diff --git a/package.json b/package.json
index 32404487c..c730d69ec 100644
--- a/package.json
+++ b/package.json
@@ -13,6 +13,7 @@
     "flatmap": "0.0.3",
     "glob": "^7.0.3",
     "ipfs-merkle-dag": "^0.6.0",
+    "is-ipfs": "^0.2.0",
     "isstream": "^0.1.2",
     "multiaddr": "^2.0.0",
     "multipart-stream": "^2.0.1",
@@ -32,7 +33,7 @@
     "aegir": "^3.2.0",
     "chai": "^3.5.0",
     "gulp": "^3.9.1",
-    "interface-ipfs-core": "^0.2.2",
+    "interface-ipfs-core": "^0.3.0",
     "ipfsd-ctl": "^0.14.0",
     "pre-commit": "^1.1.2",
     "stream-equal": "^0.1.8",
@@ -93,4 +94,4 @@
     "url": "https://github.com/ipfs/js-ipfs-api/issues"
   },
   "homepage": "https://github.com/ipfs/js-ipfs-api"
-}
\ No newline at end of file
+}
diff --git a/src/api/cat.js b/src/api/cat.js
index 6a9639688..8b61f66a1 100644
--- a/src/api/cat.js
+++ b/src/api/cat.js
@@ -1,7 +1,27 @@
 'use strict'
 
-const argCommand = require('../cmd-helpers').argCommand
+const bs58 = require('bs58')
+const isIPFS = require('is-ipfs')
+const promisify = require('promisify-es6')
 
 module.exports = (send) => {
-  return argCommand(send, 'cat')
+  const cat = promisify((multihash, callback) => {
+    try {
+      multihash = cleanMultihash(multihash)
+    } catch (err) {
+      return callback(err)
+    }
+    send('cat', multihash, null, null, callback)
+  })
+  return cat
+}
+
+function cleanMultihash (multihash) {
+  if (!isIPFS.multihash(multihash)) {
+    throw new Error('not valid multihash')
+  }
+  if (Buffer.isBuffer(multihash)) {
+    return bs58.encode(multihash)
+  }
+  return multihash
 }
diff --git a/test/api/add.spec.js b/test/api/add.spec.js
deleted file mode 100644
index 67c190235..000000000
--- a/test/api/add.spec.js
+++ /dev/null
@@ -1,16 +0,0 @@
-/* eslint-env mocha */
-/* globals apiClients */
-'use strict'
-
-const test = require('interface-ipfs-core')
-
-const common = {
-  setup: function (cb) {
-    cb(null, apiClients.a)
-  },
-  teardown: function (cb) {
-    cb()
-  }
-}
-
-test.files(common)
diff --git a/test/api/cat.spec.js b/test/api/cat.spec.js
deleted file mode 100644
index 0e5a9508e..000000000
--- a/test/api/cat.spec.js
+++ /dev/null
@@ -1,77 +0,0 @@
-/* eslint-env mocha */
-/* globals apiClients */
-'use strict'
-
-const expect = require('chai').expect
-const isNode = require('detect-node')
-const fs = require('fs')
-const streamifier = require('streamifier')
-
-const path = require('path')
-const streamEqual = require('stream-equal')
-
-let testfile
-let testfileBig
-
-testfile = fs.readFileSync(path.join(__dirname, '/../testfile.txt'))
-testfileBig = fs.readFileSync(path.join(__dirname, '/../15mb.random'))
-
-describe('.cat', () => {
-  it('cat', (done) => {
-    apiClients.a
-      .cat('Qma4hjFTnCasJ8PVp3mZbZK5g2vGDT4LByLJ7m8ciyRFZP', (err, res) => {
-        expect(err).to.not.exist
-
-        let buf = ''
-        res
-          .on('error', (err) => {
-            expect(err).to.not.exist
-          })
-          .on('data', (data) => {
-            buf += data
-          })
-          .on('end', () => {
-            expect(buf).to.be.equal(testfile.toString())
-            done()
-          })
-      })
-  })
-
-  it('cat BIG file', (done) => {
-    if (!isNode) {
-      return done()
-    }
-
-    apiClients.a.cat('Qme79tX2bViL26vNjPsF3DP1R9rMKMvnPYJiKTTKPrXJjq', (err, res) => {
-      expect(err).to.not.exist
-
-      // Do not blow out the memory of nodejs :)
-      const bigStream = streamifier.createReadStream(testfileBig)
-      streamEqual(res, bigStream, (err, equal) => {
-        expect(err).to.not.exist
-        expect(equal).to.be.true
-        done()
-      })
-    })
-  })
-
-  describe('promise', () => {
-    it('cat', (done) => {
-      return apiClients.a.cat('Qma4hjFTnCasJ8PVp3mZbZK5g2vGDT4LByLJ7m8ciyRFZP')
-        .then((res) => {
-          let buf = ''
-          res
-            .on('error', (err) => {
-              throw err
-            })
-            .on('data', (data) => {
-              buf += data
-            })
-            .on('end', () => {
-              expect(buf).to.be.equal(testfile.toString())
-              done()
-            })
-        })
-    })
-  })
-})
diff --git a/test/api/files.spec.js b/test/api/files.spec.js
index d46254c99..e7f97a0f4 100644
--- a/test/api/files.spec.js
+++ b/test/api/files.spec.js
@@ -5,12 +5,25 @@
 const expect = require('chai').expect
 const isNode = require('detect-node')
 const path = require('path')
+const test = require('interface-ipfs-core')
 
 let testfile
 
 testfile = require('fs').readFileSync(path.join(__dirname, '/../testfile.txt'))
 
-describe('.files', () => {
+// Load the add/cat/get/ls commands from interface-ipfs-core
+const common = {
+  setup: function (cb) {
+    cb(null, apiClients.a)
+  },
+  teardown: function (cb) {
+    cb()
+  }
+}
+test.files(common)
+
+// Describe the (mfs) tests
+describe('.files (pseudo mfs)', () => {
   it('files.mkdir', (done) => {
     apiClients.a.files.mkdir('/test-folder', function (err) {
       expect(err).to.not.exist