diff --git a/modules/yieldoneBidAdapter.js b/modules/yieldoneBidAdapter.js
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+++ b/modules/yieldoneBidAdapter.js
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+import * as utils from 'src/utils';
+import {config} from 'src/config';
+import {registerBidder} from 'src/adapters/bidderFactory';
+
+const BIDDER_CODE = 'yieldone';
+const ENDPOINT_URL = '//y.one.impact-ad.jp/h_bid';
+
+export const spec = {
+  code: BIDDER_CODE,
+  aliases: ['y1'],
+  isBidRequestValid: function(bid) {
+    return !!(bid.params.placementId);
+  },
+  buildRequests: function(validBidRequests) {
+    return validBidRequests.map(bidRequest => {
+      const params = bidRequest.params;
+      const sizes = utils.parseSizesInput(bidRequest.sizes)[0];
+      const width = sizes.split('x')[0];
+      const height = sizes.split('x')[1];
+      const placementId = params.placementId;
+      const cb = Math.floor(Math.random() * 99999999999);
+      const referrer = encodeURIComponent(utils.getTopWindowUrl());
+      const bidId = bidRequest.bidId;
+      const payload = {
+        v: 'hb1',
+        p: placementId,
+        w: width,
+        h: height,
+        cb: cb,
+        r: referrer,
+        uid: bidId,
+        t: 'i'
+      };
+      return {
+        method: 'GET',
+        url: ENDPOINT_URL,
+        data: payload,
+      }
+    });
+  },
+  interpretResponse: function(serverResponse, bidRequest) {
+    const bidResponses = [];
+    const response = serverResponse.body;
+    const crid = response.crid || 0;
+    const width = response.width || 0;
+    const height = response.height || 0;
+    const cpm = response.cpm * 1000 || 0;
+    if (width !== 0 && height !== 0 && cpm !== 0 && crid !== 0) {
+      const dealId = response.dealid || '';
+      const currency = response.currency || 'JPY';
+      const netRevenue = (response.netRevenue === undefined) ? true : response.netRevenue;
+      const referrer = utils.getTopWindowUrl();
+      const bidResponse = {
+        requestId: bidRequest.data.uid,
+        cpm: cpm,
+        width: response.width,
+        height: response.height,
+        creativeId: crid,
+        dealId: dealId,
+        currency: currency,
+        netRevenue: netRevenue,
+        ttl: config.getConfig('_bidderTimeout'),
+        referrer: referrer,
+        ad: response.adTag
+      };
+      bidResponses.push(bidResponse);
+    }
+    return bidResponses;
+  }
+}
+registerBidder(spec);
diff --git a/modules/yieldoneBidAdapter.md b/modules/yieldoneBidAdapter.md
new file mode 100644
index 00000000000..f1f48637927
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+++ b/modules/yieldoneBidAdapter.md
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+# Overview
+
+```
+Module Name: YIELDONE Bidder Adapter
+Module Type: Bidder Adapter
+Maintainer: y1dev@platform-one.co.jp
+```
+
+# Description
+
+Connect to YIELDONE for bids.
+
+THE YIELDONE adapter requires setup and approval from the Rubicon Project team. Please reach out to your account team or y1s@platform-one.co.jp for more information.
