diff --git a/BuildServer/lib/builder.ts b/BuildServer/lib/builder.ts
index 7713291..deae832 100644
--- a/BuildServer/lib/builder.ts
+++ b/BuildServer/lib/builder.ts
@@ -197,7 +197,6 @@ export const build = (settings: Settings, options, buildCallback) => {
                     release,
                     reponame,
                     rev,
-                    tmp,
                     versionInfo,
                 }, (processErr, result) => {
                     if (processErr) {
diff --git a/BuildServer/lib/routes/artifact.ts b/BuildServer/lib/routes/artifact.ts
index 57b3f60..188236c 100644
--- a/BuildServer/lib/routes/artifact.ts
+++ b/BuildServer/lib/routes/artifact.ts
@@ -1,8 +1,10 @@
 "use strict";
 
+import * as express from "express";
+
 import { getSettings } from "../settings-wrapper";
 
-export default (req, res) => {
+export default ((req, res) => {
     const options = {
         branch: `/refs/heads/${req.params.branch}`,
         branchName: req.params.branch,
@@ -17,4 +19,4 @@ export default (req, res) => {
     const pathParts = [settings.releasepath, options.owner, options.reponame, options.branch, options.rev, options.file];
 
     res.sendfile(pathParts.join("/"));
-};
+}) as express.RequestHandler;
diff --git a/BuildServer/lib/routes/index.ts b/BuildServer/lib/routes/index.ts
index 125109f..f65483d 100644
--- a/BuildServer/lib/routes/index.ts
+++ b/BuildServer/lib/routes/index.ts
@@ -1,11 +1,13 @@
 "use strict";
 
+import * as express from "express";
+
 import artifact from "./artifact";
 import * as manual from "./manual";
 import postreceive from "./postreceive";
 import release from "./release";
 import * as status from "./status";
 
-const index = (req, res) => res.render("index", { title: `Express<br/>\r\n${req}` });
+const index: express.RequestHandler = (req, res) => res.render("index", { title: `Express<br/>\r\n${req}` });
 
 export { index, postreceive, manual, status, artifact, release };
diff --git a/BuildServer/lib/routes/manual.ts b/BuildServer/lib/routes/manual.ts
index baebd88..7391572 100644
--- a/BuildServer/lib/routes/manual.ts
+++ b/BuildServer/lib/routes/manual.ts
@@ -1,12 +1,14 @@
 "use strict";
 
+import * as express from "express";
 import * as _ from "underscore";
+
 import { build } from "../builder";
 import { getSettings } from "../settings-wrapper";
 
-export const get = (req, res) => res.render("manual");
+export const get: express.RequestHandler = (req, res) => res.render("manual");
 
-export const post = (req, res) => {
+export const post: express.RequestHandler = (req, res) => {
     const settings = getSettings(req.app);
 
     const options = {
diff --git a/BuildServer/lib/routes/postreceive.ts b/BuildServer/lib/routes/postreceive.ts
index 73deefe..3d87b13 100644
--- a/BuildServer/lib/routes/postreceive.ts
+++ b/BuildServer/lib/routes/postreceive.ts
@@ -1,13 +1,23 @@
 "use strict";
 
+import * as express from "express";
 import * as JSONParse from "json-parse-safe";
+
 import { build } from "../builder";
 import { commentOnPullRequest } from "../commenter";
 import { getSettings } from "../settings-wrapper";
+import { HookParameters, HookPullRequestPayload, HookPushPayload } from "../types";
+
+interface IBaseRepoOptions {
+    branch: string;
+    branchname?: string;
+    owner: string;
+    reponame: string;
+}
 
-const getBranchDescription = (options) => `${options.owner}/${options.reponame}:${options.branchname || options.branch}`;
+const getBranchDescription = (options: IBaseRepoOptions) => `${options.owner}/${options.reponame}:${options.branchname || options.branch}`;
 
-const processPush = (req, res, payload) => {
+const processPush = (req: express.Request, res: express.Response, payload: HookPushPayload) => {
     const settings = getSettings(req.app);
     const repository = payload.repository;
     const options = {
@@ -27,7 +37,7 @@ const processPush = (req, res, payload) => {
     });
 };
 
