diff --git a/codex/slots/proofs/backends/circomcompat.nim b/codex/slots/proofs/backends/circomcompat.nim
index 780921ca..70ff4dff 100644
--- a/codex/slots/proofs/backends/circomcompat.nim
+++ b/codex/slots/proofs/backends/circomcompat.nim
@@ -20,8 +20,11 @@ import ../../types
 import ../../../stores
 import ../../../merkletree
 import ../../../codextypes
+import ../../../contracts
 
-export circomcompat
+import ./converters
+
+export circomcompat, converters
 
 type
   CircomCompat* = object
@@ -32,40 +35,24 @@ type
     numSamples    : int     # number of samples per slot
     r1csPath      : string  # path to the r1cs file
     wasmPath      : string  # path to the wasm file
-    zKeyPath      : string  # path to the zkey file
+    zkeyPath      : string  # path to the zkey file
     backendCfg    : ptr CircomBn254Cfg
-
-  CircomG1* = G1
-  CircomG2* = G2
-
-  CircomProof*  = Proof
-  CircomKey*    = VerifyingKey
-  CircomInputs* = Inputs
+    vkp*          : ptr CircomKey
 
 proc release*(self: CircomCompat) =
-  ## Release the backend
+  ## Release the ctx
   ##
 
-  self.backendCfg.unsafeAddr.releaseCfg()
+  if not isNil(self.backendCfg):
+    self.backendCfg.unsafeAddr.releaseCfg()
 
-proc getVerifyingKey*(
-  self: CircomCompat): ?!ptr CircomKey =
-  ## Get the verifying key
-  ##
-
-  var
-    cfg: ptr CircomBn254Cfg = self.backendCfg
-    vkpPtr: ptr VerifyingKey = nil
-
-  if cfg.getVerifyingKey(vkpPtr.addr) != ERR_OK or vkpPtr == nil:
-    return failure("Failed to get verifying key")
-
-  success vkpPtr
+  if not isNil(self.vkp):
+    self.vkp.unsafeAddr.release_key()
 
 proc prove*[H](
   self: CircomCompat,
-  input: ProofInput[H]): ?!CircomProof =
-  ## Encode buffers using a backend
+  input: ProofInputs[H]): ?!CircomProof =
+  ## Encode buffers using a ctx
   ##
 
   # NOTE: All inputs are statically sized per circuit
@@ -86,43 +73,43 @@ proc prove*[H](
 
   # TODO: All parameters should match circom's static parametter
   var
-    backend: ptr CircomCompatCtx
+    ctx: ptr CircomCompatCtx
 
   defer:
-    if backend != nil:
-      backend.addr.releaseCircomCompat()
+    if ctx != nil:
+      ctx.addr.releaseCircomCompat()
 
   if initCircomCompat(
     self.backendCfg,
-    addr backend) != ERR_OK or backend == nil:
-    raiseAssert("failed to initialize CircomCompat backend")
+    addr ctx) != ERR_OK or ctx == nil:
+    raiseAssert("failed to initialize CircomCompat ctx")
 
   var
     entropy = input.entropy.toBytes
     dataSetRoot = input.datasetRoot.toBytes
     slotRoot = input.slotRoot.toBytes
 
-  if backend.pushInputU256Array(
+  if ctx.pushInputU256Array(
     "entropy".cstring, entropy[0].addr, entropy.len.uint32) != ERR_OK:
     return failure("Failed to push entropy")
 
-  if backend.pushInputU256Array(
+  if ctx.pushInputU256Array(
     "dataSetRoot".cstring, dataSetRoot[0].addr, dataSetRoot.len.uint32) != ERR_OK:
     return failure("Failed to push data set root")
 
-  if backend.pushInputU256Array(
+  if ctx.pushInputU256Array(
     "slotRoot".cstring, slotRoot[0].addr, slotRoot.len.uint32) != ERR_OK:
     return failure("Failed to push data set root")
 
-  if backend.pushInputU32(
+  if ctx.pushInputU32(
     "nCellsPerSlot".cstring, input.nCellsPerSlot.uint32) != ERR_OK:
     return failure("Failed to push nCellsPerSlot")
 
-  if backend.pushInputU32(
+  if ctx.pushInputU32(
     "nSlotsPerDataSet".cstring, input.nSlotsPerDataSet.uint32) != ERR_OK:
     return failure("Failed to push nSlotsPerDataSet")
 
-  if backend.pushInputU32(
+  if ctx.pushInputU32(
     "slotIndex".cstring, input.slotIndex.uint32) != ERR_OK:
     return failure("Failed to push slotIndex")
 
