diff --git a/shell/client/grainview.js b/shell/client/grainview.js
index 7bf8e051e5..f6ee1ab0f6 100644
--- a/shell/client/grainview.js
+++ b/shell/client/grainview.js
@@ -42,6 +42,8 @@ GrainView = class GrainView {
       this.revealIdentity();
     }
 
+    this.enableInlinePowerbox = new ReactiveVar(false);
+
     // We manage our Blaze view directly in order to get more control over when iframes get
     // re-rendered. E.g. if we were to instead use a template with {{#each grains}} iterating over
     // the list of open grains, all grains might get re-rendered whenever a grain is removed from the
@@ -617,6 +619,18 @@ GrainView = class GrainView {
     this._generatedApiToken = newApiToken;
     this._dep.changed();
   }
+
+  startInlinePowerbox(inlinePowerboxState) {
+    this.inlinePowerboxState = inlinePowerboxState;
+    if (inlinePowerboxState.isForeground) {
+      this.enableInlinePowerbox.set(true);
+    } else {
+      state.source.postMessage({
+        rpcId: inlinePowerboxState.rpcId,
+        error: "Cannot start inline powerbox when app is not in foreground",
+      }, inlinePowerboxState.origin);
+    }
+  }
 };
 
 const onceConditionIsTrue = (condition, continuation) => {
diff --git a/shell/client/shell.html b/shell/client/shell.html
index 9343663632..af64ae8bf0 100644
--- a/shell/client/shell.html
+++ b/shell/client/shell.html
@@ -155,6 +155,7 @@ <h4>Notice from Admin</h4>
     {{/if}}
     </div>
   {{/with}}
+  <input type="text" class="inline-powerbox">
 </template>
 
 <template name="invalidToken">
diff --git a/shell/client/shell.scss b/shell/client/shell.scss
index 0399b06895..3d82ffd339 100644
--- a/shell/client/shell.scss
+++ b/shell/client/shell.scss
@@ -450,3 +450,8 @@ body>.popup.admin-alert>.frame>p {
     font-size: 30px;
   }
 }
+
+.inline-powerbox {
+  // Hack to make it effectively invisible, but not be treated as un-focusable by browsers
+  margin: -10000px;
+}
diff --git a/shell/server/core.js b/shell/server/core.js
index 47feab5b1a..a264b335cb 100644
--- a/shell/server/core.js
+++ b/shell/server/core.js
@@ -226,6 +226,38 @@ Meteor.methods({
 
     Notifications.update({userId: Meteor.userId()}, {$set: {isUnread: false}}, {multi: true});
   },
+  offerExternalWebSession(grainId, identityId, url) {
+    check(grainId, String);
+    check(identityId, String);
+    check(url, String);
+
+    const db = this.connection.sandstormDb;
+
+    // Check that the the identityId matches and has permission to view this grain
+    if (!db.userHasIdentity(Meteor.userId(), identityId)) {
+      throw new Meteor.Error(403, "Logged in user doesn't own the supplied identity.");
+    }
+    const requirement = {
+      permissionsHeld: {
+        grainId: grainId,
+        identityId: identityId,
+        permissions: [], // We only want to check for the implicit view permission
+      },
+    };
+    if (!checkRequirements([requirement])) {
+      throw new Meteor.Error(403, "This identity doesn't have view permissions to the grain.");
+    }
+    const requirements = []; // We don't actually want the user's permission check as a requirement.
+    const grainOwner = {grain: {
+      grainId: grainId,
+      introducerIdentity: identityId,
+      saveLabel: url + " websession",
+    }};
+    const sturdyRef = waitPromise(saveFrontendRef(
+      {externalWebSession: {url: url}}, grainOwner, requirements)).sturdyRef;
+
+    return sturdyRef.toString();
+  }
 });
 
