diff --git a/packages/netlify-cms-backend-bitbucket/babel.config.js b/packages/netlify-cms-backend-bitbucket/babel.config.js
new file mode 100644
index 00000000..8bb1d682
--- /dev/null
+++ b/packages/netlify-cms-backend-bitbucket/babel.config.js
@@ -0,0 +1,3 @@
+const config = require('../../babel.config.js');
+
+module.exports = config;
diff --git a/packages/netlify-cms-backend-bitbucket/package.json b/packages/netlify-cms-backend-bitbucket/package.json
new file mode 100644
index 00000000..09c8a088
--- /dev/null
+++ b/packages/netlify-cms-backend-bitbucket/package.json
@@ -0,0 +1,41 @@
+{
+  "name": "netlify-cms-backend-bitbucket",
+  "description": "Bitbucket backend for Netlify CMS",
+  "version": "2.0.0-alpha.0",
+  "license": "MIT",
+  "main": "dist/netlify-cms-backend-bitbucket.js",
+  "keywords": [
+    "netlify",
+    "netlify-cms",
+    "backend",
+    "bitbucket"
+  ],
+  "sideEffects": false,
+  "scripts": {
+    "watch": "webpack -w",
+    "build": "cross-env NODE_ENV=production webpack"
+  },
+  "dependencies": {
+    "js-base64": "^2.4.8",
+    "semaphore": "^1.1.0"
+  },
+  "devDependencies": {
+    "@babel/cli": "^7.0.0-beta.54",
+    "@babel/core": "^7.0.0-beta.54",
+    "cross-env": "^5.2.0",
+    "rollup": "^0.63.2",
+    "rollup-plugin-babel": "^4.0.0-beta.7",
+    "webpack": "^4.16.1",
+    "webpack-cli": "^3.1.0"
+  },
+  "peerDependencies": {
+    "immutable": "^3.7.6",
+    "lodash": "^4.17.10",
+    "netlify-cms-lib-auth": "2.0.0-alpha.0",
+    "netlify-cms-lib-util": "2.0.0-alpha.0",
+    "netlify-cms-ui-default": "2.0.0-alpha.0",
+    "prop-types": "^15.6.2",
+    "react": "^16.4.1",
+    "react-emotion": "^9.2.6"
+  }
+}
diff --git a/packages/netlify-cms-backend-bitbucket/src/API.js b/packages/netlify-cms-backend-bitbucket/src/API.js
new file mode 100644
index 00000000..a97f828d
--- /dev/null
+++ b/packages/netlify-cms-backend-bitbucket/src/API.js
@@ -0,0 +1,151 @@
+import { flow } from "lodash";
+import {
+  LocalForage,
+  unsentRequest,
+  responseParser,
+  then,
+  basename,
+  Cursor,
+  APIError
+} from "netlify-cms-lib-util";
+
+export default class API {
+  constructor(config) {
+    this.api_root = config.api_root || "https://api.bitbucket.org/2.0";
+    this.branch = config.branch || "master";
+    this.repo = config.repo || "";
+    this.requestFunction = config.requestFunction || unsentRequest.performRequest;
+    // Allow overriding this.hasWriteAccess
+    this.hasWriteAccess = config.hasWriteAccess || this.hasWriteAccess;
+    this.repoURL = this.repo ? `/repositories/${ this.repo }` : "";
+  }
+
+  buildRequest = req => flow([
+    unsentRequest.withRoot(this.api_root),
+    unsentRequest.withTimestamp,
+  ])(req);
+
+  request = req => flow([
+    this.buildRequest,
+    this.requestFunction,
+    p => p.catch(err => Promise.reject(new APIError(err.message, null, "BitBucket"))),
+  ])(req);
+
+  requestJSON = req => flow([
+    unsentRequest.withDefaultHeaders({ "Content-Type": "application/json" }),
+    this.request,
+    then(responseParser({ format: "json" })),
+    p => p.catch(err => Promise.reject(new APIError(err.message, null, "BitBucket"))),
+  ])(req);
+  requestText = req => flow([
+    unsentRequest.withDefaultHeaders({ "Content-Type": "text/plain" }),
+    this.request,
+    then(responseParser({ format: "text" })),
+    p => p.catch(err => Promise.reject(new APIError(err.message, null, "BitBucket"))),
+  ])(req);
+
+  user = () => this.request("/user");
+  hasWriteAccess = user => this.request(this.repoURL).then(res => res.ok);
+
+  isFile = ({ type }) => type === "commit_file";
+  processFile = file => ({
+    ...file,
+    name: basename(file.path),
+    download_url: file.links.self.href,
+
+    // BitBucket does not return file SHAs, but it does give us the
+    // commit SHA. Since the commit SHA will change if any files do,
+    // we can construct an ID using the commit SHA and the file path
+    // that will help with caching (though not as well as a normal
+    // SHA, since it will change even if the individual file itself
+    // doesn't.)
