool })
+	if ok && z.IsZero() {
+		return nil
+	}
+	var zero T
+	if v == zero {
+		return nil
+	}
+	return &v
 }
 
 type Plan struct {

api/materialize/views.go

@@ -40,7 +40,6 @@ func FromPricingHuJSON(data []byte) (fs []control.Feature, err error) {
 		for feature, f := range p.Features {
 			fn := feature.WithPlan(plan)
 
-			divide := values.Coalesce(f.Divide, &apitypes.Divide{})
 			ff := control.Feature{
 				FeaturePlan: fn,
 
@@ -55,8 +54,10 @@ func FromPricingHuJSON(data []byte) (fs []control.Feature, err error) {
 				Mode:      values.Coalesce(f.Mode, "graduated"),
 				Aggregate: values.Coalesce(f.Aggregate, "sum"),
 
-				TransformDenominator: divide.By,
-				TransformRoundUp:     divide.Rounding == "up",
+				TransformDenominator: f.Divide.By,
+				TransformRoundUp:     f.Divide.Rounding == "up",
+
+				Tax: f.Tax,
 			}
 
 			if len(f.Tiers) > 0 {
@@ -110,13 +111,14 @@ func ToPricingJSON(fs []control.Feature) ([]byte, error) {
 			Mode:      values.ZeroIf(f.Mode, "graduated"),
 			Aggregate: values.ZeroIf(f.Aggregate, "sum"),
 			Tiers:     tiers,
+			Tax:       f.Tax,
 		}
 		if f.TransformDenominator != 0 {
 			var round string
 			if f.TransformRoundUp {
 				round = "up"
 			}
-			af.Divide = &apitypes.Divide{
+			af.Divide = apitypes.Divide{
 				By:       f.TransformDenominator,
 				Rounding: round,
 			}

api/materialize/views_test.go

@@ -11,6 +11,7 @@ import (
 	"tier.run/client/tier"
 	"tier.run/control"
 	"tier.run/refs"
+	"tier.run/types/tax"
 )
 
 func TestPricingHuJSON(t *testing.T) {
@@ -41,6 +42,13 @@ func TestPricingHuJSON(t *testing.T) {
 					}
 				},
 			},
+			"plan:tax@1": {
+				"features": {
+					"feature:tax:not:included": {
+						"tax": {"included": true},
+					},
+				},
+			},
 		}
 	}`)
 
@@ -63,6 +71,16 @@ func TestPricingHuJSON(t *testing.T) {
 			Aggregate:   "sum",       // defaults
 			Base:        100,
 		},
+		{
+			PlanTitle:   "plan:tax@1",
+			Title:       "feature:tax:not:included@plan:tax@1",
+			FeaturePlan: refs.MustParseFeaturePlan("feature:tax:not:included@plan:tax@1"),
+			Currency:    "usd",
+			Interval:    "@monthly",
+			Mode:        "graduated", // defaults
+			Aggregate:   "sum",
+			Tax:         tax.Settings{Included: true},
+		},
 		{
 			PlanTitle:   "Just an example plan to show off features",
 			Title:       "feature:volume@plan:example@1",
@@ -123,6 +141,14 @@ func TestPricingHuJSON(t *testing.T) {
 						"divide": {"by": 100, "rounding": "up"},
 					}
 				}
+			},
+			"plan:tax@1": {
+				"title": "plan:tax@1",
+				"features": {
+					"feature:tax:not:included": {
+						"tax": {"included": true}
+					}
+				}
 			}
 		}
 	}`)
@@ -134,6 +160,7 @@ func diffJSON(t *testing.T, got, want []byte) {
 	t.Helper()
 
 	format := func(b []byte) string {
+		t.Helper()
 		b, err := hujson.Standardize(b)
 		if err != nil {
 			t.Fatal(err)

client/tier/client.go

@@ -17,6 +17,7 @@ import (
 	"tier.run/api/apitypes"
 	"tier.run/fetch"
 	"tier.run/refs"
+	"tier.run/types/tax"
 )
 
 // ClockHeader is the header used to pass the clock ID to the tier sidecar.
@@ -305,14 +306,12 @@ type CheckoutParams struct {
 	RequireBillingAddress bool
 }
 
-type Taxation = apitypes.Taxation
-
 type ScheduleParams struct {
 	Info            *OrgInfo
 	Phases          []Phase
 	PaymentMethodID string
 
-	Tax Taxation
+	Tax tax.Applied
 }
 
 func (c *Client) Schedule(ctx context.Context, org string, p *ScheduleParams) (*apitypes.ScheduleResponse, error) {

cmd/tier/tier.go

@@ -29,6 +29,7 @@ import (
 	"tier.run/control"
 	"tier.run/profile"
 	"tier.run/stripe"
+	"tier.run/types/tax"
 	"tier.run/version"
 )
 
