diff --git a/.github/workflows/pr-workflow.yaml b/.github/workflows/pr-workflow.yaml
index 534b8405..68ff3e48 100644
--- a/.github/workflows/pr-workflow.yaml
+++ b/.github/workflows/pr-workflow.yaml
@@ -6,7 +6,7 @@ jobs:
     name: Mabl Test
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@master
+      - uses: actions/checkout@main
 
       - name: Install dependencies
         run: npm ci
@@ -29,4 +29,11 @@ jobs:
         with:
           application-id: D6uz-lhAGBYuTTc6Jj_w0Q-a
           environment-id: I9tfo2dWd7WSigXcO91feA-e
-          browser-types: chrome
+          browser-types: |
+            chrome
+          plan-labels: |
+            canary
+            smoke-test
+          http-headers: |
+            X-Test-Header-1: 1234
+            X-Test-Header-2: 5678
\ No newline at end of file
diff --git a/.github/workflows/push-workflow.yaml b/.github/workflows/push-workflow.yaml
index 2253bd28..141a7460 100644
--- a/.github/workflows/push-workflow.yaml
+++ b/.github/workflows/push-workflow.yaml
@@ -7,7 +7,7 @@ jobs:
     name: Mabl Test
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@master
+      - uses: actions/checkout@main
 
       - name: Install dependencies
         run: npm ci
@@ -30,4 +30,12 @@ jobs:
         with:
           application-id: D6uz-lhAGBYuTTc6Jj_w0Q-a
           environment-id: I9tfo2dWd7WSigXcO91feA-e
-          browser-types: chrome
+          browser-types: |
+            chrome
+          plan-labels: |
+            canary
+            smoke-test
+          http-headers: |
+            X-Test-Header-1: 1234
+            X-Test-Header-2: 5678
+
diff --git a/README.md b/README.md
index 6c5d7430..9cd4317c 100644
--- a/README.md
+++ b/README.md
@@ -7,12 +7,12 @@ test runs associated with that deployment and waiting for their results.
 
 For more complex use cases, see the [setup-mabl-cli](https://github.com/marketplace/actions/setup-mabl-cli) Action to access the CLI directly.
 
-### Example workflow:
+### Example workflow: Simple
 
 ```
 on: [push]
 
-name: mabl
+name: mabl Simple Example
 
 jobs:
   test:
@@ -32,6 +32,50 @@ jobs:
           environment-id: <your-environment-id-e>
 ```
 
+### Example workflow: Complete
+
+Using all available flags.
+
+```
+on: [push]
+
+name: mabl Complex Example
+
+jobs:
+  test:
+    name: mabl Test
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+
+      - name: Functional test deployment
+        id: mabl-test-deployment
+        uses: mablhq/github-run-tests-action@v1
+        env:
+          MABL_API_KEY: ${{ secrets.MABL_API_KEY }}
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        with:
+          application-id: <your-application-id-a>
+          environment-id: <your-environment-id-e>
+          uri: <your-override-url>
+          mabl-branch: <your-mabl-branch-name>
+          # Runs for both browsers
+          browser-types: |
+            chrome
+            firefox
+          # Runs plans matching ANY of the following labels AND the environment/application IDs above
+          plan-labels: |
+            canary
+            smoke-test
+          http-headers: |
+            My-Header:the-value
+            My-Other-Header:the-second-value
+          continue-on-failure: true
+          rebaseline-images: true
+          set-static-baseline: true
+          event-time: <your-event-time-epoch-milliseconds>
+```
+
 ### Environment variables
 
