diff --git a/apps/contribution/contracts/Contribution.sol b/apps/contribution/contracts/Contribution.sol
index 4dcb62f..1717717 100644
--- a/apps/contribution/contracts/Contribution.sol
+++ b/apps/contribution/contracts/Contribution.sol
@@ -7,17 +7,25 @@ interface IToken {
   function mintFor(address contributorAccount, uint256 amount, uint256 contributionId) public;
 }
 
+interface ContributorInterface {
+  function getContributorAddressById(uint256 contributorId) public view returns (address);
+  function getContributorIdByAddress(address contributorAccount) public view returns (uint256);
+  // TODO Maybe use for validation
+  // function exists(uint256 contributorId) public view returns (bool);
+}
+
 contract Contribution is AragonApp {
   bytes32 public constant ADD_CONTRIBUTION_ROLE = keccak256("ADD_CONTRIBUTION_ROLE");
   bytes32 public constant VETO_CONTRIBUTION_ROLE = keccak256("VETO_CONTRIBUTION_ROLE");
 
   bytes32 public constant KERNEL_APP_ADDR_NAMESPACE = 0xd6f028ca0e8edb4a8c9757ca4fdccab25fa1e0317da1188108f7d2dee14902fb;
+
   // ensure alphabetic order
   enum Apps { Contribution, Contributor, Proposal, Token }
   bytes32[4] public appIds;
 
   struct ContributionData {
-    address contributor;
+    uint256 contributorId;
     uint256 amount;
     bool claimed;
     bytes32 hashDigest;
@@ -28,19 +36,22 @@ contract Contribution is AragonApp {
     bool vetoed;
     bool exists;
   }
+
   string internal name_;
   string internal symbol_;
 
-  mapping(uint256 => address) contributionOwner;
-  mapping(address => uint256[]) ownedContributions;
+  // map contribution ID to contributor
+  mapping(uint256 => uint256) public contributionOwner;
+  // map contributor to contribution IDs
+  mapping(uint256 => uint256[]) public ownedContributions;
 
   mapping(uint256 => ContributionData) public contributions;
   uint256 public contributionsCount;
 
   uint256 public blocksToWait = 0;
 
-  event ContributionAdded(uint256 id, address indexed contributor, uint256 amount);
-  event ContributionClaimed(uint256 id, address indexed contributor, uint256 amount);
+  event ContributionAdded(uint256 id, uint256 indexed contributorId, uint256 amount);
+  event ContributionClaimed(uint256 id, uint256 indexed contributorId, uint256 amount);
   event ContributionVetoed(uint256 id, address vetoedByAccount);
 
   function initialize(bytes32[4] _appIds) public onlyInit {
@@ -48,11 +59,29 @@ contract Contribution is AragonApp {
     initialized();
   }
 
+  // TODO refactor into a single function
   function getTokenContract() public view returns (address) {
     IKernel k = IKernel(kernel());
-
     return k.getApp(KERNEL_APP_ADDR_NAMESPACE, appIds[uint8(Apps.Token)]);
   }
+  function getContributorContract() public view returns (address) {
+    IKernel k = IKernel(kernel());
+    return k.getApp(KERNEL_APP_ADDR_NAMESPACE, appIds[uint8(Apps.Contributor)]);
+  }
+
+  function getContributorIdByAddress(address contributorAccount) public view returns (uint256) {
+    address contributor = getContributorContract();
+    return ContributorInterface(contributor).getContributorIdByAddress(contributorAccount);
+  }
+
+  function getContributorAddressById(uint256 contributorId) public view returns (uint256) {
+    address contributor = getContributorContract();
+    return ContributorInterface(contributor).getContributorAddressById(contributorId);
+  }
+
+  //
+  // Token standard functions (ERC 721)
+  //
 
   function name() external view returns (string) {
     return name_;
@@ -62,30 +91,38 @@ contract Contribution is AragonApp {
     return symbol_;
   }
 
