diff --git a/docs/client/docs.js b/docs/client/docs.js
index c057ef71bd..3ac001e554 100644
--- a/docs/client/docs.js
+++ b/docs/client/docs.js
@@ -335,6 +335,7 @@ var toc = [
     "audit-argument-checks",
     "backbone",
     "bootstrap",
+    "browser-policy",
     "coffeescript",
     "d3",
     "force-ssl",
diff --git a/docs/client/packages.html b/docs/client/packages.html
index 0ee701bbe8..077e4f1cd1 100644
--- a/docs/client/packages.html
+++ b/docs/client/packages.html
@@ -22,6 +22,7 @@ and removed with:
 {{> pkg_audit_argument_checks}}
 {{> pkg_backbone}}
 {{> pkg_bootstrap}}
+{{> pkg_browser_policy}}
 {{> pkg_coffeescript}}
 {{> pkg_d3}}
 {{> pkg_force_ssl}}
diff --git a/docs/client/packages/browser-policy.html b/docs/client/packages/browser-policy.html
new file mode 100644
index 0000000000..f7676e7445
--- /dev/null
+++ b/docs/client/packages/browser-policy.html
@@ -0,0 +1,156 @@
+<template name="pkg_browser_policy">
+{{#better_markdown}}
+## `browser-policy`
+
+The `browser-policy` package lets you set security-related policies that will be
+enforced by newer browsers. These policies help you prevent and mitigate common
+attacks like cross-site scripting and clickjacking.
+
+`browser-policy` lets you configure the HTTP headers X-Frame-Options and
+Content-Security-Policy. X-Frame-Options tells the browser which websites are
+allowed to frame your app. You should only let trusted websites frame your app,
+because malicious sites could harm your users
+with <a href="https://www.owasp.org/index.php/Clickjacking">clickjacking
+attacks</a>.
+<a href="https://developer.mozilla.org/en-US/docs/Security/CSP/Introducing_Content_Security_Policy">Content-Security-Policy</a>
+tells the browser where your app can load content from, which encourages safe
+practices and mitigates the damage of a cross-site-scripting attack.
+
+For most apps, we recommend that you take the following steps when using
+`browser-policy`:
+
+* Call `BrowserPolicy.enableContentSecurityPolicy()` to enable a starter policy
+for your app. With this starter policy, your app's client code will be able to
+load content (images, scripts, fonts, etc.) only from its own origin, except
+that XMLHttpRequests and WebSocket connections can go to any origin. Further,
+your app's client code will not be able to use functions such as `eval()` that
+convert strings to code.
+* You can use the functions described below to customize the content
+security policy. If your app does not need any inline Javascript such as inline
+`<script>` tags, we recommend that you modify the policy by calling
+`BrowserPolicy.disallowInlineScripts()` in server code. This will result in one
+extra round trip when your app is loaded, but will help prevent cross-site
+scripting attacks by disabling all scripts except those loaded from a `script
+src` attribute.
+* If your app does not need to be framed by other websites, call
+`BrowserPolicy.allowFramingBySameOrigin()` to help prevent clickjacking attacks.
+
+Meteor determines the browser policy when the server starts up, so you should
+call `BrowserPolicy` functions in top-level application code or in
+`Meteor.startup`.
+
+#### Frame options
+
+You can use the following functions to specify which websites are allowed to
+frame your app:
+<dl class="callbacks">
+{{#dtdd "BrowserPolicy.disallowFraming()"}}
+Your app will never render inside a frame or iframe.
+{{/dtdd}}
+
+{{#dtdd "BrowserPolicy.allowFramingByOrigin(origin)"}}
+Your app will only render inside frames loaded by `origin`. You can only call
+this function once with a single origin, and cannot use wildcards or specify
+multiple origins that are allowed to frame your app. (This is a limitation of
+the X-Frame-Options header.) Example values of `origin` include
+"http://example.com" and "https://foo.example.com". Note that this value of the
+X-Frame-Options header is not yet supported in Chrome or Safari and will be
+ignored in those browsers.