+    ...(file.commit && file.commit.hash
+        ? { id: `${ file.commit.hash }/${ file.path }` }
+        : {}),
+  });
+  processFiles = files => files.filter(this.isFile).map(this.processFile);
+
+  readFile = async (path, sha, { ref = this.branch, parseText = true } = {}) => {
+    const cacheKey = parseText ? `bb.${ sha }` : `bb.${ sha }.blob`;
+    const cachedFile = sha ? await LocalForage.getItem(cacheKey) : null;
+    if (cachedFile) { return cachedFile; }
+    const result = await this.request({
+      url: `${ this.repoURL }/src/${ ref }/${ path }`,
+      cache: "no-store",
+    }).then(parseText ? responseParser({ format: "text" }) : responseParser({ format: "blob" }));
+    if (sha) { LocalForage.setItem(cacheKey, result); }
+    return result;
+  }
+
+  getEntriesAndCursor = jsonResponse => {
+    const { size: count, page: index, pagelen: pageSize, next, previous: prev, values: entries } = jsonResponse;
+    const pageCount = (pageSize && count) ? Math.ceil(count / pageSize) : undefined;
+    return {
+      entries,
+      cursor: Cursor.create({
+        actions: [...(next ? ["next"] : []), ...(prev ? ["prev"] : [])],
+        meta: { index, count, pageSize, pageCount },
+        data: { links: { next, prev } },
+      }),
+    };
+  }
+
+  listFiles = async path => {
+    const { entries, cursor } = await flow([
+      // sort files by filename ascending
+      unsentRequest.withParams({ sort: "-path" }),
+      this.requestJSON,
+      then(this.getEntriesAndCursor),
+    ])(`${ this.repoURL }/src/${ this.branch }/${ path }`);
+    return { entries: this.processFiles(entries), cursor };
+  }
+
+  traverseCursor = async (cursor, action) => flow([
+    this.requestJSON,
+    then(this.getEntriesAndCursor),
+    then(({ cursor: newCursor, entries }) => ({ cursor: newCursor, entries: this.processFiles(entries) })),
+  ])(cursor.data.getIn(["links", action]));
+
+  listAllFiles = async path => {
+    const { cursor: initialCursor, entries: initialEntries } = await this.listFiles(path);
+    const entries = [...initialEntries];
+    let currentCursor = initialCursor;
+    while (currentCursor && currentCursor.actions.has("next")) {
+      const { cursor: newCursor, entries: newEntries } = await this.traverseCursor(currentCursor, "next");
+      entries.push(...newEntries);
+      currentCursor = newCursor;
+    }
+    return this.processFiles(entries);
+  };
+
+  uploadBlob = async item => {
+    const contentBase64 = await (has(item, 'toBase64') ? item.toBase64() : Promise.resolve(item.raw));
+    const formData = new FormData();
+    formData.append(item.path, contentBase64);
+
+    return flow([
+      unsentRequest.withMethod("POST"),
+      unsentRequest.withBody(formData),
+      this.request,
+      then(() => ({ ...item, uploaded: true })),
+    ])(`${ this.repoURL }/src`);
+  };
+
+  persistFiles = (files, { commitMessage, newEntry }) => Promise.all(
+    files.filter(({ uploaded }) => !uploaded).map(this.uploadBlob)
+  );
+
+  deleteFile = (path, message, options={}) => {
+    const branch = options.branch || this.branch;
+    const body = new FormData();
+    body.append('files', path);
+    if (message && message !== "") {
+      body.append("message", message);
+    }
+    return flow([
+      unsentRequest.withMethod("POST"),
+      unsentRequest.withBody(body),
+      this.request,
+    ])(`${ this.repoURL }/src`);
+  };
+}
diff --git a/packages/netlify-cms-backend-bitbucket/src/AuthenticationPage.js b/packages/netlify-cms-backend-bitbucket/src/AuthenticationPage.js
new file mode 100644
index 00000000..5bd915ab
--- /dev/null
+++ b/packages/netlify-cms-backend-bitbucket/src/AuthenticationPage.js
@@ -0,0 +1,52 @@
+import React from 'react';
+import PropTypes from 'prop-types';
+import styled from 'react-emotion';
+import { NetlifyAuthenticator } from 'netlify-cms-lib-auth';
