diff --git a/src/core/order-coordinator.ts b/src/core/order-coordinator.ts
index 8a457c6..16fa766 100644
--- a/src/core/order-coordinator.ts
+++ b/src/core/order-coordinator.ts
@@ -166,14 +166,16 @@ export async function placeOrder(
   }
   lockOperating(locks, timers, pendings, type, log);
   try {
+    const closePosition = reduceOnly ? true : undefined;
     const order = await routeLimitOrder({
       adapter,
       symbol,
       side,
       quantity,
       price: priceNum,
-      timeInForce: "GTX",
+      timeInForce: reduceOnly ? "GTC" : "GTX",
       reduceOnly: reduceOnly ? true : undefined,
+      closePosition,
     });
     pendings[type] = String(order.orderId);
     log("order", `挂限价单: ${side} @ ${priceNum} 数量 ${quantity} reduceOnly=${reduceOnly}`);
@@ -216,12 +218,14 @@ export async function placeMarketOrder(
   await deduplicateOrders(adapter, symbol, openOrders, locks, timers, pendings, type, side, log);
   lockOperating(locks, timers, pendings, type, log);
   try {
+    const closePosition = reduceOnly ? true : undefined;
     const order = await routeMarketOrder({
       adapter,
       symbol,
       side,
       quantity,
       reduceOnly: reduceOnly ? true : undefined,
+      closePosition,
     });
     pendings[type] = String(order.orderId);
     log("order", `市价单: ${side} 数量 ${quantity} reduceOnly=${reduceOnly}`);
diff --git a/src/exchanges/lighter/adapter.ts b/src/exchanges/lighter/adapter.ts
index c521790..7bef7fd 100644
--- a/src/exchanges/lighter/adapter.ts
+++ b/src/exchanges/lighter/adapter.ts
@@ -158,12 +158,23 @@ export class LighterExchangeAdapter implements ExchangeAdapter {
   }
 
   private logError(context: string, error: unknown): void {
-    if (process.env.LIGHTER_DEBUG === "1" || process.env.LIGHTER_DEBUG === "true") {
-      console.error(`[LighterExchangeAdapter] ${context} failed: ${extractMessage(error)}`);
+    if (process.env.LIGHTER_DEBUG !== "1" && process.env.LIGHTER_DEBUG !== "true") {
+      return;
     }
+    if (isSuccessfulResponse(error)) {
+      console.info(`[LighterExchangeAdapter] ${context}: ${JSON.stringify(error)}`);
+      return;
+    }
+    console.error(`[LighterExchangeAdapter] ${context} failed: ${extractMessage(error)}`);
   }
 }
 
+function isSuccessfulResponse(value: unknown): value is { code?: number } {
+  if (typeof value !== "object" || value == null) return false;
+  const code = (value as { code?: unknown }).code;
+  return typeof code === "number" && code === 200;
+}
+
 function resolveApiKeys(credentials: LighterCredentials): Record<number, string> {
   if (credentials.apiKeys && Object.keys(credentials.apiKeys).length) {
     return credentials.apiKeys;
diff --git a/src/exchanges/lighter/flags.ts b/src/exchanges/lighter/flags.ts
new file mode 100644
index 0000000..a525d94
--- /dev/null
+++ b/src/exchanges/lighter/flags.ts
@@ -0,0 +1,30 @@
+const TRUE_VALUES = new Set(["1", "true", "yes", "y", "on"]);
+const FALSE_VALUES = new Set(["0", "false", "no", "n", "off"]);
+
+export function normalizeBooleanFlag(value: unknown): boolean | null {
+  if (typeof value === "boolean") return value;
+  if (typeof value === "number") {
+    if (value === 1) return true;
+    if (value === 0) return false;
+    return null;
+  }
+  if (typeof value === "string") {
+    const normalized = value.trim().toLowerCase();
+    if (!normalized) return null;
+    if (TRUE_VALUES.has(normalized)) return true;
+    if (FALSE_VALUES.has(normalized)) return false;
+    return null;
+  }
+  if (typeof value === "bigint") {
+    if (value === 1n) return true;
+    if (value === 0n) return false;
+    return null;
+  }
+  return null;
+}
+
