diff --git a/.prettierignore b/.prettierignore
index e4fb6197..a37ce996 100644
--- a/.prettierignore
+++ b/.prettierignore
@@ -24,4 +24,5 @@ zp-relayer/poolTxs.db
 *.md
 *.yml
 **/lib/
-**/build/
\ No newline at end of file
+**/build/
+**/*.json
\ No newline at end of file
diff --git a/README.md b/README.md
index f5d9f3f0..aacaa9c2 100644
--- a/README.md
+++ b/README.md
@@ -71,6 +71,13 @@ For a detailed description of each method's payload you can refer to [`zp-relaye
 
 - `/merkle/root/:index?` - get Merkle Tree root at specified index.
 
+- `/siblings?index=${index}` - get left siblings starting from a leaf node at `index` up to the tree root.
+
+    **Response**
+    ```
+    "${height}${sibling_index}${sibling_value}"[]
+    ```
+
 - `/job/:id` - information about user's job state.
     
     **Response**
diff --git a/yarn.lock b/yarn.lock
index 2b5acd1b..ab00c681 100644
--- a/yarn.lock
+++ b/yarn.lock
@@ -3497,6 +3497,13 @@ libzkbob-rs-node@0.1.27:
   dependencies:
     cargo-cp-artifact "^0.1"
 
+libzkbob-rs-node@0.2.1:
+  version "0.2.1"
+  resolved "https://registry.yarnpkg.com/libzkbob-rs-node/-/libzkbob-rs-node-0.2.1.tgz#58340fce40c5ba06641f3b3afb131ccfe5fef634"
+  integrity sha512-Qh2EXpXTVOi1CZ6bvbKjXRw9dkoXgq7ss/YX+fxpJGYRAa6UIyt+Lrv4jZrSddNOGMrlItkDFtNOsXZVfdFSRw==
+  dependencies:
+    cargo-cp-artifact "^0.1"
+
 libzkbob-rs-wasm-web@^0.7.0:
   version "0.7.0"
   resolved "https://registry.yarnpkg.com/libzkbob-rs-wasm-web/-/libzkbob-rs-wasm-web-0.7.0.tgz#2bd54bb0687a0194ce7c3e43ceecb55a378dba06"
diff --git a/zp-relayer/endpoints.ts b/zp-relayer/endpoints.ts
index b0b855b9..368748bf 100644
--- a/zp-relayer/endpoints.ts
+++ b/zp-relayer/endpoints.ts
@@ -5,6 +5,7 @@ import { poolTxQueue } from './queue/poolTxQueue'
 import config from './config'
 import {
   checkGetLimits,
+  checkGetSiblings,
   checkGetTransactions,
   checkGetTransactionsV2,
   checkMerkleRootErrors,
@@ -251,6 +252,25 @@ async function getLimits(req: Request, res: Response) {
   res.json(limitsFetch)
 }
 
+function getSiblings(req: Request, res: Response) {
+  const errors = checkGetSiblings(req.query)
+  if (errors) {
+    logger.info('Request errors: %o', errors)
+    res.status(400).json({ errors })
+    return
+  }
+
+  const index = req.query.index as unknown as number
+
+  if (index >= pool.state.getNextIndex()) {
+    res.status(400).json({ errors: ['Index out of range'] })
+    return
+  }
+
+  const siblings = pool.state.getSiblings(index)
+  res.json(siblings)
+}
+
 function getParamsHash(type: 'tree' | 'transfer') {
   const hash = type === 'tree' ? pool.treeParamsHash : pool.transferParamsHash
   return (req: Request, res: Response) => {
@@ -272,6 +292,7 @@ export default {
   relayerInfo,
   getFee,
   getLimits,
+  getSiblings,
   getParamsHash,
   root,
 }
diff --git a/zp-relayer/package.json b/zp-relayer/package.json
index e6b77302..b99d1e37 100644
--- a/zp-relayer/package.json
+++ b/zp-relayer/package.json
@@ -26,7 +26,7 @@
     "express-winston": "4.2.0",
     "gas-price-oracle": "0.5.1",
     "ioredis": "5.2.4",
-    "libzkbob-rs-node": "0.1.27",
+    "libzkbob-rs-node": "0.2.1",
     "node-fetch": "^2.6.1",
     "promise-retry": "^2.0.1",
     "web3": "1.7.4",
diff --git a/zp-relayer/router.ts b/zp-relayer/router.ts
index f0f480d8..20177c0f 100644
--- a/zp-relayer/router.ts
+++ b/zp-relayer/router.ts
@@ -1,6 +1,7 @@
 import express, { NextFunction, Request, Response } from 'express'
 import cors from 'cors'
 import endpoints from './endpoints'
+import { logger } from './services/appLogger'
 
 function wrapErr(f: (_req: Request, _res: Response, _next: NextFunction) => Promise<void> | void) {
   return async (req: Request, res: Response, next: NextFunction) => {
@@ -21,7 +22,7 @@ router.use(express.text())
 