@@ -132,7 +119,7 @@ proc prove*[H](
   slotProof.setLen(self.datasetDepth) # zero pad inputs to correct size
 
   # arrays are always flattened
-  if backend.pushInputU256Array(
+  if ctx.pushInputU256Array(
     "slotProof".cstring,
     slotProof[0].addr,
     uint (slotProof[0].len * slotProof.len)) != ERR_OK:
@@ -144,14 +131,14 @@ proc prove*[H](
       data = s.cellData
 
     merklePaths.setLen(self.slotDepth) # zero pad inputs to correct size
-    if backend.pushInputU256Array(
+    if ctx.pushInputU256Array(
       "merklePaths".cstring,
       merklePaths[0].addr,
       uint (merklePaths[0].len * merklePaths.len)) != ERR_OK:
         return failure("Failed to push merkle paths")
 
     data.setLen(self.cellElms * 32) # zero pad inputs to correct size
-    if backend.pushInputU256Array(
+    if ctx.pushInputU256Array(
       "cellData".cstring,
       data[0].addr,
       data.len.uint) != ERR_OK:
@@ -163,7 +150,7 @@ proc prove*[H](
   let proof =
     try:
       if (
-        let res = self.backendCfg.proveCircuit(backend, proofPtr.addr);
+        let res = self.backendCfg.proveCircuit(ctx, proofPtr.addr);
         res != ERR_OK) or
         proofPtr == nil:
         return failure("Failed to prove - err code: " & $res)
@@ -175,55 +162,66 @@ proc prove*[H](
 
   success proof
 
-proc verify*(
+proc verify*[H](
   self: CircomCompat,
   proof: CircomProof,
-  inputs: CircomInputs,
-  vkp: CircomKey): ?!bool =
-  ## Verify a proof using a backend
+  inputs: ProofInputs[H]): ?!bool =
+  ## Verify a proof using a ctx
   ##
 
   var
-    proofPtr : ptr Proof = unsafeAddr proof
-    inputsPtr: ptr Inputs = unsafeAddr inputs
-    vpkPtr: ptr CircomKey = unsafeAddr vkp
+    proofPtr = unsafeAddr proof
+    inputs = inputs.toCircomInputs()
 
-  let res = verifyCircuit(proofPtr, inputsPtr, vpkPtr)
-  if res == ERR_OK:
-    success true
-  elif res == ERR_FAILED_TO_VERIFY_PROOF:
-    success false
-  else:
-    failure("Failed to verify proof - err code: " & $res)
+  try:
+    let res = verifyCircuit(proofPtr, inputs.addr, self.vkp)
+    if res == ERR_OK:
+      success true
+    elif res == ERR_FAILED_TO_VERIFY_PROOF:
+      success false
+    else:
+      failure("Failed to verify proof - err code: " & $res)
+  finally:
+    inputs.releaseCircomInputs()
 
 proc init*(
   _: type CircomCompat,
   r1csPath      : string,
   wasmPath      : string,
-  zKeyPath      : string = "",
+  zkeyPath      : string = "",
   slotDepth     = DefaultMaxSlotDepth,
   datasetDepth  = DefaultMaxDatasetDepth,
   blkDepth      = DefaultBlockDepth,
   cellElms      = DefaultCellElms,
   numSamples    = DefaultSamplesNum): CircomCompat =
-  ## Create a new backend
+  ## Create a new ctx
   ##
 
   var cfg: ptr CircomBn254Cfg
+  var zkey = if zkeyPath.len > 0: zkeyPath.cstring else: nil
+
   if initCircomConfig(
     r1csPath.cstring,
     wasmPath.cstring,
-    if zKeyPath.len > 0: zKeyPath.cstring else: nil,
-    addr cfg) != ERR_OK or cfg == nil:
+    zkey, cfg.addr) != ERR_OK or cfg == nil:
+      if cfg != nil: cfg.addr.releaseCfg()
       raiseAssert("failed to initialize circom compat config")
 
