diff --git a/.gitignore b/.gitignore
index f8db48c..779c82c 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,2 +1,3 @@
 node_modules
-reports
\ No newline at end of file
+reports
+junit.xml
\ No newline at end of file
diff --git a/cases/sep10.test.js b/cases/sep10.test.js
index f2767d4..4c8f8c7 100644
--- a/cases/sep10.test.js
+++ b/cases/sep10.test.js
@@ -2,11 +2,17 @@ import { fetch } from "./util/fetchShim";
 import JWT from "jsonwebtoken";
 import TOML from "toml";
 import StellarSDK from "stellar-sdk";
+import friendbot from "./util/friendbot";
+import getSep10Token from "./util/sep10";
 
+// Friendbot usage makes this very slow.  Need to create an account pool at
+// the beginning and reuse them.
+jest.setTimeout(100000);
 const url = process.env.DOMAIN;
 const account = "GCQJX6WGG7SSFU2RBO5QANTFXY7C5GTTFJDCBAAO42JCCFIMZ7PEBURP";
 const secret = "SAUOSXXF7ZDO5PKHRFR445DRKZ66Q5HIM2HIPQGWBTUKJZQAOP3VGH3L";
 const keyPair = StellarSDK.Keypair.fromSecret(secret);
+const server = new StellarSDK.Server("https://horizon-testnet.stellar.org");
 