-const processPullRequest = (req, res, payload) => {
+const processPullRequest = (req: express.Request, res: express.Response, payload: HookPullRequestPayload) => {
     const action = payload.action;
     const pullRequestNumber = payload.number;
     const pullRequest = payload.pull_request;
@@ -44,6 +54,7 @@ const processPullRequest = (req, res, payload) => {
     const base = pullRequest.base;
     const baseRepo = base.repo;
     const baseRepoOptions = {
+        branch: `refs/heads/${base.ref}`,
         branchname: base.ref,
         owner: baseRepo.owner.name || baseRepo.owner.login,
         reponame: baseRepo.name,
@@ -79,7 +90,7 @@ const processPullRequest = (req, res, payload) => {
         return res.send("");
     }
 
-    return commentOnPullRequest(settings, (action === "closed" && masterOptions) || options, (err, data) => {
+    return commentOnPullRequest(settings, options, (err, data) => {
         if (err) {
             console.log(`Unable to post comment: ${err}`);
         }
@@ -96,23 +107,27 @@ const getPayload = (body) => {
     return JSONParse(body.payload).value;
 };
 
-export default (req, res) => {
+const getParameters = (req: express.Request): HookParameters => ({
+    eventType: req.header("x-github-event") as any,
+    payload: getPayload(req.body),
+});
+
+export default ((req, res) => {
     if (!req.body || (!req.body.payload && !req.body.repository)) {
         return res.end();
     }
 
-    const eventType = req.header("x-github-event");
-    const payload = getPayload(req.body);
+    const parameters = getParameters(req);
 
-    if (eventType === "push") {
-        return processPush(req, res, payload);
+    if (parameters.eventType === "push") {
+        return processPush(req, res, parameters.payload);
     }
 
-    if (eventType === "pull_request") {
-        return processPullRequest(req, res, payload);
+    if (parameters.eventType === "pull_request") {
+        return processPullRequest(req, res, parameters.payload);
     }
 
-    console.log(`Got "${eventType}" event:`);
+    console.log(`Got "${parameters.eventType}" event:`);
 
     return res.send("Only push/pull_request events are supported");
-};
+}) as express.RequestHandler;
diff --git a/BuildServer/lib/routes/release.ts b/BuildServer/lib/routes/release.ts
index e46f512..2793fe8 100644
--- a/BuildServer/lib/routes/release.ts
+++ b/BuildServer/lib/routes/release.ts
@@ -1,6 +1,7 @@
 "use strict";
 
 import { create as createArchiver } from "archiver";
+import * as express from "express";
 import { join } from "path";
 
 import { readReport } from "../report-processor";
@@ -24,7 +25,7 @@ const getDatePart = (report) => {
     return `${year}.${month}.${day}.${hours}.${minutes}.${seconds}`;
 };
 
-export default (req, res, next) => {
+export default ((req, res, next) => {
     const options = {
         branch: `/refs/heads/${req.params.branch}`,
         branchName: req.params.branch,
@@ -43,10 +44,10 @@ export default (req, res, next) => {
         const archive = createArchiver("zip");
 
         archive.on("error", next);
-        res.attachment(`${options.reponame}.${getDatePart(report)}.${options.rev}.zip`, ".");
+        res.attachment(`${options.reponame}.${getDatePart(report)}.${options.rev}.zip`);
         archive.pipe(res);
         archive.directory(releasePath, false);
 
         return archive.finalize();
     });
-};
+}) as express.RequestHandler;
diff --git a/BuildServer/lib/routes/status.ts b/BuildServer/lib/routes/status.ts
index 7140fdc..9cdf802 100644
--- a/BuildServer/lib/routes/status.ts
+++ b/BuildServer/lib/routes/status.ts
@@ -1,5 +1,6 @@
 "use strict";
 
+import * as express from "express";
 import * as _ from "underscore";
 import { parse } from "url";
 
@@ -35,7 +36,7 @@ const parseOptionsFromReferer = (path, callback) => {
     });
 };
 
