diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 55e2c8f..de16c2f 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -39,9 +39,6 @@ jobs:
       - name: Build package
         run: npm run build
 
-      - name: Install Git-Mob (link)
-        run: npm link
-
       - name: Run lint and tests
         run: npm run checks
 
diff --git a/CHANGELOG.md b/CHANGELOG.md
index c8e1e8d..6ce9661 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -2,6 +2,35 @@
 
 Follows [Semantic Versioning](https://semver.org/).
 
+## git-mob-core 0.6.0 current
+
+### Added
+
+```ts
+gitMobConfig = {
+  localTemplate(): <Promise<boolean>>,
+  fetchFromGitHub(): <Promise<boolean>>,
+};
+
+gitConfig = {
+  getLocalCommitTemplate(): <Promise<string>>,
+  getGlobalCommitTemplate(): <Promise<string>>,
+};
+
+gitRevParse = {
+  insideWorkTree(): string,
+  topLevelDirectory(): boolean,
+};
+```
+
+## git-mob 2.5.0 current
+
+### Added
+
+- Integrated git-mob-core for main `git mob` features
+- Reduced the calls to `git` CLI to speed up command execution for `git mob`
+- Convert src git-mob and spec files from JS to TS
+
 ## git-mob-core 0.5.0 10-06-2023
 
 ### Added
diff --git a/package-lock.json b/package-lock.json
index c68a39e..da23d1e 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -1,12 +1,12 @@
 {
   "name": "git-mob-workspace",
-  "version": "2.3.5",
+  "version": "2.4.1",
   "lockfileVersion": 2,
   "requires": true,
   "packages": {
     "": {
       "name": "git-mob-workspace",
-      "version": "2.3.5",
+      "version": "2.4.1",
       "hasInstallScript": true,
       "license": "MIT",
       "workspaces": [
@@ -1778,6 +1778,12 @@
         "@babel/types": "^7.3.0"
       }
     },
+    "node_modules/@types/common-tags": {
+      "version": "1.8.3",
+      "resolved": "https://registry.npmjs.org/@types/common-tags/-/common-tags-1.8.3.tgz",
+      "integrity": "sha512-v3smfzf7umSwpkJrmlUe+apSv6bVnrIFCeBeprnP4f8lIh6pECZxyD50e8yFwfouIt85TdxN5yXiFwS5fnsS3w==",
+      "dev": true
+    },
     "node_modules/@types/eslint": {
       "version": "7.29.0",
       "resolved": "https://registry.npmjs.org/@types/eslint/-/eslint-7.29.0.tgz",
@@ -11285,7 +11291,7 @@
       }
     },
     "packages/bob": {
-      "version": "1.1.0",
+      "version": "1.0.0",
       "license": "ISC",
       "dependencies": {
         "esbuild": "^0.17.4",
@@ -11368,7 +11374,7 @@
       "license": "MIT",
       "dependencies": {
         "common-tags": "^1.8.0",
-        "git-mob-core": "^0.3.0",
+        "git-mob-core": "^0.5.0",
         "minimist": "^1.2.6",
         "update-notifier": "^5.1.0"
       },
@@ -11383,6 +11389,7 @@
       },
       "devDependencies": {
         "@ava/typescript": "^3.0.1",
+        "@types/common-tags": "^1.8.3",
         "@types/node": "^18.7.14",
         "@types/sinon": "^10.0.13",
         "ava": "^5.0.1",
@@ -11399,7 +11406,7 @@
       }
     },
     "packages/git-mob-core": {
-      "version": "0.4.0",
+      "version": "0.5.0",
       "license": "MIT",
       "devDependencies": {
         "@types/jest": "^29.5.0",
@@ -12744,6 +12751,12 @@
         "@babel/types": "^7.3.0"
       }
     },
+    "@types/common-tags": {
+      "version": "1.8.3",
+      "resolved": "https://registry.npmjs.org/@types/common-tags/-/common-tags-1.8.3.tgz",
+      "integrity": "sha512-v3smfzf7umSwpkJrmlUe+apSv6bVnrIFCeBeprnP4f8lIh6pECZxyD50e8yFwfouIt85TdxN5yXiFwS5fnsS3w==",
+      "dev": true
+    },
     "@types/eslint": {
       "version": "7.29.0",
       "resolved": "https://registry.npmjs.org/@types/eslint/-/eslint-7.29.0.tgz",
@@ -15436,6 +15449,7 @@
       "version": "file:packages/git-mob",
       "requires": {
         "@ava/typescript": "^3.0.1",
+        "@types/common-tags": "*",
         "@types/node": "^18.7.14",
         "@types/sinon": "^10.0.13",
         "ava": "^5.0.1",
@@ -15443,7 +15457,7 @@
         "common-tags": "^1.8.0",
         "env-cmd": "^10.1.0",
         "eol": "^0.9.1",
-        "git-mob-core": "^0.3.0",
+        "git-mob-core": "^0.5.0",
         "minimist": "^1.2.6",
         "rimraf": "^3.0.2",
         "sinon": "^14.0.0",
diff --git a/packages/bob/git-mob.config.js b/packages/bob/git-mob.config.js
index 92a4ed7..daf48c2 100644
--- a/packages/bob/git-mob.config.js
+++ b/packages/bob/git-mob.config.js
@@ -2,7 +2,7 @@ const glob = require('glob');
 
 const baseConfig = {
   entryPoints: [
-    './src/git-mob.js',
+    './src/git-mob.ts',
     './src/solo.js',
     './src/git-add-coauthor.ts',
     './src/git-delete-coauthor.js',
diff --git a/packages/git-mob-core/README.md b/packages/git-mob-core/README.md
index fdeb897..f6ba612 100644
--- a/packages/git-mob-core/README.md
+++ b/packages/git-mob-core/README.md
@@ -15,22 +15,38 @@ npm i git-mob-core
 ```TS
 saveNewCoAuthors(authors): <Promise<Author[]>>
 getAllAuthors(): <Promise<Author[]>>
-getPrimaryAuthor(): Author | null
+getPrimaryAuthor(): Author | undefined
 getSelectedCoAuthors(allAuthors): Author[]
 setCoAuthors(keys): <Promise<Author[]>>
 setPrimaryAuthor(author): void
-solo(): void
+solo(): <Promise<void>>
 updateGitTemplate(selectedAuthors): void
 fetchGitHubAuthors(userNames: string[], userAgent: string): <Promise<Author[]>>
 pathToCoAuthors(): string
 getConfig(prop: string): string | undefined
 updateConfig(prop: string, value: string): void
+gitMobConfig = {
+  localTemplate(): <Promise<boolean>>,
+  fetchFromGitHub(): <Promise<boolean>>,
+};
+
+gitConfig = {
+  getLocalCommitTemplate(): <Promise<string>>,
+  getGlobalCommitTemplate(): <Promise<string>>,
+};
+
+gitRevParse = {
+  insideWorkTree(): string,
+  topLevelDirectory(): boolean,
+};
 class Author
 ```
 
 ## Author class
 
 ```TS
+class Author;
+
 // Properties
 Author.key: string
 Author.name: string
diff --git a/packages/git-mob-core/package.json b/packages/git-mob-core/package.json
index 7997e7c..f5bde73 100644
--- a/packages/git-mob-core/package.json
+++ b/packages/git-mob-core/package.json
@@ -2,6 +2,7 @@
   "name": "git-mob-core",
   "version": "0.5.0",
   "description": "Core Git Mob library to manage co-authoring",
+  "homepage": "https://github.com/rkotze/git-mob/blob/master/packages/git-mob-core/README.md",
   "main": "./dist/index.js",
   "types": "./dist/index.d.ts",
   "scripts": {
diff --git a/packages/git-mob-core/src/commands.js b/packages/git-mob-core/src/commands.js
index 402d1e3..3cb44e6 100644
--- a/packages/git-mob-core/src/commands.js
+++ b/packages/git-mob-core/src/commands.js
@@ -1,26 +1,5 @@
-const { exec } = require('child_process');
-const { promisify } = require('util');
 const { silentRun } = require('./silent-run');
-const { getConfig } = require('./config-manager');
-
-/**
- * Runs the given command in a shell.
