diff --git a/src/asset.cpp b/src/asset.cpp
index e747897..3d9abbf 100644
--- a/src/asset.cpp
+++ b/src/asset.cpp
@@ -28,6 +28,11 @@ Asset *Asset::createNonNativeAsset(QString code, const KeyPair &issuer)
     }
 }
 
+Asset *Asset::createNonNativeAsset(QString code, QString issuer)
+{
+    return Asset::createNonNativeAsset(code, KeyPair::fromAccountId(issuer));
+}
+
 Asset *Asset::create(QString type, QString code, QString issuer) {
     if (type == "native") {
         return new AssetTypeNative();
diff --git a/src/asset.h b/src/asset.h
index fcda58a..10a8384 100644
--- a/src/asset.h
+++ b/src/asset.h
@@ -16,6 +16,8 @@ class Asset
 {
 public:
     virtual ~Asset(){}
+
+
     /**
      * Creates one of AssetTypeCreditAlphaNum4 or AssetTypeCreditAlphaNum12 object based on a <code>code</code> length
      * @param code Asset code
@@ -23,6 +25,7 @@ class Asset
      */
     static Asset* createNonNativeAsset(QString code, KeyPair* issuer);
     static Asset* createNonNativeAsset(QString code, const KeyPair& issuer);//makes a copy of issuer
+    static Asset* createNonNativeAsset(QString code, QString issuer);
     static Asset* create(QString type, QString code, QString issuer);
     /**
      * Generates Asset object from a given XDR object
@@ -45,6 +48,8 @@ class Asset
      * Generates XDR object from a given Asset object
      */
     virtual stellar::Asset toXdr() = 0;
+
+    virtual QString toString() const = 0;
 };
 
 Asset* checkNotNull(Asset* asset, const char *error);
diff --git a/src/assettypecreditalphanum.cpp b/src/assettypecreditalphanum.cpp
index 5b30fb3..8c8d0f2 100644
--- a/src/assettypecreditalphanum.cpp
+++ b/src/assettypecreditalphanum.cpp
@@ -18,11 +18,15 @@ AssetTypeCreditAlphaNum::~AssetTypeCreditAlphaNum()
     delete m_issuer;
 }
 
-const KeyPair &AssetTypeCreditAlphaNum::getIssuer() {
+QString AssetTypeCreditAlphaNum::getCode() const{
+    return m_code;
+}
+
+const KeyPair &AssetTypeCreditAlphaNum::getIssuer() const{
     return *m_issuer;
 }
 
-uint AssetTypeCreditAlphaNum::hashCode() {
+uint AssetTypeCreditAlphaNum::hashCode() const{
     return qHash(m_issuer->getAccountId() + this->getCode());
 }
 
@@ -33,3 +37,8 @@ bool AssetTypeCreditAlphaNum::equals(Asset *object) {
     }
     return false;
 }
+
+QString AssetTypeCreditAlphaNum::toString() const
+{
+    return getCode()+":"+this->getIssuer().getAccountId();
+}
diff --git a/src/assettypecreditalphanum.h b/src/assettypecreditalphanum.h
index c0ef13d..d72708d 100644
--- a/src/assettypecreditalphanum.h
+++ b/src/assettypecreditalphanum.h
@@ -30,18 +30,18 @@ class AssetTypeCreditAlphaNum : public Asset
     /**
      * Returns asset code
      */
-    QString getCode() {
-        return m_code;
-    }
+    QString getCode() const;
 
     /**
      * Returns asset issuer
      */
-    const KeyPair &getIssuer();
+    const KeyPair &getIssuer() const;
 
-    uint hashCode();
+    uint hashCode() const;
 
     bool equals(Asset* object);
+
+    virtual QString toString() const;
 };
 
 #endif // ASSETTYPECREDITALPHANUM_H
diff --git a/src/assettypenative.cpp b/src/assettypenative.cpp
index 625187f..4e5e1d3 100644
--- a/src/assettypenative.cpp
+++ b/src/assettypenative.cpp
@@ -14,7 +14,7 @@ bool AssetTypeNative::equals(Asset* object) {
     return dynamic_cast<AssetTypeNative*>(object);
 }
 
-int AssetTypeNative::hashCode() {
+uint AssetTypeNative::hashCode() {
     return 0;
 }
 
@@ -23,3 +23,8 @@ stellar::Asset AssetTypeNative::toXdr() {
     xdr.type = stellar::AssetType::ASSET_TYPE_NATIVE;
     return xdr;
 }
+
+QString AssetTypeNative::toString() const
+{
+    return QString("native");
+}
diff --git a/src/assettypenative.h b/src/assettypenative.h
index ee053d0..8d30980 100644
--- a/src/assettypenative.h
+++ b/src/assettypenative.h
@@ -18,9 +18,11 @@ class AssetTypeNative : public Asset
 
     bool equals(Asset *object);
 