+  var
+    vkpPtr: ptr VerifyingKey = nil
+
+  if cfg.getVerifyingKey(vkpPtr.addr) != ERR_OK or vkpPtr == nil:
+    if vkpPtr != nil: vkpPtr.addr.releaseKey()
+    raiseAssert("Failed to get verifying key")
+
   CircomCompat(
     r1csPath    : r1csPath,
     wasmPath    : wasmPath,
-    zKeyPath    : zKeyPath,
-    backendCfg  : cfg,
+    zkeyPath    : zkeyPath,
     slotDepth   : slotDepth,
     datasetDepth: datasetDepth,
     blkDepth    : blkDepth,
     cellElms    : cellElms,
-    numSamples  : numSamples)
+    numSamples  : numSamples,
+    backendCfg  : cfg,
+    vkp         : vkpPtr)
diff --git a/codex/slots/proofs/backends/converters.nim b/codex/slots/proofs/backends/converters.nim
new file mode 100644
index 00000000..b405ab1f
--- /dev/null
+++ b/codex/slots/proofs/backends/converters.nim
@@ -0,0 +1,70 @@
+## Nim-Codex
+## Copyright (c) 2024 Status Research & Development GmbH
+## Licensed under either of
+##  * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE))
+##  * MIT license ([LICENSE-MIT](LICENSE-MIT))
+## at your option.
+## This file may not be copied, modified, or distributed except according to
+## those terms.
+
+{.push raises: [].}
+
+import pkg/circomcompat
+
+import ../../../contracts
+import ../../types
+import ../../../merkletree
+
+type
+  CircomG1* = G1
+  CircomG2* = G2
+
+  CircomProof*  = Proof
+  CircomKey*    = VerifyingKey
+  CircomInputs* = Inputs
+
+proc toCircomInputs*(inputs: ProofInputs[Poseidon2Hash]): CircomInputs =
+  var
+    slotIndex = inputs.slotIndex.toF.toBytes.toArray32
+    datasetRoot = inputs.datasetRoot.toBytes.toArray32
+    entropy = inputs.entropy.toBytes.toArray32
+
+    elms = [
+      entropy,
+      datasetRoot,
+      slotIndex
+    ]
+
+  let inputsPtr = allocShared0(32 * elms.len)
+  copyMem(inputsPtr, addr elms[0], elms.len * 32)
+
+  CircomInputs(
+    elms: cast[ptr array[32, byte]](inputsPtr),
+    len: elms.len.uint)
+
+proc releaseCircomInputs*(inputs: var CircomInputs) =
+  if not inputs.elms.isNil:
+    deallocShared(inputs.elms)
+    inputs.elms = nil
+
+func toG1*(g: CircomG1): G1Point =
+  G1Point(
+    x: UInt256.fromBytesLE(g.x),
+    y: UInt256.fromBytesLE(g.y))
+
+func toG2*(g: CircomG2): G2Point =
+  G2Point(
+    x: [
+      UInt256.fromBytesLE(g.x[0]),
+      UInt256.fromBytesLE(g.x[1])
+    ],
+    y: [
+      UInt256.fromBytesLE(g.y[0]),
+      UInt256.fromBytesLE(g.y[1])
+    ])
+
+func toGroth16Proof*(proof: CircomProof): Groth16Proof =
+  Groth16Proof(
+    a: proof.a.toG1,
+    b: proof.b.toG2,
+    c: proof.c.toG1)
diff --git a/codex/slots/proofs/prover.nim b/codex/slots/proofs/prover.nim
index 3161c78f..9077c478 100644
--- a/codex/slots/proofs/prover.nim
+++ b/codex/slots/proofs/prover.nim
@@ -30,25 +30,27 @@ import ../types
 
 export backends
 
-type
-  AnyProof* = CircomProof
-  AnyInputs* = CircomInputs
-  AnyKeys* = CircomKey
-  AnyHash* = Poseidon2Hash
-  AnyBackend* = CircomCompat
-  AnyBuilder* = Poseidon2Builder
-  AnySampler* = Poseidon2Sampler
+logScope:
+  topics = "codex prover"
 
+type
+  AnyBackend* = CircomCompat
+  AnyProof* = CircomProof
+
+  AnySampler* = Poseidon2Sampler
+  AnyBuilder* = Poseidon2Builder
+
+  AnyProofInputs* = ProofInputs[Poseidon2Hash]
   Prover* = ref object of RootObj
     backend: AnyBackend
     store: BlockStore
+    nSamples: int
 
 proc prove*(
   self: Prover,
   slotIdx: int,
   manifest: Manifest,
-  challenge: ProofChallenge,
-  nSamples = DefaultSamplesNum): Future[?!AnyProof] {.async.} =
+  challenge: ProofChallenge): Future[?!(AnyProofInputs, AnyProof)] {.async.} =
   ## Prove a statement using backend.
   ## Returns a future that resolves to a proof.
 