 - `MABL_API_KEY` {string} - Your mabl API key
@@ -55,18 +99,21 @@ jobs:
   Use the
   [curl builder](https://app.mabl.com/workspaces/-/settings/apis#api-docs-selector-dropdown-button)
   to find the id.
-- `browser-types` {string} {optional}: comma separated override for browser
+- `browser-types` {string} (optional): comma or new line separated override for browser
   types to test e.g. `chrome, firefox, safari, internet_explorer`. If not
   provided, mabl will test the browsers configured on the triggered test.
-- `uri` {string} {optional} the base uri to test against. If provided, this will
+- `plan-labels` {string} (optional): comma or new line separated plan labels to test. Plans matching **any** label will be run. e.g. `smoke-test, beta-feature`. Note: additional selection criteria must also be met like application-id or environment-id, if supplied.
+- `uri` {string} (optional) the base uri to test against. If provided, this will
   override the default uri associated with the environment in mabl
+- `mabl-branch` {string} (optional) run tests on the mabl branch of tests with this name. Defaults to `master`.
+- `http-headers` {string} (optional) Headers to add to all requests e.g. "My-Header:the-value" (comma or new line delimited).
 - `rebaseline-images` {boolean} (optional) - Set `true` to reset the visual
   baseline to the current deployment
-- `set-static-baseline` {boolean} {optional} - Set `true` to use current
+- `set-static-baseline` {boolean} (optional) - Set `true` to use current
   deployment as an exact static baseline. If set, mabl will **not** model
   dynamic areas and will use the current deployment as the pixel-exact visual
   baseline.
-- `continue-on-failure` {boolean} {optional} - Set to true to continue the build
+- `continue-on-failure` {boolean} (optional) - Set to true to continue the build
   even if there are test failures
 - `event-time` {int64} (optional) - Event time the deployment occurred in UTC
   epoch milliseconds. Defaults to now.
diff --git a/action.yml b/action.yml
index 1374817c..1078899f 100644
--- a/action.yml
+++ b/action.yml
@@ -6,26 +6,38 @@ branding:
 inputs:
   application-id:
     description: ^
-      'the mabl id for the deployed application.  You can get the id using the
+      'Mabl id for the deployed application.  You can get the id using the
       curl builder at https://app.mabl.com/workspaces/-/settings/apis. Either
       this or environment-id must be provided'
     required: false
   environment-id:
     description: ^
-      'the mabl id for the deployed environment. You can get the id using the
+      'Mabl id for the deployed environment. You can get the id using the
       curl builder at https://app.mabl.com/workspaces/-/settings/apis.  Either
       this or application-id must be provided'
     required: false
   browser-types:
     description: ^
-      'override for the browser types to test (comma separated).  If not provided, mabl will test
-      the browsers configured on the triggered test plans.'
+      'Override browser types to test.  If not provided, mabl will test
+      the browsers configured on the triggered test plans (comma or new line delimited).'
+    required: false
+  plan-labels:
+    description: ^
+      'Include all plans with ANY of the supplied labels (comma or new line delimited).'
     required: false
   uri:
     description: ^
-      'the base uri to test against.  If provided, this will override the default uri
+      'Base URI to test against.  If provided, this will override the default URI
       associated with the environment in mabl'
     required: false
+  mabl-branch:
+    description: ^
+      'Run tests on the mabl branch of tests with this name. Defaults to "master".'
+    required: false
+  http-headers:
+    description: ^
+      'Headers to add to all requests e.g. "My-Header:the-value" (comma or new line delimited).'
+    required: false
   rebaseline-images:
     description: ^
       'Set to true to reset the visual baseline to the current deployment'
@@ -44,23 +56,23 @@ inputs:
     required: false
     default: false
   event-time:
-    description: "The event time the deployment happened at.  Defaults to now."
+    description: "Event time the deployment occurred.  Defaults to now."
     required: false
 outputs:
   mabl-deployment-id:
-    description: "mabl deployment event id"
+    description: "Mabl deployment event id"
   plans_run:
-    description: "total number of mabl plans run against this deployment.  A mabl plan is a collection of similarly configured tests."
+    description: "Total number of mabl plans run against this deployment.  A mabl plan is a collection of similarly configured tests."
   plans_passed:
-    description: "number of mabl plans that passed against this deployment.  A mabl plan is a collection of similarly configured tests."
+    description: "Number of mabl plans that passed against this deployment.  A mabl plan is a collection of similarly configured tests."
   plans_failed:
-    description: "number of mabl plans that failed against this deployment.  A mabl plan is a collection of similarly configured tests."
+    description: "Number of mabl plans that failed against this deployment.  A mabl plan is a collection of similarly configured tests."
   tests_run:
-    description: "total number of mabl tests run against this deployment."
+    description: "Total number of mabl tests run against this deployment."
   tests_passed:
-    description: "number of mabl tests that passed against this deployment."
+    description: "Number of mabl tests that passed against this deployment."
   tests_failed:
-    description: "number of mabl tests that failed against this deployment."
+    description: "Number of mabl tests that failed against this deployment."
 