 saveFrontendRef = (frontendRef, owner, requirements) => {
@@ -320,6 +352,8 @@ restoreInternal = (tokenId, ownerPattern, requirements, parentToken) => {
       return {cap: makeIpNetwork(tokenId)};
     } else if (token.frontendRef.ipInterface) {
       return {cap: makeIpInterface(tokenId)};
+    } else if (token.frontendRef.externalWebSession) {
+      return {cap: makeExternalWebSession(token.frontendRef.externalWebSession.url)};
     } else {
       throw new Meteor.Error(500, 'Unknown frontend token type.');
     }
diff --git a/shell/server/drivers/external-ui-view.js b/shell/server/drivers/external-ui-view.js
index 39ad25276d..b50ef36b97 100644
--- a/shell/server/drivers/external-ui-view.js
+++ b/shell/server/drivers/external-ui-view.js
@@ -20,7 +20,9 @@ const Capnp = Npm.require('capnp');
 const Url = Npm.require('url');
 const Http = Npm.require('http');
 const Https = Npm.require('https');
+const Dns = Npm.require('dns');
 const ApiSession = Capnp.importSystem('sandstorm/api-session.capnp').ApiSession;
+const WebSession = Capnp.importSystem('sandstorm/web-session.capnp').WebSession;
 
 WrappedUiView = class WrappedUiView {
   constructor(token, proxy) {
@@ -83,7 +85,7 @@ ExternalUiView = class ExternalUiView {
       };
     }
 
-    return {session: new Capnp.Capability(new ExternalWebSession(this.url, this.grainId, options), ApiSession)};
+    return {session: new Capnp.Capability(new ExternalWebSession(this.url, options), ApiSession)};
   }
 };
 
@@ -125,13 +127,17 @@ const responseCodes = {
   505: {type: 'serverError'},
 };
 
+makeExternalWebSession = function (url, options) {
+  return new Capnp.Capability(new ExternalWebSession(url, options), WebSession);
+}
+
 ExternalWebSession = class ExternalWebSession {
-  constructor(url, grainId, options) {
+  constructor(url, options) {
     const parsedUrl = Url.parse(url);
     this.host = parsedUrl.hostname;
     this.port = parsedUrl.port;
     this.protocol = parsedUrl.protocol;
-    this.grainId = grainId;
+    this.path = parsedUrl.path;
     this.options = options || {};
   }
 
