@@ -55,6 +55,22 @@ c.ObserveHash(cap[i])
 	}
 }
 
+func (c *ChallengerChip) ObserveExtensionElement(element QuadraticExtension) {
+	c.ObserveElements(element[:])
+}
+
+func (c *ChallengerChip) ObserveExtensionElements(elements []QuadraticExtension) {
+	for i := 0; i < len(elements); i++ {
+		c.ObserveExtensionElement(elements[i])
+	}
+}
+
+func (c *ChallengerChip) ObserveOpenings(openings FriOpenings) {
+	for i := 0; i < len(openings.Batches); i++ {
+		c.ObserveExtensionElements(openings.Batches[i].values)
+	}
+}
+
 func (c *ChallengerChip) GetChallenge() F {
 	if len(c.inputBuffer) != 0 || len(c.outputBuffer) == 0 {
 		c.duplexing()
@@ -66,12 +82,51 @@
 	return challenge
 }
 
-func (c *ChallengerChip) GetNChallenges(n int) []F {
+func (c *ChallengerChip) GetNChallenges(n uint64) []F {
 	challenges := make([]F, n)
-	for i := 0; i < n; i++ {
+	for i := uint64(0); i < n; i++ {
 		challenges[i] = c.GetChallenge()
 	}
 	return challenges
+}
+
+func (c *ChallengerChip) GetExtensionChallenge() QuadraticExtension {
+	values := c.GetNChallenges(2)
+	return QuadraticExtension{values[0], values[1]}
+}
+
+func (c *ChallengerChip) GetHash() Hash {
+	return [4]F{c.GetChallenge(), c.GetChallenge(), c.GetChallenge(), c.GetChallenge()}
+}
+
+func (c *ChallengerChip) GetFriChallenges(commitPhaseMerkleCaps []MerkleCap, finalPoly PolynomialCoeffs, powWitness F, degreeBits uint64, config FriConfig) FriChallenges {
+	numFriQueries := config.NumQueryRounds
+	ldeSize := 1 << (degreeBits + config.RateBits)
+	friAlpha := c.GetExtensionChallenge()
+
+	var friBetas []QuadraticExtension
+	for i := 0; i < len(commitPhaseMerkleCaps); i++ {
+		c.ObserveCap(commitPhaseMerkleCaps[i])
+		friBetas = append(friBetas, c.GetExtensionChallenge())
+	}
+
+	c.ObserveExtensionElements(finalPoly.Coeffs)
+
+	hash := c.GetHash()
+	powInputs := append(hash[:], powWitness)
+
+	friPowResponse := c.poseidonChip.HashNoPad(powInputs)[0]
+	friQueryIndices := c.GetNChallenges(numFriQueries)
+
+	// need to modulo lde size on fri query indices
+	_ = ldeSize
+
+	return FriChallenges{
+		FriAlpha:         friAlpha,
+		FriBetas:         friBetas,
+		FriPowResponse:   friPowResponse,
+		FriQueryIndicies: friQueryIndices,
+	}
 }
 
 func clearBuffer(buffer []F) []F {

@@ -48,9 +48,9 @@ challengerChip.ObserveHash(circuitDigest)
 	challengerChip.ObserveHash(publicInputHash)
 	challengerChip.ObserveCap(wiresCap[:])
 
-	nbChallenges := 2
-	plonkBetas := challengerChip.GetNChallenges(nbChallenges)
-	plonkGammas := challengerChip.GetNChallenges(nbChallenges)
+	numChallenges := uint64(2)
+	plonkBetas := challengerChip.GetNChallenges(numChallenges)
+	plonkGammas := challengerChip.GetNChallenges(numChallenges)
 
 	expectedPlonkBetas := [2]frontend.Variable{
 		frontend.Variable("4678728155650926271"),

@@ -0,0 +1,25 @@
+package plonky2_verifier
+
+import (
+	. "gnark-ed25519/field"
+)
+
+type FriOpeningBatch struct {
+	values []QuadraticExtension
+}
+
+type FriOpenings struct {
+	Batches []FriOpeningBatch
+}
+
+func (c *OpeningSet) ToFriOpenings() FriOpenings {
+	values := c.Constants
+	values = append(values, c.PlonkSigmas...)
+	values = append(values, c.Wires...)
+	values = append(values, c.PlonkZs...)
+	values = append(values, c.PartialProducts...)
+	values = append(values, c.QuotientPolys...)
+	zetaBatch := FriOpeningBatch{values: values}
+	zetaNextBatch := FriOpeningBatch{values: c.PlonkZsNext}
+	return FriOpenings{Batches: []FriOpeningBatch{zetaBatch, zetaNextBatch}}
+}

@@ -105,5 +105,19 @@ NumPublicInputs      uint64
 	KIs                  []F
 	NumPartialProducts   uint64
 	CircuitDigest        Hash
-	// TODO: add SelectorsInfo and Gates
+}
+
+type ProofChallenges struct {
+	PlonkBetas    []F
+	PlonkGammas   []F
+	PlonkAlphas   []F
+	PlonkZeta     QuadraticExtension
+	FriChallenges FriChallenges
+}
+
+type FriChallenges struct {
+	FriAlpha         QuadraticExtension
+	FriBetas         []QuadraticExtension
+	FriPowResponse   F
+	FriQueryIndicies []F
 }

