diff --git a/src/contract/highloadWallet/HighloadQueryId.js b/src/contract/highloadWallet/HighloadQueryId.js
new file mode 100644
index 0000000..4c96929
--- /dev/null
+++ b/src/contract/highloadWallet/HighloadQueryId.js
@@ -0,0 +1,105 @@
+const BIT_NUMBER_SIZE = 10n; // 10 bit
+const SHIFT_SIZE = 13n; // 13 bit
+const MAX_BIT_NUMBER = 1022n;
+const MAX_SHIFT = 8191n; // 2^13 = 8192
+
+class HighloadQueryId {
+    constructor() {
+        /**
+         * @private
+         * @type {bigint} [0 .. 8191]
+         */
+        this.shift = 0n;
+        /**
+         * @private
+         * @type {bigint} [0 .. 1022]
+         */
+        this.bitnumber = 0n;
+    }
+
+    /**
+     * @param shift {bigint}
+     * @param bitnumber {bigint}
+     * @return {HighloadQueryId}
+     */
+    static fromShiftAndBitNumber(shift, bitnumber) {
+        const q = new HighloadQueryId();
+        q.shift = shift;
+        if (q.shift < 0) throw new Error('invalid shift');
+        if (q.shift > MAX_SHIFT) throw new Error('invalid shift');
+        q.bitnumber = bitnumber;
+        if (q.bitnumber < 0) throw new Error('invalid bitnumber');
+        if (q.bitnumber > MAX_BIT_NUMBER) throw new Error('invalid bitnumber');
+        return q;
+    }
+
+    increase() {
+        this.bitnumber += 1n;
+
+        if (this.shift === MAX_SHIFT && this.bitnumber > (MAX_BIT_NUMBER - 1n)) {
+            throw new Error('Overload'); // NOTE: we left one queryId for emergency withdraw
+        }
+
+        if (this.bitnumber > MAX_BIT_NUMBER) {
+            this.bitnumber = 0n;
+            this.shift += 1n;
+            if (this.shift > MAX_SHIFT) {
+                throw new Error('Overload')
+            }
+        }
+    }
+
+    isEnd() {
+        return this.bitnumber >= (MAX_BIT_NUMBER - 1n) && this.shift === MAX_SHIFT; // NOTE: we left one queryId for emergency withdraw
+    }
+
+    /**
+     * @return {bigint}
+     */
+    getShift() {
+        return this.shift;
+    }
+
+    /**
+     * @return {bigint}
+     */
+    getBitNumber() {
+        return this.bitnumber;
+    }
+
+    /**
+     * @return {bigint}
+     */
+    getQueryId() {
+        return (this.shift << BIT_NUMBER_SIZE) + this.bitnumber;
+    }
+
+    /**
+     * @param queryId   {bigint}
+     * @return {HighloadQueryId}
+     */
+    static fromQueryId(queryId) {
+        const shift = queryId >> BIT_NUMBER_SIZE;
+        const bitnumber = queryId & 1023n;
+        return this.fromShiftAndBitNumber(shift, bitnumber);
+    }
+
+    /**
+     * @param i {bigint}
+     * @return {HighloadQueryId}
+     */
+    static fromSeqno(i) {
+        const shift = i / 1023n;
+        const bitnumber = i % 1023n;
+        return this.fromShiftAndBitNumber(shift, bitnumber);
+    }
+
+    /**
+     * @return {bigint} [0 .. 8380415]
+     */
+    toSeqno() {
+        return this.bitnumber + this.shift * 1023n;
+    }
+}
+
+module.exports = {HighloadQueryId};
diff --git a/src/test-highload-query-id.js b/src/test-highload-query-id.js
new file mode 100644
index 0000000..e1b54dd
--- /dev/null
+++ b/src/test-highload-query-id.js
@@ -0,0 +1,41 @@
+const {HighloadQueryId} = require("./contract/highloadWallet/HighloadQueryId");
+
+if (HighloadQueryId.fromSeqno(0n).toSeqno() !== 0n) throw new Error();
+
+const i = HighloadQueryId.fromSeqno(1022n);
+if (i.toSeqno() !== 1022n) throw new Error();
+const i2 = HighloadQueryId.fromSeqno(1023n);
+if (i2.toSeqno() !== 1023n) throw new Error();
+const i3 = HighloadQueryId.fromSeqno(1024n);
+if (i3.toSeqno() !== 1024n) throw new Error();
+const i4 = HighloadQueryId.fromSeqno(8380415n);
+if (i4.toSeqno() !== 8380415n) throw new Error();
+
+
+const queryId = new HighloadQueryId();
+console.log(queryId.getQueryId(), queryId.isEnd());
+
+const MAX = (2n ** 13n) * 1023n - 2n;
+for (let i = 0; i < MAX; i++) {
+    queryId.increase();
+
+    const q = queryId.getQueryId();
+    const q2 = HighloadQueryId.fromQueryId(q);
+
+    if (queryId.getShift() !== q2.getShift()) throw new Error()
+    if (queryId.getBitNumber() !== q2.getBitNumber()) throw new Error()
+    if (q2.getQueryId() !== q) throw new Error();
+
+    const q3 = HighloadQueryId.fromShiftAndBitNumber(queryId.getShift(), queryId.getBitNumber());
+    if (queryId.getShift() !== q3.getShift()) throw new Error()
+    if (queryId.getBitNumber() !== q3.getBitNumber()) throw new Error()
+    if (q3.getQueryId() !== q) throw new Error();
+
+    if (queryId.isEnd()) {
+        console.log('END')
+    }
+}
+console.log(queryId.shift);
+console.log(queryId.bitnumber);
+
+console.log(queryId.getQueryId(), queryId.isEnd());
\ No newline at end of file