- * @param {string} command The command to execute
- * @returns {Promise} stdout string
- */
-async function silentExec(command) {
-  const execAsync = promisify(exec);
-  try {
-    const cmdConfig = {};
-    const processCwd = getConfig('processCwd');
-    if (processCwd) cmdConfig.cwd = processCwd;
-    const response = await execAsync(command, cmdOptions(cmdConfig));
-
-    return response.stdout;
-  } catch (error) {
-    return `GitMob silentExec: "${command}" ${error.message}`;
-  }
-}
+const { execCommand } = require('./git-mob-api/exec-command');
 
 function handleResponse(query) {
   try {
@@ -77,20 +56,13 @@ function gitAddCoAuthor(coAuthor) {
 }
 
 async function getRepoAuthors() {
-  return silentExec(`git shortlog -sen HEAD`);
+  return execCommand('git shortlog -sen HEAD');
 }
 
 function removeGitMobSection() {
   return silentRun(`git config --global --remove-section git-mob`);
 }
 
-function cmdOptions(extendOptions = {}) {
-  return {
-    ...extendOptions,
-    encoding: 'utf8',
-  };
-}
-
 module.exports = {
   config: {
     getAll,
diff --git a/packages/git-mob-core/src/git-mob-api/errors/author-not-found.ts b/packages/git-mob-core/src/git-mob-api/errors/author-not-found.ts
new file mode 100644
index 0000000..65ad55f
--- /dev/null
+++ b/packages/git-mob-core/src/git-mob-api/errors/author-not-found.ts
@@ -0,0 +1,5 @@
+export class AuthorNotFound extends Error {
+  constructor(initials: string) {
+    super(`Author with initials "${initials}" not found!`);
+  }
+}
diff --git a/packages/git-mob-core/src/git-mob-api/exec-command.ts b/packages/git-mob-core/src/git-mob-api/exec-command.ts
new file mode 100644
index 0000000..b947bae
--- /dev/null
+++ b/packages/git-mob-core/src/git-mob-api/exec-command.ts
@@ -0,0 +1,39 @@
+import { exec } from 'node:child_process';
+import { promisify } from 'node:util';
+import { getConfig as cmGetConfig } from '../config-manager';
+
+type ExecCommandOptions = {
+  encoding: string;
+  cwd?: string;
+};
+
+// Runs the given command in a shell.
+export async function execCommand(command: string): Promise<string> {
+  const cmdConfig: ExecCommandOptions = { encoding: 'utf8' };
+  const processCwd = cmGetConfig('processCwd');
+  if (processCwd) cmdConfig.cwd = processCwd;
+  const execAsync = promisify(exec);
+  const { stderr, stdout } = await execAsync(command, cmdConfig);
+
+  if (stderr) {
+    throw new Error(`GitMob execCommand: "${command}" ${stderr.trim()}`);
+  }
+
+  return stdout.trim();
+}
+
+export async function getConfig(key: string) {
+  try {
+    return await execCommand(`git config --get ${key}`);
+  } catch {
+    return undefined;
+  }
+}
+
+export async function getAllConfig(key: string) {
+  try {
+    return await execCommand(`git config --get-all ${key}`);
+  } catch {
+    return undefined;
+  }
+}
diff --git a/packages/git-mob-core/src/git-mob-api/git-authors/fetch-github-authors.spec.ts b/packages/git-mob-core/src/git-mob-api/git-authors/fetch-github-authors.spec.ts
index 2271631..e18ee72 100644
--- a/packages/git-mob-core/src/git-mob-api/git-authors/fetch-github-authors.spec.ts
+++ b/packages/git-mob-core/src/git-mob-api/git-authors/fetch-github-authors.spec.ts
@@ -9,6 +9,7 @@ const ghRkotzeResponse = {
   id: 123,
   login: 'rkotze',
   name: 'Richard Kotze',
+  stars: 2,
 };
 
 const ghDidelerResponse = {
@@ -83,6 +84,26 @@ test('Query for two GitHub users and build AuthorList', async () => {
   ]);
 });
 
+test('Handle GitHub user with no name', async () => {
+  mockedFetch.mockResolvedValue(
+    buildBasicResponse({
+      id: 329,
+      name: null,
+      login: 'kotze',
+    })
+  );
+
+  const actualAuthorList = await fetchGitHubAuthors(['kotze'], agentHeader);
+
+  expect(actualAuthorList).toEqual([
+    {
+      key: 'kotze',
+      name: 'kotze',
+      email: '329+kotze@users.noreply.github.com',
+    },
+  ]);
+});
+
 test('Error if no user agent specified', async () => {
   await expect(fetchGitHubAuthors(['badrequestuser'], '')).rejects.toThrow(
     /Error no user-agent header string given./
diff --git a/packages/git-mob-core/src/git-mob-api/git-authors/fetch-github-authors.ts b/packages/git-mob-core/src/git-mob-api/git-authors/fetch-github-authors.ts
index 1a473b7..16b98a7 100644
--- a/packages/git-mob-core/src/git-mob-api/git-authors/fetch-github-authors.ts
+++ b/packages/git-mob-core/src/git-mob-api/git-authors/fetch-github-authors.ts
@@ -14,7 +14,7 @@ const getHeaders: RequestOptions = {
 type GitHubUser = {
   id: number;
   login: string;
-  name: string;
+  name?: string;
 };
 
 function validateGhUser(o: any): o is GitHubUser {
@@ -49,7 +49,7 @@ async function fetchGitHubAuthors(
     if (validateGhUser(ghUser.data)) {
       const { login, id, name } = ghUser.data;
       authorAuthorList.push(
-        new Author(login, name, `${id}+${login}@users.noreply.github.com`)
+        new Author(login, name || login, `${id}+${login}@users.noreply.github.com`)
       );
     }
   }
diff --git a/packages/git-mob-core/src/git-mob-api/git-authors/index.js b/packages/git-mob-core/src/git-mob-api/git-authors/index.js
index 98502a4..7473881 100644
--- a/packages/git-mob-core/src/git-mob-api/git-authors/index.js
+++ b/packages/git-mob-core/src/git-mob-api/git-authors/index.js
@@ -3,7 +3,7 @@ const os = require('os');
 const path = require('path');
 const { promisify } = require('util');
 const { Author } = require('../author');
-const { topLevelDirectory } = require('../../git-rev-parse');
+const { topLevelDirectory } = require('../git-rev-parse');
 
 function gitAuthors(readFilePromise, writeFilePromise, overwriteFilePromise) {
   async function readFile(path) {
diff --git a/packages/git-mob-core/src/git-mob-api/git-authors/index.spec.js b/packages/git-mob-core/src/git-mob-api/git-authors/index.spec.js
index 73c1ab4..f3a549c 100644
--- a/packages/git-mob-core/src/git-mob-api/git-authors/index.spec.js
+++ b/packages/git-mob-core/src/git-mob-api/git-authors/index.spec.js
@@ -1,7 +1,7 @@
 const path = require('path');
 const fs = require('fs');
 const { Author } = require('../author');
-const { topLevelDirectory } = require('../../git-rev-parse');
+const { topLevelDirectory } = require('../git-rev-parse');
 const { gitAuthors, pathToCoAuthors } = require('.');
 
 const validJsonString = `
diff --git a/packages/git-mob-core/src/git-mob-api/git-config.ts b/packages/git-mob-core/src/git-mob-api/git-config.ts
new file mode 100644
index 0000000..58f25ba
--- /dev/null
+++ b/packages/git-mob-core/src/git-mob-api/git-config.ts
@@ -0,0 +1,9 @@
+import { getConfig } from './exec-command';
+
+export async function getLocalCommitTemplate() {
+  return getConfig('--local commit.template');
+}
+
+export async function getGlobalCommitTemplate() {
+  return getConfig('--global commit.template');
+}
diff --git a/packages/git-mob-core/src/git-mob-api/git-mob-config.ts b/packages/git-mob-core/src/git-mob-api/git-mob-config.ts
new file mode 100644
index 0000000..027f63c
--- /dev/null
+++ b/packages/git-mob-core/src/git-mob-api/git-mob-config.ts
@@ -0,0 +1,15 @@
+import { getConfig, getAllConfig } from './exec-command';
+
+export async function localTemplate() {
+  const localTemplate = await getConfig('--local git-mob-config.use-local-template');
+  return localTemplate === 'true';
+}
+
+export async function fetchFromGitHub() {
+  const githubFetch = await getConfig('--global git-mob-config.github-fetch');
+  return githubFetch === 'true';
+}
+
+export async function getSetCoAuthors() {
+  return getAllConfig('--global git-mob.co-author');
+}
diff --git a/packages/git-mob-core/src/git-rev-parse.js b/packages/git-mob-core/src/git-mob-api/git-rev-parse.ts
similarity index 64%
rename from packages/git-mob-core/src/git-rev-parse.js
rename to packages/git-mob-core/src/git-mob-api/git-rev-parse.ts
index 5db5186..ab5deb0 100644
--- a/packages/git-mob-core/src/git-rev-parse.js
+++ b/packages/git-mob-core/src/git-mob-api/git-rev-parse.ts
@@ -1,11 +1,12 @@
-const { silentRun } = require('./silent-run');
+import { silentRun } from '../silent-run';
 
 /**
  * Computes the path to the top-level directory of the git repository.