-const createShowReport = (res) => (err, inputOptions) => {
+const createShowReport = (res: express.Response) => (err, inputOptions) => {
     const options = {
         ...inputOptions || {},
         err,
@@ -44,7 +45,7 @@ const createShowReport = (res) => (err, inputOptions) => {
     res.render("status", options);
 };
 
-export const image = (req, res) => {
+export const image: express.RequestHandler = (req, res) => {
     const getAdditionalOptions = (err, options) => {
         if (err === "ReportFileNotFound") {
             return { status: "Building" };
@@ -106,7 +107,7 @@ export const image = (req, res) => {
     });
 };
 
-export const page = (req, res) => {
+export const page: express.RequestHandler = (req, res) => {
     const options = {
         branch: `/refs/heads/${req.params.branch}`,
         branchName: req.params.branch,
@@ -118,10 +119,10 @@ export const page = (req, res) => {
     getReport(getSettings(req.app), options, createShowReport(res));
 };
 
-export const pageFromGithub = (req, res) => parseOptionsFromReferer(req.params[0], (err, options) => {
+export const pageFromGithub: express.RequestHandler = (req, res) => parseOptionsFromReferer(req.params[0], (err, options) => {
     if (err) {
         return createShowReport(res)(err, options);
     }
 
-    return getReport(req.app /* xxx */, options, createShowReport(res));
+    return getReport(getSettings(req.app), options, createShowReport(res));
 });
diff --git a/BuildServer/lib/task-processor.ts b/BuildServer/lib/task-processor.ts
index e874300..91b005f 100644
--- a/BuildServer/lib/task-processor.ts
+++ b/BuildServer/lib/task-processor.ts
@@ -3,7 +3,7 @@
 import * as _ from "underscore";
 
 import tasks from "./tasks";
-import { MessagesRoot, Settings, TaskInfo, TaskProcessor, TaskProcessorCallback, TaskProcessorCore } from "./types";
+import { MessagesRoot, ProcessTaskContext, Settings, TaskInfo, TaskProcessor, TaskProcessorCallback, TaskProcessorCore } from "./types";
 
 // TaskProcessor does not look like EventEmitter, so no need to extend EventEmitter and use `emit' here.
 const createTaskProcessor = (task: TaskInfo, outerProcessor: TaskProcessorCore, callback: TaskProcessorCallback) => {
@@ -66,7 +66,7 @@ const addFlag = (flags) => (flagName) => {
 
 const containsFlag = (flags) => (flagName) => flags[flagName];
 
-export const processTask = (settings: Settings, task, context, callback) => {
+export const processTask = (settings: Settings, task, context: ProcessTaskContext, callback) => {
     const errors: MessagesRoot = { $allMessages: [] };
     const warns: MessagesRoot = { $allMessages: [] };
     const infos: MessagesRoot = { $allMessages: [] };
diff --git a/BuildServer/lib/tasks/dotnetbuilderwrapper.ts b/BuildServer/lib/tasks/dotnetbuilderwrapper.ts
index 77f9cc9..fc9763a 100644
--- a/BuildServer/lib/tasks/dotnetbuilderwrapper.ts
+++ b/BuildServer/lib/tasks/dotnetbuilderwrapper.ts
@@ -1,12 +1,12 @@
 "use strict";
 
-import { spawn } from "child_process";
+import { ChildProcess, spawn } from "child_process";
 import * as JSONParse from "json-parse-safe";
 import { WritableStreamBuffer } from "stream-buffers";
 
 import { Task } from "../types";
 
-const wrapBuilder = (builder, input, onExit) => {
+const wrapBuilder = (builder: ChildProcess, input: string, onExit: (code: number, result: string, builderError: string) => void) => {
     const stdoutPromise = new Promise((resolve, reject) => {
         const streamBuffer = new WritableStreamBuffer();
         builder.stdout
@@ -39,8 +39,8 @@ const wrapBuilder = (builder, input, onExit) => {
 