 router.use((err: any, req: Request, res: Response, next: NextFunction) => {
   if (err) {
-    console.error('Request error:', err)
+    logger.error('Request error:', err)
     return res.sendStatus(500)
   }
   next()
@@ -37,6 +38,7 @@ router.get('/job/:id', wrapErr(endpoints.getJob))
 router.get('/info', wrapErr(endpoints.relayerInfo))
 router.get('/fee', wrapErr(endpoints.getFee))
 router.get('/limits', wrapErr(endpoints.getLimits))
+router.get('/siblings', wrapErr(endpoints.getSiblings))
 router.get('/params/hash/tree', wrapErr(endpoints.getParamsHash('tree')))
 router.get('/params/hash/tx', wrapErr(endpoints.getParamsHash('transfer')))
 
diff --git a/zp-relayer/state/PoolState.ts b/zp-relayer/state/PoolState.ts
index 9e98d766..90542312 100644
--- a/zp-relayer/state/PoolState.ts
+++ b/zp-relayer/state/PoolState.ts
@@ -100,6 +100,10 @@ export class PoolState {
     return this.tree.getNextIndex()
   }
 
+  getSiblings(index: number) {
+    return this.tree.getLeftSiblings(index)
+  }
+
   addTx(i: number, tx: Buffer) {
     this.txs.add(i, tx)
   }
diff --git a/zp-relayer/test/worker-tests/poolWorker.test.ts b/zp-relayer/test/worker-tests/poolWorker.test.ts
index 29d97824..0d67da6c 100644
--- a/zp-relayer/test/worker-tests/poolWorker.test.ts
+++ b/zp-relayer/test/worker-tests/poolWorker.test.ts
@@ -16,14 +16,7 @@ import { GasPrice } from '../../services/gas-price'
 import { redis } from '../../services/redisClient'
 import { initializeDomain } from '../../utils/EIP712SaltedPermit'
 import { FlowOutputItem } from '../../../test-flow-generator/src/types'
-import {
-  disableMining,
-  enableMining,
-  evmRevert,
-  evmSnapshot,
-  mintTokens,
-  newConnection,
-} from './utils'
+import { disableMining, enableMining, evmRevert, evmSnapshot, mintTokens, newConnection } from './utils'
 import { validateTx } from '../../validateTx'
 import flow from '../flows/flow_independent_deposits_5.json'
 import flowDependentDeposits from '../flows/flow_dependent_deposits_2.json'
@@ -151,7 +144,7 @@ describe('poolWorker', () => {
     await mintTokens(deposit.txTypeData.from as string, parseInt(deposit.txTypeData.amount))
     await sentWorker.pause()
 
-    const mockPoolWorker = await createPoolTxWorker(gasPriceService, async () => { }, workerMutex, newConnection())
+    const mockPoolWorker = await createPoolTxWorker(gasPriceService, async () => {}, workerMutex, newConnection())
     mockPoolWorker.run()
     await mockPoolWorker.waitUntilReady()
 
@@ -242,7 +235,7 @@ describe('poolWorker', () => {
     })
 
     const sentJob = (await sentTxQueue.getJob(sentId)) as Job
-    const [status, sentHash,] = await sentJob.waitUntilFinished(sentQueueEvents)
+    const [status, sentHash] = await sentJob.waitUntilFinished(sentQueueEvents)
     expect(status).eq(SentTxState.MINED)
     expect(txHash).not.eq(sentHash)
 
diff --git a/zp-relayer/validation/validation.ts b/zp-relayer/validation/validation.ts
index bbae2aa9..de46f670 100644
--- a/zp-relayer/validation/validation.ts
+++ b/zp-relayer/validation/validation.ts
@@ -15,6 +15,14 @@ ajv.addKeyword({
   errors: true,
 })
 
+ajv.addKeyword({
+  keyword: 'isDivBy128',
+  validate: (schema: any, n: number) => {
+    return n % 128 === 0
+  },
+  errors: true,
+})
+
 const AjvString: JSONSchemaType<string> = { type: 'string' }
 
 const AjvNullableAddress: JSONSchemaType<string> = {
@@ -146,6 +154,20 @@ const AjvMerkleRootSchema: JSONSchemaType<{
   required: ['index'],
 }
 
+const AjvGetSiblingsSchema: JSONSchemaType<{
+  index: string | number
+}> = {
+  type: 'object',
+  properties: {
+    index: {
+      type: 'integer',
+      minimum: 1,
+      isDivBy128: true,
+    },
+  },
+  required: ['index'],
+}
+
 function checkErrors<T>(schema: JSONSchemaType<T>) {
   const validate = ajv.compile(schema)
   return (data: any) => {
@@ -165,3 +187,4 @@ export const checkSendTransactionsErrors = checkErrors(AjvSendTransactionsSchema
 export const checkGetTransactions = checkErrors(AjvGetTransactionsSchema)
 export const checkGetTransactionsV2 = checkErrors(AjvGetTransactionsV2Schema)
 export const checkGetLimits = checkErrors(AjvGetLimitsSchema)
+export const checkGetSiblings = checkErrors(AjvGetSiblingsSchema)