diff --git a/codex/contracts/config.nim b/codex/contracts/config.nim
index d97c7786..fd6a1fa8 100644
--- a/codex/contracts/config.nim
+++ b/codex/contracts/config.nim
@@ -17,13 +17,15 @@ type
     period*: UInt256 # proofs requirements are calculated per period (in seconds)
     timeout*: UInt256 # mark proofs as missing before the timeout (in seconds)
     downtime*: uint8 # ignore this much recent blocks for proof requirements
+    zkeyHash*: string # hash of the zkey file which is linked to the verifier
 
 
 func fromTuple(_: type ProofConfig, tupl: tuple): ProofConfig =
   ProofConfig(
     period: tupl[0],
     timeout: tupl[1],
-    downtime: tupl[2]
+    downtime: tupl[2],
+    zkeyHash: tupl[3]
   )
 
 func fromTuple(_: type CollateralConfig, tupl: tuple): CollateralConfig =
diff --git a/codex/contracts/market.nim b/codex/contracts/market.nim
index 538b44ac..01b3fd32 100644
--- a/codex/contracts/market.nim
+++ b/codex/contracts/market.nim
@@ -38,6 +38,11 @@ proc approveFunds(market: OnChainMarket, amount: UInt256) {.async.} =
 
   discard await token.increaseAllowance(market.contract.address(), amount).confirm(1)
 
+method getZkeyHash*(market: Market): Future[?string] {.async.} =
+  let config = await market.contract.config()
+  let period = config.proofs.period
+  return
+
 method getSigner*(market: OnChainMarket): Future[Address] {.async.} =
   return await market.signer.getAddress()
 
diff --git a/codex/market.nim b/codex/market.nim
index bf78ddeb..88179570 100644
--- a/codex/market.nim
+++ b/codex/market.nim
@@ -30,6 +30,9 @@ type
     expiry*: UInt256
   ProofChallenge* = array[32, byte]
 
+method getZkeyHash*(market: Market): Future[?string] {.base, async.} =
+  raiseAssert("not implemented")
+
 method getSigner*(market: Market): Future[Address] {.base, async.} =
   raiseAssert("not implemented")
 
diff --git a/vendor/codex-contracts-eth b/vendor/codex-contracts-eth
index b5f33992..d4007711 160000
--- a/vendor/codex-contracts-eth
+++ b/vendor/codex-contracts-eth
@@ -1 +1 @@
-Subproject commit b5f33992b67df3733042a7d912c854700e8c863c
+Subproject commit d40077118dd552b44d20830d0510934d36e5cd97