  * @returns {string} Path to the top-level directory of the git repository.
  */
-function topLevelDirectory() {
-  return silentRun('git rev-parse --show-toplevel').stdout.trim();
+function topLevelDirectory(): string {
+  const { stdout } = silentRun('git rev-parse --show-toplevel');
+  return stdout.toString().trim();
 }
 
 /**
@@ -16,7 +17,4 @@ function insideWorkTree() {
   return silentRun('git rev-parse --is-inside-work-tree').status === 0;
 }
 
-module.exports = {
-  topLevelDirectory,
-  insideWorkTree,
-};
+export { topLevelDirectory, insideWorkTree };
diff --git a/packages/git-mob-core/src/git-mob-api/resolve-git-message-path.js b/packages/git-mob-core/src/git-mob-api/resolve-git-message-path.js
index 50436e8..160fce3 100644
--- a/packages/git-mob-core/src/git-mob-api/resolve-git-message-path.js
+++ b/packages/git-mob-core/src/git-mob-api/resolve-git-message-path.js
@@ -2,7 +2,7 @@ const path = require('path');
 const os = require('os');
 
 const { config } = require('../commands');
-const { topLevelDirectory } = require('../git-rev-parse');
+const { topLevelDirectory } = require('./git-rev-parse');
 
 function setCommitTemplate() {
   if (!config.has('commit.template')) {
diff --git a/packages/git-mob-core/src/index.spec.ts b/packages/git-mob-core/src/index.spec.ts
index d64c34a..44215b0 100644
--- a/packages/git-mob-core/src/index.spec.ts
+++ b/packages/git-mob-core/src/index.spec.ts
@@ -2,16 +2,24 @@ import { mob } from './commands';
 import { Author } from './git-mob-api/author';
 import { gitAuthors } from './git-mob-api/git-authors';
 import { gitMessage } from './git-mob-api/git-message';
+import { AuthorNotFound } from './git-mob-api/errors/author-not-found';
+import {
+  getGlobalCommitTemplate,
+  getLocalCommitTemplate,
+} from './git-mob-api/git-config';
 import { setCoAuthors, updateGitTemplate } from '.';
 
 jest.mock('./commands');
 jest.mock('./git-mob-api/git-authors');
 jest.mock('./git-mob-api/git-message');
 jest.mock('./git-mob-api/resolve-git-message-path');
+jest.mock('./git-mob-api/git-config');
 
 const mockedGitAuthors = jest.mocked(gitAuthors);
 const mockedGitMessage = jest.mocked(gitMessage);
 const mockedMob = jest.mocked(mob);
+const mockedGetGlobalCommitTemplate = jest.mocked(getGlobalCommitTemplate);
+const mockedGetLocalCommitTemplate = jest.mocked(getLocalCommitTemplate);
 
 describe('Git Mob API', () => {
   function buildAuthors(keys: string[]) {
@@ -33,8 +41,28 @@ describe('Git Mob API', () => {
   }
 
   afterEach(() => {
-    mockedMob.usingLocalTemplate.mockReset();
-    mockedMob.usingGlobalTemplate.mockReset();
+    mockedMob.removeGitMobSection.mockReset();
+    mockedGetGlobalCommitTemplate.mockReset();
+    mockedGetLocalCommitTemplate.mockReset();
+  });
+
+  it('missing author to pick for list throws error', async () => {
+    const authorKeys = ['ab', 'cd'];
+    const mockWriteCoAuthors = jest.fn(async () => undefined);
+    const mockRemoveCoAuthors = jest.fn(async () => '');
+    mockedGitAuthors.mockReturnValue(buildMockGitAuthors([...authorKeys, 'ef']));
+
+    mockedGitMessage.mockReturnValue({
+      writeCoAuthors: mockWriteCoAuthors,
+      readCoAuthors: () => '',
+      removeCoAuthors: mockRemoveCoAuthors,
+    });
+
+    await expect(async () => {
+      await setCoAuthors([...authorKeys, 'rk']);
+    }).rejects.toThrow(AuthorNotFound);
+
+    expect(mob.removeGitMobSection).not.toHaveBeenCalled();
   });
 
   it('apply co-authors to git config and git message', async () => {
@@ -82,7 +110,7 @@ describe('Git Mob API', () => {
     const mockWriteCoAuthors = jest.fn();
     const mockRemoveCoAuthors = jest.fn();
 
-    mockedMob.usingLocalTemplate.mockReturnValue(true);
+    mockedGetLocalCommitTemplate.mockResolvedValueOnce('template/path');
     mockedGitMessage.mockReturnValue({
       writeCoAuthors: mockWriteCoAuthors,
       readCoAuthors: () => '',
@@ -91,8 +119,8 @@ describe('Git Mob API', () => {
 
     await updateGitTemplate(authorList);
 
-    expect(mockedMob.usingLocalTemplate).toBeCalledTimes(1);
-    expect(mockedMob.getGlobalTemplate).toBeCalledTimes(1);
+    expect(mockedGetLocalCommitTemplate).toBeCalledTimes(1);
+    expect(mockedGetGlobalCommitTemplate).toBeCalledTimes(1);
     expect(mockWriteCoAuthors).toBeCalledTimes(2);
     expect(mockWriteCoAuthors).toBeCalledWith(authorList);
     expect(mockRemoveCoAuthors).not.toHaveBeenCalled();
diff --git a/packages/git-mob-core/src/index.ts b/packages/git-mob-core/src/index.ts
index 37f4ad1..f824801 100644
--- a/packages/git-mob-core/src/index.ts
+++ b/packages/git-mob-core/src/index.ts
@@ -1,20 +1,33 @@
 import { mob, config } from './commands';
 import { Author } from './git-mob-api/author';
+import { AuthorNotFound } from './git-mob-api/errors/author-not-found';
 import { gitAuthors } from './git-mob-api/git-authors';
 import { gitMessage } from './git-mob-api/git-message';
+import {
+  localTemplate,
+  fetchFromGitHub,
+  getSetCoAuthors,
+} from './git-mob-api/git-mob-config';
+import {
+  getLocalCommitTemplate,
+  getGlobalCommitTemplate,
+} from './git-mob-api/git-config';
 import {
   resolveGitMessagePath,
   setCommitTemplate,
 } from './git-mob-api/resolve-git-message-path';
+import { insideWorkTree, topLevelDirectory } from './git-mob-api/git-rev-parse';
+import { getConfig } from './git-mob-api/exec-command';
 
 async function getAllAuthors() {
   const gitMobAuthors = gitAuthors();
   return gitMobAuthors.toList(await gitMobAuthors.read());
 }
 
-async function setCoAuthors(keys: string[]) {
-  await solo();
+async function setCoAuthors(keys: string[]): Promise<Author[]> {
   const selectedAuthors = pickSelectedAuthors(keys, await getAllAuthors());
+  await solo();
+
   for (const author of selectedAuthors) {
     mob.gitAddCoAuthor(author.toString());
   }
@@ -24,28 +37,40 @@ async function setCoAuthors(keys: string[]) {
 }
 
 async function updateGitTemplate(selectedAuthors?: Author[]) {
-  const usingLocal = mob.usingLocalTemplate();
-  const gitTemplate = gitMessage(
-    resolveGitMessagePath(config.get('commit.template'))
-  );
+  const [usingLocal, templatePath] = await Promise.all([
+    getLocalCommitTemplate(),
+    getConfig('commit.template'),
+  ]);
+
+  const gitTemplate = gitMessage(resolveGitMessagePath(templatePath));
 
   if (selectedAuthors && selectedAuthors.length > 0) {
     if (usingLocal) {
-      await gitMessage(mob.getGlobalTemplate()).writeCoAuthors(selectedAuthors);
+      await gitMessage(await getGlobalCommitTemplate()).writeCoAuthors(
+        selectedAuthors
+      );
     }
 
     return gitTemplate.writeCoAuthors(selectedAuthors);
   }
 
   if (usingLocal) {
-    await gitMessage(mob.getGlobalTemplate()).removeCoAuthors();
+    await gitMessage(await getGlobalCommitTemplate()).removeCoAuthors();
   }
 