@@ -67,7 +69,7 @@ proc prove*(
     error "Unable to create data sampler", err = err.msg
     return failure(err)
 
-  without proofInput =? await sampler.getProofInput(challenge, nSamples), err:
+  without proofInput =? await sampler.getProofInput(challenge, self.nSamples), err:
     error "Unable to get proof input for slot", err = err.msg
     return failure(err)
 
@@ -76,23 +78,24 @@ proc prove*(
     error "Unable to prove slot", err = err.msg
     return failure(err)
 
-  success proof
+  success (proofInput, proof)
 
 proc verify*(
   self: Prover,
   proof: AnyProof,
-  inputs: AnyInputs,
-  vpk: AnyKeys): Future[?!bool] {.async.} =
+  inputs: AnyProofInputs): Future[?!bool] {.async.} =
   ## Prove a statement using backend.
   ## Returns a future that resolves to a proof.
 
-  self.backend.verify(proof, inputs, vpk)
+  self.backend.verify(proof, inputs)
 
 proc new*(
   _: type Prover,
   store: BlockStore,
-  backend: AnyBackend): Prover =
+  backend: AnyBackend,
+  nSamples: int): Prover =
 
   Prover(
     backend: backend,
-    store: store)
+    store: store,
+    nSamples: nSamples)
diff --git a/codex/slots/sampler/sampler.nim b/codex/slots/sampler/sampler.nim
index e04805db..aef3545d 100644
--- a/codex/slots/sampler/sampler.nim
+++ b/codex/slots/sampler/sampler.nim
@@ -91,7 +91,7 @@ proc getSample*[T, H](
 proc getProofInput*[T, H](
   self: DataSampler[T, H],
   entropy: ProofChallenge,
-  nSamples: Natural): Future[?!ProofInput[H]] {.async.} =
+  nSamples: Natural): Future[?!ProofInputs[H]] {.async.} =
   ## Generate proofs as input to the proving circuit.
   ##
 
@@ -124,7 +124,7 @@ proc getProofInput*[T, H](
       (await self.getSample(cellIdx, slotTreeCid, slotRoot)).valueOr:
         return failure("Failed to get sample")
 
-  success ProofInput[H](
+  success ProofInputs[H](
     entropy: entropy,
     datasetRoot: datasetRoot,
     slotProof: slotProof.path,
diff --git a/codex/slots/types.nim b/codex/slots/types.nim
index de515e9c..04690adc 100644
--- a/codex/slots/types.nim
+++ b/codex/slots/types.nim
@@ -17,7 +17,7 @@ type
     datasetRoot*: H
     entropy*: H
 
-  ProofInput*[H] = object
+  ProofInputs*[H] = object
     entropy*: H
     datasetRoot*: H
     slotIndex*: Natural
diff --git a/tests/circuits/fixtures/proof_main.wasm b/tests/circuits/fixtures/proof_main.wasm
index dc2f607f..30fe6f0e 100644
Binary files a/tests/circuits/fixtures/proof_main.wasm and b/tests/circuits/fixtures/proof_main.wasm differ
diff --git a/tests/circuits/fixtures/proof_main.zkey b/tests/circuits/fixtures/proof_main.zkey
new file mode 100644
index 00000000..81188f21
Binary files /dev/null and b/tests/circuits/fixtures/proof_main.zkey differ
diff --git a/tests/codex/slots/backends/helpers.nim b/tests/codex/slots/backends/helpers.nim
index 65e424ba..e81762cf 100644
--- a/tests/codex/slots/backends/helpers.nim
+++ b/tests/codex/slots/backends/helpers.nim
@@ -2,8 +2,10 @@
 import std/sequtils
 import std/sugar
 import std/strutils
+import std/options
 
 import pkg/poseidon2
+import pkg/poseidon2/io
 import pkg/constantine/math/arithmetic
 import pkg/constantine/math/io/io_bigints
 import pkg/constantine/math/io/io_fields
@@ -15,7 +17,7 @@ import pkg/codex/utils/json
 
 export types
 
-func fromCircomData*[H](cellData: seq[byte]): seq[H] =
+func fromCircomData*(_: type Poseidon2Hash, cellData: seq[byte]): seq[Poseidon2Hash] =
   var
     pos = 0
     cellElms: seq[Bn254Fr]
@@ -30,43 +32,40 @@ func fromCircomData*[H](cellData: seq[byte]): seq[H] =
 