@@ -165,129 +171,151 @@ ExternalWebSession = class ExternalWebSession {
     const _this = this;
     const session = _this;
     return new Promise((resolve, reject) => {
-      const options = _.clone(session.options);
-      options.headers = options.headers || {};
-      options.path = path;
-      options.method = method;
-      if (contentType) {
-        options.headers['content-type'] = contentType;
-      }
-
-      // set accept header
-      if ('accept' in context) {
-        options.headers.accept = context.accept.map((acceptedType) => {
-          return acceptedType.mimeType + '; ' + acceptedType.qValue;
-        }).join(', ');
-      } else if (!('accept' in options.headers)) {
-        options.headers.accept = '*/*';
-      }
-
-      // set cookies
-      if (context.cookies && context.cookies.length > 0) {
-        options.headers.cookies = options.headers.cookies || '';
-        context.cookies.forEach((keyVal) => {
-          options.headers.cookies += keyVal.key + '=' + keyVal.val + ',';
-        });
-        options.headers.cookies = options.headers.cookies.slice(0, -1);
-      }
-
-      options.host = session.host;
-      options.port = session.port;
-
-      let requestMethod = Http.request;
-      if (session.protocol === 'https:') {
-        requestMethod = Https.request;
-      }
-
-      req = requestMethod(options, (resp) => {
-        const buffers = [];
-        const statusInfo = responseCodes[resp.statusCode];
-
-        const rpcResponse = {};
-
-        switch (statusInfo.type) {
-          case 'content':
-            resp.on('data', (buf) => {
-              buffers.push(buf);
-            });
-
-            resp.on('end', () => {
-              const content = {};
-              rpcResponse.content = content;
-
-              content.statusCode = statusInfo.code;
-              if ('content-encoding' in resp.headers) content.encoding = resp.headers['content-encoding'];
-              if ('content-language' in resp.headers) content.language = resp.headers['content-language'];
-              if ('content-type' in resp.headers) content.language = resp.headers['content-type'];
-              if ('content-disposition' in resp.headers) {
-                const disposition = resp.headers['content-disposition'];
-                const parts = disposition.split(';');
-                if (parts[0].toLowerCase().trim() === 'attachment') {
-                  parts.forEach((part) => {
-                    const splitPart = part.split('=');
-                    if (splitPart[0].toLowerCase().trim() === 'filename') {
-                      content.disposition = {download: splitPart[1].trim()};
-                    }
-                  });
+      Dns.lookup(_this.host, 4, (err, address) => { // TODO(someday): handle ipv6
+        if (err) {
+          reject(err);
+          return;
+        }
+        if (address.lastIndexOf("10.", 0) === 0 ||
+            address.lastIndexOf("127.", 0) === 0 ||
+            address.lastIndexOf("192.168.", 0) === 0) {
+          // Block the most commonly used private ip ranges as a security measure.
+          reject("Domain resolved to an invalid IP: " + address);
+          return;
+        }
+        const options = _.clone(session.options);
+        options.headers = options.headers || {};
+        if (_this.path) {
+          options.path = _this.path;
+          if (_this.path[_this.path.length - 1] !== "/") {
+            options.path += "/";
+          }
+          options.path += path;
+        } else {
+          options.path = path;
+        }
+        options.path = (_this.path || "") + path;
+        options.method = method;
+        if (contentType) {
+          options.headers['content-type'] = contentType;
+        }
+
+        // set accept header
+        if ('accept' in context) {
+          options.headers.accept = context.accept.map((acceptedType) => {
+            return acceptedType.mimeType + '; ' + acceptedType.qValue;
+          }).join(', ');
+        } else if (!('accept' in options.headers)) {
+          options.headers.accept = '*/*';
+        }
+
+        // set cookies
+        if (context.cookies && context.cookies.length > 0) {
+          options.headers.cookies = options.headers.cookies || '';
+          context.cookies.forEach((keyVal) => {
+            options.headers.cookies += keyVal.key + '=' + keyVal.val + ',';
+          });
+          options.headers.cookies = options.headers.cookies.slice(0, -1);
+        }
+
+        options.host = session.host;
+        options.port = session.port;
+
+        let requestMethod = Http.request;
+        if (session.protocol === 'https:') {
+          requestMethod = Https.request;
+        }
+
+        req = requestMethod(options, (resp) => {
+          const buffers = [];
+          const statusInfo = responseCodes[resp.statusCode];
+
+          const rpcResponse = {};
+
+          switch (statusInfo.type) {
+            case 'content':
+              resp.on('data', (buf) => {
+                buffers.push(buf);
+              });
+
+              resp.on('end', () => {
+                const content = {};
+                rpcResponse.content = content;
+
+                content.statusCode = statusInfo.code;
+                if ('content-encoding' in resp.headers) content.encoding = resp.headers['content-encoding'];
+                if ('content-language' in resp.headers) content.language = resp.headers['content-language'];
+                if ('content-type' in resp.headers) content.language = resp.headers['content-type'];
+                if ('content-disposition' in resp.headers) {
+                  const disposition = resp.headers['content-disposition'];
+                  const parts = disposition.split(';');
+                  if (parts[0].toLowerCase().trim() === 'attachment') {
+                    parts.forEach((part) => {
+                      const splitPart = part.split('=');
+                      if (splitPart[0].toLowerCase().trim() === 'filename') {
+                        content.disposition = {download: splitPart[1].trim()};
+                      }
+                    });
+                  }
                 }
-              }
 