   return gitTemplate.removeCoAuthors();
 }
 
 function pickSelectedAuthors(keys: string[], authorMap: Author[]): Author[] {
-  return authorMap.filter(author => keys.includes(author.key));
+  const selectedAuthors = [];
+  for (const key of keys) {
+    const author = authorMap.find(author => author.key === key);
+
+    if (!author) throw new AuthorNotFound(key);
+    selectedAuthors.push(author);
+  }
+
+  return selectedAuthors;
 }
 
 function getSelectedCoAuthors(allAuthors: Author[]) {
@@ -71,8 +96,6 @@ function getPrimaryAuthor() {
   if (name && email) {
     return new Author('prime', name, email);
   }
-
-  return null;
 }
 
 function setPrimaryAuthor(author: Author): void {
@@ -92,6 +115,22 @@ export {
   updateGitTemplate,
 };
 
+export const gitMobConfig = {
+  localTemplate,
+  fetchFromGitHub,
+  getSetCoAuthors,
+};
+
+export const gitConfig = {
+  getLocalCommitTemplate,
+  getGlobalCommitTemplate,
+};
+
+export const gitRevParse = {
+  insideWorkTree,
+  topLevelDirectory,
+};
+
 export { saveNewCoAuthors } from './git-mob-api/manage-authors/add-new-coauthor';
 export { pathToCoAuthors } from './git-mob-api/git-authors';
 export { fetchGitHubAuthors } from './git-mob-api/git-authors/fetch-github-authors';
diff --git a/packages/git-mob-core/src/silent-run.js b/packages/git-mob-core/src/silent-run.js
index b6372af..ef9bdc4 100644
--- a/packages/git-mob-core/src/silent-run.js
+++ b/packages/git-mob-core/src/silent-run.js
@@ -17,17 +17,10 @@ const { getConfig } = require('./config-manager');
  * @returns {ChildProcess.SpawnResult} object from child_process.spawnSync
  */
 function silentRun(command) {
-  const cmdConfig = { shell: true };
+  const cmdConfig = { shell: true, encoding: 'utf8' };
   const processCwd = getConfig('processCwd');
   if (processCwd) cmdConfig.cwd = processCwd;
-  return spawnSync(command, cmdOptions(cmdConfig));
-}
-
-function cmdOptions(extendOptions = {}) {
-  return {
-    ...extendOptions,
-    encoding: 'utf8',
-  };
+  return spawnSync(command, cmdConfig);
 }
 
 exports.silentRun = silentRun;
diff --git a/packages/git-mob/package.json b/packages/git-mob/package.json
index 9b4f90e..6d74d0d 100644
--- a/packages/git-mob/package.json
+++ b/packages/git-mob/package.json
@@ -2,6 +2,7 @@
   "name": "git-mob",
   "version": "2.4.0",
   "description": "CLI tool for adding co-authors to commits.",
+  "homepage": "https://github.com/rkotze/git-mob/blob/master/packages/git-mob/README.md",
   "scripts": {
     "build": "rimraf dist && bob",
     "test:w": "npm run build -- -w -t & env-cmd -f test-helpers/env.js ava --watch --serial --no-worker-threads",
@@ -61,12 +62,13 @@
   ],
   "dependencies": {
     "common-tags": "^1.8.0",
-    "git-mob-core": "^0.4.0",
+    "git-mob-core": "^0.5.0",
     "minimist": "^1.2.6",
     "update-notifier": "^5.1.0"
   },
   "devDependencies": {
     "@ava/typescript": "^3.0.1",
+    "@types/common-tags": "^1.8.3",
     "@types/node": "^18.7.14",
     "@types/sinon": "^10.0.13",
     "ava": "^5.0.1",
diff --git a/packages/git-mob/src/check-author.spec.js b/packages/git-mob/src/check-author.spec.ts
similarity index 71%
rename from packages/git-mob/src/check-author.spec.js
rename to packages/git-mob/src/check-author.spec.ts
index 9df3bf5..3f7015b 100644
--- a/packages/git-mob/src/check-author.spec.js
+++ b/packages/git-mob/src/check-author.spec.ts
@@ -1,15 +1,18 @@
 import os from 'node:os';
 import test from 'ava';
-
+import type { Author } from 'git-mob-core';
 import { configWarning } from './check-author';
 
 test('does not print warning when config present', t => {
-  const actual = configWarning({ name: 'John Doe', email: 'jdoe@example.com' });
-  t.is(actual, undefined);
+  const actual = configWarning({
+    name: 'John Doe',
+    email: 'jdoe@example.com',
+  } as Author);
+  t.is(actual, '');
 });
 
 test('prints warning and missing config when one argument is missing', t => {
-  const actual = configWarning({ name: 'John Doe', email: '' });
+  const actual = configWarning({ name: 'John Doe', email: '' } as Author);
   const expected =
     'Warning: Missing information for the primary author. Set with:' +
     os.EOL +
@@ -18,7 +21,7 @@ test('prints warning and missing config when one argument is missing', t => {
 });
 
 test('prints warning and missing config when both arguments are missing', t => {
-  const actual = configWarning({ name: '', email: '' });
+  const actual = configWarning({ name: '', email: '' } as Author);
   const expected =
     'Warning: Missing information for the primary author. Set with:' +
     os.EOL +
diff --git a/packages/git-mob/src/check-author.js b/packages/git-mob/src/check-author.ts
similarity index 77%
rename from packages/git-mob/src/check-author.js
rename to packages/git-mob/src/check-author.ts
index fbfbc86..ba0fd38 100644
--- a/packages/git-mob/src/check-author.js
+++ b/packages/git-mob/src/check-author.ts
@@ -1,7 +1,8 @@
 import os from 'node:os';
+import type { Author } from 'git-mob-core';
 
-function configWarning({ name, email }) {
-  let result;
+function configWarning({ name, email }: Author) {
+  let result = '';
   if (name === '' || email === '') {
     result = 'Warning: Missing information for the primary author. Set with:';
   }
diff --git a/packages/git-mob/src/git-authors/author-base-format.ts b/packages/git-mob/src/git-authors/author-base-format.ts
index 1d2dfe2..c528d5c 100644
--- a/packages/git-mob/src/git-authors/author-base-format.ts
+++ b/packages/git-mob/src/git-authors/author-base-format.ts
@@ -1,3 +1,5 @@
+import type { Author } from 'git-mob-core';
+
 export function authorBaseFormat({ name, email }: Author): string {
   return `${name} <${email}>`;
 }
diff --git a/packages/git-mob/src/git-authors/compose-authors.ts b/packages/git-mob/src/git-authors/compose-authors.ts
deleted file mode 100644
index 55e01be..0000000
--- a/packages/git-mob/src/git-authors/compose-authors.ts
+++ /dev/null
@@ -1,67 +0,0 @@
-import type { Author } from 'git-mob-core';
-import { fetchGitHubAuthors } from 'git-mob-core';
-import { saveAuthorList } from '../manage-authors/add-coauthor';
-import { mobConfig } from '../git-mob-commands';
-import { authorBaseFormat } from './author-base-format';
-
-async function composeAuthors(
-  initials: string[],
-  coAuthorList: AuthorList,
-  getAuthors = fetchGitHubAuthors,
-  saveAuthors = saveAuthorList
-): Promise<string[]> {
-  const missing = findMissingAuthors(initials, coAuthorList);
-  if (missing.length > 0 && mobConfig.fetchFromGitHub()) {
-    const fetchedAuthors = await getAuthors(missing, 'git-mob-cli');
-    const gitMobList = {
-      coauthors: { ...coAuthorList, ...transformToAuthorList(fetchedAuthors) },
-    };
-    await saveAuthors(gitMobList);
-    return buildFormatAuthorList(initials, gitMobList.coauthors);
-  }
-
-  return buildFormatAuthorList(initials, coAuthorList);