+  // Balance is amount of ERC271 tokens, not amount of kredits
   function balanceOf(address owner) public view returns (uint256) {
     require(owner != address(0));
-    return ownedContributions[owner].length;
+    uint256 contributorId = getContributorIdByAddress(owner);
+    return ownedContributions[contributorId].length;
   }
 
   function ownerOf(uint256 contributionId) public view returns (address) {
     require(exists(contributionId));
-    return contributions[contributionId].contributor;
+    uint256 contributorId = contributions[contributionId].contributorId;
+    return getContributorAddressById(contributorId);
   }
 
-  function tokenOfOwnerByIndex(address contributor, uint256 index) public view returns (uint256) {
-    return ownedContributions[contributor][index];
+  function tokenOfOwnerByIndex(address owner, uint256 index) public view returns (uint256) {
+    uint256 contributorId = getContributorIdByAddress(owner);
+    return ownedContributions[contributorId][index];
   }
 
   function tokenMetadata(uint256 contributionId) public view returns (string) {
     return contributions[contributionId].tokenMetadataURL;
   }
 
-  function getContribution(uint256 contributionId) public view returns (uint256 id, address contributor, uint256 amount, bool claimed, bytes32 hashDigest, uint8 hashFunction, uint8 hashSize, uint claimAfterBlock, bool exists, bool vetoed) {
+  //
+  // Custom functions
+  //
+
+  function getContribution(uint256 contributionId) public view returns (uint256 id, uint256 contributorId, uint256 amount, bool claimed, bytes32 hashDigest, uint8 hashFunction, uint8 hashSize, uint claimAfterBlock, bool exists, bool vetoed) {
     id = contributionId;
     ContributionData storage c = contributions[id];
     return (
       id,
-      c.contributor,
+      c.contributorId,
       c.amount,
       c.claimed,
       c.hashDigest,
@@ -97,14 +134,14 @@ contract Contribution is AragonApp {
     );
   }
 
-  function add(uint256 amount, address contributorAccount, bytes32 hashDigest, uint8 hashFunction, uint8 hashSize) public isInitialized auth(ADD_CONTRIBUTION_ROLE) {
+  function add(uint256 amount, uint256 contributorId, bytes32 hashDigest, uint8 hashFunction, uint8 hashSize) public isInitialized auth(ADD_CONTRIBUTION_ROLE) {
     //require(canPerform(msg.sender, ADD_CONTRIBUTION_ROLE, new uint256[](0)), 'nope');
     uint256 contributionId = contributionsCount + 1;
     ContributionData storage c = contributions[contributionId];
     c.exists = true;
     c.amount = amount;
     c.claimed = false;
-    c.contributor = contributorAccount;
+    c.contributorId = contributorId;
     c.hashDigest = hashDigest;
     c.hashFunction = hashFunction;
     c.hashSize = hashSize;
@@ -112,10 +149,10 @@ contract Contribution is AragonApp {
 
     contributionsCount++;
 
-    contributionOwner[contributionId] = contributorAccount;
-    ownedContributions[contributorAccount].push(contributionId);
+    contributionOwner[contributionId] = contributorId;
+    ownedContributions[contributorId].push(contributionId);
 
-    emit ContributionAdded(contributionId, contributorAccount, amount);
+    emit ContributionAdded(contributionId, contributorId, amount);
   }
 
   function veto(uint256 contributionId) public isInitialized auth(VETO_CONTRIBUTION_ROLE) {
@@ -136,8 +173,9 @@ contract Contribution is AragonApp {
 
     c.claimed = true;
     address token = getTokenContract();
-    IToken(token).mintFor(c.contributor, c.amount, contributionId);
-    emit ContributionClaimed(contributionId, c.contributor, c.amount);
+    address contributorAccount = getContributorAddressById(c.contributorId);
+    IToken(token).mintFor(contributorAccount, c.amount, contributionId);
+    emit ContributionClaimed(contributionId, c.contributorId, c.amount);
   }
 
