diff --git a/modules/mantisBidAdapter.js b/modules/mantisBidAdapter.js
new file mode 100644
index 00000000000..61b7c31c8e4
--- /dev/null
+++ b/modules/mantisBidAdapter.js
@@ -0,0 +1,310 @@
+import {registerBidder} from '../src/adapters/bidderFactory.js';
+import { getStorageManager } from '../src/storageManager.js';
+
+export const storage = getStorageManager();
+
+function inIframe() {
+  try {
+    return window.self !== window.top && !window.mantis_link;
+  } catch (e) {
+    return true;
+  }
+}
+function pixel(url, parent) {
+  var img = document.createElement('img');
+  img.src = url;
+  img.style.cssText = 'display:none !important;';
+  (parent || document.body).appendChild(img);
+}
+export function onVisible(win, element, doOnVisible, time, pct) {
+  var started = null;
+  var notified = false;
+  var onNotVisible = null;
+  var whenNotVisible = function () {
+    if (notified && onNotVisible) {
+      onNotVisible();
+    }
+    notified = false;
+  };
+  var interval;
+  var listener;
+  var doCheck = function (winWidth, winHeight, rect) {
+    var hidden = typeof document.hidden !== 'undefined' && document.hidden;
+    if (rect.width == 0 || rect.height == 0 || hidden) {
+      return whenNotVisible();
+    }
+    var minHeight = (rect.height * pct);
+    var minWidth = (rect.width * pct);
+    var inView = (
+      (
+        (rect.top < 0 && rect.bottom >= minHeight) ||
+        (rect.top > 0 && (winHeight - rect.top) >= minHeight)
+      ) &&
+      (
+        (rect.left < 0 && rect.right >= minWidth) ||
+        (rect.left > 0 && (winWidth - rect.left) >= minWidth)
+      )
+    );
+    if (!inView) {
+      return whenNotVisible();
+    }
+    if (!started && time) {
+      started = Date.now();
+      return whenNotVisible();
+    }
+    if (time && Date.now() - started < time) {
+      return whenNotVisible();
+    }
+    if (notified) {
+      return;
+    }
+    doOnVisible(function (ack) {
+      if (ack) {
+        notified = true;
+      } else {
+        interval && clearInterval(interval);
+        listener && listener();
+      }
+    }, function (onHidden) {
+      onNotVisible = onHidden;
+    });
+  };
+  if (isAmp()) {
+    listener = win.context.observeIntersection(function (changes) {
+      changes.forEach(function (change) {
+        doCheck(change.rootBounds.width, change.rootBounds.height, change.boundingClientRect);
+      });
+    });
+  }
+  interval = setInterval(function () {
+    var winHeight = (win.innerHeight || document.documentElement.clientHeight);
+    var winWidth = (win.innerWidth || document.documentElement.clientWidth);
+    doCheck(winWidth, winHeight, element.getBoundingClientRect());
+  }, 100);
+}
+function storeUuid(uuid) {
+  if (window.mantis_uuid) {
+    return false;
+  }
+  window.mantis_uuid = uuid;
+  if (storage.hasLocalStorage()) {
+    try {
+      storage.setDataInLocalStorage('mantis:uuid', uuid);
+    } catch (ex) {
+    }
+  }
+}
+
+function onMessage(type, callback) {
+  window.addEventListener('message', function (event) {
+    if (event.data.mantis && event.data.type == type) {
+      callback(event.data.data);
+    }
+  }, false);
+}
+function isSendable(val) {
+  if (val === null || val === undefined) {
+    return false;
+  }
+  if (typeof val === 'string') {
+    return !(!val || /^\s*$/.test(val));
+  }
+  if (typeof val === 'number') {
+    return !isNaN(val);
+  }
+  return true;
+}
+function isObject(value) {
+  return Object.prototype.toString.call(value) === '[object Object]';
+}
+function isAmp() {
+  return typeof window.context === 'object' && (window.context.tagName === 'AMP-AD' || window.context.tagName === 'AMP-EMBED');
+}
+function isSecure() {
+  return document.location.protocol === 'https:';
+}
+function isArray(value) {
+  return Object.prototype.toString.call(value) === '[object Array]';
