diff --git a/parsers.go b/parsers.go
index 57b38c7..5ffcefe 100644
--- a/parsers.go
+++ b/parsers.go
@@ -1,14 +1,168 @@
 package gocircomprover
 
 import (
+	"bytes"
 	"encoding/hex"
+	"encoding/json"
 	"fmt"
 	"math/big"
+	"strconv"
 	"strings"
 
 	bn256 "github.com/ethereum/go-ethereum/crypto/bn256/cloudflare"
 )
 
+type ProvingKeyString struct {
+	A          [][]string          `json:"A"`
+	B2         [][][]string        `json:"B2"`
+	B1         [][]string          `json:"B1"`
+	C          [][]string          `json:"C"`
+	NVars      int                 `json:"nVars"`
+	NPublic    int                 `json:"nPublic"`
+	VkAlpha1   []string            `json:"vk_alfa_1"`
+	VkDelta1   []string            `json:"vk_delta_1"`
+	VkBeta1    []string            `json:"vk_beta_1"`
+	VkBeta2    [][]string          `json:"vk_beta_2"`
+	VkDelta2   [][]string          `json:"vk_delta_2"`
+	HExps      [][]string          `json:"hExps"`
+	DomainSize int                 `json:"domainSize"`
+	PolsA      []map[string]string `json:"polsA"`
+	PolsB      []map[string]string `json:"polsB"`
+	PolsC      []map[string]string `json:"polsC"`
+}
+
+type WitnessString []string
+
+func ParseProvingKey(pkJson []byte) (*ProvingKey, error) {
+	var pkStr ProvingKeyString
+	err := json.Unmarshal(pkJson, &pkStr)
+	if err != nil {
+		return nil, err
+	}
+	pk, err := provingKeyStringToProvingKey(pkStr)
+	return pk, err
+}
+
+func provingKeyStringToProvingKey(ps ProvingKeyString) (*ProvingKey, error) {
+	var p ProvingKey
+	var err error
+
+	p.A, err = arrayStringToG1(ps.A)
+	if err != nil {
+		return nil, err
+	}
+	p.B2, err = arrayStringToG2(ps.B2)
+	if err != nil {
+		return nil, err
+	}
+	p.B1, err = arrayStringToG1(ps.B1)
+	if err != nil {
+		return nil, err
+	}
+	p.C, err = arrayStringToG1(ps.C)
+	if err != nil {
+		return nil, err
+	}
+
+	p.NVars = ps.NVars
+	p.NPublic = ps.NPublic
+
+	p.VkAlpha1, err = stringToG1(ps.VkAlpha1)
+	if err != nil {
+		return nil, err
+	}
+
+	p.VkDelta1, err = stringToG1(ps.VkDelta1)
+	if err != nil {
+		return nil, err
+	}
+
+	p.VkBeta1, err = stringToG1(ps.VkBeta1)
+	if err != nil {
+		return nil, err
+	}
+	p.VkBeta2, err = stringToG2(ps.VkBeta2)
+	if err != nil {
+		return nil, err
+	}
+	p.VkDelta2, err = stringToG2(ps.VkDelta2)
+	if err != nil {
+		return nil, err
+	}
+
+	p.HExps, err = arrayStringToG1(ps.HExps)
+	if err != nil {
+		return nil, err
+	}
+
+	p.DomainSize = ps.DomainSize
+
+	p.PolsA, err = polsStringToBigInt(ps.PolsA)
+	if err != nil {
+		return nil, err
+	}
+	p.PolsB, err = polsStringToBigInt(ps.PolsB)
+	if err != nil {
+		return nil, err
+	}
+	p.PolsC, err = polsStringToBigInt(ps.PolsC)
+	if err != nil {
+		return nil, err
+	}
+
+	return &p, nil
+}
+
+// polsStringToBigInt is for taking string polynomials and converting it to *big.Int polynomials
+func polsStringToBigInt(s []map[string]string) ([]map[int]*big.Int, error) {
+	var o []map[int]*big.Int
+	for i := 0; i < len(s); i++ {
+		// var oi map[int]*big.Int
+		oi := make(map[int]*big.Int)
+		for j, v := range s[i] {
+			si, err := stringToBigInt(v)
+			if err != nil {
+				return o, err
+			}
+			// oi = append(oi, si)
+			jInt, err := strconv.Atoi(j)
+			if err != nil {
+				fmt.Println(j)
+				return o, err
+			}
+			fmt.Println(jInt, si)
+			oi[jInt] = si
+		}
+		o = append(o, oi)
+	}
+	return o, nil
+}
+
+func arrayStringToBigInt(s []string) ([]*big.Int, error) {
+	var o []*big.Int
+	for i := 0; i < len(s); i++ {
+		si, err := stringToBigInt(s[i])
+		if err != nil {
+			return o, nil
+		}
+		o = append(o, si)
+	}
+	return o, nil
+}
+
+func stringToBigInt(s string) (*big.Int, error) {
+	base := 10
+	if bytes.HasPrefix([]byte(s), []byte("0x")) {
+		base = 16
+		s = strings.TrimPrefix(s, "0x")
+	}
+	n, ok := new(big.Int).SetString(s, base)
+	if !ok {
+		return nil, fmt.Errorf("Can not parse string to *big.Int: %s", s)
+	}
+	return n, nil
+}
+
 func addZPadding(b []byte) []byte {
 	var z [32]byte
 	var r []byte
diff --git a/prover.go b/prover.go
new file mode 100644
index 0000000..8160070
--- /dev/null
+++ b/prover.go
@@ -0,0 +1,36 @@
+package gocircomprover
+
+import (
+	"math/big"
+
+	bn256 "github.com/ethereum/go-ethereum/crypto/bn256/cloudflare"
+)
+
+type Proof struct {
+	A *bn256.G1
+	B *bn256.G2
+	C *bn256.G1
+}
+
+type ProvingKey struct {
+	A          []*bn256.G1
+	B2         []*bn256.G2
+	B1         []*bn256.G1
+	C          []*bn256.G1
+	NVars      int
+	NPublic    int
+	VkAlpha1   *bn256.G1
+	VkDelta1   *bn256.G1
+	VkBeta1    *bn256.G1
+	VkBeta2    *bn256.G2
+	VkDelta2   *bn256.G2
+	HExps      []*bn256.G1
+	DomainSize int
+	PolsA      []map[int]*big.Int
+	PolsB      []map[int]*big.Int
+	PolsC      []map[int]*big.Int
+}
+
+type Witness []*big.Int
+
+var R, _ = new(big.Int).SetString("21888242871839275222246405745257275088548364400416034343698204186575808495617", 10)