   function exists(uint256 contributionId) view public returns (bool) {
diff --git a/config/seeds.js b/config/seeds.js
index 8dce01e..a6d0562 100644
--- a/config/seeds.js
+++ b/config/seeds.js
@@ -1,12 +1,12 @@
 const contractCalls = [
   ['Contributor', 'add', [{ account: '0x7e8f313c56f809188313aa274fa67ee58c31515d', name: 'bumi', isCore: true, kind: 'person', url: '', github_username: 'bumi', github_uid: 318, wiki_username: 'bumi' }, { gasLimit: 200000 }]],
   ['Contributor', 'add', [{ account: '0x49575f3DD9a0d60aE661BC992f72D837A77f05Bc', name: 'raucao', isCore: true, kind: 'person', url: '', github_username: 'skddc', github_uid: 842, wiki_username: 'raucau' }, { gasLimit: 200000 }]],
-  ['Proposal', 'addProposal', [{ contributorId: 2, amount: 500, kind: 'code', description: '[67P/kredits-contracts] Ran the seeds', url: '' }, { gasLimit: 350000 }]],
-  ['Proposal', 'addProposal', [{ contributorId: 3, amount: 500, kind: 'code', description: '[67P/kredits-contracts] Ran the seeds', url: '' }, { gasLimit: 350000 }]],
-  ['Proposal', 'addProposal', [{ contributorId: 3, amount: 500, kind: 'code', description: '[67P/kredits-contracts] Hacked on kredits', url: '' }, { gasLimit: 350000 }]],
-  ['Proposal', 'vote', [1, { gasLimit: 550000 }]],
-  ['Contribution', 'addContribution', [{ contributorAccount: '0x49575f3DD9a0d60aE661BC992f72D837A77f05Bc', amount: 5000, kind: 'dev', description: '[67P/kredits-contracts] Introduce contribution token', url: '' }, { gasLimit: 350000 }]],
-  ['Contribution', 'addContribution', [{ contributorAccount: '0x7e8f313c56f809188313aa274fa67ee58c31515d', amount: 1500, kind: 'dev', description: '[67P/kredits-web] Reviewed stuff', url: '' }, { gasLimit: 350000 }]],
+  // ['Proposal', 'addProposal', [{ contributorId: 2, amount: 500, kind: 'code', description: '[67P/kredits-contracts] Ran the seeds', url: '' }, { gasLimit: 350000 }]],
+  // ['Proposal', 'addProposal', [{ contributorId: 3, amount: 500, kind: 'code', description: '[67P/kredits-contracts] Ran the seeds', url: '' }, { gasLimit: 350000 }]],
+  // ['Proposal', 'addProposal', [{ contributorId: 3, amount: 500, kind: 'code', description: '[67P/kredits-contracts] Hacked on kredits', url: '' }, { gasLimit: 350000 }]],
+  // ['Proposal', 'vote', [1, { gasLimit: 550000 }]],
+  ['Contribution', 'addContribution', [{ contributorId: 2, amount: 5000, kind: 'dev', description: '[67P/kredits-contracts] Introduce contribution token', url: '' }, { gasLimit: 350000 }]],
+  ['Contribution', 'addContribution', [{ contributorId: 3, amount: 1500, kind: 'dev', description: '[67P/kredits-web] Reviewed stuff', url: '' }, { gasLimit: 350000 }]],
   ['Contribution', 'claim', [1, { gasLimit: 300000 }]]
 ];
 const funds = [
diff --git a/lib/abis/Contribution.json b/lib/abis/Contribution.json
index 0f2b683..d2ae07f 100644
--- a/lib/abis/Contribution.json
+++ b/lib/abis/Contribution.json
@@ -1 +1 @@
-[{"constant":true,"inputs":[],"name":"hasInitialized","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"ADD_CONTRIBUTION_ROLE","outputs":[{"name":"","type":"bytes32"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[{"name":"","type":"uint256"}],"name":"contributions","outputs":[{"name":"contributor","type":"address"},{"name":"amount","type":"uint256"},{"name":"claimed","type":"bool"},{"name":"hashDigest","type":"bytes32"},{"name":"hashFunction","type":"uint8"},{"name":"hashSize","type":"uint8"},{"name":"tokenMetadataURL","type":"string"},{"name":"claimAfterBlock","type":"uint256"},{"name":"vetoed","type":"bool"},{"name":"exists","type":"bool"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[{"name":"_script","type":"bytes"}],"name":"getEVMScriptExecutor","outputs":[{"name":"","type":"address"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"getRecoveryVault","outputs":[{"name":"","type":"address"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"contributionsCount","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[{"name":"token","type":"address"}],"name":"allowRecoverability","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"appId","outputs":[{"name":"","type":"bytes32"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"getInitializationBlock","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"KERNEL_APP_ADDR_NAMESPACE","outputs":[{"name":"","type":"bytes32"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"_token","type":"address"}],"name":"transferToVault","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[{"name":"_sender","type":"address"},{"name":"_role","type":"bytes32"},{"name":"_params","type":"uint256[]"}],"name":"canPerform","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"getEVMScriptRegistry","outputs":[{"name":"","type":"address"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"kernel","outputs":[{"name":"","type":"address"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"blocksToWait","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"isPetrified","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[{"name":"","type":"uint256"}],"name":"appIds","outputs":[{"name":"","type":"bytes32"