+}
+
+function jsonToQuery(data, chain, form) {
+  var parts = form || [];
+  for (var key in data) {
+    var queryKey = key;
+    if (chain) {
+      queryKey = chain + '[' + key + ']';
+    }
+    var val = data[key];
+    if (isArray(val)) {
+      for (var index = 0; index < val.length; index++) {
+        var akey = queryKey + '[' + index + ']';
+        var aval = val[index];
+        if (isObject(aval)) {
+          jsonToQuery(aval, akey, parts);
+        }
+      }
+    } else if (isObject(val) && val != data) {
+      jsonToQuery(val, queryKey, parts);
+    } else if (isSendable(val)) {
+      parts.push(queryKey + '=' + encodeURIComponent(val));
+    }
+  }
+  return parts.join('&');
+}
+
+function buildMantisUrl(path, data, domain) {
+  var params = {
+    referrer: document.referrer,
+    tz: new Date().getTimezoneOffset(),
+    buster: new Date().getTime(),
+    secure: isSecure(),
+    version: 9
+  };
+
+  if (window.mantis_uuid) {
+    params.uuid = window.mantis_uuid;
+  } else if (storage.hasLocalStorage()) {
+    var localUuid = storage.getDataFromLocalStorage('mantis:uuid');
+    if (localUuid) {
+      params.uuid = localUuid;
+    }
+  }
+  if (!inIframe()) {
+    try {
+      params.title = window.top.document.title;
+      params.referrer = window.top.document.referrer;
+      params.url = window.top.document.location.href;
+    } catch (ex) {
+    }
+  } else {
+    params.iframe = true;
+  }
+  if (isAmp()) {
+    params.amp = true;
+    if (!params.url && window.context.canonicalUrl) {
+      params.url = window.context.canonicalUrl;
+    }
+    if (!params.url && window.context.location) {
+      params.url = window.context.location.href;
+    }
+    if (!params.referrer && window.context.referrer) {
+      params.referrer = window.context.referrer;
+    }
+  }
+  Object.keys(data).forEach(function (key) {
+    params[key] = data[key];
+  });
+  var query = jsonToQuery(params);
+  return (window.mantis_domain === undefined ? domain || 'https://mantodea.mantisadnetwork.com' : window.mantis_domain) + path + '?' + query;
+}
+
+export const spec = {
+  code: 'mantis',
+  supportedMediaTypes: ['banner'],
+  isBidRequestValid: function (bid) {
+    return !!(bid.params.property && (bid.params.code || bid.params.zoneId || bid.params.zone));
+  },
+  buildRequests: function (validBidRequests, bidderRequest) {
+    var property = null;
+    validBidRequests.some(function (bid) {
+      if (bid.params.property) {
+        property = bid.params.property;
+        return true;
+      }
+    });
+    const query = {
+      measurable: true,
+      usp: bidderRequest && bidderRequest.uspConsent,
+      bids: validBidRequests.map(function (bid) {
+        return {
+          bidId: bid.bidId,
+          config: bid.params,
+          sizes: bid.sizes.map(function (size) {
+            return {width: size[0], height: size[1]};
+          })
+        };
+      }),
+      property: property
+    };
+
+    if (bidderRequest && bidderRequest.gdprConsent && bidderRequest.gdprConsent.gdprApplies) {
+      // we purposefully do not track data for users in the EU
+      query.consent = false;
+    }
+
+    return {
+      method: 'GET',
+      url: buildMantisUrl('/prebid/display', query) + '&foo',
+      data: ''
+    };
+  },
+  interpretResponse: function (serverResponse) {
+    storeUuid(serverResponse.body.uuid);
+    return serverResponse.body.ads.map(function (ad) {
+      return {
+        requestId: ad.bid,
+        cpm: ad.cpm,
+        width: ad.width,
+        height: ad.height,
+        ad: ad.html,
+        meta: {
+          advertiserDomains: ad.domains || []
+        },
+        ttl: ad.ttl || serverResponse.body.ttl || 86400,
+        creativeId: ad.view,
+        netRevenue: true,
+        currency: 'USD'
