diff --git a/modules/adhashBidAdapter.js b/modules/adhashBidAdapter.js
new file mode 100644
index 00000000000..b30f9cebbc1
--- /dev/null
+++ b/modules/adhashBidAdapter.js
@@ -0,0 +1,102 @@
+import { registerBidder } from '../src/adapters/bidderFactory.js';
+import includes from 'core-js-pure/features/array/includes.js';
+import { BANNER } from '../src/mediaTypes.js';
+
+const VERSION = '1.0';
+
+export const spec = {
+  code: 'adhash',
+  url: 'https://bidder.adhash.org/rtb?version=' + VERSION + '&prebid=true',
+  supportedMediaTypes: [ BANNER ],
+
+  isBidRequestValid: (bid) => {
+    try {
+      const { publisherId, platformURL } = bid.params;
+      return (
+        includes(Object.keys(bid.mediaTypes), BANNER) &&
+        typeof publisherId === 'string' &&
+        publisherId.length === 42 &&
+        typeof platformURL === 'string' &&
+        platformURL.length >= 13
+      );
+    } catch (error) {
+      return false;
+    }
+  },
+
+  buildRequests: (validBidRequests, bidderRequest) => {
+    const { gdprConsent } = bidderRequest;
+    const { url } = spec;
+    const bidRequests = [];
+    let referrer = '';
+    if (bidderRequest && bidderRequest.refererInfo) {
+      referrer = bidderRequest.refererInfo.referer;
+    }
+    for (var i = 0; i < validBidRequests.length; i++) {
+      var index = Math.floor(Math.random() * validBidRequests[i].sizes.length);
+      var size = validBidRequests[i].sizes[index].join('x');
+      bidRequests.push({
+        method: 'POST',
+        url: url,
+        bidRequest: validBidRequests[i],
+        data: {
+          timezone: new Date().getTimezoneOffset() / 60,
+          location: referrer,
+          publisherId: validBidRequests[i].params.publisherId,
+          size: {
+            screenWidth: window.screen.width,
+            screenHeight: window.screen.height
+          },
+          navigator: {
+            platform: window.navigator.platform,
+            language: window.navigator.language,
+            userAgent: window.navigator.userAgent
+          },
+          creatives: [{
+            size: size,
+            position: validBidRequests[i].adUnitCode
+          }],
+          blockedCreatives: [],
+          currentTimestamp: new Date().getTime(),
+          recentAds: [],
+          GDPR: gdprConsent
+        },
+        options: {
+          withCredentials: false,
+          crossOrigin: true
+        },
+      });
+    }
+    return bidRequests;
+  },
+
+  interpretResponse: (serverResponse, request) => {
+    const responseBody = serverResponse ? serverResponse.body : {};
+
+    if (!responseBody.creatives || responseBody.creatives.length === 0) {
+      return [];
+    }
+
+    const publisherURL = JSON.stringify(request.bidRequest.params.platformURL);
+    const oneTimeId = request.bidRequest.adUnitCode + Math.random().toFixed(16).replace('0.', '.');
+    const bidderResponse = JSON.stringify({ responseText: JSON.stringify(responseBody) });
+    const requestData = JSON.stringify(request.data);
+
+    return [{
+      requestId: request.bidRequest.bidId,
+      cpm: responseBody.creatives[0].costEUR,
+      ad:
+        `<div id="${oneTimeId}"></div>
+        <script src="https://bidder.adhash.org/static/scripts/creative.min.js"></script>
+        <script>callAdvertiser(${bidderResponse},['${oneTimeId}'],${requestData},${publisherURL})</script>`,
+      width: request.bidRequest.sizes[0][0],
+      height: request.bidRequest.sizes[0][1],
+      creativeId: request.bidRequest.adUnitCode,
+      netRevenue: true,
+      currency: 'EUR',
+      ttl: 60
+    }];
+  }
+};
+
+registerBidder(spec);
diff --git a/modules/adhashBidAdapter.md b/modules/adhashBidAdapter.md
new file mode 100644
index 00000000000..c1093e0ccd7
--- /dev/null
+++ b/modules/adhashBidAdapter.md
@@ -0,0 +1,43 @@
+# Overview
+
+```
+Module Name: AdHash Bidder Adapter
+Module Type: Bidder Adapter
+Maintainer: damyan@adhash.org
+```
+
+# Description
+
+Here is what you need for Prebid integration with AdHash:
+1. Register with AdHash.