@@ -279,7 +280,7 @@ func runTier(cmd string, args []string) (err error) {
 		cancelURL := fs.String("cancel_url", "", "sets the cancel URL for use with -checkout")
 		requireBillingAddress := fs.Bool("require_billing_address", false, "require billing address for use with --checkout")
 		paymentMethod := fs.String("paymentmethod", "", "sets the Stripe payment method for the subscription (e.g. pm_123). It is ignored with --checkout")
-		tax := fs.String("tax", "", "sets the Stripe tax rate for the subscription ('auto' is currently the only supported value)")
+		taxtype := fs.String("tax", "", "sets the Stripe tax rate for the subscription ('auto' is currently the only supported value)")
 		if err := fs.Parse(args); err != nil {
 			return err
 		}
@@ -293,8 +294,8 @@ func runTier(cmd string, args []string) (err error) {
 			fmt.Fprintln(stderr, "tier: the -cancel flag must be used without arguments")
 			return errUsage
 		}
-		if *tax != "" && *tax != "auto" {
-			fmt.Fprintf(stderr, "tier: invalid tax rate %q\n", *tax)
+		if *taxtype != "" && *taxtype != "auto" {
+			fmt.Fprintf(stderr, "tier: invalid tax rate %q\n", *taxtype)
 			return errUsage
 		}
 
@@ -324,7 +325,7 @@ func runTier(cmd string, args []string) (err error) {
 					Email: *email,
 				},
 				PaymentMethodID: *paymentMethod,
-				Tax:             tier.Taxation{Automatic: *tax == "auto"},
+				Tax:             tax.Applied{Automatically: *taxtype == "auto"},
 			}
 			switch {
 			case *trial > 0:

control/client.go

@@ -12,6 +12,7 @@ import (
 	"golang.org/x/sync/errgroup"
 	"tier.run/refs"
 	"tier.run/stripe"
+	"tier.run/types/tax"
 	"tier.run/values"
 )
 
@@ -106,6 +107,8 @@ type Feature struct {
 
 	TransformDenominator int  // the denominator for transforming usage
 	TransformRoundUp     bool // whether to round up transformed usage; otherwise round down
+
+	Tax tax.Settings
 }
 
 // TODO(bmizerany): remove FQN and replace with simply adding the version to
@@ -330,9 +333,13 @@ func (c *Client) pushFeature(ctx context.Context, f Feature) (providerID string,
 		data.Set("metadata", "tier.limit", limit)
 	}
 
+	if f.Tax.Included {
+		data.Set("tax_behavior", "inclusive")
+	} else {
+		data.Set("tax_behavior", "exclusive")
+	}
+
 	// TODO(bmizerany): data.Set("active", ?)
-	// TODO(bmizerany): data.Set("tax_behavior", "?")
-	// TODO(bmizerany): data.Set("transform_quantity", "?")
 	// TODO(bmizerany): data.Set("currency_options", "?")
 
 	var v struct {
@@ -374,6 +381,7 @@ type stripePrice struct {
 		DivideBy int    `json:"divide_by"`
 		Round    string `json:"round"`
 	} `json:"transform_quantity"`
+	TaxBehavior string `json:"tax_behavior"`
 }
 
 func stripePriceToFeature(p stripePrice) Feature {
@@ -388,6 +396,7 @@ func stripePriceToFeature(p stripePrice) Feature {
 		Aggregate:            aggregateFromStripe[p.Recurring.AggregateUsage],
 		TransformDenominator: p.TransformQuantity.DivideBy,
 		TransformRoundUp:     p.TransformQuantity.Round == "up",
+		Tax:                  tax.Settings{Included: p.TaxBehavior == "inclusive"},
 	}
 
 	if len(p.Tiers) == 0 && p.Recurring.UsageType == "metered" {

control/client_test.go

@@ -10,6 +10,7 @@ import (
 	"kr.dev/diff"
 	"tier.run/refs"
 	"tier.run/stripe/stroke"
+	"tier.run/types/tax"
 )
 
 func newTestClient(t *testing.T) *Client {
@@ -80,6 +81,14 @@ func TestRoundTrip(t *testing.T) {
 				{Upto: 1, Price: 100, Base: 0},
 			},
 		},
+		{
+			FeaturePlan: refs.MustParseFeaturePlan("feature:tax@0"),
+			Interval:    "@daily",
+			Currency:    "eur",
+			Title:       "Test2",
+			Base:        1000,
+			Tax:         tax.Settings{Included: true},
+		},
 	}
 
 	if !slices.IsSortedFunc(want, func(a, b Feature) bool {