+import { AuthenticationPage, Icon } from 'netlify-cms-ui-default';
+
+const LoginButtonIcon = styled(Icon)`
+  margin-right: 18px;
+`
+
+export default class BitbucketAuthenticationPage extends React.Component {
+  static propTypes = {
+    onLogin: PropTypes.func.isRequired,
+    inProgress: PropTypes.bool,
+  };
+
+  state = {};
+
+  handleLogin = (e) => {
+    e.preventDefault();
+    const cfg = {
+      base_url: this.props.base_url,
+      site_id: (document.location.host.split(':')[0] === 'localhost') ? 'cms.netlify.com' : this.props.site_id,
+      auth_endpoint: this.props.authEndpoint,
+    };
+    const auth = new NetlifyAuthenticator(cfg);
+
+    auth.authenticate({ provider: 'bitbucket', scope: 'repo' }, (err, data) => {
+      if (err) {
+        this.setState({ loginError: err.toString() });
+        return;
+      }
+      this.props.onLogin(data);
+    });
+  };
+
+  render() {
+    return (
+      <AuthenticationPage
+        onLogin={this.handleLogin}
+        loginDisabled={this.props.inProgress}
+        loginErrorMessage={this.state.loginError}
+        renderButtonContent={() => (
+          <React.Fragment>
+            <LoginButtonIcon type="bitbucket"/>
+            {inProgress ? "Logging in..." : "Login with Bitbucket"}
+          </React.Fragment>
+        )}
+      />
+    );
+  }
+}
diff --git a/packages/netlify-cms-backend-bitbucket/src/implementation.js b/packages/netlify-cms-backend-bitbucket/src/implementation.js
new file mode 100644
index 00000000..40ba7938
--- /dev/null
+++ b/packages/netlify-cms-backend-bitbucket/src/implementation.js
@@ -0,0 +1,224 @@
+import semaphore from "semaphore";
+import { flow, trimStart } from "lodash";
+import {
+  CURSOR_COMPATIBILITY_SYMBOL,
+  filterByPropExtension,
+  resolvePromiseProperties,
+  then,
+  unsentRequest,
+} from "netlify-cms-lib-util";
+import { NetlifyAuthenticator } from 'netlify-cms-lib-auth';
+import AuthenticationPage from "./AuthenticationPage";
+import API from "./API";
+
+const MAX_CONCURRENT_DOWNLOADS = 10;
+
+// Implementation wrapper class
+export default class Bitbucket {
+  constructor(config, options={}) {
+    this.config = config;
+    this.options = {
+      proxied: false,
+      API: null,
+      updateUserCredentials: async () => null,
+      ...options,
+    };
+
+    if (this.options.useWorkflow) {
+      throw new Error("The BitBucket backend does not support the Editorial Workflow.");
+    }
+
+    if (!this.options.proxied && !config.getIn(["backend", "repo"], false)) {
+      throw new Error("The BitBucket backend needs a \"repo\ in the backend configuration.");
+    }
+
+    this.api = this.options.API || null;
+
+    this.updateUserCredentials = this.options.updateUserCredentials;
+
+    this.repo = config.getIn(["backend", "repo"], "");
+    this.branch = config.getIn(["backend", "branch"], "master");
+    this.api_root = config.getIn(["backend", "api_root"], "https://api.bitbucket.org/2.0");
+    this.base_url = config.get("base_url");
+    this.site_id = config.get("site_id");
+    this.token = "";
+  }
+
+  authComponent() {
+    return AuthenticationPage;
+  }
+
+  setUser(user) {
+    this.token = user.token;
+    this.api = new API({ requestFunction: this.apiRequestFunction, branch: this.branch, repo: this.repo });
+  }
+
+  restoreUser(user) {
+    return this.authenticate(user);
+  }
+
+  authenticate(state) {
+    this.token = state.token;
+    this.refreshToken = state.refresh_token;
+    this.api = new API({ requestFunction: this.apiRequestFunction, branch: this.branch, repo: this.repo, api_root: this.api_root });
+
+    return this.api.user().then(user =>
+      this.api.hasWriteAccess(user).then(isCollab => {
+        if (!isCollab) throw new Error("Your BitBucker user account does not have access to this repo.");