+{{/dtdd}}
+
+{{#dtdd "BrowserPolicy.allowFramingBySameOrigin()"}}
+Your app will only render inside frames loaded by webpages on the same origin as
+your app.
+{{/dtdd}}
+
+{{#dtdd "BrowserPolicy.allowFramingByAnyOrigin()"}}
+Your app can be framed by any website.
+{{/dtdd}}
+</dl>
+
+#### Content options
+
+You can use the functions in this section to control how different types of
+content can be loaded on your site. In order to use any of these functions, you
+must first call `BrowserPolicy.enableContentSecurityPolicy()`, which enables the
+starter policy described above. This section covers additional functions that
+you can use to tighten or relax restrictions on what content your app can use.
+
+You can use the following functions to adjust policies on where Javascript and
+CSS can be run:
+
+<dl class="callbacks">
+{{#dtdd "BrowserPolicy.allowInlineScripts()"}}
+Allows inline `<script>` tags, `javascript:` URLs, and inline event handlers.
+{{/dtdd}}
+
+{{#dtdd "BrowserPolicy.disallowInlineScripts()"}}
+Disallows inline Javascript. Calling this function results in an extra
+round-trip on page load to retrieve Meteor runtime configuration that is usually
+part of an inline script tag.
+{{/dtdd}}
+
+{{#dtdd "BrowserPolicy.allowEval()"}}
+Allows the creation of Javascript code from strings using function such as `eval()`.
+{{/dtdd}}
+
+{{#dtdd "BrowserPolicy.disallowEval()"}}
+Disallows eval and related functions.
+{{/dtdd}}
+
+{{#dtdd "BrowserPolicy.allowInlineStyles()"}}
+Allows inline style tags and style attributes.
+{{/dtdd}}
+
+{{#dtdd "BrowserPolicy.disallowInlineStyles()"}}
+Disallows inline CSS.
+{{/dtdd}}
+</dl>
+
+Finally, you can configure a whitelist of allowed requests that various types of
+content can make. The following functions are defined for the content types
+script, object, image, media, font, and connect.
+
+<dl class="callbacks">
+{{#dtdd "BrowserPolicy.allow&lt;ContentType&gt;Origin(origin)"}}
+Allows this type of content to be loaded from the given origin. `origin` is a
+string and can include an optional scheme (such as `http` or `https`), an
+optional wildcard at the beginning, and an optional port which can be a
+wildcard. Examples include `example.com`, `https://*.example.com`, and
+`example.com:*`. You can call these functions multiple times with different
+origins to specify a whitelist of allowed origins.
+{{/dtdd}}
+
+{{#dtdd "BrowserPolicy.allow&lt;ContentType&gt;DataUrl()"}}
+Allows this type of content to be loaded from a `data:` URL.
+{{/dtdd}}
+
+{{#dtdd "BrowserPolicy.allow&lt;ContentType&gt;SameOrigin()"}}
+Allows this type of content to be loaded from the same origin as your app.
+{{/dtdd}}
+
+{{#dtdd "BrowserPolicy.disallow&lt;ContentType&gt;()"}}
+Disallows this type of content on your app.
+{{/dtdd}}
+</dl>
+
+These functions are also defined for the content type `AllContent`, which is a
+shorthand for calling one of the above functions once for each content type.
+For example, if you want to allow the origin `https://foo.com` for all types of
+content but you want to disable `<object>` tags, you can call
+`BrowserPolicy.allowAllContentOrigin("https://foo.com")` followed by
+`BrowserPolicy.disallowObject()`.
+
+Other examples of using the `BrowserPolicy` API:
+
+* `BrowserPolicy.disallowObject()` causes the browser to disallow all
+`<object>` tags.
+* `BrowserPolicy.allowImageOrigin("https://example.com")`
+allows images to have their `src` attributes point to images served from
+`https://example.com`.
