synapsecns · ChiTimesChi · May 2, 2025 · May 2, 2025 · May 2, 2025 · May 2, 2025
@@ -85,6 +85,29 @@ export const getChains = async (): Promise<Chains> => {
   }
 }
 
+export const getGasZipBlockHeightMap = async (): Promise<
+  Map<number, number>
+> => {
+  const response = await getWithTimeout(
+    'Gas.Zip API',
+    `${GAS_ZIP_API_URL}/admin/indexer`,
+    GAS_ZIP_API_TIMEOUT
+  )
+  if (!response) {
+    return new Map()
+  }
+  const data: { chain: any; head: any }[] = await response.json()
+  return new Map(
+    data
+      .filter((item) => {
+        const chainNum = Number(item.chain)
+        const headNum = Number(item.head)
+        return Number.isInteger(chainNum) && Number.isInteger(headNum)
+      })
+      .map((item) => [Number(item.chain), Number(item.head)])
+  )
+}
+
 export const getGasZipQuote = async (
   originChainId: number,
   destChainId: number,

@@ -16,17 +16,24 @@ import {
   SynapseModuleSet,
 } from '../module'
 import { ChainProvider } from '../router'
-import { Chains, getChains, getGasZipQuote } from './api'
+import {
+  Chains,
+  getChains,
+  getGasZipBlockHeightMap,
+  getGasZipQuote,
+} from './api'
 import { GasZipModule } from './gasZipModule'
 import { applySlippage, encodeZapData } from '../swap'
 import {
   ETH_NATIVE_TOKEN_ADDRESS,
   isNativeToken,
   isSameAddress,
   logExecutionTime,
+  logger,
 } from '../utils'
 
 const MEDIAN_TIME_GAS_ZIP = 30
+const GAS_ZIP_MAX_BLOCK_AGE_MS = 5 * 60 * 1000
 
 export class GasZipModuleSet extends SynapseModuleSet {
   public readonly moduleName = 'Gas.zip'
@@ -125,6 +132,10 @@ export class GasZipModuleSet extends SynapseModuleSet {
     if (!allowMultipleTxs && !isSameAddress(bridgeToken.destToken, toToken)) {
       return undefined
     }
+    const syncedPromise = this.checkBlockHeights(
+      bridgeToken.originChainId,
+      bridgeToken.destChainId
+    )
     const quote = await getGasZipQuote(
       bridgeToken.originChainId,
       bridgeToken.destChainId,
@@ -154,6 +165,11 @@ export class GasZipModuleSet extends SynapseModuleSet {
         toRecipient
       ),
     }
+    // Verify that both chains are up to date before returning the route
+    const synced = await syncedPromise
+    if (!synced) {
+      return undefined
+    }
     return route
   }
 
@@ -168,6 +184,7 @@ export class GasZipModuleSet extends SynapseModuleSet {
     tokenOut: string,
     amountIn: BigNumberish
   ): Promise<BridgeRoute[]> {
+    const syncedPromise = this.checkBlockHeights(originChainId, destChainId)
     // Check that both chains are supported by gas.zip
     const supportedChainIds = await this.getAllChainIds()
     if (
@@ -204,6 +221,11 @@ export class GasZipModuleSet extends SynapseModuleSet {
       },
       bridgeModuleName: this.moduleName,
     }
+    // Verify that both chains are up to date before returning the route
+    const synced = await syncedPromise
+    if (!synced) {
+      return []
+    }
     return [route]
   }
 
@@ -293,4 +315,61 @@ export class GasZipModuleSet extends SynapseModuleSet {
       ).data,
     })
   }
+
+  /**
+   * Checks if the latest block heights reported by gas.zip are within the maximum age.
+   * Both chains must be up to date to enable the bridge.
+   */
+  private async checkBlockHeights(
+    originChainId: number,
+    destChainId: number
+  ): Promise<boolean> {
+    const blockHeightMap = await getGasZipBlockHeightMap()
+    const [originSynced, destSynced] = await Promise.all([
+      this.checkBlockHeight(originChainId, blockHeightMap.get(originChainId)),
+      this.checkBlockHeight(destChainId, blockHeightMap.get(destChainId)),
+    ])
+    return originSynced && destSynced
+  }
+
+  /**
+   * Checks if the block height is within the maximum age for a chain.
+   */
+  private async checkBlockHeight(
+    chainId: number,
+    blockHeight?: number
+  ): Promise<boolean> {
+    if (!blockHeight) {
+      logger.info(`Gas.zip block height not found for chain ${chainId}`)
+      return false
+    }
+    const provider = this.providers[chainId]
+    if (!provider) {
+      logger.info(`Provider not found for chain ${chainId}`)
+      return false
+    }
+    let block
+    try {
+      block = await provider.getBlock(blockHeight)
+    } catch (error) {
+      logger.error(
+        `Block height ${blockHeight} for chain ${chainId} not found: ${error}`
+      )
+      return false
+    }
+    if (!block) {
+      logger.error(
+        `Null block for chain ${chainId} at block height ${blockHeight}`
+      )
+      return false
+    }
+    const blockAge = Date.now() - block.timestamp * 1000
+    const result = 0 <= blockAge && blockAge <= GAS_ZIP_MAX_BLOCK_AGE_MS
+    if (!result) {
+      logger.info(
+        `Block height ${blockHeight} for chain ${chainId} is too old: ${blockAge} ms (allowed: 0 .. ${GAS_ZIP_MAX_BLOCK_AGE_MS} ms)`
+      )
+    }
+    return result
+  }
 }