   cellElms
 
-func toPublicInputs*[H](input: ProofInput[H]): PublicInputs[H] =
-  PublicInputs[H](
-    slotIndex: input.slotIndex,
-    datasetRoot: input.datasetRoot,
-    entropy: input.entropy
-  )
-
-proc toCircomInputs*[H](inputs: PublicInputs[H]): CircomInputs =
-  var
-    slotIndex = inputs.slotIndex.toF.toBytes.toArray32
-    datasetRoot = inputs.datasetRoot.toBytes.toArray32
-    entropy = inputs.entropy.toBytes.toArray32
-
-    elms = [
-      entropy,
-      datasetRoot,
-      slotIndex
-    ]
-
-  let inputsPtr = allocShared0(32 * elms.len)
-  copyMem(inputsPtr, addr elms[0], elms.len * 32)
-
-  CircomInputs(
-    elms: cast[ptr array[32, byte]](inputsPtr),
-    len: elms.len.uint
-  )
-
-proc releaseNimInputs*(inputs: var CircomInputs) =
-  if not inputs.elms.isNil:
-    deallocShared(inputs.elms)
-    inputs.elms = nil
-
 func toJsonDecimal*(big: BigInt[254]): string =
   let s = big.toDecimal.strip( leading = true, trailing = false, chars = {'0'} )
   if s.len == 0: "0" else: s
 
-func toJson*[H](input: ProofInput[H]): JsonNode =
+func toJson*(g1: CircomG1): JsonNode =
+  %* {
+    "x": Bn254Fr.fromBytes(g1.x).get.toBig.toJsonDecimal,
+    "y": Bn254Fr.fromBytes(g1.y).get.toBig.toJsonDecimal
+  }
+
+func toJson*(g2: CircomG2): JsonNode =
+  %* {
+    "x": [
+      Bn254Fr.fromBytes(g2.x[0]).get.toBig.toJsonDecimal,
+      Bn254Fr.fromBytes(g2.x[1]).get.toBig.toJsonDecimal],
+    "y": [
+      Bn254Fr.fromBytes(g2.y[0]).get.toBig.toJsonDecimal,
+      Bn254Fr.fromBytes(g2.y[1]).get.toBig.toJsonDecimal]
+  }
+
+proc toJson*(vpk: VerifyingKey): JsonNode =
+  let
+    ic = toSeq(cast[ptr UncheckedArray[CircomG1]](vpk.ic).toOpenArray(0, vpk.icLen.int - 1))
+
+  echo ic.len
+  %* {
+    "alpha1": vpk.alpha1.toJson,
+    "beta2": vpk.beta2.toJson,
+    "gamma2": vpk.gamma2.toJson,
+    "delta2": vpk.delta2.toJson,
+    "ic": ic.mapIt( it.toJson )
+  }
+
+func toJson*(input: ProofInputs[Poseidon2Hash]): JsonNode =
   var
     input = input
 
@@ -79,14 +78,14 @@ func toJson*[H](input: ProofInput[H]): JsonNode =
     "slotRoot": input.slotRoot.toDecimal,
     "slotProof": input.slotProof.mapIt( it.toBig.toJsonDecimal ),
     "cellData": input.samples.mapIt(
-      toSeq( it.cellData.elements(H) ).mapIt( it.toBig.toJsonDecimal )
+      toSeq( it.cellData.elements(Poseidon2Hash) ).mapIt( it.toBig.toJsonDecimal )
     ),
     "merklePaths": input.samples.mapIt(
       it.merklePaths.mapIt( it.toBig.toJsonDecimal )
     )
   }
 
-func jsonToProofInput*[H](inputJson: JsonNode): ProofInput[H] =
+func jsonToProofInput*(_: type Poseidon2Hash, inputJson: JsonNode): ProofInputs[Poseidon2Hash] =
   let
     cellData =
       inputJson["cellData"].mapIt(
@@ -107,7 +106,7 @@ func jsonToProofInput*[H](inputJson: JsonNode): ProofInput[H] =
             block:
               var
                 big: BigInt[254]
-                hash: H
+                hash: Poseidon2Hash
               assert bool(big.fromDecimal( it.getStr ))
               hash.fromBig( big )
               hash
@@ -118,7 +117,7 @@ func jsonToProofInput*[H](inputJson: JsonNode): ProofInput[H] =
       block:
         var
           big: BigInt[254]
-          hash: H
+          hash: Poseidon2Hash
         assert bool(big.fromDecimal( it.str ))
         hash.fromBig( big )
         hash
@@ -127,7 +126,7 @@ func jsonToProofInput*[H](inputJson: JsonNode): ProofInput[H] =
     datasetRoot = block:
       var
         big: BigInt[254]
-        hash: H
+        hash: Poseidon2Hash
       assert bool(big.fromDecimal( inputJson["dataSetRoot"].str ))
       hash.fromBig( big )
       hash
@@ -135,7 +134,7 @@ func jsonToProofInput*[H](inputJson: JsonNode): ProofInput[H] =
     slotRoot = block:
       var
         big: BigInt[254]
-        hash: H
+        hash: Poseidon2Hash
       assert bool(big.fromDecimal( inputJson["slotRoot"].str ))
       hash.fromBig( big )
       hash
@@ -143,7 +142,7 @@ func jsonToProofInput*[H](inputJson: JsonNode): ProofInput[H] =
     entropy = block:
       var
         big: BigInt[254]
-        hash: H
+        hash: Poseidon2Hash
       assert bool(big.fromDecimal( inputJson["entropy"].str ))
       hash.fromBig( big )
       hash
@@ -152,7 +151,7 @@ func jsonToProofInput*[H](inputJson: JsonNode): ProofInput[H] =
     nSlotsPerDataSet = inputJson["nSlotsPerDataSet"].getInt
     slotIndex = inputJson["slotIndex"].getInt
 
