diff --git a/clients/js/Makefile b/clients/js/Makefile
index 0c0da1ff9..98bb6ed9b 100644
--- a/clients/js/Makefile
+++ b/clients/js/Makefile
@@ -15,8 +15,8 @@ dependencies: node_modules
 
 build: node_modules $(SOURCE_FILES)
 	@mkdir -p build
-	@touch -m build
 	npm run build
+	@touch -m build
 
 install: build
 	@echo Linking binaries
diff --git a/clients/js/evm.ts b/clients/js/evm.ts
index a831a32da..c88b82629 100644
--- a/clients/js/evm.ts
+++ b/clients/js/evm.ts
@@ -104,6 +104,38 @@ export async function query_contract_evm(
   return result
 }
 
+export async function getImplementation(
+  network: "MAINNET" | "TESTNET" | "DEVNET",
+  chain: EVMChainName,
+  module: "Core" | "NFTBridge" | "TokenBridge",
+  contract_address: string | undefined,
+  _rpc: string | undefined
+): Promise<ethers.BigNumber> {
+  let n = NETWORKS[network][chain]
+  let rpc: string | undefined = _rpc ?? n.rpc;
+  if (rpc === undefined) {
+    throw Error(`No ${network} rpc defined for ${chain} (see networks.ts)`)
+  }
+
+  let contracts: Contracts = CONTRACTS[network][chain]
+
+  switch (module) {
+    case "Core":
+      contract_address = contract_address ? contract_address : contracts.core;
+      break
+    case "TokenBridge":
+      contract_address = contract_address ? contract_address : contracts.token_bridge;
+      break
+    case "NFTBridge":
+      contract_address = contract_address ? contract_address : contracts.nft_bridge;
+      break
+    default:
+      impossible(module)
+  }
+
+  return (await getStorageAt(rpc, contract_address, _IMPLEMENTATION_SLOT, ["address"]))[0]
+}
+
 export async function execute_governance_evm(
   payload: Payload,
   vaa: Buffer,
diff --git a/clients/js/main.ts b/clients/js/main.ts
index 6aa9e1034..4eda9b40b 100644
--- a/clients/js/main.ts
+++ b/clients/js/main.ts
@@ -5,7 +5,7 @@ import { hideBin } from "yargs/helpers";
 
 import { isTerraChain, assertEVMChain, CONTRACTS, setDefaultWasm } from "@certusone/wormhole-sdk";
 import { execute_governance_solana } from "./solana";
-import { execute_governance_evm, hijack_evm, query_contract_evm, setStorageAt } from "./evm";
+import { execute_governance_evm, getImplementation, hijack_evm, query_contract_evm, setStorageAt } from "./evm";
 import { execute_governance_terra } from "./terra";
 import * as vaa from "./vaa";
 import { impossible, Payload, serialiseVAA, VAA } from "./vaa";
@@ -309,6 +309,11 @@ yargs(hideBin(process.argv))
         const result = await setStorageAt(argv["rpc"], evm_address(argv["contract-address"]), argv["storage-slot"], ["uint256"], [argv["value"]]);
         console.log(result);
       })
+      .command("chains", "Return all EVM chains",
+        async (_) => {
+          console.log(Object.values(CHAINS).map(id => toChainName(id)).filter(name => isEVMChain(name)).join(" "))
+        }
+      )
       .command("info", "Query info about the on-chain state of the contract", (yargs) => {
         return yargs
           .option("chain", {
@@ -337,6 +342,13 @@ yargs(hideBin(process.argv))
             describe: "Contract to query (override config)",
             type: "string",
             required: false,
+          })
+          .option("implementation-only", {
+            alias: "i",
+            describe: "Only query implementation (faster)",
+            type: "boolean",
+            default: false,
+            required: false,
           });
       }, async (argv) => {
         assertChain(argv["chain"])
@@ -354,7 +366,11 @@ yargs(hideBin(process.argv))
           | "NFTBridge"
           | "TokenBridge";
         let rpc = argv["rpc"] ?? NETWORKS[network][argv["chain"]].rpc
-        console.log(JSON.stringify(await query_contract_evm(network, argv["chain"], module, argv["contract-address"], rpc), null, 2))
+        if (argv["implementation-only"]) {
+          console.log(await getImplementation(network, argv["chain"], module, argv["contract-address"], rpc))
+        } else {
+          console.log(JSON.stringify(await query_contract_evm(network, argv["chain"], module, argv["contract-address"], rpc), null, 2))
+        }
       })
       .command("hijack", "Override the guardian set of the core bridge contract during testing (anvil or hardhat)", (yargs) => {
         return yargs