+* `BrowserPolicy.allowConnectOrigin("https://example.com")` allows XMLHttpRequest
+and WebSocket connections to `https://example.com`.
+
+
+{{/better_markdown}}
+</template>
diff --git a/packages/browser-policy/.gitignore b/packages/browser-policy/.gitignore
new file mode 100644
index 0000000000..677a6fc263
--- /dev/null
+++ b/packages/browser-policy/.gitignore
@@ -0,0 +1 @@
+.build*
diff --git a/packages/browser-policy/browser-policy-test.js b/packages/browser-policy/browser-policy-test.js
new file mode 100644
index 0000000000..cf9ddd9e59
--- /dev/null
+++ b/packages/browser-policy/browser-policy-test.js
@@ -0,0 +1,123 @@
+var cspsEqual = function (csp1, csp2) {
+  var cspToObj = function (csp) {
+    csp = csp.substring(0, csp.length - 1);
+    var parts = _.map(csp.split("; "), function (part) {
+      return part.split(" ");
+    });
+    var keys = _.map(parts, _.first);
+    var values = _.map(parts, _.rest);
+    _.each(values, function (value) {
+      value.sort();
+    });
+    return _.object(keys, values);
+  };
+
+  return EJSON.equals(cspToObj(csp1), cspToObj(csp2));
+};
+
+Tinytest.add("browser-policy - csp", function (test) {
+  var defaultCsp = "default-src 'self'; script-src 'self' 'unsafe-inline'; " +
+        "connect-src * 'self'; img-src data: 'self'; style-src 'self' 'unsafe-inline';"
+  BrowserPolicy.enableContentSecurityPolicy(true /* enable for tests */);
+
+  // Default policy
+  test.isTrue(cspsEqual(BrowserPolicy._constructCsp(), defaultCsp));
+  test.isTrue(BrowserPolicy.inlineScriptsAllowed(true /* tests-only flag */));
+
+  // Redundant whitelisting (inline scripts already allowed in default policy)
+  BrowserPolicy.allowInlineScripts();
+  test.isTrue(cspsEqual(BrowserPolicy._constructCsp(), defaultCsp));
+
+  // Disallow inline scripts
+  BrowserPolicy.disallowInlineScripts();
+  test.isTrue(cspsEqual(BrowserPolicy._constructCsp(),
+                        "default-src 'self'; script-src 'self'; " +
+                        "connect-src * 'self'; img-src data: 'self'; style-src 'self' 'unsafe-inline';"));
+  test.isFalse(BrowserPolicy.inlineScriptsAllowed(true));
+
+  // Allow eval
+  BrowserPolicy.allowEval();
+  test.isTrue(cspsEqual(BrowserPolicy._constructCsp(), "default-src 'self'; script-src 'self' 'unsafe-eval'; " +
+                        "connect-src * 'self'; img-src data: 'self'; style-src 'self' 'unsafe-inline';"));
+
+  // Disallow inline styles
+  BrowserPolicy.disallowInlineStyles();
+  test.isTrue(cspsEqual(BrowserPolicy._constructCsp(), "default-src 'self'; script-src 'self' 'unsafe-eval'; " +
+                        "connect-src * 'self'; img-src data: 'self'; style-src 'self';"));
+
+  // Allow data: urls everywhere
+  BrowserPolicy.allowAllContentDataUrl();
+  test.isTrue(cspsEqual(BrowserPolicy._constructCsp(),
+                        "default-src 'self' data:; script-src 'self' 'unsafe-eval' data:; " +
+                        "connect-src * data: 'self'; img-src data: 'self'; style-src 'self' data:;"));
+
+  // Disallow everything
+  BrowserPolicy.disallowAllContent();
+  test.isTrue(cspsEqual(BrowserPolicy._constructCsp(), "default-src 'none';"));
+  test.isFalse(BrowserPolicy.inlineScriptsAllowed(true));
+
+  // Put inline scripts back in
+  BrowserPolicy.allowInlineScripts();
+  test.isTrue(cspsEqual(BrowserPolicy._constructCsp(),
+                        "default-src 'none'; script-src 'unsafe-inline';"));
+  test.isTrue(BrowserPolicy.inlineScriptsAllowed(true));
+
+  // Add 'self' to all content types
+  BrowserPolicy.allowAllContentSameOrigin();
+  test.isTrue(cspsEqual(BrowserPolicy._constructCsp(),
+                        "default-src 'self'; script-src 'self' 'unsafe-inline';"));
+  test.isTrue(BrowserPolicy.inlineScriptsAllowed(true));
+
+  // Disallow all content except same-origin scripts
+  BrowserPolicy.disallowAllContent();
+  BrowserPolicy.allowScriptSameOrigin();
+  test.isTrue(cspsEqual(BrowserPolicy._constructCsp(),
+                        "default-src 'none'; script-src 'self';"));
+  test.isFalse(BrowserPolicy.inlineScriptsAllowed(true));
+
+  // Starting with all content same origin, disallowScript() and then allow
+  // inline scripts. Result should be that that only inline scripts can execute,
+  // not same-origin scripts.