-    int hashCode();
+    uint hashCode();
 
     stellar::Asset toXdr();
+
+    QString toString() const;
 };
 
 #endif // ASSETTYPENATIVE_H
diff --git a/src/requests/accountsrequestbuilder.cpp b/src/requests/accountsrequestbuilder.cpp
index f7999a2..61942cd 100644
--- a/src/requests/accountsrequestbuilder.cpp
+++ b/src/requests/accountsrequestbuilder.cpp
@@ -16,6 +16,18 @@ AccountResponse* AccountsRequestBuilder::account(KeyPair *account) {
     return this->account(this->buildUri());
 }
 
+AccountsRequestBuilder &AccountsRequestBuilder::signer(KeyPair *accountID)
+{
+    addParameter("signer", accountID->getAccountId());
+    return *this;
+}
+
+AccountsRequestBuilder &AccountsRequestBuilder::asset(Asset *asset)
+{
+    RequestBuilder::setAssetParameter("asset",asset);
+    return *this;
+}
+
 AccountsRequestBuilder &AccountsRequestBuilder::cursor(QString token) {
     RequestBuilder::cursor(token);
     return *this;
diff --git a/src/requests/accountsrequestbuilder.h b/src/requests/accountsrequestbuilder.h
index b14ccfc..53b0a0c 100644
--- a/src/requests/accountsrequestbuilder.h
+++ b/src/requests/accountsrequestbuilder.h
@@ -30,6 +30,23 @@ class AccountsRequestBuilder : public RequestBuilder
       */
      AccountResponse *account(KeyPair* account);
 
+     /**
+      * @brief signer  filters accounts who have a given signer account id
+      * @see <a href="https://www.stellar.org/developers/horizon/reference/endpoints/accounts.html">Accounts</a>
+      * @param token Account ID
+      * @return AccountsRequestBuilder
+      */
+     AccountsRequestBuilder& signer(KeyPair* accountID);
+
+
+     /**
+      * @brief asset  filters accounts who have a given trustline
+      * @see <a href="https://www.stellar.org/developers/horizon/reference/endpoints/accounts.html">Accounts</a>
+      * @param asset issued asset to filter with
+      * @return AccountsRequestBuilder
+      */
+     AccountsRequestBuilder& asset(Asset* asset);
+
 
      AccountsRequestBuilder& cursor(QString token);
 
diff --git a/src/requests/requestbuilder.cpp b/src/requests/requestbuilder.cpp
index e7fccd0..d540f96 100644
--- a/src/requests/requestbuilder.cpp
+++ b/src/requests/requestbuilder.cpp
@@ -99,6 +99,18 @@ RequestBuilder &RequestBuilder::setAssetsParameter(QString name, QList<Asset *>
     return *this;
 }
 
+RequestBuilder &RequestBuilder::setAssetParameter(QString name, Asset* asset) {
+
+        if (dynamic_cast<AssetTypeNative*>(asset)) {
+            this->addParameter(name, "native");
+        } else if (AssetTypeCreditAlphaNum * creditAsset = dynamic_cast<AssetTypeCreditAlphaNum*>(asset)) {
+            this->addParameter(name, creditAsset->getCode()+"%3A"+creditAsset->getIssuer().getAccountId());//%3A is ":"  we already encode it to dont reencode everything
+
+        } else {
+            throw std::runtime_error("unsupported asset");
+        }
+    return *this;
+}
 
 QUrl RequestBuilder::buildUri() {
     QString base = this->m_uri.toString();
diff --git a/src/requests/requestbuilder.h b/src/requests/requestbuilder.h
index d6254c8..7eb4168 100644
--- a/src/requests/requestbuilder.h
+++ b/src/requests/requestbuilder.h
@@ -68,12 +68,7 @@ class RequestBuilder
      RequestBuilder& asc();
      RequestBuilder& desc();
 
-     /**
-      * Sets a parameter consisting of a comma separated list of assets on the request.
-      * @param name the name of the query parameter
-      * @param assets the list of assets to be serialized into the query parameter value
-      */
-     RequestBuilder& setAssetsParameter(QString name, QList<Asset*> assets);
+
 
      QUrl buildUri();
      void setRequestUri(QUrl &uri);//useful for the links
@@ -82,6 +77,15 @@ class RequestBuilder
 