-}
-
-function findMissingAuthors(
-  initialList: string[],
-  coAuthorList: AuthorList
-): string[] {
-  return initialList.filter(initials => !containsAuthor(initials, coAuthorList));
-}
-
-function containsAuthor(initials: string, coauthors: AuthorList): boolean {
-  return initials in coauthors;
-}
-
-function transformToAuthorList(authors: Author[]): AuthorList {
-  const authorList: AuthorList = {};
-
-  for (const author of authors) {
-    authorList[author.key] = {
-      name: author.name,
-      email: author.email,
-    };
-  }
-
-  return authorList;
-}
-
-function buildFormatAuthorList(
-  initialsList: string[],
-  coAuthorList: AuthorList
-): string[] {
-  return initialsList.map(initials => {
-    if (!containsAuthor(initials, coAuthorList)) {
-      noAuthorFoundError(initials);
-    }
-
-    return authorBaseFormat(coAuthorList[initials]);
-  });
-}
-
-function noAuthorFoundError(initials: string): Error {
-  throw new Error(`Author with initials "${initials}" not found!`);
-}
-
-export { findMissingAuthors, composeAuthors };
diff --git a/packages/git-mob/src/git-authors/compose-authors.spec.ts b/packages/git-mob/src/git-authors/save-missing-authors.spec.ts
similarity index 51%
rename from packages/git-mob/src/git-authors/compose-authors.spec.ts
rename to packages/git-mob/src/git-authors/save-missing-authors.spec.ts
index 5dadb7b..1e71346 100644
--- a/packages/git-mob/src/git-authors/compose-authors.spec.ts
+++ b/packages/git-mob/src/git-authors/save-missing-authors.spec.ts
@@ -1,33 +1,18 @@
 import test from 'ava';
 import type { SinonSandbox, SinonStub } from 'sinon';
 import { createSandbox, assert } from 'sinon';
+import { Author } from 'git-mob-core';
 import { mobConfig } from '../git-mob-commands';
-import { composeAuthors, findMissingAuthors } from './compose-authors';
-
-const authorsJson = {
-  coauthors: {
-    jd: {
-      name: 'Jane Doe',
-      email: 'jane@findmypast.com',
-    },
-    fb: {
-      name: 'Frances Bar',
-      email: 'frances-bar@findmypast.com',
-    },
-  },
-};
+import { saveMissingAuthors, findMissingAuthors } from './save-missing-authors';
+
+const savedAuthors = [
+  new Author('jd', 'Jane Doe', 'jane@findmypast.com'),
+  new Author('fb', 'Frances Bar', 'frances-bar@findmypast.com'),
+];
 
 const gitHubAuthors = [
-  {
-    key: 'rkotze',
-    name: 'Richard',
-    email: 'rich@gitmob.com',
-  },
-  {
-    key: 'dideler',
-    name: 'Denis',
-    email: 'denis@gitmob.com',
-  },
+  new Author('rkotze', 'Richard', 'rich@gitmob.com'),
+  new Author('dideler', 'Denis', 'denis@gitmob.com'),
 ];
 
 let sandbox: SinonSandbox;
@@ -42,16 +27,31 @@ test.afterEach(() => {
   sandbox.restore();
 });
 
+test('Search from GitHub not enabled', async t => {
+  const fetchAuthorsStub = sandbox.stub().resolves(gitHubAuthors);
+  sandbox.stub(mobConfig, 'fetchFromGitHub').returns(false);
+
+  t.deepEqual(
+    await saveMissingAuthors(
+      ['rkotze', 'dideler', 'jd'],
+      savedAuthors,
+      fetchAuthorsStub,
+      saveCoauthorStub
+    ),
+    []
+  );
+});
+
 test('Find missing author initials "rkotze" and "dideler" to an array', t => {
   const missingCoAuthor = findMissingAuthors(
     ['rkotze', 'dideler', 'jd'],
-    authorsJson.coauthors
+    savedAuthors
   );
   t.deepEqual(missingCoAuthor, ['rkotze', 'dideler']);
 });
 
 test('No missing author initials', t => {
-  const missingCoAuthor = findMissingAuthors(['jd', 'fb'], authorsJson.coauthors);
+  const missingCoAuthor = findMissingAuthors(['jd', 'fb'], savedAuthors);
   t.deepEqual(missingCoAuthor, []);
 });
 
@@ -59,9 +59,9 @@ test('Search GitHub for missing co-authors', async t => {
   const fetchAuthorsStub = sandbox.stub().resolves(gitHubAuthors);
   sandbox.stub(mobConfig, 'fetchFromGitHub').returns(true);
 
-  await composeAuthors(
+  await saveMissingAuthors(
     ['rkotze', 'dideler', 'jd'],
-    authorsJson.coauthors,
+    savedAuthors,
     fetchAuthorsStub,
     saveCoauthorStub
   );
@@ -74,9 +74,9 @@ test('Create author list from GitHub and co-author file', async t => {
   const fetchAuthorsStub = sandbox.stub().resolves(gitHubAuthors);
   sandbox.stub(mobConfig, 'fetchFromGitHub').returns(true);
 
-  const authorList = await composeAuthors(
+  const authorList = await saveMissingAuthors(
     ['rkotze', 'dideler', 'jd'],
-    authorsJson.coauthors,
+    savedAuthors,
     fetchAuthorsStub,
     saveCoauthorStub
   );
@@ -84,84 +84,35 @@ test('Create author list from GitHub and co-author file', async t => {
   const expectedAuthorList = [
     'Richard <rich@gitmob.com>',
     'Denis <denis@gitmob.com>',
-    'Jane Doe <jane@findmypast.com>',
   ];
 
   t.deepEqual(authorList, expectedAuthorList);
 });
 
 test('Save missing co-author', async t => {
-  const rkotzeAuthor = [
-    {
-      key: 'rkotze',
-      name: 'Richard',
-      email: 'rich@gitmob.com',
-    },
-  ];
+  const rkotzeAuthor = [new Author('rkotze', 'Richard', 'rich@gitmob.com')];
   const fetchAuthorsStub = sandbox.stub().resolves(rkotzeAuthor);
   sandbox.stub(mobConfig, 'fetchFromGitHub').returns(true);
 
-  await composeAuthors(
+  await saveMissingAuthors(
     ['rkotze', 'jd'],
-    authorsJson.coauthors,
+    savedAuthors,
     fetchAuthorsStub,
     saveCoauthorStub
   );
 
-  const rkotzeAuthorList = {
-    rkotze: {
-      name: 'Richard',
-      email: 'rich@gitmob.com',
-    },
-  };
+  const rkotzeAuthorList = [new Author('rkotze', 'Richard', 'rich@gitmob.com')];
 
   t.notThrows(() => {
-    assert.calledWith(saveCoauthorStub, {
-      coauthors: {
-        ...authorsJson.coauthors,
-        ...rkotzeAuthorList,
-      },
-    });
+    assert.calledWith(saveCoauthorStub, rkotzeAuthorList);
   }, 'Not called with GitMobCoauthors type');
 });
 
-test('Create author list from co-author file only', async t => {
-  const fetchAuthorsStub = sandbox.stub().resolves([]);
-
-  const authorList = await composeAuthors(
-    ['jd'],
-    authorsJson.coauthors,
-    fetchAuthorsStub,
-    saveCoauthorStub
-  );
-
-  const expectedAuthorList = ['Jane Doe <jane@findmypast.com>'];
-
-  t.deepEqual(authorList, expectedAuthorList);
-});
-
 test('Throw error if author not found', async t => {
-  const fetchAuthorsStub = sandbox.stub().resolves(gitHubAuthors);
+  const fetchAuthorsStub = sandbox.stub().rejects();
+  sandbox.stub(mobConfig, 'fetchFromGitHub').returns(true);
 
   await t.throwsAsync(async () =>
-    composeAuthors(
-      ['rkotze', 'dideler', 'james'],
-      authorsJson.coauthors,
-      fetchAuthorsStub
-    )
+    saveMissingAuthors(['rkotze', 'dideler'], savedAuthors, fetchAuthorsStub)
   );
 });
-
-test('Throw error if author not found because fetch from GitHub is false', async t => {
-  const fetchAuthorsStub = sandbox.stub().resolves(gitHubAuthors);
-
-  const error = await t.throwsAsync(async () =>