-              content.body = {};
-              content.body.bytes = Buffer.concat(buffers);
+                content.body = {};
+                content.body.bytes = Buffer.concat(buffers);
 
+                resolve(rpcResponse);
+              });
+              break;
+            case 'noContent':
+              const noContent = {};
+              rpcResponse.noContent = noContent;
+              noContent.setShouldResetForm = statusInfo.shouldResetForm;
               resolve(rpcResponse);
-            });
-            break;
-          case 'noContent':
-            const noContent = {};
-            rpcResponse.noContent = noContent;
-            noContent.setShouldResetForm = statusInfo.shouldResetForm;
-            resolve(rpcResponse);
-            break;
-          case 'redirect':
-            const redirect = {};
-            rpcResponse.redirect = redirect;
-            redirect.isPermanent = statusInfo.isPermanent;
-            redirect.switchToGet = statusInfo.switchToGet;
-            if ('location' in resp.headers) redirect.location = resp.headers.location;
-            resolve(rpcResponse);
-            break;
-          case 'clientError':
-            const clientError = {};
-            rpcResponse.clientError = clientError;
-            clientError.statusCode = statusInfo.clientErrorCode;
-            clientError.descriptionHtml = statusInfo.descriptionHtml;
-            resolve(rpcResponse);
-            break;
-          case 'serverError':
-            const serverError = {};
-            rpcResponse.serverError = serverError;
-            clientError.descriptionHtml = statusInfo.descriptionHtml;
-            resolve(rpcResponse);
-            break;
-          default: // ???
-            err = new Error('Invalid status code ' + resp.statusCode + ' received in response.');
-            reject(err);
-            break;
-        }
-      });
+              break;
+            case 'redirect':
+              const redirect = {};
+              rpcResponse.redirect = redirect;
+              redirect.isPermanent = statusInfo.isPermanent;
+              redirect.switchToGet = statusInfo.switchToGet;
+              if ('location' in resp.headers) redirect.location = resp.headers.location;
+              resolve(rpcResponse);
+              break;
+            case 'clientError':
+              const clientError = {};
+              rpcResponse.clientError = clientError;
+              clientError.statusCode = statusInfo.clientErrorCode;
+              clientError.descriptionHtml = statusInfo.descriptionHtml;
+              resolve(rpcResponse);
+              break;
+            case 'serverError':
+              const serverError = {};
+              rpcResponse.serverError = serverError;
+              clientError.descriptionHtml = statusInfo.descriptionHtml;
+              resolve(rpcResponse);
+              break;
+            default: // ???
+              err = new Error('Invalid status code ' + resp.statusCode + ' received in response.');
+              reject(err);
+              break;
+          }
+        });
 
-      req.on('error', (e) => {
-        reject(e);
-      });
+        req.on('error', (e) => {
+          reject(e);
+        });
 
-      req.setTimeout(15000, () => {
-        req.abort();
-        err = new Error('Request timed out.');
-        err.kjType = 'overloaded';
-        reject(err);
-      });
+        req.setTimeout(15000, () => {
+          req.abort();
+          err = new Error('Request timed out.');
+          err.kjType = 'overloaded';
+          reject(err);
+        });
 
-      if (content) {
-        req.end(content);
-      } else {
-        req.end();
-      }
+        if (content) {
+          req.end(content);
+        } else {
+          req.end();
+        }
+      });
     });
   }
 };
diff --git a/shell/shared/grain.js b/shell/shared/grain.js
index 63c4d62e10..16233eaee3 100644
--- a/shell/shared/grain.js
+++ b/shell/shared/grain.js
@@ -814,6 +814,80 @@ if (Meteor.isClient) {
     }
   });
 