+      };
+    });
+  },
+  getUserSyncs: function (syncOptions, serverResponses, gdprConsent, uspConsent) {
+    if (syncOptions.iframeEnabled) {
+      return [{
+        type: 'iframe',
+        url: buildMantisUrl('/prebid/iframe', {gdpr: gdprConsent, uspConsent: uspConsent})
+      }];
+    }
+    if (syncOptions.pixelEnabled) {
+      return [{
+        type: 'image',
+        url: buildMantisUrl('/prebid/pixel', {gdpr: gdprConsent, uspConsent: uspConsent})
+      }];
+    }
+  }
+};
+
+export function sfPostMessage ($sf, width, height, callback) {
+  var viewed = false;
+  // eslint-disable-next-line no-undef
+  $sf.ext.register(width, height, function () {
+    // eslint-disable-next-line no-undef
+    if ($sf.ext.inViewPercentage() < 50 || viewed) {
+      return;
+    }
+    viewed = true;
+    callback();
+  });
+};
+
+export function iframePostMessage (win, name, callback) {
+  var frames = document.getElementsByTagName('iframe');
+  for (var i = 0; i < frames.length; i++) {
+    var frame = frames[i];
+    if (frame.name == name) {
+      onVisible(win, frame, function (stop) {
+        callback();
+        stop();
+      }, 1000, 0.50);
+    }
+  }
+}
+
+onMessage('iframe', function (data) {
+  if (window.$sf) {
+    sfPostMessage(window.$sf, data.width, data.height, () => pixel(data.pixel));
+  } else {
+    iframePostMessage(window, data.frame, () => pixel(data.pixel));
+  }
+});
+
+registerBidder(spec);
diff --git a/test/spec/modules/mantisBidAdapter_spec.js b/test/spec/modules/mantisBidAdapter_spec.js
new file mode 100644
index 00000000000..579f41e620d
--- /dev/null
+++ b/test/spec/modules/mantisBidAdapter_spec.js
@@ -0,0 +1,361 @@
+import {expect} from 'chai';
+import {spec, storage} from 'modules/mantisBidAdapter.js';
+import {newBidder} from 'src/adapters/bidderFactory.js';
+import {sfPostMessage, iframePostMessage} from 'modules/mantisBidAdapter';
+
+describe('MantisAdapter', function () {
+  const adapter = newBidder(spec);
+  const sandbox = sinon.sandbox.create();
+  let clock;
+
+  beforeEach(function () {
+    clock = sandbox.useFakeTimers();
+  });
+
+  afterEach(function () {
+    sandbox.restore();
+  });
+
+  describe('isBidRequestValid', function () {
+    let bid = {
+      'bidder': 'mantis',
+      'params': {
+        'property': '10433394',
+        'zone': 'zone'
+      },
+      'adUnitCode': 'adunit-code',
+      'sizes': [[300, 250], [300, 600]],
+      'bidId': '30b31c1838de1e',
+      'bidderRequestId': '22edbae2733bf6',
+      'auctionId': '1d1a030790a475',
+    };
+
+    it('should return true when required params found', function () {
+      expect(spec.isBidRequestValid(bid)).to.equal(true);
+    });
+
+    it('should return false when required params are not passed', function () {
+      let bid = Object.assign({}, bid);
+      delete bid.params;
+      bid.params = {};
+      expect(spec.isBidRequestValid(bid)).to.equal(false);
+    });
+  });
+
+  describe('viewability', function() {
+    it('iframe (viewed)', () => {
+      let viewed = false;
+
+      sandbox.stub(document, 'getElementsByTagName').withArgs('iframe').returns([
+        {
+          name: 'mantis',
+          getBoundingClientRect: () => ({
+            top: 10,
+            bottom: 260,
+            left: 10,
+            right: 190,
+            width: 300,
+            height: 250
+          })
+        }
+      ]);
+
+      iframePostMessage({innerHeight: 500, innerWidth: 500}, 'mantis', () => viewed = true);
+
+      sandbox.clock.runAll();
+
+      expect(viewed).to.equal(true);
+    });
+
+    it('safeframe (viewed)', () => {
+      let viewed = false;
+
+      sfPostMessage({
+        ext: {
+          register: (width, height, callback) => {
+            expect(width).to.equal(100);
+            expect(height).to.equal(200);