+        return Object.assign({}, user, { token: state.token, refresh_token: state.refresh_token });
+      })
+    );
+  }
+
+  getRefreshedAccessToken() {
+    if (this.refreshedTokenPromise) {
+      return this.refreshedTokenPromise;
+    }
+
+    // instantiating a new Authenticator on each refresh isn't ideal,
+    if (!this.auth) {
+      const cfg = {
+        base_url: this.base_url,
+        site_id: this.site_id,
+      };
+      this.authenticator = new Authenticator(cfg);
+    }
+
+    this.refreshedTokenPromise = this.authenticator.refresh({ provider: "bitbucket", refresh_token: this.refreshToken })
+      .then(({ token, refresh_token }) => {
+        this.token = token;
+        this.refreshToken = refresh_token;
+        this.refreshedTokenPromise = undefined;
+        this.updateUserCredentials({ token, refresh_token });
+        return token;
+      });
+
+    return this.refreshedTokenPromise;
+  }
+
+  logout() {
+    this.token = null;
+    return;
+  }
+
+  getToken() {
+    if (this.refreshedTokenPromise) {
+      return this.refreshedTokenPromise;
+    }
+
+    return Promise.resolve(this.token);
+  }
+
+  apiRequestFunction = async req => {
+    const token = this.refreshedTokenPromise ? await this.refreshedTokenPromise : this.token;
+    return flow([
+      unsentRequest.withHeaders({ Authorization: `Bearer ${ token }` }),
+      unsentRequest.performRequest,
+      then(async res => {
+        if (res.status === 401) {
+          const json = (await res.json().catch(() => null));
+          if (json && json.type === "error" && /^access token expired/i.test(json.error.message)) {
+            const newToken = await this.getRefreshedAccessToken();
+            const reqWithNewToken = unsentRequest.withHeaders({ Authorization: `Bearer ${ newToken }` }, req);
+            return unsentRequest.performRequest(reqWithNewToken);
+          }
+        }
+        return res;
+      }),
+    ])(req);
+  };
+
+  entriesByFolder(collection, extension) {
+    const listPromise = this.api.listFiles(collection.get("folder"));
+    return resolvePromiseProperties({
+      files: listPromise
+        .then(({ entries }) => entries)
+        .then(filterByPropExtension(extension, "path"))
+        .then(this.fetchFiles),
+      cursor: listPromise.then(({ cursor }) => cursor),
+    }).then(({ files, cursor }) => {
+      files[CURSOR_COMPATIBILITY_SYMBOL] = cursor;
+      return files;
+    });
+  }
+
+  allEntriesByFolder(collection, extension) {
+    return this.api.listAllFiles(collection.get("folder"))
+      .then(filterByPropExtension(extension, "path"))
+      .then(this.fetchFiles);
+  }
+
+  entriesByFiles(collection) {
+    const files = collection.get("files").map(collectionFile => ({
+      path: collectionFile.get("file"),
+      label: collectionFile.get("label"),
+    }));
+    return this.fetchFiles(files);
+  }
+
+  fetchFiles = (files) => {
+    const sem = semaphore(MAX_CONCURRENT_DOWNLOADS);
+    const promises = [];
+    files.forEach((file) => {
+      promises.push(new Promise((resolve, reject) => (
+        sem.take(() => this.api.readFile(file.path, file.id).then((data) => {
+          resolve({ file, data });
+          sem.leave();
+        }).catch((error = true) => {
+          sem.leave();
+          console.error(`failed to load file from BitBucket: ${ file.path }`);
+          resolve({ error });
+        }))
+      )));
+    });
+    return Promise.all(promises)
+      .then(loadedEntries => loadedEntries.filter(loadedEntry => !loadedEntry.error));
+  }
+
+  getEntry(collection, slug, path) {
+    return this.api.readFile(path).then(data => ({
+      file: { path },
+      data,
+    }));
+  }
+
+  getMedia() {
+    const sem = semaphore(MAX_CONCURRENT_DOWNLOADS);
+
+    return this.api.listAllFiles(this.config.get("media_folder"))