+  BrowserPolicy.disallowAllContent();
+  BrowserPolicy.allowAllContentSameOrigin();
+  test.isTrue(cspsEqual(BrowserPolicy._constructCsp(), "default-src 'self';"));
+  BrowserPolicy.disallowScript();
+  test.isTrue(cspsEqual(BrowserPolicy._constructCsp(),
+                        "default-src 'self'; script-src 'none';"));
+  BrowserPolicy.allowInlineScripts();
+  test.isTrue(cspsEqual(BrowserPolicy._constructCsp(),
+                        "default-src 'self'; script-src 'unsafe-inline';"));
+
+  // Starting with all content same origin, allow inline scripts. (Should result
+  // in both same origin and inline scripts allowed.)
+  BrowserPolicy.disallowAllContent();
+  BrowserPolicy.allowAllContentSameOrigin();
+  BrowserPolicy.allowInlineScripts();
+  test.isTrue(cspsEqual(BrowserPolicy._constructCsp(),
+                        "default-src 'self'; script-src 'self' 'unsafe-inline';"));
+  BrowserPolicy.disallowInlineScripts();
+  test.isTrue(cspsEqual(BrowserPolicy._constructCsp(),
+                        "default-src 'self'; script-src 'self';"));
+
+  // Allow same origin for all content, then disallow object entirely.
+  BrowserPolicy.disallowAllContent();
+  BrowserPolicy.allowAllContentSameOrigin();
+  BrowserPolicy.disallowObject();
+  test.isTrue(cspsEqual(BrowserPolicy._constructCsp(),
+                        "default-src 'self'; object-src 'none';"));
+});
+
+Tinytest.add("browser-policy - x-frame-options", function (test) {
+  BrowserPolicy._reset();
+  BrowserPolicy.disallowFraming();
+  test.equal(BrowserPolicy._constructXFrameOptions(), "DENY");
+  BrowserPolicy.allowFramingBySameOrigin();
+  test.equal(BrowserPolicy._constructXFrameOptions(), "SAMEORIGIN");
+  BrowserPolicy.allowFramingByOrigin("foo.com");
+  test.equal(BrowserPolicy._constructXFrameOptions(), "ALLOW-FROM foo.com");
+  test.throws(function () {
+    BrowserPolicy.allowFramingByOrigin("bar.com");
+  });
+  BrowserPolicy.allowFramingByAnyOrigin();
+  test.isFalse(BrowserPolicy._constructXFrameOptions());
+});
diff --git a/packages/browser-policy/browser-policy.js b/packages/browser-policy/browser-policy.js
new file mode 100644
index 0000000000..a605d7f13e
--- /dev/null
+++ b/packages/browser-policy/browser-policy.js
@@ -0,0 +1,284 @@
+// To enable CSP, call BrowserPolicy.enableContentSecurityPolicy(). This enables
+// the following default policy:
+// No eval or other string-to-code, and content can only be loaded from the
+// same origin as the app (except for XHRs and websocket connections, which can
+// go to any origin).