 runs:
   using: "node12"
diff --git a/package.json b/package.json
index 4e09d2ff..c548fef7 100644
--- a/package.json
+++ b/package.json
@@ -1,6 +1,6 @@
 {
   "name": "mabl-github-deployments-action",
-  "version": "1.9.0",
+  "version": "1.10.0",
   "description": "mabl github action for GitHub pipelines integration",
   "main": "lib/src/index.js",
   "scripts": {
diff --git a/src/constants.ts b/src/constants.ts
new file mode 100644
index 00000000..5fd2a2e4
--- /dev/null
+++ b/src/constants.ts
@@ -0,0 +1,26 @@
+export const USER_AGENT = 'mabl-github-run-tests-action';
+
+export enum ActionInputs {
+  ApplicationId = 'application-id',
+  BrowserTypes = 'browser-types',
+  ContinueOnFailure = 'continue-on-failure',
+  EnvironmentId = 'environment-id',
+  EventTime = 'event-time',
+  HttpHeaders = 'http-headers',
+  MablBranch = 'mabl-branch',
+  PlanLabels = 'plan-labels',
+  RebaselineImages = 'rebaseline-images',
+  SetStaticBaseline = 'set-static-baseline',
+  Uri = 'uri',
+}
+
+export enum ActionOutputs {
+  DeploymentId = 'mabl-deployment-id',
+  // Note: from here down is snake case, not dash case
+  PlansRun = 'plans_run',
+  PlansPassed = 'plans_passed',
+  PlansFailed = 'plans_failed',
+  TestsRun = 'tests_run',
+  TestsPassed = 'tests_passed',
+  TestsFailed = 'tests_failed',
+}
diff --git a/src/entities/Environment.ts b/src/entities/Environment.ts
new file mode 100644
index 00000000..687192a0
--- /dev/null
+++ b/src/entities/Environment.ts
@@ -0,0 +1,9 @@
+export interface Environment {
+  id: string;
+  created_time: number;
+  created_by_id: string;
+  last_updated_time: number;
+  last_updated_by_id: string;
+  organization_id: string;
+  name: string;
+}
diff --git a/src/index.ts b/src/index.ts
index c514736a..a1685cc7 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -11,9 +11,11 @@ import {prettyFormatExecution} from './table';
 import * as core from '@actions/core';
 import * as github from '@actions/github';
 import {Option} from './interfaces';
+import {Environment} from './entities/Environment';
+import {ActionInputs, ActionOutputs, USER_AGENT} from './constants';
 
 const DEFAULT_MABL_APP_URL = 'https://app.mabl.com';
-const EXECUTION_POLL_INTERVAL_MILLIS = 10000;
+const EXECUTION_POLL_INTERVAL_MILLIS = 10_000;
 const EXECUTION_COMPLETED_STATUSES = [
   'succeeded',
   'failed',
@@ -23,45 +25,65 @@ const EXECUTION_COMPLETED_STATUSES = [
 ];
 const GITHUB_BASE_URL = 'https://api.github.com';
 
-async function run(): Promise<void> {
+export function optionalArrayInput(name: string): string[] {
+  // Note: GitHub Action inputs default to '' for undefined inputs, remove these
+  return core
+    .getInput(name, {
+      required: false,
+    })
+    .split(/[,\n]/)
+    .filter((item) => item.length)
+    .map((item) => item.trim());
+}
+
+export function optionalInput(name: string): string | undefined {
+  const rawValue = core.getInput(name, {
+    required: false,
+  });
+
+  if (rawValue.length > 0) {
+    return rawValue;
+  }
+  return;
+}
+
+export function booleanInput(name: string): boolean {
+  return (
+    core
+      .getInput(name, {
+        required: false,
+      })
+      .toLowerCase() === 'true'
+  );
+}
+
+export async function run(): Promise<void> {
   try {
     core.startGroup('Gathering inputs');
-    const applicationId: string = core.getInput('application-id', {
-      required: false,
-    });
-    const environmentId: string = core.getInput('environment-id', {
-      required: false,
-    });
+    const applicationId = optionalInput(ActionInputs.ApplicationId);
+    const environmentId = optionalInput(ActionInputs.EnvironmentId);
 