 describe("SEP10", () => {
   let toml;
@@ -187,4 +193,146 @@ describe("SEP10", () => {
       });
     });
   });
+
+  describe("signers support", () => {
+    afterAll(async () => {
+      console.log("DESTROY ALL FRIENDS");
+      await friendbot.destroyAllFriends();
+    });
+
+    /**
+     * Removing the masterWeight for an account means that it can
+     * no longer sign for itself.  This should mean that it can't
+     * get a token with its own signature.
+     */
+    it("fails for an account that can't sign for itself", async () => {
+      const accountA = StellarSDK.Keypair.random();
+      await friendbot(accountA);
+      const accountData = await server.loadAccount(accountA.publicKey());
+      const transaction = new StellarSDK.TransactionBuilder(accountData, {
+        fee: StellarSDK.BASE_FEE,
+        networkPassphrase: StellarSDK.Networks.TESTNET
+      })
+        .addOperation(
+          StellarSDK.Operation.setOptions({
+            masterWeight: 0
+          })
+        )
+        .setTimeout(30)
+        .build();
+      transaction.sign(accountA);
+      await server.submitTransaction(transaction);
+      const token = await getSep10Token(url, accountA, [accountA]);
+      expect(token).toBeFalsy();
+    });
+
+    it("succeeds for a signer of an account", async () => {
+      const userAccount = StellarSDK.Keypair.random();
+      const signerAccount = StellarSDK.Keypair.random();
+      await Promise.all([friendbot(userAccount), friendbot(signerAccount)]);
+      const accountData = await server.loadAccount(userAccount.publicKey());
+      const transaction = new StellarSDK.TransactionBuilder(accountData, {
+        fee: StellarSDK.BASE_FEE,
+        networkPassphrase: StellarSDK.Networks.TESTNET
+      })
+        .addOperation(
+          StellarSDK.Operation.setOptions({
+            lowThreshold: 1,
+            medThreshold: 1,
+            highThreshold: 1,
+            signer: {
+              ed25519PublicKey: signerAccount.publicKey(),
+              weight: 1
+            }
+          })
+        )
+        .setTimeout(30)
+        .build();
+      transaction.sign(userAccount);
+      await server.submitTransaction(transaction);
+      const token = await getSep10Token(url, userAccount, [signerAccount]);
+      expect(token).toBeTruthy();
+    });
+
+    /**
+     * In this test case, since we have a signer with only half the required
+     * weight of the thresholds, a malicious actor might try to sign twice
+     * with the same key hoping the server doesn't de-duplicate signers, and
+     * count its weight twice.
+     */
+    it("fails when trying to reuse the same signer to gain weight", async () => {
+      const userAccount = StellarSDK.Keypair.random();
+      const signerAccount = StellarSDK.Keypair.random();
+      await Promise.all([friendbot(userAccount), friendbot(signerAccount)]);
+      const accountData = await server.loadAccount(userAccount.publicKey());
+      const transaction = new StellarSDK.TransactionBuilder(accountData, {
+        fee: StellarSDK.BASE_FEE,
+        networkPassphrase: StellarSDK.Networks.TESTNET
+      })
+        .addOperation(
+          StellarSDK.Operation.setOptions({
+            lowThreshold: 2,
+            medThreshold: 2,
+            highThreshold: 2,
+            signer: {
+              ed25519PublicKey: signerAccount.publicKey(),
+              weight: 1
+            }
+          })
+        )
+        .setTimeout(30)
+        .build();
+      transaction.sign(userAccount);
+      await server.submitTransaction(transaction);
+      const token = await getSep10Token(url, userAccount, [
+        signerAccount,
+        signerAccount
+      ]);
+      expect(token).toBeFalsy();
+    });
+
+    it("succeeds with multiple signers", async () => {
+      const userAccount = StellarSDK.Keypair.random();
+      const signerAccount1 = StellarSDK.Keypair.random();
+      const signerAccount2 = StellarSDK.Keypair.random();
+      await Promise.all([
+        friendbot(userAccount),
+        friendbot(signerAccount1),
+        friendbot(signerAccount2)
+      ]);
+      const accountData = await server.loadAccount(userAccount.publicKey());
+      const transaction = new StellarSDK.TransactionBuilder(accountData, {
+        fee: StellarSDK.BASE_FEE,
+        networkPassphrase: StellarSDK.Networks.TESTNET
+      })
+        .addOperation(
+          StellarSDK.Operation.setOptions({
+            lowThreshold: 2,
+            medThreshold: 2,
+            highThreshold: 2,
+            signer: {
+              ed25519PublicKey: signerAccount1.publicKey(),
+              weight: 1
+            }
+          })
+        )
+        .addOperation(
+          StellarSDK.Operation.setOptions({
+            signer: {
+              ed25519PublicKey: signerAccount2.publicKey(),
+              weight: 1
+            }
+          })
+        )
+        .setTimeout(30)
+        .build();
+      transaction.sign(userAccount);
+      await server.submitTransaction(transaction);
+      const token = await getSep10Token(url, userAccount, [
+        signerAccount1,
+        signerAccount2
+      ]);
+      expect(token).toBeTruthy();
+    });
+  });
 });
diff --git a/cases/util/friendbot.js b/cases/util/friendbot.js
new file mode 100644
index 0000000..dc186f8
--- /dev/null
+++ b/cases/util/friendbot.js
@@ -0,0 +1,36 @@
+import { fetch } from "./fetchShim";
+import StellarSdk from "stellar-sdk";
+
+const friends = [];
+async function friendbot(keyPair) {
+  const response = await fetch(
+    `https://friendbot.stellar.org/?addr=${keyPair.publicKey()}`
+  );
+  friends.push(keyPair);
+  expect(response.status).toEqual(200);
+}
+
+friendbot.destroyAllFriends = async function() {
+  if (friends.length === 0) return;
+  const accountData = await server.loadAccount(friends[0].publicKey());
+  const transactionBuilder = new StellarSDK.TransactionBuilder(accountData, {
+    fee: StellarSDK.BASE_FEE,
+    networkPassphrase: StellarSDK.Networks.TESTNET
+  });
+  friends.forEach(keyPair => {
+    transactionBuilder.addOperation(
+      StellarSdk.Operations.accountMerge({
+        destination: "GAIH3ULLFQ4DGSECF2AR555KZ4KNDGEKN4AFI4SU2M7B43MGK3QJZNSR",
+        source: keyPair.publicKey()
+      })
+    );
+  });
+
+  const tx = transactionBuilder.setTimeout(30).build();
+  friends.forEach(keyPair => {
+    tx.sign(keyPair);
+  });
+  await server.submitTransaction(tx);
+};
+
+export default friendbot;
diff --git a/cases/util/sep10.js b/cases/util/sep10.js
index 071f6c8..f35b864 100644
--- a/cases/util/sep10.js
+++ b/cases/util/sep10.js
@@ -2,7 +2,8 @@ import TOML from "toml";
 import StellarSDK from "stellar-sdk";
 import { fetch } from "./fetchShim";
 
-export default async function getSep10Token(domain, keyPair) {
+export default async function getSep10Token(domain, keyPair, signers) {
+  if (!signers) signers = [keyPair];
   let response = await fetch(domain + "/.well-known/stellar.toml");
   const text = await response.text();
   const toml = TOML.parse(text);
@@ -14,7 +15,9 @@ export default async function getSep10Token(domain, keyPair) {
     json.transaction,
     json.network_passphrase
   );
-  tx.sign(keyPair);
+  signers.forEach(keyPair => {
+    tx.sign(keyPair);
+  });
   let resp = await fetch(toml.WEB_AUTH_ENDPOINT, {
     method: "POST",
     headers: {