+//
+// Apps should call BrowserPolicy.allowFramingBySameOrigin() to allow only
+// same-origin pages to frame their apps, if they don't explicitly want to be
+// framed by third-party sites.
+//
+// Apps should call BrowserPolicy.disallowInlineScripts() if they are not using
+// any inline script tags and are willing to accept an extra round trip on page
+// load.
+//
+// BrowserPolicy functions for tweaking CSP:
+// allowInlineScripts()
+// disallowInlineScripts(): adds extra round-trip to page load time
+// allowInlineStyles()
+// disallowInlineStyles()
+// allowEval()
+// disallowEval()
+//
+// For each type of content (script, object, image, media, font, connect,
+// style), there are the following functions:
+// allow<content type>Origin(origin): allows the type of content to be loaded
+// from the given origin
+// allow<content type>DataUrl(): allows the content to be loaded from data: URLs
+// allow<content type>SameOrigin(): allows the content to be loaded from the
+// same origin
+// disallow<content type>(): disallows this type of content all together (can't
+// be called for script)
+//
+// The following functions allow you to set rules for all types of content at
+// once:
+// allowAllContentOrigin(origin)
+// allowAllContentDataUrl()
+// allowAllContentSameOrigin()
+// disallowAllContent()
+//
+//
+// For controlling which origins can frame this app,
+// BrowserPolicy.disallowFraming()
+// BrowserPolicy.allowFramingByOrigin(origin)
+// BrowserPolicy.allowFramingBySameOrigin()
+// BrowserPolicy.allowFramingByAnyOrigin();
+
+var xFrameOptions;
+var cspSrcs;
+
+// CSP keywords have to be single-quoted.
+var unsafeInline = "'unsafe-inline'";
+var unsafeEval = "'unsafe-eval'";
+var selfKeyword = "'self'";
+var noneKeyword = "'none'";
+
+var cspEnabled = false;
+var cspEnabledForTests = false;
+
+BrowserPolicy = {};
+
+// Exported for tests.
+var constructXFrameOptions = BrowserPolicy._constructXFrameOptions =
+      function () {
+        return xFrameOptions;
+      };
+
+var constructCsp = BrowserPolicy._constructCsp = function () {
+  cspSrcs = cspSrcs || {};
+
+  var header = _.map(cspSrcs, function (srcs, directive) {
+    srcs = srcs || [];
+    if (_.isEmpty(srcs))
+      srcs = [noneKeyword];
+    var directiveCsp = _.uniq(srcs).join(" ");
+    return directive + " " + directiveCsp + ";";
+  });
+
+  header = header.join(" ");
+  return header;
+};
+
+var parseCsp = function (csp) {
+  var policies = csp.split("; ");
+  cspSrcs = {};
+  _.each(policies, function (policy) {
+    if (policy[policy.length - 1] === ";")
+      policy = policy.substring(0, policy.length - 1);
+    var srcs = policy.split(" ");
+    var directive = srcs[0];
+    if (_.indexOf(srcs, noneKeyword) !== -1)
+      cspSrcs[directive] = null;
+    else
+      cspSrcs[directive] = srcs.slice(1);
+  });
+
+  if (cspSrcs["default-src"] === undefined)
+    throw new Error("Content Security Policies used with " +
+                    "browser-policy must specify a default-src.");
+
+  // Copy default-src sources to other directives.