-    const apiKey: string = process.env.MABL_API_KEY || '';
+    const apiKey = process.env.MABL_API_KEY;
     if (!apiKey) {
-      core.setFailed('MABL_API_KEY required');
+      core.setFailed('env var MABL_API_KEY required');
+      return;
     }
 
+    const planLabels = optionalArrayInput(ActionInputs.PlanLabels);
+
     // plan override options
-    const browserTypes: string = core.getInput('browser-types', {
-      required: false,
-    });
-    const uri: string = core.getInput('uri', {required: false});
+    const browserTypes = optionalArrayInput(ActionInputs.BrowserTypes);
+    const httpHeaders = optionalArrayInput(ActionInputs.HttpHeaders);
+    const uri = optionalInput(ActionInputs.Uri);
+    const mablBranch = optionalInput(ActionInputs.MablBranch);
 
     // deployment action options
-    const rebaselineImages: boolean = parseBoolean(
-      core.getInput('rebaseline-images', {
-        required: false,
-      }),
-    );
-    const setStaticBaseline: boolean = parseBoolean(
-      core.getInput('set-static-baseline', {
-        required: false,
-      }),
-    );
-
-    const continueOnPlanFailure: boolean = parseBoolean(
-      core.getInput('continue-on-failure', {required: false}),
-    );
+    const rebaselineImages = booleanInput(ActionInputs.RebaselineImages);
+    const setStaticBaseline = booleanInput(ActionInputs.SetStaticBaseline);
+    const continueOnPlanFailure = booleanInput(ActionInputs.ContinueOnFailure);
 
     const pullRequest = await getRelatedPullRequest();
-    const eventTimeString = core.getInput('event-time', {required: false});
+    const eventTimeString = optionalInput(ActionInputs.EventTime);
     const eventTime = eventTimeString ? parseInt(eventTimeString) : Date.now();
 
     let properties: DeploymentProperties = {
@@ -92,6 +114,10 @@ async function run(): Promise<void> {
         ? github.context.payload.pull_request?.head?.sha
         : process.env.GITHUB_SHA;
 
+    if (mablBranch) {
+      core.info(`Using mabl branch [${mablBranch}]`);
+    }
+
     core.info(`Using git revision [${revision}]`);
     core.endGroup();
 
@@ -101,28 +127,40 @@ async function run(): Promise<void> {
 
     // send the deployment
     const deployment: Deployment = await apiClient.postDeploymentEvent(
-      applicationId,
-      environmentId,
       browserTypes,
-      uri,
+      planLabels,
+      httpHeaders,
       rebaselineImages,
       setStaticBaseline,
-      revision,
       eventTime,
       properties,
+      applicationId,
+      environmentId,
+      uri,
+      revision,
+      mablBranch,
     );
 
-    core.setOutput('mabl-deployment-id', deployment.id);
+    core.setOutput(ActionOutputs.DeploymentId, deployment.id);
 
-    let outputLink: string = baseApiUrl;
+    let appOrEnv: Application | Environment | undefined;
     if (applicationId) {
-      const application: Application = await apiClient.getApplication(
-        applicationId,
+      appOrEnv = await apiClient.getApplication(applicationId);
+    } else if (environmentId) {
+      appOrEnv = await apiClient.getEnvironment(environmentId);
+    }
+
+    // Check we have minimum viable config
+    if (!appOrEnv) {
+      core.setFailed(
+        'Invalid configuration. Valid "application-id" or "environment-id" must be set. No tests started.',
       );
-      outputLink = `${baseApiUrl}/workspaces/${application.organization_id}/events/${deployment.id}`;
-      core.info(`Deployment triggered. View output at: ${outputLink}`);
+      return; // exit
     }
 