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"VETO_CONTRIBUTION_ROLE","outputs":[{"name":"","type":"bytes32"}],"payable":false,"stateMutability":"view","type":"function"},{"anonymous":false,"inputs":[{"indexed":false,"name":"id","type":"uint256"},{"indexed":true,"name":"contributor","type":"address"},{"indexed":false,"name":"amount","type":"uint256"}],"name":"ContributionAdded","type":"event"},{"anonymous":false,"inputs":[{"indexed":false,"name":"id","type":"uint256"},{"indexed":true,"name":"contributor","type":"address"},{"indexed":false,"name":"amount","type":"uint256"}],"name":"ContributionClaimed","type":"event"},{"anonymous":false,"inputs":[{"indexed":false,"name":"id","type":"uint256"},{"indexed":false,"name":"vetoedByAccount","type":"address"}],"name":"ContributionVetoed","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"name":"executor","type":"address"},{"indexed":false,"name":"script","type":"bytes"},{"indexed":false,"name":"input","type":"bytes"},{"indexed":false,"name":"returnData","type":"bytes"}],"name":"ScriptResult","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"name":"vault","type":"address"},{"indexed":true,"name":"token","type":"address"},{"indexed":false,"name":"amount","type":"uint256"}],"name":"RecoverToVault","type":"event"},{"constant":false,"inputs":[{"name":"_appIds","type":"bytes32[4]"}],"name":"initialize","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[],"name":"getTokenContract","outputs":[{"name":"","type":"address"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"name","outputs":[{"name":"","type":"string"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"symbol","outputs":[{"name":"","type":"string"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[{"name":"owner","type":"address"}],"name":"balanceOf","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[{"name":"contributionId","type":"uint256"}],"name":"ownerOf","outputs":[{"name":"","type":"address"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[{"name":"contributor","type":"address"},{"name":"index","type":"uint256"}],"name":"tokenOfOwnerByIndex","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[{"name":"contributionId","type":"uint256"}],"name":"tokenMetadata","outputs":[{"name":"","type":"string"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[{"name":"contributionId","type":"uint256"}],"name":"getContribution","outputs":[{"name":"id","type":"uint256"},{"name":"contributor","type":"address"},{"name":"amount","type":"uint256"},{"name":"claimed","type":"bool"},{"name":"hashDigest","type":"bytes32"},{"name":"hashFunction","type":"uint8"},{"name":"hashSize","type":"uint8"},{"name":"claimAfterBlock","type":"uint256"},{"name":"exists","type":"bool"},{"name":"vetoed","type":"bool"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"amount","type":"uint256"},{"name":"contributorAccount","type":"address"},{"name":"hashDigest","type":"bytes32"},{"name":"hashFunction","type":"uint8"},{"name":"hashSize","type":"uint8"}],"name":"add","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"inputs":[{"name":"contributionId","type":"uint256"}],"name":"veto","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"inputs":[{"name":"contributionId","type":"uint256"}],"name":"claim","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[{"name":"contributionId","type":"uint256"}],"name":"exists","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"view","type":"function"}]
\ No newline at end of file
+[{"constant":true,"inputs":[],"name":"hasInitialized","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"ADD_CONTRIBUTION_ROLE","outputs":[{"name":"","type":"bytes32"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[{"name":"","type":"uint256"}],"name":"contributions","outputs":[{"name":"contributorId","type":"uint256"},{"name":"amount","type":"uint256"},{"name":"claimed","type":"bool"},{"name":"hashDigest","type":"bytes32"},{"name":"hashFunction","type":"uint8"},{"name":"hashSize","type":"uint8"},{"name":"tokenMetadataURL","type":"string"},{"name":"claimAfterBlock","type":"uint256"},{"name":"vetoed","type":"bool"},{"name":"exists","type":"bool"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[{"name":"_script","type":"bytes"}],"name":"getEVMScriptExecutor","outputs":[{"name":"","type":"address"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"getRecoveryVault","outputs":[{"name":"","type":"address"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"contributionsCount","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[{"name":"token","type":"address"}],"name":"allowRecoverability","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"appId","outputs":[{"name":"","type":"bytes32"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[{"name":"","type":"uint256"},{"name":"","type":"uint256"}],"name":"ownedContributions","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"getInitializationBlock","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"KERNEL_APP_ADDR_NAMESPACE","outputs":[{"name":"","type":"bytes32"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"_token","type":"address"}],"name":