+export function coerceBooleanFlag(value: unknown, fallback = false): boolean {
+  const normalized = normalizeBooleanFlag(value);
+  if (normalized == null) return fallback;
+  return normalized;
+}
diff --git a/src/exchanges/lighter/gateway.ts b/src/exchanges/lighter/gateway.ts
index 174fd3c..4b8189c 100644
--- a/src/exchanges/lighter/gateway.ts
+++ b/src/exchanges/lighter/gateway.ts
@@ -35,6 +35,8 @@ import {
 } from "./constants";
 import { decimalToScaled, scaledToDecimalString, scaleQuantityWithMinimum } from "./decimal";
 import { lighterOrderToAster, toAccountSnapshot, toDepth, toKlines, toOrders, toTicker } from "./mappers";
+import { normalizeOrderIdentity, orderIdentityEquals } from "./order-identity";
+import { shouldResetMarketOrders } from "./order-feed";
 
 interface SimpleEvent<T> {
   add(handler: (value: T) => void): void;
@@ -178,6 +180,7 @@ export class LighterGateway {
   private marketId: number | null = null;
   private priceDecimals: number | null = null;
   private sizeDecimals: number | null = null;
+  private readonly orderIndexByClientId = new Map<string, string>();
 
   private ws: WebSocket | null = null;
   private reconnectTimer: ReturnType<typeof setTimeout> | null = null;
@@ -299,9 +302,12 @@ export class LighterGateway {
       if (process.env.LIGHTER_DEBUG === "1" || process.env.LIGHTER_DEBUG === "true") {
         this.logger("createOrder.sendTx.response", response);
       }
+      const clientOrderIndexStr = signParams.clientOrderIndex.toString();
       return lighterOrderToAster(this.displaySymbol, {
-        order_index: Number(signParams.clientOrderIndex % 1_000_000_000n),
-        client_order_index: Number(signParams.clientOrderIndex),
+        order_index: clientOrderIndexStr,
+        client_order_index: clientOrderIndexStr,
+        order_id: clientOrderIndexStr,
+        client_order_id: clientOrderIndexStr,
         market_index: signParams.marketIndex,
         initial_base_amount: baseAmountScaledString,
         remaining_base_amount: baseAmountScaledString,
@@ -325,14 +331,8 @@ export class LighterGateway {
     await this.ensureInitialized();
     const marketIndex = params.marketIndex ?? this.marketId;
     if (marketIndex == null) throw new Error("Market index unknown");
-    // Parse order id to BigInt without precision loss; prefer string input
-    let indexValue: bigint;
-    if (typeof params.orderId === "string") {
-      indexValue = BigInt(params.orderId);
-    } else {
-      // Fallback for numeric ids (may be unsafe if beyond 2^53-1)
-      indexValue = BigInt(Math.trunc(params.orderId));
-    }
+    const resolvedOrderId = this.resolveOrderIndex(String(params.orderId));
+    const indexValue = BigInt(resolvedOrderId);
     const { apiKeyIndex, nonce } = this.nonceManager.next();
     try {
       const signed = await this.signer.signCancelOrder({
@@ -344,10 +344,7 @@ export class LighterGateway {
       const auth = await this.ensureAuthToken();
       await this.http.sendTransaction(signed.txType, signed.txInfo, { authToken: auth });
       // Optimistically remove the order locally to avoid stale duplicates until WS confirms
-      const key = String(params.orderId);
-      this.orderMap.delete(key);
-      this.orders = Array.from(this.orderMap.values());
-      this.emitOrders();
+      this.removeOrderLocally(String(params.orderId));
     } catch (error) {
       this.nonceManager.acknowledgeFailure(apiKeyIndex);
       throw error;
@@ -843,19 +840,22 @@ export class LighterGateway {
     const marketKeys = Object.keys(ordersObject);
     if (snapshot && marketKeys.length === 0) {
       this.orderMap.clear();
+      this.orderIndexByClientId.clear();