-    composeAuthors(
-      ['rkotze', 'dideler', 'jd'],
-      authorsJson.coauthors,
-      fetchAuthorsStub
-    )
-  );
-
-  t.regex(error ? error.message : '', /author with initials "rkotze" not found!/i);
-});
diff --git a/packages/git-mob/src/git-authors/save-missing-authors.ts b/packages/git-mob/src/git-authors/save-missing-authors.ts
new file mode 100644
index 0000000..9c61e8a
--- /dev/null
+++ b/packages/git-mob/src/git-authors/save-missing-authors.ts
@@ -0,0 +1,36 @@
+import type { Author } from 'git-mob-core';
+import { fetchGitHubAuthors, saveNewCoAuthors } from 'git-mob-core';
+import { mobConfig } from '../git-mob-commands';
+
+async function saveMissingAuthors(
+  initials: string[],
+  coAuthorList: Author[],
+  getAuthors = fetchGitHubAuthors,
+  saveAuthors = saveNewCoAuthors
+): Promise<string[]> {
+  if (!mobConfig.fetchFromGitHub()) {
+    return [];
+  }
+
+  const missing = findMissingAuthors(initials, coAuthorList);
+  if (missing.length > 0) {
+    const fetchedAuthors: Author[] = await getAuthors(missing, 'git-mob-cli');
+    await saveAuthors(fetchedAuthors);
+    return fetchedAuthors.map(author => author.toString());
+  }
+
+  return [];
+}
+
+function findMissingAuthors(
+  initialList: string[],
+  coAuthorList: Author[]
+): string[] {
+  return initialList.filter(initials => !containsAuthor(initials, coAuthorList));
+}
+
+function containsAuthor(initials: string, coauthors: Author[]): boolean {
+  return coauthors.some(author => author.key === initials);
+}
+
+export { findMissingAuthors, saveMissingAuthors };
diff --git a/packages/git-mob/src/git-mob.js b/packages/git-mob/src/git-mob.js
deleted file mode 100644
index 0b7fabb..0000000
--- a/packages/git-mob/src/git-mob.js
+++ /dev/null
@@ -1,164 +0,0 @@
-import os from 'node:os';
-import minimist from 'minimist';
-import { oneLine, stripIndents } from 'common-tags';
-
-import { getAllAuthors, getPrimaryAuthor } from 'git-mob-core';
-import { config, revParse } from '../src/git-commands';
-import { gitAuthors } from '../src/git-authors';
-import { gitMessage, gitMessagePath, commitTemplatePath } from '../src/git-message';
-import { checkForUpdates, runHelp, runVersion, printList } from '../src/helpers';
-import { configWarning } from '../src/check-author';
-import { red, yellow } from '../src/colours';
-import {
-  getCoAuthors,
-  isCoAuthorSet,
-  resetMob,
-  addCoAuthor,
-  setGitAuthor,
-  mobConfig,
-} from '../src/git-mob-commands';
-import { composeAuthors } from './git-authors/compose-authors';
-
-checkForUpdates();
-
-const argv = minimist(process.argv.slice(2), {
-  boolean: ['h', 'v', 'l', 'o'],
-
-  alias: {
-    h: 'help',
-    v: 'version',
-    l: 'list',
-    o: 'override',
-  },
-});
-
-execute(argv);
-
-async function execute(args) {
-  if (args.help) {
-    runHelp();
-    process.exit(0);
-  }
-
-  if (args.version) {
-    runVersion();
-    process.exit(0);
-  }
-
-  if (args.list) {
-    await listCoAuthors();
-    process.exit(0);
-  }
-
-  if (!revParse.insideWorkTree()) {
-    console.error('Error: not a Git repository');
-    process.exit(1);
-  }
-
-  if (args.override) {
-    setAuthor(args._);
-  } else {
-    runMob(args._);
-  }
-}
-
-function runMob(args) {
-  if (args.length === 0) {
-    printMob();
-    if (config.usingLocalTemplate() && isCoAuthorSet()) {
-      gitMessage(gitMessagePath()).writeCoAuthors(getCoAuthors().split(os.EOL));
-    }
-  } else {
-    setMob(args);
-  }
-}
-
-function printMob() {
-  const gitAuthor = getPrimaryAuthor();
-  console.log(author(gitAuthor));
-
-  if (isCoAuthorSet()) {
-    console.log(getCoAuthors());
-  }
-
-  if (!mobConfig.useLocalTemplate() && config.usingLocalTemplate()) {
-    console.log(
-      yellow(stripIndents`Warning: Git Mob uses Git global config.
-    Using local commit.template could mean your template does not have selected co-authors appended after switching projects.
-    See: https://github.com/rkotze/git-mob/discussions/81`)
-    );
-  }
-
-  if (configWarning(gitAuthor)) {
-    console.warn(red(configWarning(gitAuthor)));
-  }
-}
-
-async function listCoAuthors() {
-  try {
-    const coAuthors = await getAllAuthors();
-
-    printList(coAuthors);
-  } catch (error) {
-    console.error(red(`Error: ${error.message}`));
-    process.exit(1);
-  }
-}
-
-async function setMob(initials) {
-  try {
-    const instance = gitAuthors();
-    const authorList = await instance.read();
-    const coauthors = await composeAuthors(initials, authorList.coauthors);
-
-    setCommitTemplate();
-    resetMob();
-
-    for (const coauthor of coauthors) {
-      addCoAuthor(coauthor);
-    }
-
-    gitMessage(gitMessagePath()).writeCoAuthors(coauthors);
-
-    if (config.usingLocalTemplate() && config.usingGlobalTemplate()) {
-      gitMessage(config.getGlobalTemplate()).writeCoAuthors(coauthors);
-    }
-
-    printMob();
-  } catch (error) {
-    console.error(red(`Error: ${error.message}`));
-    if (error.message.includes('not found!')) {
-      console.log(
-        yellow(
-          'Run "git config --global git-mob-config.github-fetch true" to fetch GitHub authors.'
-        )
-      );
-    }
-
-    process.exit(1);
-  }
-}
-
-async function setAuthor(initials) {
-  try {
-    const instance = gitAuthors();
-    const authorList = await instance.read();
-    const authors = instance.author(initials.shift(), authorList);
-
-    setGitAuthor(authors.name, authors.email);
-    runMob(initials);
-  } catch (error) {
-    console.error(red(`Error: ${error.message}`));
-    process.exit(1);
-  }
-}
-
-function author({ name, email }) {
-  return oneLine`${name} <${email}>`;
-}
-
-function setCommitTemplate() {
-  if (!config.hasTemplatePath()) {
-    config.setTemplatePath(commitTemplatePath());
-  }
-}
diff --git a/packages/git-mob/src/git-mob.spec.js b/packages/git-mob/src/git-mob.spec.ts
similarity index 87%
rename from packages/git-mob/src/git-mob.spec.js
rename to packages/git-mob/src/git-mob.spec.ts
index 0dc8714..bdab7ec 100644
--- a/packages/git-mob/src/git-mob.spec.js
+++ b/packages/git-mob/src/git-mob.spec.ts
@@ -1,5 +1,5 @@
 import { EOL } from 'node:os';
-import test, { before, after, afterEach, skip } from 'ava';
+import test from 'ava';
 import { stripIndent } from 'common-tags';
 import { auto } from 'eol';
 import { temporaryDirectory } from 'tempy';
@@ -20,11 +20,15 @@ import {
   tearDown,
 } from '../test-helpers';
 
+const { before, after, afterEach, skip } = test;
+
 before('setup', () => {
   setup();
+  setCoauthorsFile();
 });
 
 after.always('final cleanup', () => {
+  deleteCoauthorsFile();
   deleteGitMessageFile();
   tearDown();
 });
@@ -45,12 +49,13 @@ test('-h prints help', t => {
 
 if (process.platform === 'win32') {
   // Windows tries to open a man page at git-doc/git-mob.html which errors.