"transferToVault","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[{"name":"_sender","type":"address"},{"name":"_role","type":"bytes32"},{"name":"_params","type":"uint256[]"}],"name":"canPerform","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"getEVMScriptRegistry","outputs":[{"name":"","type":"address"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"kernel","outputs":[{"name":"","type":"address"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"blocksToWait","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"isPetrified","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[{"name":"","type":"uint256"}],"name":"appIds","outputs":[{"name":"","type":"bytes32"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"VETO_CONTRIBUTION_ROLE","outputs":[{"name":"","type":"bytes32"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[{"name":"","type":"uint256"}],"name":"contributionOwner","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"anonymous":false,"inputs":[{"indexed":false,"name":"id","type":"uint256"},{"indexed":true,"name":"contributorId","type":"uint256"},{"indexed":false,"name":"amount","type":"uint256"}],"name":"ContributionAdded","type":"event"},{"anonymous":false,"inputs":[{"indexed":false,"name":"id","type":"uint256"},{"indexed":true,"name":"contributorId","type":"uint256"},{"indexed":false,"name":"amount","type":"uint256"}],"name":"ContributionClaimed","type":"event"},{"anonymous":false,"inputs":[{"indexed":false,"name":"id","type":"uint256"},{"indexed":false,"name":"vetoedByAccount","type":"address"}],"name":"ContributionVetoed","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"name":"executor","type":"address"},{"indexed":false,"name":"script","type":"bytes"},{"indexed":false,"name":"input","type":"bytes"},{"indexed":false,"name":"returnData","type":"bytes"}],"name":"ScriptResult","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"name":"vault","type":"address"},{"indexed":true,"name":"token","type":"address"},{"indexed":false,"name":"amount","type":"uint256"}],"name":"RecoverToVault","type":"event"},{"constant":false,"inputs":[{"name":"_appIds","type":"bytes32[4]"}],"name":"initialize","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[],"name":"getTokenContract","outputs":[{"name":"","type":"address"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"getContributorContract","outputs":[{"name":"","type":"address"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[{"name":"contributorAccount","type":"address"}],"name":"getContributorIdByAddress","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[{"name":"contributorId","type":"uint256"}],"name":"getContributorAddressById","outputs":[{"name":"","type":"address"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"name","outputs":[{"name":"","type":"string"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[],"name":"symbol","outputs":[{"name":"","type":"string"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[{"name":"owner","type":"address"}],"name":"balanceOf","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[{"name":"contributionId","type":"uint256"}],"name":"ownerOf","outputs":[{"name":"","type":"address"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[{"name":"owner","type":"address"},{"name":"index","type":"uint256"}],"name":"tokenOfOwnerByIndex","outputs":[{"name":"","type":"uint256"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[{"name":"contributionId","type":"uint256"}],"name":"tokenMetadata","outputs":[{"name":"","type":"string"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":true,"inputs":[{"name":"contributionId","type":"uint256"}],"name":"getContribution","outputs":[{"name":"id","type":"uint256"},{"name":"contributorId","type":"uint256"},{"name":"amount","type":"uint256"},{"name":"claimed","type":"bool"},{"name":"hashDigest","type":"bytes32"},{"name":"hashFunction","type":"uint8"},{"name":"hashSize","type":"uint8"},{"name":"claimAfterBlock","type":"uint256"},{"name":"exists","type":"bool"},{"name":"vetoed","type":"bool"}],"payable":false,"stateMutability":"view","type":"function"},{"constant":false,"inputs":[{"name":"amount","type":"uint256"},{"name":"contributorId","type":"uint256"},{"name":"hashDigest","type":"bytes32"},{"name":"hashFunction","type":"uint8"},{"name":"hashSize","type":"uint8"}],"name":"add","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"inputs":[{"name":"contributionId","type":"uint256"}],"name":"veto","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":false,"inputs":[{"name":"contributionId","type":"uint256"}],"name":"claim","outputs":[],"payable":false,"stateMutability":"nonpayable","type":"function"},{"constant":true,"inputs":[{"name":"contributionId","type":"uint256"}],"name":"exists","outputs":[{"name":"","type":"bool"}],"payable":false,"stateMutability":"view","type":"function"}]
\ No newline at end of file
diff --git a/lib/contracts/contribution.js b/lib/contracts/contribution.js
index 2e33494..ae7e450 100644
--- a/lib/contracts/contribution.js
+++ b/lib/contracts/contribution.js
@@ -29,15 +29,33 @@ class Contribution extends Base {
 