-  ProofInput[H](
+  ProofInputs[Poseidon2Hash](
     entropy: entropy,
     slotIndex: slotIndex,
     datasetRoot: datasetRoot,
@@ -161,7 +160,7 @@ func jsonToProofInput*[H](inputJson: JsonNode): ProofInput[H] =
     nCellsPerSlot: nCellsPerSlot,
     nSlotsPerDataSet: nSlotsPerDataSet,
     samples: zip(cellData, merklePaths)
-      .mapIt(Sample[H](
+      .mapIt(Sample[Poseidon2Hash](
         cellData: it[0],
         merklePaths: it[1]
       ))
diff --git a/tests/codex/slots/backends/testcircomcompat.nim b/tests/codex/slots/backends/testcircomcompat.nim
index e6a31c15..bc6240d3 100644
--- a/tests/codex/slots/backends/testcircomcompat.nim
+++ b/tests/codex/slots/backends/testcircomcompat.nim
@@ -3,8 +3,9 @@ import std/sequtils
 import std/sugar
 import std/options
 
-import pkg/chronos
 import ../../../asynctest
+
+import pkg/chronos
 import pkg/poseidon2
 import pkg/datastore
 
@@ -16,10 +17,6 @@ import pkg/codex/codextypes
 import pkg/codex/manifest
 import pkg/codex/stores
 
-import pkg/constantine/math/arithmetic
-import pkg/constantine/math/io/io_fields
-import pkg/constantine/math/io/io_bigints
-
 import ./helpers
 import ../helpers
 
@@ -27,56 +24,50 @@ suite "Test Circom Compat Backend - control inputs":
   let
     r1cs = "tests/circuits/fixtures/proof_main.r1cs"
     wasm = "tests/circuits/fixtures/proof_main.wasm"
+    zkey = "tests/circuits/fixtures/proof_main.zkey"
 
   var
     circom: CircomCompat
-    verifyingKeyPtr: ptr CircomKey
-    proofInput: ProofInput[Poseidon2Hash]
-    publicInputs: CircomInputs
+    proofInputs: ProofInputs[Poseidon2Hash]
 
   setup:
     let
       inputData = readFile("tests/circuits/fixtures/input.json")
       inputJson = parseJson(inputData)
 
-    proofInput = jsonToProofInput[Poseidon2Hash](inputJson)
-    publicInputs = toPublicInputs[Poseidon2Hash](proofInput).toCircomInputs
-
-    # circom = CircomCompat.init(r1cs, wasm, zkey)
-    circom = CircomCompat.init(r1cs, wasm)
-    verifyingKeyPtr = circom.getVerifyingKey().tryGet
+    proofInputs = Poseidon2Hash.jsonToProofInput(inputJson)
+    circom = CircomCompat.init(r1cs, wasm, zkey)
 
   teardown:
-    publicInputs.releaseNimInputs()      # this is allocated by nim
-    verifyingKeyPtr.addr.releaseKey()    # this comes from the rust FFI
-    circom.release()                     # this comes from the rust FFI
+    circom.release()  # this comes from the rust FFI
 
   test "Should verify with correct inputs":
     let
-      proof = circom.prove(proofInput).tryGet
+      proof = circom.prove(proofInputs).tryGet
 
-    check circom.verify(proof, publicInputs, verifyingKeyPtr[]).tryGet
+    check circom.verify(proof, proofInputs).tryGet
 
   test "Should not verify with incorrect inputs":
-    proofInput.slotIndex = 1 # change slot index
+    proofInputs.slotIndex = 1 # change slot index
 
     let
-      proof = circom.prove(proofInput).tryGet
+      proof = circom.prove(proofInputs).tryGet
 
