diff --git a/models/signature.go b/models/signature.go
index 08d39e9..baba62c 100644
--- a/models/signature.go
+++ b/models/signature.go
@@ -1,5 +1,7 @@
 package models
 
+import "encoding/json"
+
 type JSONSignature struct {
 	Type string `json:"type"`
 	ED25519Signature
@@ -12,11 +14,31 @@ type ED25519Signature struct {
 	Signature string `json:"signature"`
 }
 
+type SignatureContent struct {
+	Index     uint64
+	Signature string
+}
+
+func (s *SignatureContent) UnmarshalJSON(raw []byte) error {
+	if len(raw) >= 2 && raw[0] == '"' && raw[len(raw)-1] == '"' {
+		return json.Unmarshal(raw, &s.Signature)
+	}
+	var t struct {
+		Index     uint64 `json:"index"`
+		Signature string `json:"signature"`
+	}
+	if err := json.Unmarshal(raw, &t); err != nil {
+		return err
+	}
+	s.Index, s.Signature = t.Index, t.Signature
+	return nil
+}
+
 type MultiED25519Signature struct {
-	PublicKeys []string `json:"public_keys"`
-	Signatures []string `json:"signatures"`
-	Threshold  uint8    `json:"threshold"`
-	Bitmap     string   `json:"bitmap"`
+	PublicKeys []string           `json:"public_keys"`
+	Signatures []SignatureContent `json:"signatures"`
+	Threshold  uint8              `json:"threshold"`
+	Bitmap     string             `json:"bitmap"`
 }
 