     Promise.all([stdoutPromise, stderrPromise, builderPromise]).then((values) => {
         const [result, builderError, code] = values;
-        onExit(code, result, builderError);
-    }).catch((err) => onExit(0, undefined, err));
+        onExit(code as number, result as string, builderError as string);
+    }).catch((err) => onExit(0, "", err));
 };
 
 export default ((params, processor) => () => {
diff --git a/BuildServer/lib/tasks/dotnetnugetprocessinternal.ts b/BuildServer/lib/tasks/dotnetnugetprocessinternal.ts
index 9e7929d..ec81bf6 100644
--- a/BuildServer/lib/tasks/dotnetnugetprocessinternal.ts
+++ b/BuildServer/lib/tasks/dotnetnugetprocessinternal.ts
@@ -2,14 +2,14 @@
 
 import { join } from "path";
 
-import { Task } from "../types";
+import { Task, TaskProcessor } from "../types";
 import sequential from "./sequential";
 
 const postfixLength = 16;
 const fourDigits = 10000;
 const twoDigits = 100;
 
-const addPostfix = (version, params, processor) => {
+const addPostfix = (version, params, processor: TaskProcessor) => {
     if (params.withoutCommitSha) {
         return version;
     }
diff --git a/BuildServer/lib/tasks/dotnetrewrite.ts b/BuildServer/lib/tasks/dotnetrewrite.ts
index 3380652..bae6f19 100644
--- a/BuildServer/lib/tasks/dotnetrewrite.ts
+++ b/BuildServer/lib/tasks/dotnetrewrite.ts
@@ -5,18 +5,19 @@ import { readFile, writeFile } from "fs";
 import * as glob from "glob";
 import { join } from "path";
 
-import { Settings, Task } from "../types";
+import { Settings, Task, TaskProcessor } from "../types";
 
 const flagDoneName = "dotnetrewriterDone";
 
-const processAssemblyInfo = (params, processor, appendInformationalVersion) => (originalContent, cb) => {
+const processAssemblyInfo = (params, processor: TaskProcessor, appendInformationalVersion: boolean) => (originalContent, cb) => {
     const processInternalsVisible = (content) => {
-        if (params.skipCodeSigning || processor.settings.xxxskipCodeSigning) {
+        if (processor.settings.skipCodeSigning || params.skipCodeSigning) {
             return content;
         }
 
+        const publicKey = processor.settings.codeSigningPublicKey;
         const pattern = /InternalsVisibleTo\s*\(\s*"([\w.]+)"\s*\)/g;
-        const replacer = (match, p1) => `InternalsVisibleTo("${p1},PublicKey=${processor.settings.codeSigningPublicKey}")`;
+        const replacer = (match, p1) => `InternalsVisibleTo("${p1},PublicKey=${publicKey}")`;
 
         return content.replace(pattern, replacer);
     };
diff --git a/BuildServer/lib/tasks/parallel.ts b/BuildServer/lib/tasks/parallel.ts
index add34db..6923e5a 100644
--- a/BuildServer/lib/tasks/parallel.ts
+++ b/BuildServer/lib/tasks/parallel.ts
@@ -2,8 +2,8 @@
 
 import { parallel } from "async";
 
-import { Task } from "../types";
+import { Task, TaskProcessor } from "../types";
 
-const mapper = (processor) => (task) => (callback) => processor.processTask(task, callback);
+const mapper = (processor: TaskProcessor) => (task) => (callback) => processor.processTask(task, callback);
 
 export default ((params, processor) => () => parallel(params.tasks.map(mapper(processor)), processor.done)) as Task;
diff --git a/BuildServer/lib/tasks/sequential.ts b/BuildServer/lib/tasks/sequential.ts
index 760d25e..7509d8a 100644
--- a/BuildServer/lib/tasks/sequential.ts
+++ b/BuildServer/lib/tasks/sequential.ts
@@ -2,8 +2,8 @@
 
 import { series } from "async";
 
-import { Task } from "../types";
+import { Task, TaskProcessor } from "../types";
 