       this.orders = [];
       this.emitOrders();
       return;
     }
     if (snapshot) {
       this.orderMap.clear();
+      this.orderIndexByClientId.clear();
     }
     for (const [market, bucket] of Object.entries(ordersObject)) {
       const marketId = Number(market);
-      const normalized = this.normalizeOrders(bucket);
-      if (Number.isFinite(marketId)) {
+      const shouldReset = shouldResetMarketOrders(bucket, snapshot);
+      if (shouldReset && Number.isFinite(marketId)) {
         this.clearOrdersForMarket(marketId);
       }
+      const normalized = this.normalizeOrders(bucket);
       if (!normalized.length) continue;
       for (const order of normalized) {
         this.applyOrderUpdate(order);
@@ -887,6 +887,7 @@ export class LighterGateway {
         this.clearOrdersForMarket(marketId);
       } else {
         this.orderMap.clear();
+        this.orderIndexByClientId.clear();
       }
     }
     for (const order of orders) {
@@ -897,26 +898,45 @@ export class LighterGateway {
   }
 
   private applyOrderUpdate(order: LighterOrder): void {
-    const key = String(order.order_index ?? order.order_id ?? order.client_order_index ?? "");
+    const orderIndex = this.extractOrderIndex(order);
+    const clientIndex = this.extractClientIndex(order);
+    if (orderIndex && clientIndex) {
+      this.orderIndexByClientId.set(clientIndex, orderIndex);
+    }
+    if (orderIndex) {
+      this.orderIndexByClientId.set(orderIndex, orderIndex);
+    }
+    const key = orderIndex ?? clientIndex;
     if (!key) return;
     const status = (order.status ?? "").toLowerCase();
     if (TERMINAL_ORDER_STATUSES.has(status)) {
+      const existing = this.orderMap.get(key);
       this.orderMap.delete(key);
+      if (existing) {
+        this.forgetOrderIdentity(existing);
+      }
       return;
     }
-    if (order.client_order_index != null || order.order_index != null) {
+    if (
+      order.client_order_index != null ||
+      order.order_index != null ||
+      order.client_order_id != null ||
+      order.order_id != null
+    ) {
       for (const [existingKey, existingOrder] of Array.from(this.orderMap.entries())) {
         if (existingKey === key) continue;
         const sameOrderIndex =
-          order.order_index != null &&
-          existingOrder.order_index != null &&
-          Number(existingOrder.order_index) === Number(order.order_index);
+          orderIdentityEquals(order.order_index, existingOrder.order_index) ||
+          orderIdentityEquals(order.order_id, existingOrder.order_id);
         const sameClientIndex =
-          order.client_order_index != null &&
-          existingOrder.client_order_index != null &&
-          Number(existingOrder.client_order_index) === Number(order.client_order_index);
+          orderIdentityEquals(order.client_order_index, existingOrder.client_order_index) ||
+          orderIdentityEquals(order.client_order_id, existingOrder.client_order_id);
         if (sameOrderIndex || sameClientIndex) {
+          const removed = this.orderMap.get(existingKey);
           this.orderMap.delete(existingKey);
+          if (removed) {
+            this.forgetOrderIdentity(removed);
+          }
         }
       }
     }
@@ -927,8 +947,12 @@ export class LighterGateway {
     const normalized = Number(marketId);
     if (!Number.isFinite(normalized)) return;
     for (const [key, existing] of Array.from(this.orderMap.entries())) {
-      if (Number(existing.market_index) === normalized) {
+      const existingMarket =
+        (existing as { market_index?: number | string; market_id?: number | string }).market_index ??