+2. Once registered and approved, you will receive a Publisher ID and Platform URL.
+3. Use the Publisher ID and Platform URL as parameters in params.
+
+Please note that a number of AdHash functionalities are not supported in the Prebid.js integration:
+* Cookie-less frequency and recency capping;
+* Audience segments;
+* Price floors and passback tags, as they are not needed in the Prebid.js setup;
+* Reservation for direct deals only, as bids are evaluated based on their price.
+
+# Test Parameters
+```
+    var adUnits = [
+        {
+            code: '/19968336/header-bid-tag-1',
+            mediaTypes: {
+                banner: {
+                    sizes: [[300, 250]]
+                }
+            },
+            bids: [
+                {
+                    bidder: 'adhash',
+                    params: {
+                        publisherId: '0x1234567890123456789012345678901234567890',
+                        platformURL: 'https://adhash.org/p/struma/'
+                    }
+                }
+            ]
+        }
+    ];
+```
\ No newline at end of file
diff --git a/test/spec/modules/adhashBidAdapter_spec.js b/test/spec/modules/adhashBidAdapter_spec.js
new file mode 100644
index 00000000000..ab4df84c093
--- /dev/null
+++ b/test/spec/modules/adhashBidAdapter_spec.js
@@ -0,0 +1,155 @@
+import { expect } from 'chai';
+import { spec } from 'modules/adhashBidAdapter.js';
+
+describe('adhashBidAdapter', function () {
+  describe('isBidRequestValid', function () {
+    const validBid = {
+      bidder: 'adhash',
+      params: {
+        publisherId: '0xc3b09b27e9c6ef73957901aa729b9e69e5bbfbfb',
+        platformURL: 'https://adhash.org/p/struma/'
+      },
+      mediaTypes: {
+        banner: {
+          sizes: [[300, 250]]
+        }
+      },
+      adUnitCode: 'adunit-code',
+      sizes: [[300, 250]],
+      bidId: '12345678901234',
+      bidderRequestId: '98765432109876',
+      auctionId: '01234567891234',
+    };
+
+    it('should return true when all mandatory parameters are there', function () {
+      expect(spec.isBidRequestValid(validBid)).to.equal(true);
+    });
+
+    it('should return false when there are no params', function () {
+      const bid = { ...validBid };
+      delete bid.params;
+      expect(spec.isBidRequestValid(bid)).to.equal(false);
+    });
+
+    it('should return false when unsupported media type is requested', function () {
+      const bid = { ...validBid };
+      bid.mediaTypes = { native: { sizes: [[300, 250]] } };
+      expect(spec.isBidRequestValid(bid)).to.equal(false);
+    });
+
+    it('should return false when publisherId is not a string', function () {
+      const bid = { ...validBid };
+      bid.params.publisherId = 123;
+      expect(spec.isBidRequestValid(bid)).to.equal(false);
+    });
+
+    it('should return false when publisherId is not valid', function () {
+      const bid = { ...validBid };
+      bid.params.publisherId = 'short string';
+      expect(spec.isBidRequestValid(bid)).to.equal(false);
+    });
+
+    it('should return false when publisherId is not a string', function () {
+      const bid = { ...validBid };
+      bid.params.platformURL = 123;
+      expect(spec.isBidRequestValid(bid)).to.equal(false);
+    });
+
+    it('should return false when publisherId is not valid', function () {
+      const bid = { ...validBid };
+      bid.params.platformURL = 'https://';
+      expect(spec.isBidRequestValid(bid)).to.equal(false);
+    });
+  });
+
+  describe('buildRequests', function () {
+    const bidRequest = {
+      params: {
+        publisherId: '0xc3b09b27e9c6ef73957901aa729b9e69e5bbfbfb'
+      },
