diff --git a/lib/revenuecat/revenuecat.go b/lib/revenuecat/revenuecat.go
new file mode 100644
index 0000000..bf86998
--- /dev/null
+++ b/lib/revenuecat/revenuecat.go
@@ -0,0 +1,68 @@
+package revenuecat
+
+import (
+	"context"
+	"fmt"
+	"net/url"
+	"time"
+
+	"github.com/wearemojo/mojo-public-go/lib/httpclient"
+	"github.com/wearemojo/mojo-public-go/lib/jsonclient"
+	"github.com/wearemojo/mojo-public-go/lib/secret"
+)
+
+const baseURL = "https://api.revenuecat.com/v1"
+
+type Client struct {
+	client *jsonclient.Client
+}
+
+func NewClient(ctx context.Context, serverTokenSecretID string) (*Client, error) {
+	if _, err := secret.Get(ctx, serverTokenSecretID); err != nil {
+		return nil, err
+	}
+
+	return &Client{
+		client: jsonclient.NewClient(
+			baseURL,
+			httpclient.NewClient(5*time.Second, roundTripper{serverTokenSecretID}),
+		),
+	}, nil
+}
+
+type UserInfoResponse struct {
+	Subscriber Subscriber `json:"subscriber"`
+}
+
+type Subscriber struct {
+	Entitlements  map[string]Entitlement  `json:"entitlements"`
+	Subscriptions map[string]Subscription `json:"subscriptions"`
+}
+
+type Entitlement struct {
+	ExpiresDate       time.Time `json:"expires_date"`
+	ProductIdentifier string    `json:"product_identifier"`
+}
+
+type Subscription struct {
+	PeriodType            PeriodType `json:"period_type"`
+	UnsubscribeDetectedAt *time.Time `json:"unsubscribe_detected_at"`
+}
+
+type PeriodType string
+
+const (
+	PeriodTypeTrial  PeriodType = "trial"
+	PeriodTypeIntro  PeriodType = "intro"
+	PeriodTypeNormal PeriodType = "normal"
+)
+
+// https://www.revenuecat.com/reference/subscribers
+// This API either fetches a user or creates one :shrug:
+// for now, we only care about the expiry date of the full_access entitlement
+// and the period type of the subscription. See useSubscriptionStateIap.ts
+func (c *Client) GetOrCreateSubscriberInfo(ctx context.Context, appUserID string) (res *UserInfoResponse, err error) {
+	escapedAppUserID := url.PathEscape(appUserID)
+	path := fmt.Sprintf("/subscribers/%s", escapedAppUserID)
+	return res, c.client.Do(ctx, "GET", path, nil, nil, &res)
+}
diff --git a/lib/revenuecat/roundtripper.go b/lib/revenuecat/roundtripper.go
new file mode 100644
index 0000000..116fa33
--- /dev/null
+++ b/lib/revenuecat/roundtripper.go
@@ -0,0 +1,30 @@
+package revenuecat
+
+import (
+	"fmt"
+	"net/http"
+
+	"github.com/wearemojo/mojo-public-go/lib/secret"
+)
+
+type roundTripper struct {
+	SecretID string
+}
+
+func (r roundTripper) RoundTrip(req *http.Request) (*http.Response, error) {
+	ctx := req.Context()
+	req = req.Clone(ctx)
+
+	apiKey, err := secret.Get(ctx, r.SecretID)
+	if err != nil {
+		return nil, err
+	}
+
+	if req.Header == nil {
+		req.Header = http.Header{}
+	}
+
+	req.Header.Set("Authorization", fmt.Sprintf("Bearer %s", apiKey))
+
+	return http.DefaultTransport.RoundTrip(req)
+}