feat: currencies endpoint (#2126)

api/openapi.yaml

@@ -9,6 +9,7 @@ info:
     OpenMeter is a cloud native usage metering service.
     The OpenMeter API allows you to ingest events, query meter usage, and manage resources.
 tags:
+  - name: Static Data
   - name: Meters
     description: Meters specify how to aggregate events for billing and analytics purposes. Meters can be configured with multiple aggregation methods and groupings. Multiple meters can be created for the same event type, enabling flexible metering scenarios.
   - name: Events
@@ -5709,6 +5710,59 @@ paths:
                 $ref: '#/components/schemas/UnexpectedProblemResponse'
       tags:
         - Portal
+  /api/v1/static/currencies:
+    get:
+      operationId: listCurrencies
+      summary: List supported currencies
+      description: List all supported currencies.
+      parameters: []
+      responses:
+        '200':
+          description: The request has succeeded.
+          content:
+            application/json:
+              schema:
+                type: array
+                items:
+                  $ref: '#/components/schemas/Currency'
+        '400':
+          description: The server cannot or will not process the request due to something that is perceived to be a client error (e.g., malformed request syntax, invalid request message framing, or deceptive request routing).
+          content:
+            application/problem+json:
+              schema:
+                $ref: '#/components/schemas/BadRequestProblemResponse'
+        '401':
+          description: The request has not been applied because it lacks valid authentication credentials for the target resource.
+          content:
+            application/problem+json:
+              schema:
+                $ref: '#/components/schemas/UnauthorizedProblemResponse'
+        '403':
+          description: The server understood the request but refuses to authorize it.
+          content:
+            application/problem+json:
+              schema:
+                $ref: '#/components/schemas/ForbiddenProblemResponse'
+        '500':
+          description: The server encountered an unexpected condition that prevented it from fulfilling the request.
+          content:
+            application/problem+json:
+              schema:
+                $ref: '#/components/schemas/InternalServerErrorProblemResponse'
+        '503':
+          description: The server is currently unable to handle the request due to a temporary overload or scheduled maintenance, which will likely be alleviated after some delay.
+          content:
+            application/problem+json:
+              schema:
+                $ref: '#/components/schemas/ServiceUnavailableProblemResponse'
+        default:
+          description: An unexpected error response.
+          content:
+            application/problem+json:
+              schema:
+                $ref: '#/components/schemas/UnexpectedProblemResponse'
+      tags:
+        - Static Data
   /api/v1/stripe/checkout/sessions:
     post:
       operationId: createStripeCheckoutSession
@@ -8700,6 +8754,29 @@ components:
       allOf:
         - $ref: '#/components/schemas/InvoiceGenericDocumentRef'
       description: CreditNoteOriginalInvoiceRef is used to reference the original invoice that a credit note is based on.
+    Currency:
+      type: object
+      required:
+        - code
+        - name
+        - symbol
+        - subunits
+      properties:
+        code:
+          allOf:
+            - $ref: '#/components/schemas/CurrencyCode'
+          description: The currency ISO code.
+        name:
+          type: string
+          description: The currency name.
+        symbol:
+          type: string
+          description: The currency symbol.
+        subunits:
+          type: integer
+          format: uint32
+          description: Subunit of the currency.
+      description: Currency describes a currency supported by OpenMeter.
     CurrencyCode:
       type: string
       minLength: 3

api/spec/src/cloud/main.tsp

@@ -253,6 +253,12 @@ namespace OpenMeterCloud.ProductCatalog {
   interface Subscriptions extends OpenMeter.ProductCatalog.Subscriptions {}
 }
 
+namespace OpenMeterCloud.Static {
+  @route("/api/v1/static")
+  @tag("Static Data")
+  interface Currencies extends OpenMeter.Static.Currencies {}
+}
+
 /**
  * A meter is a configuration that defines how to match and aggregate events.
  */

api/spec/src/main.tsp

@@ -20,6 +20,7 @@ import "./notification";
 import "./entitlements";
 import "./billing";
 import "./productcatalog";
+import "./static";
 
 using TypeSpec.Http;
 using TypeSpec.Rest;

api/spec/src/static/currencies.tsp

@@ -0,0 +1,30 @@
+namespace OpenMeter.Static;
+
+using TypeSpec.Http;
+using TypeSpec.OpenAPI;
+
+/**
+ * Currency describes a currency supported by OpenMeter.
+ */
+@friendlyName("Currency")
+model Currency {
+  /**
+   * The currency ISO code.
+   */
+  code: CurrencyCode;
+
+  /**
+   * The currency name.
+   */
+  name: string;
+
+  /**
+   * The currency symbol.
+   */
+  symbol: string;
+
+  /**
+   * Subunit of the currency.
+   */
+  subunits: uint32;
+}

api/spec/src/static/main.tsp

@@ -0,0 +1,11 @@
+import "@typespec/http";
+import "@typespec/openapi";
+import "@typespec/openapi3";
+
+import "..";
+
+// Package Contents
+import "./currencies.tsp";
+import "./routes.tsp";
+
+namespace OpenMeter.Static;