+      sizes: [[300, 250]],
+      adUnitCode: 'adUnitCode'
+    };
+    it('should build the request correctly', function () {
+      const result = spec.buildRequests(
+        [ bidRequest ],
+        { gdprConsent: true, refererInfo: { referer: 'http://example.com/' } }
+      );
+      expect(result.length).to.equal(1);
+      expect(result[0].method).to.equal('POST');
+      expect(result[0].url).to.equal('https://bidder.adhash.org/rtb?version=1.0&prebid=true');
+      expect(result[0].bidRequest).to.equal(bidRequest);
+      expect(result[0].data).to.have.property('timezone');
+      expect(result[0].data).to.have.property('location');
+      expect(result[0].data).to.have.property('publisherId');
+      expect(result[0].data).to.have.property('size');
+      expect(result[0].data).to.have.property('navigator');
+      expect(result[0].data).to.have.property('creatives');
+      expect(result[0].data).to.have.property('blockedCreatives');
+      expect(result[0].data).to.have.property('currentTimestamp');
+      expect(result[0].data).to.have.property('recentAds');
+    });
+    it('should build the request correctly without referer', function () {
+      const result = spec.buildRequests([ bidRequest ], { gdprConsent: true });
+      expect(result.length).to.equal(1);
+      expect(result[0].method).to.equal('POST');
+      expect(result[0].url).to.equal('https://bidder.adhash.org/rtb?version=1.0&prebid=true');
+      expect(result[0].bidRequest).to.equal(bidRequest);
+      expect(result[0].data).to.have.property('timezone');
+      expect(result[0].data).to.have.property('location');
+      expect(result[0].data).to.have.property('publisherId');
+      expect(result[0].data).to.have.property('size');
+      expect(result[0].data).to.have.property('navigator');
+      expect(result[0].data).to.have.property('creatives');
+      expect(result[0].data).to.have.property('blockedCreatives');
+      expect(result[0].data).to.have.property('currentTimestamp');
+      expect(result[0].data).to.have.property('recentAds');
+    });
+  });
+
+  describe('interpretResponse', function () {
+    const request = {
+      data: { some: 'data' },
+      bidRequest: {
+        bidId: '12345678901234',
+        adUnitCode: 'adunit-code',
+        sizes: [[300, 250]],
+        params: {
+          platformURL: 'https://adhash.org/p/struma/'
+        }
+      }
+    };
+
+    it('should interpret the response correctly', function () {
+      const serverResponse = {
+        body: {
+          creatives: [{
+            costEUR: 1.234
+          }]
+        }
+      };
+      const result = spec.interpretResponse(serverResponse, request);
+      expect(result.length).to.equal(1);
+      expect(result[0].requestId).to.equal('12345678901234');
+      expect(result[0].cpm).to.equal(1.234);
+      expect(result[0].width).to.equal(300);
+      expect(result[0].height).to.equal(250);
+      expect(result[0].creativeId).to.equal('adunit-code');
+      expect(result[0].netRevenue).to.equal(true);
+      expect(result[0].currency).to.equal('EUR');
+      expect(result[0].ttl).to.equal(60);
+    });
+
+    it('should return empty array when there are no creatives returned', function () {
+      expect(spec.interpretResponse({body: {creatives: []}}, request).length).to.equal(0);
+    });
+
+    it('should return empty array when there is no creatives key in the response', function () {
+      expect(spec.interpretResponse({body: {}}, request).length).to.equal(0);
+    });
+
+    it('should return empty array when something is not right', function () {
+      expect(spec.interpretResponse(null, request).length).to.equal(0);
+    });
+  });
+});