@@ -1,43 +1,58 @@
 package plonky2_verifier
 
-// import (
-// 	. "gnark-ed25519/field"
-// 	"gnark-ed25519/poseidon"
+import (
+	. "gnark-ed25519/field"
+	"gnark-ed25519/poseidon"
 
-// 	"github.com/consensys/gnark/frontend"
-// )
+	"github.com/consensys/gnark/frontend"
+)
 
-// type VerifierChip struct {
-// 	api          frontend.API
-// 	field        frontend.API
-// 	poseidonChip poseidon.PoseidonChip
-// }
+type VerifierChip struct {
+	api          frontend.API
+	field        frontend.API
+	poseidonChip poseidon.PoseidonChip
+}
 
-// func (c *VerifierChip) GetPublicInputsHash(publicInputs []F) poseidon.HashOutput {
-// 	return c.poseidonChip.HashNoPad(publicInputs)
-// }
+func (c *VerifierChip) GetPublicInputsHash(publicInputs []F) Hash {
+	return c.poseidonChip.HashNoPad(publicInputs)
+}
 
-// func (c *VerifierChip) GetChallenges(proofWithPis ProofWithPublicInputs, publicInputsHash Hash, commonData CommonCircuitData) {
-// 	config := commonData.Config
-// 	numChallenges := int(config.NumChallenges)
-// 	challenger := NewChallengerChip(c.api, c.field, c.poseidonChip)
+func (c *VerifierChip) GetChallenges(proofWithPis ProofWithPublicInputs, publicInputsHash Hash, commonData CommonCircuitData) ProofChallenges {
+	config := commonData.Config
+	numChallenges := config.NumChallenges
+	challenger := NewChallengerChip(c.api, c.field, c.poseidonChip)
+
+	challenger.ObserveHash(commonData.CircuitDigest)
+	challenger.ObserveHash(publicInputsHash)
+	challenger.ObserveCap(proofWithPis.Proof.WiresCap)
+	plonkBetas := challenger.GetNChallenges(numChallenges)
+	plonkGammas := challenger.GetNChallenges(numChallenges)
+
+	challenger.ObserveCap(proofWithPis.Proof.PlonkZsPartialProductsCap)
+	plonkAlphas := challenger.GetNChallenges(numChallenges)
 
-// 	challenger.ObserveHash(commonData.CircuitDigest)
-// 	challenger.ObserveHash(publicInputsHash)
-// 	challenger.ObserveCap(proofWithPis.Proof.WiresCap)
-// 	plonkBetas := challenger.GetNChallenges(numChallenges)
-// 	plonkGammas := challenger.GetNChallenges(numChallenges)
+	challenger.ObserveCap(proofWithPis.Proof.QuotientPolysCap)
+	plonkZeta := challenger.GetExtensionChallenge()
 
-// 	challenger.ObserveCap(proofWithPis.Proof.PlonkZsPartialProductsCap)
-// 	plonkAlphas := challenger.GetNChallenges(numChallenges)
+	_, _, _, _ = plonkAlphas, plonkBetas, plonkGammas, plonkZeta
 
-// 	challenger.ObserveCap(proofWithPis.Proof.QuotientPolysCap)
-// 	plonkZeta := challenger.GetNChallenges(numChallenges)
+	challenger.ObserveOpenings(proofWithPis.Proof.Openings.ToFriOpenings())
 
-// 	challenger.ObserveOpenings(proofWithPis.Proof.Openings)
-// }
+	return ProofChallenges{
+		PlonkBetas:  plonkBetas,
+		PlonkGammas: plonkGammas,
+		PlonkAlphas: plonkAlphas,
+		PlonkZeta:   plonkZeta,
+		FriChallenges: challenger.GetFriChallenges(
+			proofWithPis.Proof.OpeningProof.CommitPhaseMerkleCaps,
+			proofWithPis.Proof.OpeningProof.FinalPoly,
+			proofWithPis.Proof.OpeningProof.PowWitness,
+			commonData.DegreeBits, config.FriConfig,
+		),
+	}
+}
 
-// func (c *VerifierChip) Verify(proofWithPis ProofWithPublicInputs, verifierData VerifierOnlyCircuitData, commonData CommonCircuitData) {
-// 	publicInputsHash := c.GetPublicInputsHash(proofWithPis.PublicInputs)
-// 	challenges := c.GetChallenges(proofWithPis, publicInputsHash, commonData)
-// }
+func (c *VerifierChip) Verify(proofWithPis ProofWithPublicInputs, verifierData VerifierOnlyCircuitData, commonData CommonCircuitData) {
+	publicInputsHash := c.GetPublicInputsHash(proofWithPis.PublicInputs)
+	_ = c.GetChallenges(proofWithPis, publicInputsHash, commonData)
+}

@@ -5,7 +5,6 @@ . "gnark-ed25519/field"
 	"math/big"
 
 	"github.com/consensys/gnark/frontend"
-	"github.com/consensys/gnark/std/math/emulated"
 )
 
 func StrArrayToBigIntArray(input []string) []big.Int {
@@ -29,7 +28,7 @@
 func Uint64ArrayToFArray(input []uint64) []F {
 	var output []F
 	for i := 0; i < len(input); i++ {
-		output = append(output, emulated.NewElement[emulated.Goldilocks](input[i]))
+		output = append(output, NewFieldElement(input[i]))
 	}
 	return output
 }