-    check circom.verify(proof, publicInputs, verifyingKeyPtr[]).tryGet == false
+    check circom.verify(proof, proofInputs).tryGet == false
 
 suite "Test Circom Compat Backend":
   let
-    slotId = 3
-    samples = 5
     ecK = 2
     ecM = 2
+    slotId = 3
+    samples = 5
     numDatasetBlocks = 8
     blockSize = DefaultBlockSize
     cellSize = DefaultCellSize
 
     r1cs = "tests/circuits/fixtures/proof_main.r1cs"
     wasm = "tests/circuits/fixtures/proof_main.wasm"
+    zkey = "tests/circuits/fixtures/proof_main.zkey"
 
   var
     store: BlockStore
@@ -84,9 +75,7 @@ suite "Test Circom Compat Backend":
     protected: Manifest
     verifiable: Manifest
     circom: CircomCompat
-    verifyingKeyPtr: ptr CircomKey
-    proofInput: ProofInput[Poseidon2Hash]
-    publicInputs: CircomInputs
+    proofInputs: ProofInputs[Poseidon2Hash]
     challenge: array[32, byte]
     builder: Poseidon2Builder
     sampler: Poseidon2Sampler
@@ -109,29 +98,24 @@ suite "Test Circom Compat Backend":
     builder = Poseidon2Builder.new(store, verifiable).tryGet
     sampler = Poseidon2Sampler.new(slotId, store, builder).tryGet
 
-    # circom = CircomCompat.init(r1cs, wasm, zkey)
-    circom = CircomCompat.init(r1cs, wasm)
-    verifyingKeyPtr = circom.getVerifyingKey().tryGet
+    circom = CircomCompat.init(r1cs, wasm, zkey)
     challenge = 1234567.toF.toBytes.toArray32
 
-    proofInput = (await sampler.getProofInput(challenge, samples)).tryGet
-    publicInputs = proofInput.toPublicInputs.toCircomInputs
+    proofInputs = (await sampler.getProofInput(challenge, samples)).tryGet
 
   teardown:
-    publicInputs.releaseNimInputs()      # this is allocated by nim
-    verifyingKeyPtr.addr.releaseKey()    # this comes from the rust FFI
-    circom.release()                     # this comes from the rust FFI
+    circom.release()  # this comes from the rust FFI
 
   test "Should verify with correct input":
     var
-      proof = circom.prove(proofInput).tryGet
+      proof = circom.prove(proofInputs).tryGet
 
-    check circom.verify(proof, publicInputs, verifyingKeyPtr[]).tryGet
+    check circom.verify(proof, proofInputs).tryGet
 
   test "Should not verify with incorrect input":
-    proofInput.slotIndex = 1 # change slot index
+    proofInputs.slotIndex = 1 # change slot index
 
     let
-      proof = circom.prove(proofInput).tryGet
+      proof = circom.prove(proofInputs).tryGet
 
-    check circom.verify(proof, publicInputs, verifyingKeyPtr[]).tryGet == false
+    check circom.verify(proof, proofInputs).tryGet == false
diff --git a/tests/codex/slots/sampler/testsampler.nim b/tests/codex/slots/sampler/testsampler.nim
index 3eeb2287..ef04656f 100644
--- a/tests/codex/slots/sampler/testsampler.nim
+++ b/tests/codex/slots/sampler/testsampler.nim
@@ -31,12 +31,12 @@ suite "Test Sampler - control samples":
   var
     inputData: string
     inputJson: JsonNode
-    proofInput: ProofInput[Poseidon2Hash]
+    proofInput: ProofInputs[Poseidon2Hash]
 
   setup:
     inputData = readFile("tests/circuits/fixtures/input.json")
     inputJson = parseJson(inputData)
-    proofInput = jsonToProofInput[Poseidon2Hash](inputJson)
+    proofInput = Poseidon2Hash.jsonToProofInput(inputJson)
 
   test "Should verify control samples":
     let
@@ -58,7 +58,7 @@ suite "Test Sampler - control samples":
           proofInput.nCellsPerSlot,
           sample.merklePaths[5..<9]).tryGet
 
-        cellData = fromCircomData[Poseidon2Hash](sample.cellData)
+        cellData = Poseidon2Hash.fromCircomData(sample.cellData)
         cellLeaf = Poseidon2Hash.spongeDigest(cellData, rate = 2).tryGet
         slotLeaf = cellProof.reconstructRoot(cellLeaf).tryGet
 