+  Template.grainView.onCreated(function () {
+    var template = Template.instance();
+    template.savedKeys = [];
+    this.autorun(function () {
+      var inlinePowerbox = template.data.enableInlinePowerbox.get();
+      if (inlinePowerbox) {
+        template.find(".inline-powerbox").focus();
+      }
+    });
+  });
+  function handleInlinePowerboxKey (event, template) {
+    var state = template.data.inlinePowerboxState;
+    switch (event.keyCode) {
+    case 13: // Enter
+    case 32: // Space
+      var url = template.savedKeys.map(function (char) {
+        return String.fromCharCode(char);
+      }).join("");
+      if (url.lastIndexOf("http", 0) === 0) {
+        var activeGrain = getActiveGrain(globalGrains.get());
+        Meteor.call("offerExternalWebSession",
+          activeGrain.grainId(), activeGrain.identityId(), url, function (err, sturdyRef) {
+            if (err) {
+              // TODO(someday): do something
+              return;
+            }
+            state.source.postMessage({
+              rpcId: state.rpcId,
+              event: {
+                webSession: {
+                  token: sturdyRef,
+                },
+              },
+            }, state.origin);
+          }
+        );
+      }
+      // Start over
+      template.savedKeys = [];
+      break;
+    default:
+      template.savedKeys.push(event.keyCode);
+    }
+    state.source.postMessage({
+      rpcId: state.rpcId,
+      event: {
+        keyCode: event.keyCode,
+      },
+    }, state.origin);
+  }
+  Template.grainView.events({
+    "blur .inline-powerbox": function (event, template) {
+      template.data.enableInlinePowerbox.set(false);
+    },
+    "keydown .inline-powerbox": function (event, template) {
+      var keyCode = event.keyCode;
+      if (keyCode === 8) { // backspace
+        handleInlinePowerboxKey(event, template);
+      }
+    },
+    "keypress .inline-powerbox": handleInlinePowerboxKey,
+    "testInput .inline-powerbox": function (ev, template) {
+      // This custom event is used solely for testing purposes. See tests/apps/powerbox.js.
+      _.each(ev.originalEvent.detail.keys, function (key) {
+        handleInlinePowerboxKey({keyCode: key.charCodeAt(0)}, template);
+      });
+    },
+    "paste .inline-powerbox": function (event, template) {
+      _.each(event.originalEvent.clipboardData.getData('text'), function (key) {
+        handleInlinePowerboxKey({keyCode: key.charCodeAt(0)}, template);
+      });
+    },
+  })
+
   Template.grainView.helpers({
     unpackedGrainState: function () {
       return mapGrainStateToTemplateData(this);
@@ -831,7 +905,7 @@ if (Meteor.isClient) {
       var grain = getActiveGrain(globalGrains.get());
       return {identities: identities,
               onPicked: function(identityId) { grain.revealIdentity(identityId) }};
-    }
+    },
   });
 
   Template.grain.helpers({
@@ -1358,6 +1432,19 @@ if (Meteor.isClient) {
             return "remove";
           }
         });
+      } else if (event.data.inlinePowerbox) {
+        var inlinePowerbox = event.data.inlinePowerbox;
+        check(inlinePowerbox, Object);
+        var rpcId = inlinePowerbox.rpcId;
+        var currentGrain = getActiveGrain(globalGrains.get());
+        var inlinePowerboxState = {
+          source: event.source,
+          rpcId: rpcId,
+          grainId: senderGrain.grainId(),
+          origin: event.origin,
+          isForeground: senderGrain === currentGrain,
+        };
+        senderGrain.startInlinePowerbox(inlinePowerboxState);
       } else {
         console.log("postMessage from app not understood: " + event.data);
         console.log(event);
diff --git a/tests/apps/powerbox.js b/tests/apps/powerbox.js
index 07f07939d8..e52313b367 100644
--- a/tests/apps/powerbox.js
+++ b/tests/apps/powerbox.js
@@ -55,7 +55,8 @@ module.exports["Test Powerbox"] = function (browser) {
           .click("#powerbox-request-form button")
           .frame("grain-frame")
           .waitForElementVisible("#request-result", short_wait)
-          .assert.containsText("#request-result", "request: footest");
+          .assert.containsText("#request-result", "request: footest")
+          .end();
     });
 };
 