+  _.each(cspSrcs, function (sources, directive) {
+    cspSrcs[directive] = _.union(sources || [], cspSrcs["default-src"] || []);
+  });
+};
+
+var removeCspSrc = function (directive, src) {
+  cspSrcs[directive] = _.without(cspSrcs[directive] || [], src);
+};
+
+var ensureDirective = function (directive) {
+  throwIfNotEnabled();
+  cspSrcs = cspSrcs || {};
+  if (! _.has(cspSrcs, directive))
+    cspSrcs[directive] = _.clone(cspSrcs["default-src"]);
+};
+
+var throwIfNotEnabled = function () {
+  if (! cspEnabled && ! cspEnabledForTests)
+    throw new Error("Enable this function by calling "+
+                    "BrowserPolicy.enableContentSecurityPolicy().");
+};
+
+WebApp.connectHandlers.use(function (req, res, next) {
+  if (xFrameOptions)
+    res.setHeader("X-Frame-Options", constructXFrameOptions());
+  if (cspEnabled)
+    res.setHeader("Content-Security-Policy", constructCsp());
+  next();
+});
+
+BrowserPolicy = _.extend(BrowserPolicy, {
+  _reset: function () {
+    xFrameOptions = null;
+    cspSrcs = null;
+    cspEnabled = false;
+  },
+
+  allowFramingBySameOrigin: function () {
+    xFrameOptions = "SAMEORIGIN";
+  },
+  disallowFraming: function () {
+    xFrameOptions = "DENY";
+  },
+  // ALLOW-FROM not supported in Chrome or Safari.
+  allowFramingByOrigin: function (origin) {
+    // Trying to specify two allow-from throws to prevent users from
+    // accidentally overwriting an allow-from origin when they think they are
+    // adding multiple origins.
+    if (xFrameOptions && xFrameOptions.indexOf("ALLOW-FROM") === 0)
+      throw new Error("You can only specify one origin that is allowed to" +
+                      " frame this app.");
+    xFrameOptions = "ALLOW-FROM " + origin;
+  },
+  allowFramingByAnyOrigin: function () {
+    xFrameOptions = null;
+  },
+
+  // _enableForTests means that you can call CSP functions, but the header won't
+  // actually be sent.
+  enableContentSecurityPolicy: function (_enableForTests) {
+    // By default, unsafe inline scripts and styles are allowed, since we expect
+    // many apps will use them for analytics, etc. Unsafe eval is disallowed, and
+    // the only allowable content source is the same origin or data, except for
+    // connect which allows anything (since meteor.com apps make websocket
+    // connections to a lot of different origins).
+    if (! _enableForTests)
+      cspEnabled = true;
+    else
+      cspEnabledForTests = true;
+    cspSrcs = {};
+    BrowserPolicy.setContentSecurityPolicy("default-src 'self'; " +
+                                           "script-src 'self' 'unsafe-inline'; " +
+                                           "connect-src *; " +
+                                           "img-src data: 'self'; " +
+                                           "style-src 'self' 'unsafe-inline';");
+  },
+
+  setContentSecurityPolicy: function (csp) {
+    throwIfNotEnabled();
+    parseCsp(csp);
+  },
+
+  // Helpers for creating content security policies
+
+  _keywordAllowed: function (directive, keyword, _calledFromTests) {
+    // All keywords are allowed if csp is not enabled and we're not in a test
+    // run. If csp is enabled or we're in a test run, then look in cspSrcs to
+    // see if it's allowed.
+    return (! cspEnabled && ! _calledFromTests) ||
+      (cspSrcs[directive] &&
+       _.indexOf(cspSrcs[directive], keyword) !== -1);
+  },
+
+  // Used by webapp to determine whether we need an extra round trip for
+  // __meteor_runtime_config__.
+  // _calledFromTests is used to indicate that we should ignore cspEnabled and
+  // instead look directly in cspSrcs to determine if the keyword is allowed.