+        (existing as { market_id?: number | string }).market_id;
+      if (Number(existingMarket) === normalized) {
         this.orderMap.delete(key);
+        this.forgetOrderIdentity(existing);
       }
     }
   }
@@ -974,6 +998,54 @@ export class LighterGateway {
     this.ordersEvent.emit(mapped);
   }
 
+  private resolveOrderIndex(orderId: string): string {
+    const normalized = normalizeOrderIdentity(orderId);
+    if (!normalized) {
+      throw new Error(`Invalid order id: ${orderId}`);
+    }
+    return this.orderIndexByClientId.get(normalized) ?? normalized;
+  }
+
+  private removeOrderLocally(orderId: string): void {
+    const key = normalizeOrderIdentity(orderId);
+    if (!key) return;
+    const existing = this.orderMap.get(key);
+    this.orderMap.delete(key);
+    this.orderIndexByClientId.delete(key);
+    if (existing) {
+      this.forgetOrderIdentity(existing);
+    }
+    this.orders = Array.from(this.orderMap.values());
+    this.emitOrders();
+  }
+
+  private extractOrderIndex(order: LighterOrder): string | null {
+    return (
+      normalizeOrderIdentity(order.order_id) ??
+      normalizeOrderIdentity(order.order_index) ??
+      null
+    );
+  }
+
+  private extractClientIndex(order: LighterOrder): string | null {
+    return (
+      normalizeOrderIdentity(order.client_order_id) ??
+      normalizeOrderIdentity(order.client_order_index) ??
+      null
+    );
+  }
+
+  private forgetOrderIdentity(order: LighterOrder): void {
+    const orderIndex = this.extractOrderIndex(order);
+    const clientIndex = this.extractClientIndex(order);
+    if (orderIndex) {
+      this.orderIndexByClientId.delete(orderIndex);
+    }
+    if (clientIndex) {
+      this.orderIndexByClientId.delete(clientIndex);
+    }
+  }
+
   private startPolling(): void {
     if (!this.pollers.ticker) {
       this.pollers.ticker = setInterval(() => {
diff --git a/src/exchanges/lighter/mappers.ts b/src/exchanges/lighter/mappers.ts
index acf572f..6c71460 100644
--- a/src/exchanges/lighter/mappers.ts
+++ b/src/exchanges/lighter/mappers.ts
@@ -19,6 +19,8 @@ import type {
   LighterOrderBookSnapshot,
   LighterPosition,
 } from "./types";
+import { coerceBooleanFlag, normalizeBooleanFlag } from "./flags";
+import { normalizeOrderIdentity } from "./order-identity";
 
 export function toDepth(symbol: string, snapshot: LighterOrderBookSnapshot): AsterDepth {
   const toLevels = (levels: LighterOrderBookLevel[]): AsterDepthLevel[] =>
@@ -74,13 +76,31 @@ export function toOrders(symbol: string, orders: LighterOrder[]): AsterOrder[] {
 }
 
 export function lighterOrderToAster(symbol: string, order: LighterOrder): AsterOrder {
-  const side: OrderSide = order.is_ask || order.side?.toLowerCase() === "sell" || order.side?.toLowerCase() === "ask"
-    ? "SELL"
-    : "BUY";
+  const booleanIsAsk = normalizeBooleanFlag(order.is_ask);
+  const normalizedSide = order.side?.toLowerCase();
+  const side: OrderSide =
+    booleanIsAsk != null
+      ? booleanIsAsk
+        ? "SELL"
+        : "BUY"
+      : normalizedSide === "sell" || normalizedSide === "ask"
+        ? "SELL"
+        : "BUY";
+  const reduceOnly = coerceBooleanFlag(order.reduce_only, false);
+  const orderIndex =
+    normalizeOrderIdentity(order.order_id) ??
+    normalizeOrderIdentity(order.order_index) ??
+    normalizeOrderIdentity(order.client_order_index) ??
+    normalizeOrderIdentity(order.client_order_id) ??
+    "";
+  const clientIndex =
+    normalizeOrderIdentity(order.client_order_id) ??
+    normalizeOrderIdentity(order.client_order_index) ??