+
+# Test Parameters
+```
+  var adUnits = [{
+    code: 'banner-ad-div',
+    sizes: [[300, 250]],
+    bids: [{
+    bidder: 'yieldone',
+      params: { 
+        placementId: '44082'
+      }
+    }]
+  }];
+```
diff --git a/test/spec/modules/yieldoneBidAdapter_spec.js b/test/spec/modules/yieldoneBidAdapter_spec.js
new file mode 100644
index 00000000000..e763257f097
--- /dev/null
+++ b/test/spec/modules/yieldoneBidAdapter_spec.js
@@ -0,0 +1,147 @@
+import { expect } from 'chai';
+import { spec } from 'modules/yieldoneBidAdapter';
+import { newBidder } from 'src/adapters/bidderFactory';
+
+const ENDPOINT = '//y.one.impact-ad.jp/h_bid';
+
+describe('yieldoneBidAdapter', function() {
+  const adapter = newBidder(spec);
+
+  describe('isBidRequestValid', () => {
+    let bid = {
+      'bidder': 'yieldone',
+      'params': {
+        placementId: '44082'
+      },
+      'adUnitCode': 'adunit-code',
+      'sizes': [
+        [300, 250]
+      ],
+      'bidId': '23beaa6af6cdde',
+      'bidderRequestId': '19c0c1efdf37e7',
+      'auctionId': '61466567-d482-4a16-96f0-fe5f25ffbdf1',
+    };
+
+    it('should return true when required params found', () => {
+      expect(spec.isBidRequestValid(bid)).to.equal(true);
+    });
+
+    it('should return false when placementId not passed correctly', () => {
+      bid.params.placementId = '';
+      expect(spec.isBidRequestValid(bid)).to.equal(false);
+    });
+
+    it('should return false when require params are not passed', () => {
+      let bid = Object.assign({}, bid);
+      bid.params = {};
+      expect(spec.isBidRequestValid(bid)).to.equal(false);
+    });
+  });
+
+  describe('buildRequests', () => {
+    let bidRequests = [
+      {
+        'bidder': 'yieldone',
+        'params': {
+          placementId: '44082'
+        },
+        'adUnitCode': 'adunit-code1',
+        'sizes': [
+          [300, 250]
+        ],
+        'bidId': '23beaa6af6cdde',
+        'bidderRequestId': '19c0c1efdf37e7',
+        'auctionId': '61466567-d482-4a16-96f0-fe5f25ffbdf1',
+      },
+      {
+        'bidder': 'yieldone',
+        'params': {
+          placementId: '44337'
+        },
+        'adUnitCode': 'adunit-code2',
+        'sizes': [
+          [300, 250]
+        ],
+        'bidId': '382091349b149f"',
+        'bidderRequestId': '"1f9c98192de251"',
+        'auctionId': '61466567-d482-4a16-96f0-fe5f25ffbdf1',
+      }
+    ];
+
+    const request = spec.buildRequests(bidRequests);
+
+    it('sends bid request to our endpoint via GET', () => {
+      expect(request[0].method).to.equal('GET');
+      expect(request[1].method).to.equal('GET');
+    });
+
+    it('attaches source and version to endpoint URL as query params', () => {
+      expect(request[0].url).to.equal(ENDPOINT);
+      expect(request[1].url).to.equal(ENDPOINT);
+    });
+  });
+
+  describe('interpretResponse', () => {
+    let bidRequest = [
+      {
+        'method': 'GET',
+        'url': '//y.one.impact-ad.jp/h_bid',
+        'data': {
+          'v': 'hb1',
+          'p': '44082',
+          'w': '300',
+          'h': '250',
+          'cb': 12892917383,
+          'r': 'http%3A%2F%2Flocalhost%3A9876%2F%3Fid%3D74552836',
+          'uid': '23beaa6af6cdde',
+          't': 'i'
+        }
+      }
+    ];
+
+    let serverResponse = {
+      body: {
+        'adTag': '<!-- adtag -->',
+        'cpm': 0.0536616,
+        'crid': '2494768',
+        'statusMessage': 'Bid available',
+        'uid': '23beaa6af6cdde',
+        'width': 300,
+        'height': 250
+      }
+    };
+
+    it('should get the correct bid response', () => {
+      let expectedResponse = [{
+        'requestId': '23beaa6af6cdde',
+        'cpm': 53.6616,
+        'width': 300,
+        'height': 250,
+        'creativeId': '2494768',
+        'dealId': '',
+        'currency': 'JPY',
+        'netRevenue': true,
+        'ttl': 3000,
+        'referrer': '',
+        'ad': '<!-- adtag -->'
+      }];
+      let result = spec.interpretResponse(serverResponse, bidRequest[0]);
+      expect(Object.keys(result)).to.deep.equal(Object.keys(expectedResponse));
+    });
+
+    it('handles empty bid response', () => {
+      let response = {
+        body: {
+          'uid': '2c0b634db95a01',
+          'height': 0,
+          'crid': '',
+          'statusMessage': 'Bid returned empty or error response',
+          'width': 0,
+          'cpm': 0
+        }
+      };
+      let result = spec.interpretResponse(response, bidRequest[0]);
+      expect(result.length).to.equal(0);
+    });
+  });
+});