+    const outputLink = `${baseApiUrl}/workspaces/${appOrEnv.organization_id}/events/${deployment.id}`;
+    core.info(`Deployment triggered. View output at: ${outputLink}`);
+
     core.startGroup('Await completion of tests');
 
     // poll Execution result until complete
@@ -161,27 +199,27 @@ async function run(): Promise<void> {
     });
 
     core.setOutput(
-      'plans_run',
+      ActionOutputs.PlansRun,
       '' + finalExecutionResult.plan_execution_metrics.total,
     );
     core.setOutput(
-      'plans_passed',
+      ActionOutputs.PlansPassed,
       '' + finalExecutionResult.plan_execution_metrics.passed,
     );
     core.setOutput(
-      'plans_failed',
+      ActionOutputs.PlansFailed,
       '' + finalExecutionResult.plan_execution_metrics.failed,
     );
     core.setOutput(
-      'tests_run',
+      ActionOutputs.TestsRun,
       '' + finalExecutionResult.journey_execution_metrics.total,
     );
     core.setOutput(
-      'tests_passed',
+      ActionOutputs.TestsPassed,
       '' + finalExecutionResult.journey_execution_metrics.passed,
     );
     core.setOutput(
-      'tests_failed',
+      ActionOutputs.TestsFailed,
       '' + finalExecutionResult.journey_execution_metrics.failed,
     );
 
@@ -205,10 +243,6 @@ async function run(): Promise<void> {
   }
 }
 
-function parseBoolean(toParse: string): boolean {
-  return toParse?.toLowerCase() === 'true';
-}
-
 function getExecutionsStillPending(
   executionResult: ExecutionResult,
 ): Execution[] {
@@ -233,7 +267,7 @@ async function getRelatedPullRequest(): Promise<Option<PullRequest>> {
       Authorization: `token ${githubToken}`,
       Accept: 'application/vnd.github.groot-preview+json',
       'Content-Type': 'application/json',
-      'User-Agent': 'mabl-action',
+      'User-Agent': USER_AGENT,
     },
   };
   const client = axios.create(config);
diff --git a/src/mablApiClient.ts b/src/mablApiClient.ts
index 87be8c8e..ae6c72a8 100644
--- a/src/mablApiClient.ts
+++ b/src/mablApiClient.ts
@@ -3,6 +3,8 @@ import {Application} from './entities/Application';
 import {Deployment, DeploymentProperties} from './entities/Deployment';
 import {ExecutionResult} from './entities/ExecutionResult';
 import axios, {AxiosInstance, AxiosRequestConfig} from 'axios';
+import {Environment} from './entities/Environment';
+import {USER_AGENT} from './constants';
 
 export class MablApiClient {
   private readonly httpClient: AxiosInstance;
@@ -12,7 +14,7 @@ export class MablApiClient {
   constructor(apiKey: string) {
     const config: AxiosRequestConfig = {
       headers: {
-        'User-Agent': 'github-run-tests-action',
+        'User-Agent': USER_AGENT,
         Accept: 'application/json',
         'Content-Type': 'application/json',
       },
@@ -58,14 +60,26 @@ export class MablApiClient {
     );
   }
 
-  async getApplication(applicationId: string): Promise<Application> {
+  async getApplication(id: string): Promise<Application> {
     try {
       return await this.makeGetRequest<Application>(
-        `${this.baseUrl}/v1/applications/${applicationId}`,
+        `${this.baseUrl}/v1/applications/${id}`,
       );
     } catch (error) {
       throw new Error(
-        `failed to get mabl application ($applicationId) from the API ${error}`,
+        `failed to get mabl application (${id}) from the API ${error}`,
+      );
+    }
+  }
+
+  async getEnvironment(id: string): Promise<Environment> {
+    try {
+      return await this.makeGetRequest<Environment>(
+        `${this.baseUrl}/v1/environments/${id}`,
+      );
+    } catch (error) {
+      throw new Error(
+        `failed to get mabl environment (${id}) from the API ${error}`,
       );
     }
   }
@@ -83,27 +97,33 @@ export class MablApiClient {
   }
 