+    "";
   return {
     // Use string order id to avoid precision loss; prefer on-chain order_index for cancellation
-    orderId: String(order.order_index ?? order.client_order_index ?? ""),
-    clientOrderId: String(order.client_order_index ?? order.order_index ?? ""),
+    orderId: orderIndex,
+    clientOrderId: clientIndex || orderIndex,
     symbol,
     side,
     type: mapOrderType(order.type),
@@ -91,8 +111,8 @@ export function lighterOrderToAster(symbol: string, order: LighterOrder): AsterO
     stopPrice: order.trigger_price ?? "0",
     time: order.created_at ?? Date.now(),
     updateTime: order.updated_at ?? Date.now(),
-    reduceOnly: Boolean(order.reduce_only),
-    closePosition: Boolean(order.reduce_only ?? order.owner_account_index === undefined ? false : order.is_ask),
+    reduceOnly,
+    closePosition: reduceOnly,
     workingType: "MARK_PRICE",
     activationPrice: order.trigger_price,
   };
diff --git a/src/exchanges/lighter/order-feed.ts b/src/exchanges/lighter/order-feed.ts
new file mode 100644
index 0000000..310c90d
--- /dev/null
+++ b/src/exchanges/lighter/order-feed.ts
@@ -0,0 +1,19 @@
+function isPlainObject(value: unknown): value is Record<string, unknown> {
+  return typeof value === "object" && value != null && !Array.isArray(value);
+}
+
+/**
+ * Determines whether a per-market websocket payload should reset the cached
+ * orders before applying its contents.
+ */
+export function shouldResetMarketOrders(bucket: unknown, snapshot: boolean): boolean {
+  if (snapshot) return true;
+  if (bucket == null) return false;
+  if (Array.isArray(bucket)) {
+    return bucket.length === 0;
+  }
+  if (isPlainObject(bucket)) {
+    return Object.keys(bucket).length === 0;
+  }
+  return false;
+}
diff --git a/src/exchanges/lighter/order-identity.ts b/src/exchanges/lighter/order-identity.ts
new file mode 100644
index 0000000..816f8a3
--- /dev/null
+++ b/src/exchanges/lighter/order-identity.ts
@@ -0,0 +1,35 @@
+/**
+ * Helpers for working with Lighter order identifiers without losing precision.
+ */
+
+/**
+ * Normalizes any order identifier into a trimmed string representation.
+ * Accepts string, number, or bigint inputs; returns null when the value
+ * cannot be represented as a meaningful identifier.
+ */
+export function normalizeOrderIdentity(value: unknown): string | null {
+  if (typeof value === "string") {
+    const trimmed = value.trim();
+    return trimmed.length > 0 ? trimmed : null;
+  }
+  if (typeof value === "number") {
+    if (!Number.isFinite(value)) {
+      return null;
+    }
+    return Math.trunc(value).toString(10);
+  }
+  if (typeof value === "bigint") {
+    return value.toString(10);
+  }
+  return null;
+}
+
+/**
+ * Compares two identifier-like values without casting through Number(),
+ * which would drop precision for large (>2^53) indices.
+ */
+export function orderIdentityEquals(a: unknown, b: unknown): boolean {
+  const left = normalizeOrderIdentity(a);
+  const right = normalizeOrderIdentity(b);
+  return left != null && right != null && left === right;
+}
diff --git a/src/exchanges/lighter/types.ts b/src/exchanges/lighter/types.ts
index b51de33..7a57197 100644
--- a/src/exchanges/lighter/types.ts
+++ b/src/exchanges/lighter/types.ts
@@ -8,12 +8,14 @@ export type LighterOrderType =
   | "take_profit_limit"
   | string;
 
+type StrOrNum = string | number;
+
 export interface LighterOrder {
-  order_index: number;
-  client_order_index: number;
-  order_id?: string;
-  client_order_id?: string;
-  market_index: number;
+  order_index: StrOrNum;
+  client_order_index: StrOrNum;
+  order_id?: string | null;
+  client_order_id?: string | null;
+  market_index: StrOrNum;
   owner_account_index?: number;
   initial_base_amount: string;
   remaining_base_amount: string;