api/spec/src/static/routes.tsp

@@ -0,0 +1,19 @@
+import "../rest.tsp";
+
+namespace OpenMeter.Static;
+
+using TypeSpec.Http;
+using TypeSpec.OpenAPI;
+
+@route("/api/v1/static")
+@tag("Static Data")
+interface Currencies {
+  /**
+   * List all supported currencies.
+   */
+  @get
+  @operationId("listCurrencies")
+  @route("/currencies")
+  @summary("List supported currencies")
+  listCurrencies(): Currency[] | OpenMeter.CommonErrors;
+}

openmeter/server/router/router.go

@@ -40,6 +40,7 @@ import (
 	plansubscription "github.com/openmeterio/openmeter/openmeter/productcatalog/subscription"
 	subscriptionhttpdriver "github.com/openmeterio/openmeter/openmeter/productcatalog/subscription/http"
 	"github.com/openmeterio/openmeter/openmeter/server/authenticator"
+	statichttpdriver "github.com/openmeterio/openmeter/openmeter/static/httpdriver"
 	"github.com/openmeterio/openmeter/openmeter/streaming"
 	"github.com/openmeterio/openmeter/openmeter/subscription"
 	"github.com/openmeterio/openmeter/pkg/errorsx"
@@ -182,6 +183,7 @@ type Router struct {
 	entitlementHandler        entitlementdriver.EntitlementHandler
 	meteredEntitlementHandler entitlementdriver.MeteredEntitlementHandler
 	notificationHandler       notificationhttpdriver.Handler
+	staticHandler             statichttpdriver.Handler
 }
 
 // Make sure we conform to ServerInterface
@@ -236,6 +238,10 @@ func NewRouter(config Config) (*Router, error) {
 		httptransport.WithErrorHandler(config.ErrorHandler),
 	)
 
+	router.staticHandler = statichttpdriver.New(
+		httptransport.WithErrorHandler(config.ErrorHandler),
+	)
+
 	// Customer
 	router.customerHandler = customerhttpdriver.New(
 		staticNamespaceDecoder,

openmeter/server/router/static.go

@@ -0,0 +1,9 @@
+package router
+
+import "net/http"
+
+// List supported currencies
+// (GET /api/v1/static/currencies)
+func (a *Router) ListCurrencies(w http.ResponseWriter, r *http.Request) {
+	a.staticHandler.ListCurrencies().ServeHTTP(w, r)
+}

openmeter/static/httpdriver/currencies.go

@@ -0,0 +1,45 @@
+package httpdriver
+
+import (
+	"context"
+	"net/http"
+
+	"github.com/invopop/gobl/currency"
+	"github.com/samber/lo"
+
+	"github.com/openmeterio/openmeter/api"
+	"github.com/openmeterio/openmeter/pkg/framework/commonhttp"
+	"github.com/openmeterio/openmeter/pkg/framework/transport/httptransport"
+)
+
+type (
+	ListCurrenciesRequest  struct{}
+	ListCurrenciesResponse []api.Currency
+	ListCurrenciesHandler  httptransport.Handler[ListCurrenciesRequest, ListCurrenciesResponse]
+)
+
+func (h *handler) ListCurrencies() ListCurrenciesHandler {
+	return httptransport.NewHandler(
+		func(ctx context.Context, r *http.Request) (ListCurrenciesRequest, error) {
+			return ListCurrenciesRequest{}, nil
+		},
+		func(ctx context.Context, request ListCurrenciesRequest) (ListCurrenciesResponse, error) {
+			defs := currency.Definitions()
+
+			return lo.Map(defs, func(def *currency.Def, _ int) api.Currency {
+				return api.Currency{
+					Code:     api.CurrencyCode(def.ISOCode),
+					Name:     def.Name,
+					Symbol:   def.Symbol,
+					Subunits: def.Subunits,
+				}
+			}), nil
+		},
+		commonhttp.JSONResponseEncoderWithStatus[ListCurrenciesResponse](http.StatusOK),
+		httptransport.AppendOptions(
+			h.options,
+			httptransport.WithOperationName("listCurrencies"),
+			httptransport.WithErrorEncoder(errorEncoder()),
+		)...,
+	)
+}

openmeter/static/httpdriver/driver.go

@@ -0,0 +1,17 @@
+package httpdriver
+
+import "github.com/openmeterio/openmeter/pkg/framework/transport/httptransport"
+
+type Handler interface {
+	ListCurrencies() ListCurrenciesHandler
+}
+
+type handler struct {
+	options []httptransport.HandlerOption
+}
+
+func New(options ...httptransport.HandlerOption) Handler {
+	return &handler{
+		options: options,
+	}
+}

openmeter/static/httpdriver/errors.go

@@ -0,0 +1,16 @@
+package httpdriver
+
+import (
+	"context"
+	"net/http"
+
+	"github.com/openmeterio/openmeter/pkg/framework/commonhttp"
+	"github.com/openmeterio/openmeter/pkg/framework/transport/httptransport"
+	"github.com/openmeterio/openmeter/pkg/models"
+)
+
+func errorEncoder() httptransport.ErrorEncoder {
+	return func(ctx context.Context, err error, w http.ResponseWriter, r *http.Request) bool {
+		return commonhttp.HandleErrorIfTypeMatches[*models.GenericUserError](ctx, http.StatusBadRequest, err, w)
+	}
+}