+      .then(files => files.map(({ id, name, download_url, path }) => {
+        const getBlobPromise = () => new Promise((resolve, reject) =>
+          sem.take(() =>
+            this.api.readFile(path, id, { parseText: false })
+              .then(resolve, reject)
+              .finally(() => sem.leave())
+          )
+        );
+
+        return { id, name, getBlobPromise, url: download_url, path };
+      }));
+  }
+
+  persistEntry(entry, mediaFiles, options = {}) {
+    return this.api.persistFiles([entry], options);
+  }
+
+  async persistMedia(mediaFile, options = {}) {
+    await this.api.persistFiles([mediaFile], options);
+    const { value, path, fileObj } = mediaFile;
+    const getBlobPromise = () => Promise.resolve(fileObj);
+    return { name: value, size: fileObj.size, getBlobPromise, path: trimStart(path, '/k') };
+  }
+
+  deleteFile(path, commitMessage, options) {
+    return this.api.deleteFile(path, commitMessage, options);
+  }
+
+  traverseCursor(cursor, action) {
+    return this.api.traverseCursor(cursor, action)
+      .then(async ({ entries, cursor: newCursor }) => ({
+        entries: await Promise.all(entries.map(file => this.api.readFile(file.path, file.id).then(data => ({ file, data })))),
+        cursor: newCursor,
+      }));
+  }
+}
diff --git a/packages/netlify-cms-backend-bitbucket/src/index.js b/packages/netlify-cms-backend-bitbucket/src/index.js
new file mode 100644
index 00000000..fdad0123
--- /dev/null
+++ b/packages/netlify-cms-backend-bitbucket/src/index.js
@@ -0,0 +1,4 @@
+export BitbucketBackend from './implementation';
+export API from './API';
+export AuthenticationPage from './AuthenticationPage';
+
diff --git a/packages/netlify-cms-backend-bitbucket/webpack.config.js b/packages/netlify-cms-backend-bitbucket/webpack.config.js
new file mode 100644
index 00000000..52d79f92
--- /dev/null
+++ b/packages/netlify-cms-backend-bitbucket/webpack.config.js
@@ -0,0 +1 @@
+module.exports = require('../../webpack.config.js');
diff --git a/packages/netlify-cms-backend-gitlab/src/AuthenticationPage.js b/packages/netlify-cms-backend-gitlab/src/AuthenticationPage.js
index 6218fad7..924fed65 100644
--- a/packages/netlify-cms-backend-gitlab/src/AuthenticationPage.js
+++ b/packages/netlify-cms-backend-gitlab/src/AuthenticationPage.js
@@ -2,7 +2,7 @@ import React from 'react';
 import PropTypes from 'prop-types';
 import styled from 'react-emotion';
 import { NetlifyAuthenticator, ImplicitAuthenticator } from 'netlify-cms-lib-auth';
-import { AuthenticationPage, Icon, buttons, shadows } from 'netlify-cms-ui-default';
+import { AuthenticationPage, Icon } from 'netlify-cms-ui-default';
 
 const LoginButtonIcon = styled(Icon)`
   margin-right: 18px;
diff --git a/src/lib/backendHelper.js b/packages/netlify-cms-lib-util/src/backendUtil.js
similarity index 89%
rename from src/lib/backendHelper.js
rename to packages/netlify-cms-lib-util/src/backendUtil.js
index 5d69a1a2..7ff9b069 100644
--- a/src/lib/backendHelper.js
+++ b/packages/netlify-cms-lib-util/src/backendUtil.js
@@ -1,8 +1,8 @@
 import { get } from "lodash";
 import { fromJS } from "immutable";
-import { fileExtension } from "Lib/pathHelper";
-import unsentRequest from "Lib/unsentRequest";
-import { CURSOR_COMPATIBILITY_SYMBOL } from "../valueObjects/Cursor";
+import { fileExtension } from "./path";
+import unsentRequest from "./unsentRequest";
+import { CURSOR_COMPATIBILITY_SYMBOL } from "./Cursor";
 
 export const filterByPropExtension = (extension, propName) => arr =>
   arr.filter(el => fileExtension(get(el, propName)) === extension);
diff --git a/src/components/UI/Icon/images/bitbucket.svg b/packages/netlify-cms-ui-default/src/Icon/images/bitbucket.svg
similarity index 100%
rename from src/components/UI/Icon/images/bitbucket.svg
rename to packages/netlify-cms-ui-default/src/Icon/images/bitbucket.svg