+
+            callback();
+          },
+          inViewPercentage: () => 60
+        }
+      }, 100, 200, () => viewed = true);
+
+      expect(viewed).to.equal(true);
+    });
+
+    it('safeframe (unviewed)', () => {
+      let viewed = false;
+
+      sfPostMessage({
+        ext: {
+          register: (width, height, callback) => {
+            expect(width).to.equal(100);
+            expect(height).to.equal(200);
+
+            callback();
+          },
+          inViewPercentage: () => 30
+        }
+      }, 100, 200, () => viewed = true);
+
+      expect(viewed).to.equal(false);
+    });
+  });
+
+  describe('buildRequests', function () {
+    let bidRequests = [
+      {
+        'bidder': 'mantis',
+        'params': {
+          'property': '10433394',
+          'zone': 'zone'
+        },
+        'adUnitCode': 'adunit-code',
+        'sizes': [[300, 250], [300, 600]],
+        'bidId': '30b31c1838de1e',
+        'bidderRequestId': '22edbae2733bf6',
+        'auctionId': '1d1a030790a475',
+      }
+    ];
+
+    it('gdpr consent not required', function () {
+      const request = spec.buildRequests(bidRequests, {gdprConsent: {gdprApplies: false}});
+
+      expect(request.url).not.to.include('consent=false');
+    });
+
+    it('gdpr consent required', function () {
+      const request = spec.buildRequests(bidRequests, {gdprConsent: {gdprApplies: true}});
+
+      expect(request.url).to.include('consent=false');
+    });
+
+    it('usp consent', function () {
+      const request = spec.buildRequests(bidRequests, {uspConsent: 'foobar'});
+
+      expect(request.url).to.include('usp=foobar');
+    });
+
+    it('domain override', function () {
+      window.mantis_domain = 'https://foo';
+      const request = spec.buildRequests(bidRequests);
+
+      expect(request.url).to.include('https://foo');
+
+      delete window.mantis_domain;
+    });
+
+    it('standard request', function () {
+      const request = spec.buildRequests(bidRequests);
+
+      expect(request.url).to.include('property=10433394');
+      expect(request.url).to.include('bids[0][bidId]=30b31c1838de1e');
+      expect(request.url).to.include('bids[0][config][zone]=zone');
+      expect(request.url).to.include('bids[0][sizes][0][width]=300');
+      expect(request.url).to.include('bids[0][sizes][0][height]=250');
+      expect(request.url).to.include('bids[0][sizes][1][width]=300');
+      expect(request.url).to.include('bids[0][sizes][1][height]=600');
+    });
+
+    it('use window uuid', function () {
+      window.mantis_uuid = 'foo';
+
+      const request = spec.buildRequests(bidRequests);
+
+      expect(request.url).to.include('uuid=foo');
+
+      delete window.mantis_uuid;
+    });
+
+    it('use storage uuid', function () {
+      sandbox.stub(storage, 'hasLocalStorage').callsFake(() => true);
+      sandbox.stub(storage, 'getDataFromLocalStorage').withArgs('mantis:uuid').returns('bar');
+
+      const request = spec.buildRequests(bidRequests);
+
+      expect(request.url).to.include('uuid=bar');
+    });
+
+    it('detect amp', function () {
+      var oldContext = window.context;
+
+      window.context = {};
+      window.context.tagName = 'AMP-AD';
+      window.context.canonicalUrl = 'foo';
+
+      const request = spec.buildRequests(bidRequests);
+
+      expect(request.url).to.include('amp=true');
+      expect(request.url).to.include('url=foo');
+
+      delete window.context.tagName;
+      delete window.context.canonicalUrl;
+
+      window.context = oldContext;
+    });
+  });
+
+  describe('getUserSyncs', function () {
+    it('iframe', function () {
+      let result = spec.getUserSyncs({
+        iframeEnabled: true
+      });
+
+      expect(result[0].type).to.equal('iframe');
+      expect(result[0].url).to.include('https://mantodea.mantisadnetwork.com/prebid/iframe');
