diff --git a/src/types/events.ts b/src/types/events.ts
index c20f5fb..77f9f42 100644
--- a/src/types/events.ts
+++ b/src/types/events.ts
@@ -16,12 +16,66 @@ export interface EventCursor {
   updatedAt: number;
 }
 
+// ---------------------------------------------------------------------------
+// Discriminated event payload interfaces
+// ---------------------------------------------------------------------------
+
+/** Subscription successfully established. */
+export interface ConnectedEvent {
+  kind: "Connected";
+  type: "connected";
+  invoiceId: string;
+}
+
+/** Subscription lost; consumers may wish to show an error or auto-retry. */
+export interface DisconnectedEvent {
+  kind: "Disconnected";
+  type: "disconnected";
+  invoiceId: string;
+  error: Error;
+}
+
+/** Reconnection attempt in progress. */
+export interface ReconnectingEvent {
+  kind: "Reconnecting";
+  type: "reconnecting";
+  invoiceId: string;
+  attempt: number;
+  delayMs: number;
+}
+
+/** Event cursor persisted to storage for crash recovery. */
+export interface CursorPersistedEvent {
+  kind: "CursorPersisted";
+  type: "cursor_persisted";
+  invoiceId: string;
+  cursor: EventCursor;
+}
+
+/**
+ * Top-level discriminated union of every SDK event payload.
+ *
+ * Use the `kind` field for exhaustive pattern-matching:
+ *
+ * ```ts
+ * function handle(event: SdkEvent) {
+ *   switch (event.kind) {
+ *     case "Connected":    // ...
+ *     case "Disconnected": // ...
+ *     case "Reconnecting": // ...
+ *     case "CursorPersisted": // ...
+ *   }
+ * }
+ * ```
+ */
+export type SdkEvent =
+  | ConnectedEvent
+  | DisconnectedEvent
+  | ReconnectingEvent
+  | CursorPersistedEvent;
+
 /** Lifecycle events emitted by SubscriptionManager for observability. */
-export type SubscriptionManagerLifecycleEvent =
-  | { type: "connected"; invoiceId: string }
-  | { type: "disconnected"; invoiceId: string; error: Error }
-  | { type: "reconnecting"; invoiceId: string; attempt: number; delayMs: number }
-  | { type: "cursor_persisted"; invoiceId: string; cursor: EventCursor };
+export type SubscriptionManagerLifecycleEvent = SdkEvent;
 
 /** Options accepted by SubscriptionManager and its per-invoice subscribe() calls. */
 export interface SubscriptionOptions {
diff --git a/src/types/receipts.ts b/src/types/receipts.ts
index 6a7fe90..8e59bc4 100644
--- a/src/types/receipts.ts
+++ b/src/types/receipts.ts
@@ -16,6 +16,11 @@ export interface PaymentReceipt {
   ledger: number;
   /** Unix timestamp (milliseconds). */
   timestamp: number;
+  /**
+   * Network fee paid for this transaction, in stroops (1 XLM = 10,000,000 stroops).
+   * Optional for backward compatibility with existing serialised receipts.
+   */
+  networkFeeStroops?: number;
 }
 
 /** One SHA-256-linked entry in a {@link ReceiptChain}. */
diff --git a/src/validators/splitRatioValidator.ts b/src/validators/splitRatioValidator.ts
index b2bcbf0..d47b7f7 100644
--- a/src/validators/splitRatioValidator.ts
+++ b/src/validators/splitRatioValidator.ts
@@ -44,6 +44,15 @@ export interface SplitConfig {
    * dealing with imprecise user input).
    */
   tolerance?: number;
+  /**
+   * Minimum share ratio per recipient, expressed as a percentage (e.g. 0.01
+   * means 0.01 %). Any recipient whose ratio falls below this threshold
+   * fails validation because the resulting dust payment would be rejected
+   * by Stellar's minimum balance check.
+   *
+   * Defaults to `0.01` (0.01 %). Set to `0` to disable the minimum check.
+   */
+  minRatioPercent?: number;
 }
 
 /** Structured validation result returned by {@link validateSplitRatios}. */
@@ -66,8 +75,9 @@ export interface SplitRatioValidationResult {
  * 1. At least one share is provided.
  * 2. No share is negative.
  * 3. No share is zero.
- * 4. No duplicate recipient addresses.
- * 5. Shares sum to 1.0 (± tolerance).
+ * 4. No recipient ratio is below `minRatioPercent` (default 0.01 %).
+ * 5. No duplicate recipient addresses.
+ * 6. Shares sum to 1.0 (± tolerance).
  *
  * @param config - The split configuration to validate.
  * @returns A structured result with `valid` and `errors` fields.
@@ -100,7 +110,20 @@ export function validateSplitRatios(
     }
   }
 
-  // 3. Duplicate address check
+  // 3. Minimum ratio check
+  const minRatioPercent = config.minRatioPercent ?? 0.01;
+  if (minRatioPercent > 0) {
+    const minShareFraction = minRatioPercent / 100;
+    for (const share of config.shares) {
+      if (share.share > 0 && share.share < minShareFraction) {
+        errors.push(
+          `Recipient ${share.address} has a ratio of ${(share.share * 100).toPrecision(4)}% which is below the minimum ${minRatioPercent}%. Increase the recipient's share or set minRatioPercent to 0 to disable this check.`,
+        );
+      }
+    }
+  }
+
+  // 4. Duplicate address check
   const seen = new Set<string>();
   for (const share of config.shares) {
     if (seen.has(share.address)) {