   }
 
-  getByContributor(contributor) {
-    return this.functions.balanceOf(contributor)
+  getByContributorId(contributorId) {
+    return this.functions.balanceOf(address)
       then((balance) => {
         count = balance.toNumber();
 
         let contributions = [];
 
         for (let index = 0; index <= count; index++) {
-          this.functions.tokenOfOwnerByIndex(contributor, index)
+          this.functions.tokenOfOwnerByIndex(address, index)
+            .then((id) => {
+              contributions.push(this.getById(id));
+            });
+        }
+
+        return RSVP.all(contributions);
+      });
+  }
+
+  getByContributorAddress(address) {
+    return this.functions.balanceOf(address)
+      then((balance) => {
+        count = balance.toNumber();
+
+        let contributions = [];
+
+        for (let index = 0; index <= count; index++) {
+          this.functions.tokenOfOwnerByIndex(address, index)
             .then((id) => {
               contributions.push(this.getById(id));
             });
@@ -56,7 +74,7 @@ class Contribution extends Base {
       .then((ipfsHashAttr) => {
         let contribution = [
           contributionAttr.amount,
-          contributionAttr.contributorAccount,
+          contributionAttr.contributorId,
           ipfsHashAttr.hashDigest,
           ipfsHashAttr.hashFunction,
           ipfsHashAttr.hashSize,