   async postDeploymentEvent(
-    applicationId: string,
-    environmentId: string,
-    browserTypes: string,
-    uri: string,
+    browserTypes: string[],
+    planLabels: string[],
+    httpHeaders: string[],
     rebaselineImages: boolean,
     setStaticBaseline: boolean,
-    revision: string | undefined,
     eventTime: number,
     properties: DeploymentProperties,
+    applicationId?: string,
+    environmentId?: string,
+    uri?: string,
+    revision?: string,
+    mablBranch?: string,
   ): Promise<Deployment> {
     try {
       const requestBody: any = this.buildRequestBody(
-        applicationId,
-        environmentId,
         browserTypes,
-        uri,
+        planLabels,
+        httpHeaders,
         rebaselineImages,
         setStaticBaseline,
         eventTime,
         properties,
+        applicationId,
+        environmentId,
+        uri,
         revision,
+        mablBranch,
       );
       return await this.makePostRequest<Deployment>(
         `${this.baseUrl}/events/deployment/`,
@@ -115,15 +135,18 @@ export class MablApiClient {
   }
 
   buildRequestBody(
-    applicationId: string,
-    environmentId: string,
-    browserTypes: string,
-    uri: string,
+    browserTypes: string[],
+    planLabels: string[],
+    httpHeaders: string[],
     rebaselineImages: boolean,
     setStaticBaseline: boolean,
     event_time: number,
     properties: DeploymentProperties,
+    applicationId?: string,
+    environmentId?: string,
+    uri?: string,
     revision?: string,
+    mablBranch?: string,
   ): any {
     const requestBody: any = {};
 
@@ -134,15 +157,37 @@ export class MablApiClient {
       requestBody.application_id = applicationId;
     }
 
+    if (mablBranch) {
+      requestBody.source_control_tag = mablBranch;
+    }
+
     const planOverrides: any = {};
-    if (browserTypes) {
-      planOverrides.browser_types = browserTypes.split(',');
+    if (browserTypes.length) {
+      planOverrides.browser_types = browserTypes;
     }
+
     if (uri) {
       planOverrides.uri = uri;
     }
+
+    if (httpHeaders.length) {
+      planOverrides.http_headers = httpHeaders.map((header) => {
+        const parts = header.split(':', 2); // allow for colon in the header value
+        return {
+          name: parts[0],
+          value: parts[1],
+          log_header_value: false,
+        };
+      });
+      planOverrides.http_headers_required = true;
+    }
+
     requestBody.plan_overrides = planOverrides;
 
+    if (planLabels.length) {
+      requestBody.plan_labels = planLabels;
+    }
+
     if (revision) {
       requestBody.revision = revision;
     }
diff --git a/test/suite.test.ts b/test/suite.test.ts
index c53e5dc8..f2883422 100644
--- a/test/suite.test.ts
+++ b/test/suite.test.ts
@@ -1,13 +1,77 @@
 import {MablApiClient} from '../src/mablApiClient';
+import { booleanInput, optionalArrayInput, optionalInput, run } from "../src";
+import { ActionInputs } from '../src/constants';
 