 type MultiAgentSignature struct {
diff --git a/models/signature_test.go b/models/signature_test.go
new file mode 100644
index 0000000..05227d6
--- /dev/null
+++ b/models/signature_test.go
@@ -0,0 +1,136 @@
+package models
+
+import (
+	"encoding/json"
+	"github.com/stretchr/testify/assert"
+	"testing"
+)
+
+func Test_unmarshalSignature0(t *testing.T) {
+	cnt := `
+{
+  "public_key": "0xde062760a3477cc7c779239cff774ac123196dac5f448126c8f10a396bdf61ff",
+  "signature": "0xcab74ee1a7be09d5dded094dbcff218f27bd451387782e76d4ab9fe5dc15d2c4c0274350869913cbcb0d24f475fe7edbf71e048e6a208f6a7ecc4a3887c63702",
+  "type": "ed25519_signature"
+}
+`
+	var s JSONSignature
+	assert.NoError(t, json.Unmarshal([]byte(cnt), &s))
+	assert.Equal(t, JSONSignature{
+		Type: "ed25519_signature",
+		ED25519Signature: ED25519Signature{
+			PublicKey: "0xde062760a3477cc7c779239cff774ac123196dac5f448126c8f10a396bdf61ff",
+			Signature: "0xcab74ee1a7be09d5dded094dbcff218f27bd451387782e76d4ab9fe5dc15d2c4c0274350869913cbcb0d24f475fe7edbf71e048e6a208f6a7ecc4a3887c63702",
+		},
+		MultiED25519Signature: MultiED25519Signature{},
+		MultiAgentSignature:   MultiAgentSignature{},
+	}, s)
+}
+
+func Test_unmarshalSignature1(t *testing.T) {
+	cnt := `
+{
+  "public_keys": [
+	"0x1b68747470733a2f2f6163636f756e74732e676f6f676c652e636f6d2073de33a2f41ce989a61922213b0de92a90b423aa36e781aa15e6d8910bf65826",
+	"0x1b68747470733a2f2f6163636f756e74732e676f6f676c652e636f6d2086b8bffaa6459d9a61a5f5c73b0ac4d8dfd33f2956b0652fbac35bda858eb71d"
+  ],
+  "signatures": [
+	{
+	  "index": 0,
+	  "signature": "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"
+	}
+  ],
+  "signatures_required": 1,
+  "type": "single_sender"
+}
+`
+	var s JSONSignature
+	assert.NoError(t, json.Unmarshal([]byte(cnt), &s))
+	assert.Equal(t, JSONSignature{
+		Type:             "single_sender",
+		ED25519Signature: ED25519Signature{},
+		MultiED25519Signature: MultiED25519Signature{
+			PublicKeys: []string{
+				"0x1b68747470733a2f2f6163636f756e74732e676f6f676c652e636f6d2073de33a2f41ce989a61922213b0de92a90b423aa36e781aa15e6d8910bf65826",
+				"0x1b68747470733a2f2f6163636f756e74732e676f6f676c652e636f6d2086b8bffaa6459d9a61a5f5c73b0ac4d8dfd33f2956b0652fbac35bda858eb71d",
+			},
+			Signatures: []SignatureContent{{
+				Index:     0,
+				Signature: "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",
+			}},
+		},
+		MultiAgentSignature: MultiAgentSignature{},
+	}, s)
+}
+
+func Test_unmarshalSignature2(t *testing.T) {
+	cnt := `
+{
+  "public_keys": [
+	"0x1b68747470733a2f2f6163636f756e74732e676f6f676c652e636f6d2073de33a2f41ce989a61922213b0de92a90b423aa36e781aa15e6d8910bf65826",
+	"0x1b68747470733a2f2f6163636f756e74732e676f6f676c652e636f6d2086b8bffaa6459d9a61a5f5c73b0ac4d8dfd33f2956b0652fbac35bda858eb71d"
+  ],
+  "signatures": [
+	"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"
+  ],
+  "signatures_required": 1,
+  "type": "single_sender"
+}
+`
+	var s JSONSignature
+	assert.NoError(t, json.Unmarshal([]byte(cnt), &s))
+	assert.Equal(t, JSONSignature{
+		Type:             "single_sender",
+		ED25519Signature: ED25519Signature{},
+		MultiED25519Signature: MultiED25519Signature{
+			PublicKeys: []string{
+				"0x1b68747470733a2f2f6163636f756e74732e676f6f676c652e636f6d2073de33a2f41ce989a61922213b0de92a90b423aa36e781aa15e6d8910bf65826",
+				"0x1b68747470733a2f2f6163636f756e74732e676f6f676c652e636f6d2086b8bffaa6459d9a61a5f5c73b0ac4d8dfd33f2956b0652fbac35bda858eb71d",
+			},
+			Signatures: []SignatureContent{{
+				Index:     0,
+				Signature: "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",
+			}},
+		},
+		MultiAgentSignature: MultiAgentSignature{},
+	}, s)
+}
+
+func Test_unmarshalSignature3(t *testing.T) {
+	cnt := `
+{
+  "sender": {
+	"public_key": "0xbee215385a76fad8117faac6e65f9934323e0f2a80ec9a219ae3399d09d74563",
+	"signature": "0x35afffb39a097f7e76f7ea40588a98ce96a324da02e1199f475928068f882766b70ee59d7d8a57cb3d0feec1a3865efbdd6c3b4230f4329de7beee83cf7aea0c",
+	"type": "ed25519_signature"
+  },
+  "secondary_signer_addresses": [],
+  "secondary_signers": [],
+  "fee_payer_address": "0x587f66c999fed81c8872c5ddabed1e7049c790d750d2a796313a32702dcff962",
+  "fee_payer_signer": {
+	"public_key": "0x1fca2d4043456ce1edfb83d2aee3537a38a58b25c1ddaa84df024905ef7e0f14",
+	"signature": "0x3e1e22b2ef32bf0e068c821983d868934508feb80156e44ecc828f8bdbe49ebbb7dc67ef8b818374def2624c71b0ea8f4f08f9d3d7c1997c37a887acd202c909",
+	"type": "ed25519_signature"
+  },
+  "type": "fee_payer_signature"
+}
+`
+	var s JSONSignature
+	assert.NoError(t, json.Unmarshal([]byte(cnt), &s))
+	assert.Equal(t, JSONSignature{
+		Type:                  "fee_payer_signature",
+		ED25519Signature:      ED25519Signature{},
+		MultiED25519Signature: MultiED25519Signature{},
+		MultiAgentSignature: MultiAgentSignature{
+			Sender: JSONSigner{
+				Type: "ed25519_signature",
+				ED25519Signature: ED25519Signature{
+					PublicKey: "0xbee215385a76fad8117faac6e65f9934323e0f2a80ec9a219ae3399d09d74563",
+					Signature: "0x35afffb39a097f7e76f7ea40588a98ce96a324da02e1199f475928068f882766b70ee59d7d8a57cb3d0feec1a3865efbdd6c3b4230f4329de7beee83cf7aea0c",
+				},
+			},
+			SecondarySignerAddresses: []string{},
+			SecondarySigners:         []JSONSigner{},
+		},
+	}, s)
+}