@@ -154,7 +154,7 @@ suite "Test Sampler":
           nSlotCells,
           sample.merklePaths[5..<sample.merklePaths.len]).tryGet
 
-        cellData = fromCircomData[Poseidon2Hash](sample.cellData)
+        cellData = Poseidon2Hash.fromCircomData(sample.cellData)
         cellLeaf = Poseidon2Hash.spongeDigest(cellData, rate = 2).tryGet
         slotLeaf = cellProof.reconstructRoot(cellLeaf).tryGet
 
diff --git a/tests/codex/slots/sampler/testutils.nim b/tests/codex/slots/sampler/testutils.nim
index 2c9520d0..1e1bef96 100644
--- a/tests/codex/slots/sampler/testutils.nim
+++ b/tests/codex/slots/sampler/testutils.nim
@@ -34,12 +34,12 @@ asyncchecksuite "Test proof sampler utils":
   var
     inputData: string
     inputJson: JsonNode
-    proofInput: ProofInput[Poseidon2Hash]
+    proofInput: ProofInputs[Poseidon2Hash]
 
   setup:
     inputData = readFile("tests/circuits/fixtures/input.json")
     inputJson = parseJson(inputData)
-    proofInput = jsonToProofInput[Poseidon2Hash](inputJson)
+    proofInput = Poseidon2Hash.jsonToProofInput(inputJson)
 
   test "Extract low bits":
     proc extract(value: uint64, nBits: int): uint64 =
diff --git a/tests/codex/slots/testprover.nim b/tests/codex/slots/testprover.nim
index 4735e871..9deed96a 100644
--- a/tests/codex/slots/testprover.nim
+++ b/tests/codex/slots/testprover.nim
@@ -18,10 +18,6 @@ import pkg/codex/stores
 import pkg/poseidon2/io
 import pkg/codex/utils/poseidon2digest
 
-import pkg/constantine/math/arithmetic
-import pkg/constantine/math/io/io_bigints
-import pkg/constantine/math/io/io_fields
-
 import ./helpers
 import ../helpers
 import ./backends/helpers
@@ -30,11 +26,11 @@ suite "Test Prover":
   let
     slotId = 1
     samples = 5
-    blockSize = DefaultBlockSize
-    cellSize = DefaultCellSize
     ecK = 3
     ecM = 2
     numDatasetBlocks = 8
+    blockSize = DefaultBlockSize
+    cellSize = DefaultCellSize
 
   var
     datasetBlocks: seq[bt.Block]
@@ -65,14 +61,9 @@ suite "Test Prover":
       wasm = "tests/circuits/fixtures/proof_main.wasm"
 
       circomBackend = CircomCompat.init(r1cs, wasm)
-      prover = Prover.new(store, circomBackend)
+      prover = Prover.new(store, circomBackend, samples)
       challenge = 1234567.toF.toBytes.toArray32
-      proof = (await prover.prove(1, verifiable, challenge, 5)).tryGet
-      key = circomBackend.getVerifyingKey().tryGet
-      builder = Poseidon2Builder.new(store, verifiable).tryGet
-      sampler = Poseidon2Sampler.new(1, store, builder).tryGet
-      proofInput = (await sampler.getProofInput(challenge, 5)).tryGet
-      inputs = proofInput.toPublicInputs.toCircomInputs
+      (inputs, proof) = (await prover.prove(1, verifiable, challenge)).tryGet
 
     check:
-      (await prover.verify(proof, inputs, key[])).tryGet == true
+      (await prover.verify(proof, inputs)).tryGet == true
diff --git a/tests/codex/testslots.nim b/tests/codex/testslots.nim
index f37e0927..2292c4f8 100644
--- a/tests/codex/testslots.nim
+++ b/tests/codex/testslots.nim
@@ -1,5 +1,7 @@
 import ./slots/testslotbuilder
 import ./slots/testsampler
 import ./slots/testconverters
+import ./slots/testbackends
+import ./slots/testprover
 
 {.warning[UnusedImport]: off.}
diff --git a/vendor/nim-circom-compat b/vendor/nim-circom-compat
index fa513b12..e710e4c3 160000
--- a/vendor/nim-circom-compat
+++ b/vendor/nim-circom-compat
@@ -1 +1 @@
-Subproject commit fa513b123e081c76ec0bb3237ad886d4830b8071
+Subproject commit e710e4c333f367353aaa1ee82a55a47326b63a65