      QString toString(Order order);
      Order orderFromString(QString s);
+
+protected:
+     /**
+      * Sets a parameter consisting of a comma separated list of assets on the request.
+      * @param name the name of the query parameter
+      * @param assets the list of assets to be serialized into the query parameter value
+      */
+     RequestBuilder& setAssetsParameter(QString name, QList<Asset*> assets);
+     RequestBuilder& setAssetParameter(QString name, Asset *asset);
 };
 
 
diff --git a/test/assettest.h b/test/assettest.h
index e9347c7..aace672 100644
--- a/test/assettest.h
+++ b/test/assettest.h
@@ -31,6 +31,7 @@ private slots:
         auto xdr = asset.toXdr();
         Asset* parsedAsset = Asset::fromXdr(xdr);
         QVERIFY(dynamic_cast<AssetTypeNative*>(parsedAsset));
+        QCOMPARE(asset.toString(),QString("native"));
     }
 
     void testAssetTypeCreditAlphaNum4() {
@@ -41,6 +42,7 @@ private slots:
         AssetTypeCreditAlphaNum4* parsedAsset = (AssetTypeCreditAlphaNum4*) Asset::fromXdr(xdr);
         QCOMPARE(code, asset.getCode());
         QCOMPARE(issuer->getAccountId(), parsedAsset->getIssuer().getAccountId());
+        QCOMPARE(asset.toString(),QString("USDA:%1").arg(issuer->getAccountId()));
     }
 
     void testAssetTypeCreditAlphaNum12() {
@@ -51,6 +53,7 @@ private slots:
         AssetTypeCreditAlphaNum12* parsedAsset = (AssetTypeCreditAlphaNum12*) Asset::fromXdr(xdr);
         QCOMPARE(code, asset.getCode());
         QCOMPARE(issuer->getAccountId(), parsedAsset->getIssuer().getAccountId());
+        QCOMPARE(asset.toString(),QString("TESTTEST:%1").arg(issuer->getAccountId()));
     }
 
 
@@ -92,6 +95,7 @@ private slots:
         QVERIFY(!AssetTypeCreditAlphaNum12("ABCDE", *issuer1).equals(new AssetTypeCreditAlphaNum12("EDCBA", *issuer1)));
         QVERIFY(!AssetTypeCreditAlphaNum12("ABCDE", *issuer1).equals(new AssetTypeCreditAlphaNum12("ABCDE", *issuer2)));
     }
+
 };
 
 ADD_TEST(AssetTest)
diff --git a/test/requests/accountsrequestbuildertest.h b/test/requests/accountsrequestbuildertest.h
index 7bd64de..1c8816e 100644
--- a/test/requests/accountsrequestbuildertest.h
+++ b/test/requests/accountsrequestbuildertest.h
@@ -5,7 +5,7 @@
 #include <QtTest>
 #include "../testcollector.h"
 #include "../../src/server.h"
-
+#include "../../src/keypair.h"
 class AccountRequestBuilderTest: public QObject
 {
     Q_OBJECT
@@ -35,6 +35,32 @@ private slots:
 
     }
 
+    void testAccountsSigner() {
+        Server* server = new Server("https://horizon-testnet.stellar.org");
+        KeyPair* signer = new KeyPair("GD42RQNXTRIW6YR3E2HXV5T2AI27LBRHOERV2JIYNFMXOBA234SWLQQB");
+        QUrl uri = server->accounts()
+                .limit(200)
+                .signer(signer)
+                .order(RequestBuilder::Order::ASC)
+                .buildUri();
+
+        QString expected("https://horizon-testnet.stellar.org/accounts?limit=200&signer=GD42RQNXTRIW6YR3E2HXV5T2AI27LBRHOERV2JIYNFMXOBA234SWLQQB&order=asc");
+        QVERIFY(uri.toString() == expected);
+    }
+
+    void testAccountsAsset() {
+        Server* server = new Server("https://horizon-testnet.stellar.org");
+        KeyPair* issuer = new KeyPair("GD42RQNXTRIW6YR3E2HXV5T2AI27LBRHOERV2JIYNFMXOBA234SWLQQB");
+        Asset* issuedAsset = Asset::createNonNativeAsset("USD",issuer);
+        QUrl uri = server->accounts()
+                .limit(200)
+                .asset(issuedAsset)
+                .order(RequestBuilder::Order::ASC)
+                .buildUri();
+
+        QString expected("https://horizon-testnet.stellar.org/accounts?limit=200&asset=USD%3AGD42RQNXTRIW6YR3E2HXV5T2AI27LBRHOERV2JIYNFMXOBA234SWLQQB&order=asc");
+        QVERIFY(uri.toString() == expected);
+    }
 };
 
 ADD_TEST(AccountRequestBuilderTest)