diff --git a/src/builder.ts b/src/builder.ts
index 08f4948..8cb5f00 100644
--- a/src/builder.ts
+++ b/src/builder.ts
@@ -1,5 +1,5 @@
 import { StrKey, Address, nativeToScVal } from '@stellar/stellar-sdk';
-import { bigintSafeStringify } from './utils.js';
+import { bigintSafeStringify, toStroops } from './utils.js';
 import { boolToScVal } from './soroban.js';
 import {
   buildBatchTransactions,
@@ -574,11 +574,24 @@ function validatePayload(streams: unknown): string[] {
         }
       }
 
-      // Validate amount field — must be a positive finite number (where present)
+      // Validate amount field — must be a bigint or a decimal string parseable by toStroops
       if (obj.amount !== undefined && obj.amount !== null) {
-        const amount = Number(obj.amount);
-        if (!Number.isFinite(amount) || amount <= 0) {
-          errors.push(`Batch item at index ${i}: amount must be a positive finite number, got "${obj.amount}"`);
+        const amt = obj.amount;
+        if (typeof amt === 'bigint') {
+          if (amt <= 0n) {
+            errors.push(`Batch item at index ${i}: amount must be a positive bigint, got ${amt.toString()}`);
+          }
+        } else if (typeof amt === 'string') {
+          try {
+            const stroops = toStroops(amt);
+            if (stroops <= 0n) {
+              errors.push(`Batch item at index ${i}: amount must be a positive value, got "${amt}"`);
+            }
+          } catch {
+            errors.push(`Batch item at index ${i}: amount must be a valid decimal string (e.g. "1000" or "1.5"), got "${amt}"`);
+          }
+        } else {
+          errors.push(`Batch item at index ${i}: amount must be a bigint or decimal string, got ${typeof amt}`);
         }
       }
     }
diff --git a/src/constants.ts b/src/constants.ts
index d6661da..2c8294c 100644
--- a/src/constants.ts
+++ b/src/constants.ts
@@ -51,6 +51,16 @@ export function clampListLimit(limit: number): number {
   return Math.min(truncated, MAX_LIST_LIMIT);
 }
 
+/**
+ * Clamp a caller-supplied pagination `offset` to a non-negative integer
+ * within the valid u32 range (`[0, 2^32 - 1]`). Non-finite or negative
+ * input returns 0 rather than producing an invalid u32 conversion.
+ */
+export function clampOffset(offset: number): number {
+  if (!Number.isFinite(offset)) return 0;
+  return Math.min(Math.max(Math.trunc(offset), 0), 0xFFFFFFFF);
+}
+
 /**
  * Bit-flags packed into the on-chain `StreamInfo.flags` (`u32`). `paused`,
  * `cancelled` and `clawback_enabled` are NOT individual struct fields -- they
diff --git a/src/factory.ts b/src/factory.ts
index 59994ec..0980f52 100644
--- a/src/factory.ts
+++ b/src/factory.ts
@@ -6,7 +6,7 @@ import { nativeToScVal, xdr, Address } from '@stellar/stellar-sdk';
 import type { ConduitConfig } from './types/index.js';
 import type { WalletAdapter } from './adapters/types.js';
 import { KeypairWalletAdapter } from './adapters/keypair.js';
-import { ZERO_ADDR, DEFAULT_LIST_LIMIT, clampListLimit } from './constants.js';
+import { ZERO_ADDR, DEFAULT_LIST_LIMIT, clampListLimit, clampOffset } from './constants.js';
 import {
   buildContractCallTx,
   simulateReadOnly,
@@ -197,7 +197,7 @@ export class FactoryModule {
       this.factoryId, 'streams_by_sender',
       [
         new Address(address).toScVal(),
-        nativeToScVal(offset, { type: 'u32' }),
+        nativeToScVal(clampOffset(offset), { type: 'u32' }),
         nativeToScVal(clampListLimit(limit), { type: 'u32' }),
       ],
     );
@@ -218,7 +218,7 @@ export class FactoryModule {
       this.factoryId, 'streams_by_recipient',
       [
         new Address(address).toScVal(),
-        nativeToScVal(offset, { type: 'u32' }),
+        nativeToScVal(clampOffset(offset), { type: 'u32' }),
         nativeToScVal(clampListLimit(limit), { type: 'u32' }),
       ],
     );
diff --git a/src/relayer/WebSocketRelayer.ts b/src/relayer/WebSocketRelayer.ts
index 1d6e056..7d523f8 100644
--- a/src/relayer/WebSocketRelayer.ts
+++ b/src/relayer/WebSocketRelayer.ts
@@ -20,6 +20,7 @@ export interface WebSocketRelayerOptions {
   maxPendingMessages?: number;
   maxReconnectAttempts?: number;
   reconnectDelayMs?: number;
+  maxReconnectDelayMs?: number;
   onStateChange?: StateChangeHandler;
 }
 
@@ -37,6 +38,7 @@ export class WebSocketRelayer {
   private reconnectExhausted = false;
   private maxReconnectAttempts: number;
   private reconnectDelayMs: number;
+  private maxReconnectDelayMs: number;
   private pendingMessages: WebSocketMessage[] = [];
   private maxPendingMessages: number;
   private stateTransition: RelayerStateTransition = 'disconnected';
@@ -45,6 +47,7 @@ export class WebSocketRelayer {
     this.url = url;
     this.maxReconnectAttempts = options?.maxReconnectAttempts ?? 5;
     this.reconnectDelayMs = options?.reconnectDelayMs ?? 1000;
+    this.maxReconnectDelayMs = options?.maxReconnectDelayMs ?? 30_000;
     this.maxPendingMessages = options?.maxPendingMessages ?? 1000;
     if (options?.onStateChange) {
       this.stateChangeHandlers.add(options.onStateChange);
@@ -304,8 +307,12 @@ export class WebSocketRelayer {
 
       this.reconnectAttempts++;
       this.emitStateChange('reconnecting');
-      await new Promise((r) => setTimeout(r, this.reconnectDelayMs * this.reconnectAttempts));
-      if (this.isDestroyed || !this.reconnectEnabled) return;
+      const delay = Math.min(
+        this.maxReconnectDelayMs,
+        this.reconnectDelayMs * 2 ** (this.reconnectAttempts - 1),
+      ) * (0.5 + Math.random() * 0.5);
+      await new Promise((r) => setTimeout(r, delay));
+      if (this.isDestroyed) return;
 
       await this.establishConnection();
     } catch {
diff --git a/src/utils.ts b/src/utils.ts
index 07f3f12..162e8c2 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -57,6 +57,9 @@ export function fromStroops(stroops: bigint, decimals = 7): string {
  * @param decimals       Token decimal places (default 7 for Stellar assets)
  */
 export function calculateRate(depositAmount: string, durationSecs: number, decimals = 7): bigint {
+  if (!Number.isInteger(durationSecs) || durationSecs <= 0) {
+    throw new Error(`durationSecs must be a positive integer, got ${durationSecs}`);
+  }
   const stroops = toStroops(depositAmount, decimals);
   const divisor = BigInt(durationSecs);
   if (divisor === 0n) return 0n;
@@ -80,6 +83,9 @@ export function calculateYield(
   durationSecs = 31_536_000,
   decimals = 7,
 ): string {
+  if (!Number.isInteger(durationSecs) || durationSecs <= 0) {
+    throw new Error(`durationSecs must be a positive integer, got ${durationSecs}`);
+  }
   const totalStroops = ratePerSecond * BigInt(durationSecs);
   return fromStroops(totalStroops, decimals);
 }