diff --git a/tests/lighter/order-feed.test.ts b/tests/lighter/order-feed.test.ts
new file mode 100644
index 0000000..9fbc24e
--- /dev/null
+++ b/tests/lighter/order-feed.test.ts
@@ -0,0 +1,26 @@
+import { describe, expect, it } from "vitest";
+import { shouldResetMarketOrders } from "../../src/exchanges/lighter/order-feed";
+
+describe("shouldResetMarketOrders", () => {
+  it("always resets on snapshots", () => {
+    expect(shouldResetMarketOrders([{ id: 1 }], true)).toBe(true);
+    expect(shouldResetMarketOrders([], true)).toBe(true);
+    expect(shouldResetMarketOrders(null, true)).toBe(true);
+  });
+
+  it("resets when array bucket is empty", () => {
+    expect(shouldResetMarketOrders([], false)).toBe(true);
+    expect(shouldResetMarketOrders([{}], false)).toBe(false);
+  });
+
+  it("resets when object bucket has no keys", () => {
+    expect(shouldResetMarketOrders({}, false)).toBe(true);
+    expect(shouldResetMarketOrders({ a: 1 }, false)).toBe(false);
+  });
+
+  it("does not reset for non-empty updates", () => {
+    expect(shouldResetMarketOrders([{ order_index: "1" }], false)).toBe(false);
+    expect(shouldResetMarketOrders(null, false)).toBe(false);
+    expect(shouldResetMarketOrders(undefined, false)).toBe(false);
+  });
+});
diff --git a/tests/lighter/order-identity.test.ts b/tests/lighter/order-identity.test.ts
new file mode 100644
index 0000000..84962c6
--- /dev/null
+++ b/tests/lighter/order-identity.test.ts
@@ -0,0 +1,23 @@
+import { describe, expect, it } from "vitest";
+import { normalizeOrderIdentity, orderIdentityEquals } from "../../src/exchanges/lighter/order-identity";
+
+describe("order identity helpers", () => {
+  it("treats large numeric strings as distinct values", () => {
+    const first = "27584547724798440";
+    const second = "27584547724798442";
+    expect(orderIdentityEquals(first, second)).toBe(false);
+    expect(orderIdentityEquals(first, first)).toBe(true);
+  });
+
+  it("considers numeric inputs equal to their string counterparts", () => {
+    expect(orderIdentityEquals(123456789, "123456789")).toBe(true);
+  });
+
+  it("normalizes whitespace-only identifiers to null", () => {
+    expect(normalizeOrderIdentity("   ")).toBeNull();
+  });
+
+  it("falls back to truncated integers for floating inputs", () => {
+    expect(normalizeOrderIdentity(42.9)).toBe("42");
+  });
+});
diff --git a/tests/lighter/orders.test.ts b/tests/lighter/orders.test.ts
new file mode 100644
index 0000000..2a7609e
--- /dev/null
+++ b/tests/lighter/orders.test.ts
@@ -0,0 +1,36 @@
+import { describe, expect, it } from "vitest";
+import { lighterOrderToAster } from "../../src/exchanges/lighter/mappers";
+import type { LighterOrder } from "../../src/exchanges/lighter/types";
+
+function createOrder(overrides: Partial<LighterOrder> = {}): LighterOrder {
+  return {
+    order_index: 1,
+    client_order_index: 1,
+    market_index: 99,
+    initial_base_amount: "0.1",
+    remaining_base_amount: "0.1",
+    price: "154.86",
+    type: "limit",
+    reduce_only: "No",
+    side: "buy",
+    ...overrides,
+  } as LighterOrder;
+}
+
+describe("lighterOrderToAster", () => {
+  it("treats textual reduce_only flags correctly", () => {
+    const nonReduce = lighterOrderToAster("USDJPY", createOrder({ reduce_only: "No" }));
+    expect(nonReduce.reduceOnly).toBe(false);
+
+    const reduce = lighterOrderToAster("USDJPY", createOrder({ reduce_only: "Yes" }));
+    expect(reduce.reduceOnly).toBe(true);
+  });
+
+  it("uses numeric is_ask flag for side inference", () => {
+    const sell = lighterOrderToAster("USDJPY", createOrder({ is_ask: 1 }));
+    expect(sell.side).toBe("SELL");
+
+    const buy = lighterOrderToAster("USDJPY", createOrder({ is_ask: 0 }));
+    expect(buy.side).toBe("BUY");
+  });
+});