-  skip('--help is intercepted by git launcher on Windows', () => {});
+  skip('--help is intercepted by git launcher on Windows', () => null);
 } else {
   test('--help is intercepted by git launcher', t => {
-    const error = t.throws(() => {
-      exec('git mob --help', { silent: true });
-    });
+    const error =
+      t.throws(() => {
+        exec('git mob --help');
+      }) || new Error('No error');
 
     t.regex(error.message, /no manual entry for git-mob/i);
   });
@@ -69,7 +74,6 @@ test('--version prints version', t => {
 });
 
 test('--list print a list of available co-authors', t => {
-  setCoauthorsFile();
   const actual = exec('git mob --list').stdout.trimEnd();
   const expected = [
     'jd, Jane Doe, jane@findmypast.com',
@@ -78,7 +82,6 @@ test('--list print a list of available co-authors', t => {
   ].join(EOL);
 
   t.is(actual, expected);
-  deleteCoauthorsFile();
 });
 
 test('prints only primary author when there is no mob', t => {
@@ -91,14 +94,14 @@ test('prints only primary author when there is no mob', t => {
 
 test('prints current mob', t => {
   addAuthor('John Doe', 'jdoe@example.com');
-  addCoAuthor('Dennis Ideler', 'dideler@findmypast.com');
-  addCoAuthor('Richard Kotze', 'rkotze@findmypast.com');
+  addCoAuthor('Jane Doe', 'jane@findmypast.com');
+  addCoAuthor('Elliot Alderson', 'ealderson@findmypast.com>');
 
   const actual = exec('git mob').stdout.trimEnd();
   const expected = stripIndent`
   John Doe <jdoe@example.com>
-  Dennis Ideler <dideler@findmypast.com>
-  Richard Kotze <rkotze@findmypast.com>`;
+  Jane Doe <jane@findmypast.com>
+  Elliot Alderson <ealderson@findmypast.com>`;
 
   t.is(actual, expected);
   // setting co-authors outside the git mob lifecycle the commit.template
@@ -134,14 +137,14 @@ test('hides warning if local git mob config template is used true', t => {
 
 test('update local commit template if using one', t => {
   addAuthor('John Doe', 'jdoe@example.com');
-  addCoAuthor('Richard Kotze', 'rkotze@gitmob.com');
+  addCoAuthor('Elliot Alderson', 'ealderson@findmypast.com');
 
   exec('git config --local commit.template ".git/.gitmessage"');
 
   exec('git mob').stdout.trimEnd();
   const actualGitMessage = readGitMessageFile();
   const expectedGitMessage = auto(
-    [EOL, EOL, 'Co-authored-by: Richard Kotze <rkotze@gitmob.com>'].join('')
+    [EOL, EOL, 'Co-authored-by: Elliot Alderson <ealderson@findmypast.com>'].join('')
   );
 
   t.is(actualGitMessage, expectedGitMessage);
@@ -149,7 +152,6 @@ test('update local commit template if using one', t => {
 });
 
 test('sets mob when co-author initials found', t => {
-  setCoauthorsFile();
   addAuthor('Billy the Kid', 'billy@example.com');
 
   const actual = exec('git mob jd ea').stdout.trimEnd();
@@ -160,12 +162,10 @@ test('sets mob when co-author initials found', t => {
   `;
 
   t.is(actual, expected);
-  deleteCoauthorsFile();
   removeCoAuthors();
 });
 
 test('sets mob and override author', t => {
-  setCoauthorsFile();
   addAuthor('Billy the Kid', 'billy@example.com');
 
   const actual = exec('git mob -o jd ea').stdout.trimEnd();
@@ -178,8 +178,18 @@ test('sets mob and override author', t => {
   removeCoAuthors();
 });
 
+test('Incorrect override author key will show error', t => {
+  addAuthor('Billy the Kid', 'billy@example.com');
+
+  const error =
+    t.throws(() => {
+      exec('git mob -o kl ea');
+    }) || new Error('No error');
+
+  t.regex(error.message, /error: kl author key not found!/i);
+});
+
 test('overwrites old mob when setting a new mob', t => {
-  setCoauthorsFile();
   setGitMessageFile();
   addAuthor('John Doe', 'jdoe@example.com');
 
@@ -202,12 +212,10 @@ test('overwrites old mob when setting a new mob', t => {
     Co-authored-by: Elliot Alderson <ealderson@findmypast.com>`);
 
   t.is(actualGitmessage, expectedGitmessage);
-  deleteCoauthorsFile();
   removeCoAuthors();
 });
 
 test('appends co-authors to an existing commit template', t => {
-  setCoauthorsFile();
   setGitMessageFile();
   addAuthor('Thomas Anderson', 'neo@example.com');
 
@@ -225,13 +233,11 @@ test('appends co-authors to an existing commit template', t => {
   t.is(actualGitMessage, expectedGitMessage);
 
   unsetCommitTemplate();
-  deleteCoauthorsFile();
   removeCoAuthors();
 });
 
 test('appends co-authors to a new commit template', t => {
   deleteGitMessageFile();
-  setCoauthorsFile();
   addAuthor('Thomas Anderson', 'neo@example.com');
 
   exec('git mob jd ea');
@@ -251,7 +257,6 @@ test('appends co-authors to a new commit template', t => {
 
   removeCoAuthors();
   unsetCommitTemplate();
-  deleteCoauthorsFile();
 });
 
 test('warns when used outside of a git repo', t => {
@@ -259,9 +264,10 @@ test('warns when used outside of a git repo', t => {
   const temporaryDir = temporaryDirectory();
   process.chdir(temporaryDir);
 
-  const error = t.throws(() => {
-    exec('git mob');
-  });
+  const error =
+    t.throws(() => {
+      exec('git mob');
+    }) || new Error('No error');
 
   t.regex(error.message, /not a git repository/i);
 
diff --git a/packages/git-mob/src/git-mob.ts b/packages/git-mob/src/git-mob.ts
new file mode 100644
index 0000000..76a8529
--- /dev/null
+++ b/packages/git-mob/src/git-mob.ts
@@ -0,0 +1,173 @@
+import os from 'node:os';
+import minimist from 'minimist';
+import { stripIndents } from 'common-tags';
+
+import {
+  getAllAuthors,
+  getPrimaryAuthor,
+  getSelectedCoAuthors,
+  gitMobConfig,
+  gitConfig,
+  gitRevParse,
+  setCoAuthors,
+  setPrimaryAuthor,
+  updateGitTemplate,
+  Author,
+} from 'git-mob-core';
+import { checkForUpdates, runHelp, runVersion, printList } from './helpers';
+import { configWarning } from './check-author';
+import { red, yellow } from './colours';
+import { saveMissingAuthors } from './git-authors/save-missing-authors';
+
+checkForUpdates();
+
+const argv = minimist(process.argv.slice(2), {
+  boolean: ['h', 'v', 'l', 'o'],
+
+  alias: {
+    h: 'help',
+    v: 'version',
+    l: 'list',
+    o: 'override',
+  },
+});
+
+execute(argv).catch(() => null);
+
+async function execute(args: minimist.ParsedArgs) {
+  if (args.help) {
+    runHelp();
+    process.exit(0);
+  }
+
+  if (args.version) {
+    runVersion();
+    process.exit(0);
+  }
+
+  if (args.list) {
+    await listCoAuthors();
+    process.exit(0);
+  }
+
+  if (!gitRevParse.insideWorkTree()) {
+    console.error(red('Error: not a Git repository'));
+    process.exit(1);
+  }
+
+  if (args.override) {
+    const initial = args._.shift();
+    if (initial) {
+      await setAuthor(initial);
+    }
+
+    await runMob(args._);
+  } else {
+    await runMob(args._);
+  }
+}
+
+async function runMob(args: string[]) {
+  if (args.length === 0) {
+    const gitAuthor = getPrimaryAuthor();
+    const [authorList, useLocalTemplate, template] = await Promise.all([
+      getAllAuthors(),
+      gitMobConfig.localTemplate(),
+      gitConfig.getLocalCommitTemplate(),
+    ]);
+    const selectedCoAuthors = getSelectedCoAuthors(authorList);
+
+    printMob(gitAuthor, selectedCoAuthors, useLocalTemplate, template);
+
+    if (template && selectedCoAuthors) {
+      await updateGitTemplate(selectedCoAuthors);
+    }
+  } else {
+    await setMob(args);
+  }
+}
+
+function printMob(
+  gitAuthor: Author | undefined,
+  selectedCoAuthors: Author[],
+  useLocalTemplate: boolean,
+  template: string | undefined
+) {
+  const theAuthor = gitAuthor || new Author('', '', '');
+  const authorWarnConfig = configWarning(theAuthor);
+  if (authorWarnConfig) {
+    console.log(red(authorWarnConfig));
+    process.exit(1);
+  }
+
+  console.log(theAuthor.toString());
+
+  if (selectedCoAuthors && selectedCoAuthors.length > 0) {
+    console.log(selectedCoAuthors.join(os.EOL));
+  }
+
+  if (!useLocalTemplate && template) {
+    console.log(
+      yellow(stripIndents`Warning: Git Mob uses Git global config.