@@ -87,7 +88,8 @@ module.exports["Test PowerboxSave"] = function (browser) {
           .click("#powerbox-request-form button")
           .frame("grain-frame")
           .waitForElementVisible("#request-result", short_wait)
-          .assert.containsText("#request-result", "request: footest");
+          .assert.containsText("#request-result", "request: footest")
+          .end();
     });
 };
 
@@ -129,7 +131,70 @@ module.exports["Test Powerbox with failing requirements"] = function (browser) {
                 .switchWindow(windows.value[1])
                 .waitForElementVisible(".grainlog-contents > pre", short_wait)
                 .assert.containsText(".grainlog-contents > pre", "Error: Requirements not satisfied")
+                .end();
             });
     })
+};
+
+// This tests the basic functionality of the inline powerbox.
+// Source: https://github.com/jparyani/sandstorm-test-app/tree/inline-powerbox
+module.exports["Install Inline Powerbox"] = function (browser) {
+  browser
+    .init()
+    .installApp("http://sandstorm.io/apps/jparyani/inline-powebox-test-1.spk", "b58a280b3ca4dc72c8fc4c7b41d3e03d", "8stkfx4ez54109qzmzjtthaq105nf7f4sqfdzzp00g22p1r3uxg0")
+    .assert.containsText("#grainTitle", "Untitled InlinePowerboxTest");
+};
+
+module.exports["Test Inline Powerbox"] = function (browser) {
+  browser
+    .waitForElementVisible("#grain-frame", short_wait)
+    .frame("grain-frame")
+    .waitForElementVisible("#inline-powerbox", short_wait)
+    .click("#inline-powerbox")
+    .frame()
+    .execute(function () {
+      // Sandstorm's inline powerbox defines a special event called testInput for testing purposes
+      var ev = new CustomEvent("testInput", {
+        detail: {
+          keys: "https://sandstorm.io/apps/jparyani/test_inline_powerbox ",
+        },
+        bubbles: false,
+        cancelable: true,
+      });
+      document.querySelector(".inline-powerbox").dispatchEvent(ev);
+    })
+    .frame("grain-frame")
+    .waitForElementVisible("#request-result", short_wait)
+    .assert.containsText("#request-result", "successfully fetched page");
+};
+
+module.exports["Install Faling Inline Powerbox"] = function (browser) {
+  browser
+    .init()
+    .installApp("http://sandstorm.io/apps/jparyani/inline-powebox-test-1.spk", "b58a280b3ca4dc72c8fc4c7b41d3e03d", "8stkfx4ez54109qzmzjtthaq105nf7f4sqfdzzp00g22p1r3uxg0")
+    .assert.containsText("#grainTitle", "Untitled InlinePowerboxTest");
+};
+
+module.exports["Test Faling Inline Powerbox"] = function (browser) {
+  browser
+    .waitForElementVisible("#grain-frame", short_wait)
+    .frame("grain-frame")
+    .waitForElementVisible("#inline-powerbox", short_wait)
+    .click("#inline-powerbox")
+    .frame()
+    .execute(function () {
+      // Sandstorm's inline powerbox defines a special event called testInput for testing purposes
+      var ev = new CustomEvent("testInput", {
+        detail: {
+          keys: "http://local.sandstorm.io " // This resolves to 127.0.0.1
+        },
+        bubbles: false,
+        cancelable: true,
+      });
+      document.querySelector(".inline-powerbox").dispatchEvent(ev);
+    })
+    .frame("grain-frame")
+    .waitForElementPresent("#request-error", short_wait)
+    .assert.containsText("#request-error", "Domain resolved to an invalid IP")
     .end();
 };