+  // XXX maybe this test interface could be cleaned up
+  inlineScriptsAllowed: function (_calledFromTests) {
+    return BrowserPolicy._keywordAllowed("script-src",
+                                         unsafeInline, _calledFromTests);
+  },
+
+  allowInlineScripts: function () {
+    ensureDirective("script-src");
+    cspSrcs["script-src"].push(unsafeInline);
+  },
+  disallowInlineScripts: function () {
+    ensureDirective("script-src");
+    removeCspSrc("script-src", unsafeInline);
+  },
+  allowEval: function () {
+    ensureDirective("script-src");
+    cspSrcs["script-src"].push(unsafeEval);
+  },
+  disallowEval: function () {
+    ensureDirective("script-src");
+    removeCspSrc("script-src", unsafeEval);
+  },
+  allowInlineStyles: function () {
+    ensureDirective("style-src");
+    cspSrcs["style-src"].push(unsafeInline);
+  },
+  disallowInlineStyles: function () {
+    ensureDirective("style-src");
+    removeCspSrc("style-src", unsafeInline);
+  },
+
+  // Functions for setting defaults
+  allowAllContentSameOrigin: function () {
+    BrowserPolicy.allowAllContentOrigin(selfKeyword);
+  },
+  allowAllContentDataUrl: function () {
+    BrowserPolicy.allowAllContentOrigin("data:");
+  },
+  allowAllContentOrigin: function (origin) {
+    ensureDirective("default-src");
+    _.each(_.keys(cspSrcs), function (directive) {
+      cspSrcs[directive].push(origin);
+    });
+  },
+  disallowAllContent: function () {
+    throwIfNotEnabled();
+    cspSrcs = {
+      "default-src": []
+    };
+  }
+});
+
+// allow<Resource>Origin, allow<Resource>Data, allow<Resource>self, and
+// disallow<Resource> methods for each type of resource.
+_.each(["script", "object", "img", "media",
+        "font", "connect", "style"],
+       function (resource) {
+         var directive = resource + "-src";
+         var methodResource;
+         if (resource !== "img") {
+           methodResource = resource.charAt(0).toUpperCase() +
+             resource.slice(1);
+         } else {
+           methodResource = "Image";
+         }
+         var allowMethodName = "allow" + methodResource + "Origin";
+         var disallowMethodName = "disallow" + methodResource;
+         var allowDataMethodName = "allow" + methodResource + "DataUrl";
+         var allowSelfMethodName = "allow" + methodResource + "SameOrigin";
+
+         BrowserPolicy[allowMethodName] = function (src) {
+           ensureDirective(directive);
+           cspSrcs[directive].push(src);
+         };
+         BrowserPolicy[disallowMethodName] = function () {
+           throwIfNotEnabled();
+           cspSrcs[directive] = [];
+         };
+         BrowserPolicy[allowDataMethodName] = function () {
+           ensureDirective(directive);
+           cspSrcs[directive].push("data:");
+         };
+         BrowserPolicy[allowSelfMethodName] = function () {
+           ensureDirective(directive);
+           cspSrcs[directive].push(selfKeyword);
+         };
+       });
diff --git a/packages/browser-policy/package.js b/packages/browser-policy/package.js
new file mode 100644
index 0000000000..ca3d0eff2f
--- /dev/null
+++ b/packages/browser-policy/package.js
@@ -0,0 +1,14 @@
+Package.describe({
+  summary: "Configure security policies enforced by the browser"
+});
+
+Package.on_use(function (api) {
+  api.use(["underscore", "webapp"], "server");
+  api.add_files("browser-policy.js", "server");
+  api.export("BrowserPolicy", "server");
+});
+
+Package.on_test(function (api) {
+  api.use(["tinytest", "browser-policy", "ejson"]);
+  api.add_files("browser-policy-test.js", "server");
+});
diff --git a/packages/webapp/package.js b/packages/webapp/package.js
index 0f89553822..ea662b2be8 100644
--- a/packages/webapp/package.js
+++ b/packages/webapp/package.js
@@ -12,6 +12,11 @@ Package.on_use(function (api) {
   api.use(['application-configuration'], {
     unordered: true
   });
+  // At response serving time, webapp uses browser-policy if it is loaded. If
+  // browser-policy is loaded, then it must be loaded after webapp
+  // (browser-policy depends on webapp). So we don't explicitly depend in any
+  // way on browser-policy here, but we use it when it is loaded, and it can be
+  // loaded after webapp.