+    Using local commit.template could mean your template does not have selected co-authors appended after switching projects.
+    See: https://github.com/rkotze/git-mob/discussions/81`)
+    );
+  }
+}
+
+async function listCoAuthors() {
+  try {
+    const coAuthors = await getAllAuthors();
+
+    printList(coAuthors);
+  } catch (error: unknown) {
+    const authorListError = error as Error;
+    console.error(red(`listCoAuthors error: ${authorListError.message}`));
+    process.exit(1);
+  }
+}
+
+async function setMob(initials: string[]) {
+  try {
+    const authorList = await getAllAuthors();
+    await saveMissingAuthors(initials, authorList);
+    const selectedCoAuthors = await setCoAuthors(initials);
+
+    const [useLocalTemplate, template] = await Promise.all([
+      gitMobConfig.localTemplate(),
+      gitConfig.getLocalCommitTemplate(),
+    ]);
+
+    const gitAuthor = getPrimaryAuthor();
+    printMob(gitAuthor, selectedCoAuthors, useLocalTemplate, template);
+  } catch (error: unknown) {
+    const setMobError = error as Error;
+    console.error(red(`setMob error: ${setMobError.message}`));
+    if (setMobError.message.includes('not found!')) {
+      console.log(
+        yellow(
+          'Run "git config --global git-mob-config.github-fetch true" to fetch GitHub authors.'
+        )
+      );
+    }
+
+    process.exit(1);
+  }
+}
+
+async function setAuthor(initial: string) {
+  try {
+    const authorList = await getAllAuthors();
+    const author = authorList.find(author => author.key === initial);
+
+    if (!author) {
+      throw new Error(`${initial} author key not found!`);
+    }
+
+    setPrimaryAuthor(author);
+  } catch (error: unknown) {
+    const setAuthorError = error as Error;
+    console.error(red(`setAuthor error: ${setAuthorError.message}`));
+    process.exit(1);
+  }
+}
diff --git a/packages/git-mob/test-helpers/env.js b/packages/git-mob/test-helpers/env.js
index 83cab7e..b4b8c17 100644
--- a/packages/git-mob/test-helpers/env.js
+++ b/packages/git-mob/test-helpers/env.js
@@ -4,6 +4,7 @@ const testHelperPath = path.join(process.cwd(), '/test-helpers');
 module.exports = {
   GITMOB_COAUTHORS_PATH: path.join(testHelperPath, '.git-coauthors'),
   GITMOB_MESSAGE_PATH: path.join(testHelperPath, '.gitmessage'),
+  GITMOB_GLOBAL_MESSAGE_PATH: path.join(testHelperPath, '.gitglobalmessage'),
   NO_UPDATE_NOTIFIER: true,
   HOME: testHelperPath,
   GITMOB_TEST_ENV_FOLDER: './test-env',
diff --git a/packages/git-mob/test-helpers/index.js b/packages/git-mob/test-helpers/index.js
index 2e13e28..f2d21a6 100644
--- a/packages/git-mob/test-helpers/index.js
+++ b/packages/git-mob/test-helpers/index.js
@@ -30,6 +30,11 @@ function addCoAuthor(name, email) {
   exec(`git config --global --add git-mob.co-author "${name} <${email}>"`);
 }
 
+function globalCommitTemplate() {
+  const tempGlobal = path.join(process.cwd(), '.gitglobalmessage');
+  exec(`git config --global --add commit.template ${tempGlobal}`);
+}
+
 function removeCoAuthors() {
   removeGitConfigSection('git-mob');
 }
@@ -65,12 +70,20 @@ function setGitMessageFile() {
 
       A commit body that goes into more detail.
     `;
-    fs.writeFileSync(process.env.GITMOB_MESSAGE_PATH, commitMessageTemplate);
+    writeNewFile(process.env.GITMOB_MESSAGE_PATH, commitMessageTemplate);
   } catch (error) {
     console.warn('Failed to create .gitmessage file.', error.message);
   }
 }
 
+function writeNewFile(filePath, text) {
+  try {
+    fs.writeFileSync(filePath, text);
+  } catch (error) {
+    console.warn(`Failed to create ${filePath} file.`, error.message);
+  }
+}
+
 function readGitMessageFile(noFile = false) {
   if (noFile && !fs.existsSync(process.env.GITMOB_MESSAGE_PATH)) {
     return undefined;
@@ -121,27 +134,22 @@ function readCoauthorsFile() {
 }
 
 function deleteCoauthorsFile() {
-  try {
-    if (fs.existsSync(process.env.GITMOB_COAUTHORS_PATH)) {
-      fs.unlinkSync(process.env.GITMOB_COAUTHORS_PATH);
-    }
-  } catch (error) {
-    console.warn(
-      'Test helpers: Failed to delete .git-coauthors file.',
-      error.message
-    );
-  }
+  deleteFile(process.env.GITMOB_COAUTHORS_PATH);
 }
 
 function deleteGitMessageFile() {
   const filePath = process.env.GITMOB_MESSAGE_PATH;
+  deleteFile(filePath);
+}
+
+function deleteFile(filePath) {
   try {
     if (fs.existsSync(filePath)) {
       fs.unlinkSync(filePath);
     }
   } catch (error) {
     console.warn(
-      'Test helpers: Failed to delete global .gitmessage file.',
+      `Test helpers: Failed to delete global ${filePath} file.`,
       error.message
     );
   }
@@ -151,7 +159,7 @@ function exec(command) {
   const spawnString = spawnSync(command, { encoding: 'utf8', shell: true });
 
   if (spawnString.status !== 0) {
-    throw new Error(`GitMob handleResponse: "${command}" 
+    throw new Error(`GitMob test helper: "${command}" 
     stdout: ${spawnString.stdout}
     ---
     stderr: ${spawnString.stderr}`);
@@ -214,12 +222,15 @@ function setup() {
   } catch (error) {
     console.log(error);
   }
-
+  writeNewFile(process.env.GITMOB_GLOBAL_MESSAGE_PATH, '');
+  globalCommitTemplate();
   process.chdir(testDir);
   exec('git init -q');
 }
 
 function tearDown() {
+  safelyRemoveGitConfigSection('commit');
+  deleteFile(process.env.GITMOB_GLOBAL_MESSAGE_PATH);
   process.chdir(process.env.HOME);
   /* eslint n/no-unsupported-features/node-builtins: 0 */
   fs.rmSync(testDir, { recursive: true });