-const mapper = (processor) => (task) => (callback) => processor.processTask(task, callback);
+const mapper = (processor: TaskProcessor) => (task) => (callback) => processor.processTask(task, callback);
 
 export default ((params, processor) => () => series(params.tasks.map(mapper(processor)), processor.done)) as Task;
diff --git a/BuildServer/lib/types/github-types.ts b/BuildServer/lib/types/github-types.ts
new file mode 100644
index 0000000..870d45e
--- /dev/null
+++ b/BuildServer/lib/types/github-types.ts
@@ -0,0 +1,50 @@
+interface IOwnerInfo {
+    readonly name: string;
+    readonly login: string;
+}
+
+interface IRepositoryInfo {
+    readonly owner: IOwnerInfo;
+    readonly name: string;
+    readonly url: string;
+}
+
+interface ITargetInfo {
+    readonly repo: IRepositoryInfo;
+    readonly ref: string;
+    readonly sha: string;
+}
+
+interface IPullRequestInfo {
+    readonly head: ITargetInfo;
+    readonly base: ITargetInfo;
+    readonly merged: boolean;
+}
+
+export interface IHookPushPayload {
+    readonly repository: IRepositoryInfo;
+    readonly ref: string;
+    readonly after: string;
+}
+
+export interface IHookPullRequestPayload {
+    readonly action: "opened" | "reopened" | "closed" | "synchronize" | "other-unsupported-actions";
+    readonly number: number;
+    readonly pull_request: IPullRequestInfo;
+}
+
+interface IHookPushParameters {
+    readonly eventType: "push";
+    readonly payload: IHookPushPayload;
+}
+
+interface IHookPullRequestParameters {
+    readonly eventType: "pull_request";
+    readonly payload: IHookPullRequestPayload;
+}
+
+interface IHookUnsupportedRequestParameters {
+    readonly eventType: "other-unsupported-events";
+}
+
+export type HookParameters = IHookPushParameters | IHookPullRequestParameters | IHookUnsupportedRequestParameters;
diff --git a/BuildServer/lib/types/index.ts b/BuildServer/lib/types/index.ts
index f1b61d1..fe46036 100644
--- a/BuildServer/lib/types/index.ts
+++ b/BuildServer/lib/types/index.ts
@@ -1,7 +1,12 @@
+import * as GithubTypes from "./github-types";
 import * as ReportTypes from "./report-types";
 import * as SettingsTypes from "./settings-types";
 import * as TaskProcessorTypes from "./task-processor-types";
 
+export type HookPushPayload = GithubTypes.IHookPushPayload;
+export type HookPullRequestPayload = GithubTypes.IHookPullRequestPayload;
+export type HookParameters = GithubTypes.HookParameters;
+
 export type Message = ReportTypes.IMessage;
 export type Messages = ReportTypes.Messages;
 export type MessagesRoot = ReportTypes.MessagesRoot;
@@ -10,6 +15,7 @@ export type ReportResult = ReportTypes.IReportResult;
 
 export type Settings = SettingsTypes.Settings;
 
+export type ProcessTaskContext = TaskProcessorTypes.IProcessTaskContext;
 export type Task = TaskProcessorTypes.Task;
 export type TaskInfo = TaskProcessorTypes.ITaskInfo;
 export type TaskProcessor = TaskProcessorTypes.ITaskProcessor;
diff --git a/BuildServer/lib/types/settings-types.ts b/BuildServer/lib/types/settings-types.ts
index d2d7aa9..ccc4848 100644
--- a/BuildServer/lib/types/settings-types.ts
+++ b/BuildServer/lib/types/settings-types.ts
@@ -1,66 +1,66 @@
 import * as Github from "github";
 
 interface IBuilderSettings {
-    builderExecutable: string;
+    readonly builderExecutable: string;
 }
 
 interface ICodeAnalysisSettingsUnsupported {
-    isCodeAnalysisUnsupported: true;
+    readonly isCodeAnalysisUnsupported: true;
 }
 
 interface ICodeAnalysisSettingsSupported {
-    eslintBrowserConfig: string;
-    ignoreCodeAnalysisByDefault: boolean;
-    isCodeAnalysisUnsupported: false;
+    readonly eslintBrowserConfig: string;
+    readonly ignoreCodeAnalysisByDefault: boolean;
+    readonly isCodeAnalysisUnsupported: false;
 }
 