   api.export(['WebApp', 'main', 'WebAppInternals'], 'server');
   api.add_files('webapp_server.js', 'server');
 });
diff --git a/packages/webapp/webapp_server.js b/packages/webapp/webapp_server.js
index af716d5d3a..3380ab81d2 100644
--- a/packages/webapp/webapp_server.js
+++ b/packages/webapp/webapp_server.js
@@ -147,7 +147,6 @@ var appUrl = function (url) {
   return true;
 };
 
-
 var runWebAppServer = function () {
   // read the control for the client we'll be serving up
   var clientJsonPath = path.join(__meteor_bootstrap__.serverDir,
@@ -231,6 +230,17 @@ var runWebAppServer = function () {
       next();
       return;
     }
+
+    if (Package["browser-policy"] &&
+        ! Package["browser-policy"].BrowserPolicy.inlineScriptsAllowed() &&
+        pathname === "/meteor_runtime_config.js") {
+      res.writeHead(200, { 'Content-type': 'application/javascript' });
+      res.write("__meteor_runtime_config__ = " +
+                JSON.stringify(__meteor_runtime_config__) + ";");
+      res.end();
+      return;
+    }
+
     if (!_.has(staticFiles, pathname)) {
       next();
       return;
@@ -387,15 +397,25 @@ var runWebAppServer = function () {
     argv = optimist(argv).boolean('keepalive').argv;
 
     var boilerplateHtmlPath = path.join(clientDir, clientJson.page);
-    boilerplateHtml =
-      fs.readFileSync(boilerplateHtmlPath, 'utf8')
-      .replace(
-        "// ##RUNTIME_CONFIG##",
-        "__meteor_runtime_config__ = " +
-          JSON.stringify(__meteor_runtime_config__) + ";")
-      .replace(
-          /##ROOT_URL_PATH_PREFIX##/g,
-        __meteor_runtime_config__.ROOT_URL_PATH_PREFIX || "");
+    boilerplateHtml = fs.readFileSync(boilerplateHtmlPath, 'utf8');
+
+    // Include __meteor_runtime_config__ in the app html, as an inline script if
+    // it's not forbidden by CSP.
+    if (! Package["browser-policy"] ||
+        Package["browser-policy"].BrowserPolicy.inlineScriptsAllowed()) {
+      boilerplateHtml = boilerplateHtml.replace(
+          /##RUNTIME_CONFIG##/,
+        "<script type='text/javascript'>__meteor_runtime_config__ = " +
+          JSON.stringify(__meteor_runtime_config__) + ";</script>");
+    } else {
+      boilerplateHtml = boilerplateHtml.replace(
+        /##RUNTIME_CONFIG##/,
+        "<script type='text/javascript' src='##ROOT_URL_PATH_PREFIX##/meteor_runtime_config.js'></script>"
+      );
+    }
+    boilerplateHtml = boilerplateHtml.replace(
+        /##ROOT_URL_PATH_PREFIX##/g,
+      __meteor_runtime_config__.ROOT_URL_PATH_PREFIX || "");
 
     // only start listening after all the startup code has run.
     var localPort = parseInt(process.env.PORT) || 0;
diff --git a/tools/app.html.in b/tools/app.html.in
index bf821f6054..e2bc250d0f 100644
--- a/tools/app.html.in
+++ b/tools/app.html.in
@@ -4,9 +4,7 @@
 {{#each stylesheets}}  <link rel="stylesheet" href="##ROOT_URL_PATH_PREFIX##{{this}}">
 {{/each}}
 
-<script type="text/javascript">
-// ##RUNTIME_CONFIG##
-</script>
+##RUNTIME_CONFIG##
 
 {{#each scripts}}  <script type="text/javascript" src="##ROOT_URL_PATH_PREFIX##{{this}}"></script>
 {{/each}}