+    });
+
+    it('pixel', function () {
+      let result = spec.getUserSyncs({
+        pixelEnabled: true
+      });
+
+      expect(result[0].type).to.equal('image');
+      expect(result[0].url).to.include('https://mantodea.mantisadnetwork.com/prebid/pixel');
+    });
+  });
+
+  describe('interpretResponse', function () {
+    it('use ad ttl if provided', function () {
+      let response = {
+        body: {
+          ttl: 360,
+          uuid: 'uuid',
+          ads: [
+            {
+              bid: 'bid',
+              cpm: 1,
+              view: 'view',
+              width: 300,
+              ttl: 250,
+              height: 250,
+              html: '<!-- Creative -->'
+            }
+          ]
+        }
+      };
+
+      let expectedResponse = [
+        {
+          requestId: 'bid',
+          cpm: 1,
+          width: 300,
+          height: 250,
+          ttl: 250,
+          ad: '<!-- Creative -->',
+          creativeId: 'view',
+          netRevenue: true,
+          meta: {
+            advertiserDomains: []
+          },
+          currency: 'USD'
+        }
+      ];
+      let bidderRequest;
+
+      let result = spec.interpretResponse(response, {bidderRequest});
+      expect(result[0]).to.deep.equal(expectedResponse[0]);
+    });
+
+    it('use global ttl if provded', function () {
+      let response = {
+        body: {
+          ttl: 360,
+          uuid: 'uuid',
+          ads: [
+            {
+              bid: 'bid',
+              cpm: 1,
+              view: 'view',
+              domains: ['foobar.com'],
+              width: 300,
+              height: 250,
+              html: '<!-- Creative -->'
+            }
+          ]
+        }
+      };
+
+      let expectedResponse = [
+        {
+          requestId: 'bid',
+          cpm: 1,
+          width: 300,
+          height: 250,
+          ttl: 360,
+          ad: '<!-- Creative -->',
+          creativeId: 'view',
+          netRevenue: true,
+          meta: {
+            advertiserDomains: ['foobar.com']
+          },
+          currency: 'USD'
+        }
+      ];
+      let bidderRequest;
+
+      let result = spec.interpretResponse(response, {bidderRequest});
+      expect(result[0]).to.deep.equal(expectedResponse[0]);
+    });
+
+    it('display ads returned', function () {
+      let response = {
+        body: {
+          uuid: 'uuid',
+          ads: [
+            {
+              bid: 'bid',
+              cpm: 1,
+              view: 'view',
+              width: 300,
+              domains: ['foobar.com'],
+              height: 250,
+              html: '<!-- Creative -->'
+            }
+          ]
+        }
+      };
+
+      let expectedResponse = [
+        {
+          requestId: 'bid',
+          cpm: 1,
+          width: 300,
+          height: 250,
+          ttl: 86400,
+          ad: '<!-- Creative -->',
+          creativeId: 'view',
+          netRevenue: true,
+          meta: {
+            advertiserDomains: ['foobar.com']
+          },
+          currency: 'USD'
+        }
+      ];
+      let bidderRequest;
+
+      sandbox.stub(storage, 'hasLocalStorage').returns(true);
+      const spy = sandbox.spy(storage, 'setDataInLocalStorage');
+
+      let result = spec.interpretResponse(response, {bidderRequest});
+
+      expect(spy.calledWith('mantis:uuid', 'uuid'));
+      expect(result[0]).to.deep.equal(expectedResponse[0]);
+      expect(window.mantis_uuid).to.equal(response.body.uuid);
+    });
+
+    it('no ads returned', function () {
+      let response = {
+        body: {
+          ads: []
+        }
+      };
+      let bidderRequest;
+
+      let result = spec.interpretResponse(response, {bidderRequest});
+      expect(result.length).to.equal(0);
+    });
+  });
+});