 type CodeAnalysisSettings = ICodeAnalysisSettingsUnsupported | ICodeAnalysisSettingsSupported;
 
 interface ICodeSigningSettingsUnsupported {
-    skipCodeSigning: true;
+    readonly skipCodeSigning: true;
 }
 
 interface ICodeSigningSettingsSupported {
-    codeSigningKeyFile: string;
-    codeSigningPublicKey: string;
-    skipCodeSigning: false;
+    readonly codeSigningKeyFile: string;
+    readonly codeSigningPublicKey: string;
+    readonly skipCodeSigning: false;
 }
 
 type CodeSigningSettings = ICodeSigningSettingsUnsupported | ICodeSigningSettingsSupported;
 
 interface IStorageSettings {
-    gitpath: string;
-    releasepath: string;
-    tmpcodepath: string;
+    readonly gitpath: string;
+    readonly releasepath: string;
+    readonly tmpcodepath: string;
 }
 
 interface INugetSettings {
-    nugetApiKey: string;
-    nugetHost: string;
+    readonly nugetApiKey: string;
+    readonly nugetHost: string;
 }
 
 interface ISmtpSettings {
-    smtp: {
-        auth: {
-            pass: string;
-            user: string;
+    readonly smtp: {
+        readonly auth: {
+            readonly pass: string;
+            readonly user: string;
         },
-        host: string;
-        receiver: string;
-        sender: string;
+        readonly host: string;
+        readonly receiver: string;
+        readonly sender: string;
     };
 }
 
 interface ISiteSettings {
-    port: number | string;
-    siteRoot: string;
-    viewspath: string;
-    faviconpath: string;
-    staticcontentpath: string;
+    readonly port: number | string;
+    readonly siteRoot: string;
+    readonly viewspath: string;
+    readonly faviconpath: string;
+    readonly staticcontentpath: string;
 }
 
 interface IGithubSettings {
-    createGithub: (repoOwner: string) => Github;
+    readonly createGithub: (repoOwner: string) => Github;
 }
 
 export type Settings = IBuilderSettings & CodeAnalysisSettings & CodeSigningSettings & IStorageSettings & INugetSettings & ISmtpSettings & ISiteSettings & IGithubSettings;
diff --git a/BuildServer/lib/types/task-processor-types.ts b/BuildServer/lib/types/task-processor-types.ts
index 68f744b..223d178 100644
--- a/BuildServer/lib/types/task-processor-types.ts
+++ b/BuildServer/lib/types/task-processor-types.ts
@@ -1,5 +1,20 @@
 import { Settings } from "./settings-types";
 
+export interface IProcessTaskContext {
+    readonly exported: string;
+    readonly release: string;
+    readonly owner: string;
+    readonly reponame: string;
+    readonly branch: string;
+    readonly rev: string;
+    readonly versionInfo: string;
+}
+
+interface ITaskProcessorContext extends IProcessTaskContext {
+    readonly addFlag: (flagName: string) => void;
+    readonly containsFlag: (flagName: string) => boolean;
+}
+
 export type TaskProcessorCallback = (err: string) => void;
 
 export interface ITaskProcessorCore {
@@ -7,7 +22,7 @@ export interface ITaskProcessorCore {
     readonly onWarn: (message: string, prefix?: string) => void;
     readonly onInfo: (message: string, prefix?: string) => void;
     readonly settings: Settings;
-    readonly context?: any;
+    readonly context: ITaskProcessorContext;
 }
 
 export interface ITaskProcessor extends ITaskProcessorCore {
@@ -17,9 +32,9 @@ export interface ITaskProcessor extends ITaskProcessorCore {
 }
 
 export interface ITaskInfo {
-    name?: string;
-    type: string;
-    params: any;
+    readonly name?: string;
+    readonly type: string;
+    readonly params: any;
 }
 
 export type Task = (params: any, processor: ITaskProcessor) => () => void;