feat(payments): implement SendInvoice

Send invoices via messages.sendMedia with InputMediaInvoice. InvoiceParams
carries the invoice fields (prices, tips, provider data, photo, the
need_*/send_*_to_provider/flexible flags); standard SendOptions apply
markup/silent/reply. Share pricesToTg with the shipping answer.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

Author: ernado

conformance_test.go

@@ -21,7 +21,6 @@ var coveredByOtherMeans = map[string]string{
 // implemented. Each is an acknowledged gap tracked in docs/roadmap.md; the
 // conformance test allows them so it can still catch *unacknowledged* drift.
 var deferredMethods = map[string]string{
-	"sendInvoice":           "payments — deferred",
 	"setPassportDataErrors": "Telegram Passport — deferred",
 }
 

payments.go

@@ -97,11 +97,7 @@ func WithPreCheckoutError(message string) PreCheckoutAnswerOption {
 func shippingOptionsToTg(options []ShippingOption) []tg.ShippingOption {
 	out := make([]tg.ShippingOption, 0, len(options))
 	for _, o := range options {
-		prices := make([]tg.LabeledPrice, 0, len(o.Prices))
-		for _, p := range o.Prices {
-			prices = append(prices, tg.LabeledPrice{Label: p.Label, Amount: int64(p.Amount)})
-		}
-		out = append(out, tg.ShippingOption{ID: o.ID, Title: o.Title, Prices: prices})
+		out = append(out, tg.ShippingOption{ID: o.ID, Title: o.Title, Prices: pricesToTg(o.Prices)})
 	}
 	return out
 }

send_invoice.go

@@ -0,0 +1,108 @@
+package botapi
+
+import (
+	"context"
+
+	"github.com/gotd/td/telegram/message"
+	"github.com/gotd/td/tg"
+)
+
+// InvoiceParams describes an invoice to send with SendInvoice.
+type InvoiceParams struct {
+	Title         string         `json:"title"`
+	Description   string         `json:"description"`
+	Payload       string         `json:"payload"` // bot-defined, not shown to the user
+	ProviderToken string         `json:"provider_token"`
+	Currency      string         `json:"currency"`
+	Prices        []LabeledPrice `json:"prices"`
+
+	MaxTipAmount        int    `json:"max_tip_amount,omitempty"`
+	SuggestedTipAmounts []int  `json:"suggested_tip_amounts,omitempty"`
+	StartParameter      string `json:"start_parameter,omitempty"`
+	ProviderData        string `json:"provider_data,omitempty"` // JSON for the payment provider
+
+	PhotoURL    string `json:"photo_url,omitempty"`
+	PhotoSize   int    `json:"photo_size,omitempty"`
+	PhotoWidth  int    `json:"photo_width,omitempty"`
+	PhotoHeight int    `json:"photo_height,omitempty"`
+
+	NeedName            bool `json:"need_name,omitempty"`
+	NeedPhoneNumber     bool `json:"need_phone_number,omitempty"`
+	NeedEmail           bool `json:"need_email,omitempty"`
+	NeedShippingAddress bool `json:"need_shipping_address,omitempty"`
+
+	SendPhoneNumberToProvider bool `json:"send_phone_number_to_provider,omitempty"`
+	SendEmailToProvider       bool `json:"send_email_to_provider,omitempty"`
+	IsFlexible                bool `json:"is_flexible,omitempty"`
+}
+
+// SendInvoice sends an invoice.
+func (b *Bot) SendInvoice(ctx context.Context, chat ChatID, params InvoiceParams, opts ...SendOption) (*Message, error) {
+	var cfg sendConfig
+	for _, o := range opts {
+		o(&cfg)
+	}
+
+	peer, err := b.resolveInputPeer(ctx, chat)
+	if err != nil {
+		return nil, err
+	}
+
+	suggested := make([]int64, len(params.SuggestedTipAmounts))
+	for i, a := range params.SuggestedTipAmounts {
+		suggested[i] = int64(a)
+	}
+	invoice := tg.Invoice{
+		NameRequested:            params.NeedName,
+		PhoneRequested:           params.NeedPhoneNumber,
+		EmailRequested:           params.NeedEmail,
+		ShippingAddressRequested: params.NeedShippingAddress,
+		Flexible:                 params.IsFlexible,
+		PhoneToProvider:          params.SendPhoneNumberToProvider,
+		EmailToProvider:          params.SendEmailToProvider,
+		Currency:                 params.Currency,
+		Prices:                   pricesToTg(params.Prices),
+		MaxTipAmount:             int64(params.MaxTipAmount),
+		SuggestedTipAmounts:      suggested,
+	}
+
+	media := &tg.InputMediaInvoice{
+		Title:       params.Title,
+		Description: params.Description,
+		Invoice:     invoice,
+		Payload:     []byte(params.Payload),
+		Provider:    params.ProviderToken,
+		StartParam:  params.StartParameter,
+	}
+	if params.ProviderData != "" {
+		media.ProviderData = tg.DataJSON{Data: params.ProviderData}
+	}
+	if params.PhotoURL != "" {
+		media.SetPhoto(tg.InputWebDocument{
+			URL:      params.PhotoURL,
+			Size:     params.PhotoSize,
+			MimeType: "image/jpeg",
+			Attributes: []tg.DocumentAttributeClass{
+				&tg.DocumentAttributeImageSize{W: params.PhotoWidth, H: params.PhotoHeight},
+			},
+		})
+	}
+
+	builder := &b.sender.To(peer).Builder
+	builder, err = b.applySendConfig(builder, cfg)
+	if err != nil {
+		return nil, err
+	}
+
+	resp, err := builder.Media(ctx, message.Media(media))
+	return b.sentMessage(ctx, peer, resp, err)
+}
+
+// pricesToTg converts Bot API labeled prices to MTProto.
+func pricesToTg(prices []LabeledPrice) []tg.LabeledPrice {
+	out := make([]tg.LabeledPrice, 0, len(prices))
+	for _, p := range prices {
+		out = append(out, tg.LabeledPrice{Label: p.Label, Amount: int64(p.Amount)})
+	}
+	return out
+}