 describe('GitHub Action tests', () => {
 
+  // Place the input into ENV var the same as in GitHub Actions
+  function setGithubInput(name: string, value: string): void {
+    process.env[`INPUT_${name.replace(/ /g, '_').toUpperCase()}`] = value;
+  }
+
+  function assertExitCode(expected: number): void {
+    expect(process.exitCode).toEqual(expected);
+  }
+
+  it('handles invalid application/environment ids', async () => {
+    setGithubInput(ActionInputs.ApplicationId, '');
+    setGithubInput(ActionInputs.EnvironmentId, '');
+    await run();
+    assertExitCode(1);
+  });
+
+  it('parses array inputs', () => {
+    setGithubInput(ActionInputs.BrowserTypes, '');
+    expect(optionalArrayInput(ActionInputs.BrowserTypes)).toEqual([]);
+
+    setGithubInput(ActionInputs.BrowserTypes, 'chrome ');
+    expect(optionalArrayInput(ActionInputs.BrowserTypes)).toEqual(['chrome']);
+
+    setGithubInput(ActionInputs.BrowserTypes, 'chrome, firefox ');
+    expect(optionalArrayInput(ActionInputs.BrowserTypes)).toEqual(['chrome', 'firefox']);
+
+    setGithubInput(ActionInputs.BrowserTypes, 'chrome\nfirefox\nsafari ');
+    expect(optionalArrayInput(ActionInputs.BrowserTypes)).toEqual(['chrome', 'firefox', 'safari']);
+  });
+
+  it('parses boolean inputs', () => {
+    setGithubInput(ActionInputs.RebaselineImages, '');
+    expect(booleanInput(ActionInputs.RebaselineImages)).toEqual(false);
+
+    setGithubInput(ActionInputs.RebaselineImages, 'false ');
+    expect(booleanInput(ActionInputs.RebaselineImages)).toEqual(false);
+
+    setGithubInput(ActionInputs.RebaselineImages, 'False ');
+    expect(booleanInput(ActionInputs.RebaselineImages)).toEqual(false);
+
+    setGithubInput(ActionInputs.RebaselineImages, 'True ');
+    expect(booleanInput(ActionInputs.RebaselineImages)).toEqual(true);
+
+    setGithubInput(ActionInputs.RebaselineImages, 'true ');
+    expect(booleanInput(ActionInputs.RebaselineImages)).toEqual(true);
+
+    setGithubInput(ActionInputs.RebaselineImages, 'TRUE');
+    expect(booleanInput(ActionInputs.RebaselineImages)).toEqual(true);
+  });
+
+
+  it('parses optional string inputs', () => {
+    setGithubInput(ActionInputs.ApplicationId, '');
+    expect(optionalInput(ActionInputs.ApplicationId)).toBeUndefined();
+
+    setGithubInput(ActionInputs.ApplicationId, 'baz ');
+    expect(optionalInput(ActionInputs.ApplicationId)).toEqual('baz');
+
+    setGithubInput(ActionInputs.ApplicationId, 'BAZ');
+    expect(optionalInput(ActionInputs.ApplicationId)).toEqual('BAZ');
+  });
+
   it('builds the request correctly with all options', () => {
     const expected = {
       environment_id: 'env',
       application_id: 'app',
       plan_overrides: {
-        browser_types: ['firefox', ' chrome', ' internet_explorer'],
+        browser_types: ['firefox', 'chrome', 'internet_explorer'],
         uri: 'uri',
       },
       actions: {rebaseline_images: true, set_static_baseline: true},
@@ -28,10 +92,9 @@ describe('GitHub Action tests', () => {
     };
     const apiClient = new MablApiClient('test');
     const requestBody = apiClient.buildRequestBody(
-      'app',
-      'env',
-      'firefox, chrome, internet_explorer',
-      'uri',
+      ['firefox', 'chrome', 'internet_explorer'],
+      [],
+      [],
       true,
       true,
 
@@ -49,6 +112,9 @@ describe('GitHub Action tests', () => {
         repository_pull_request_merged_at: '2019',
         repository_pull_request_created_at: '2019',
       },
+      'app',
+      'env',
+      'uri',
       'abcs',
     );
     expect(expected).toStrictEqual(requestBody);
@@ -57,7 +123,21 @@ describe('GitHub Action tests', () => {
   it('builds the request correctly with some options', () => {
     const expected = {
       application_id: 'app',
-      plan_overrides: {uri: 'uri'},
+      plan_labels: ['alpha', 'beta'],
+      plan_overrides: {
+        uri: 'uri',
+        browser_types: ['chrome', 'firefox'],
+        http_headers: [{
+          name: 'Header-Uno',
+          value: 'value-uno',
+          log_header_value: false,
+        }, {
+          name: 'Header-Dos',
+          value: 'value-dos',
+          log_header_value: false,
+        }],
+        http_headers_required: true
+      },
       actions: {},
       revision: 'abcs',
       properties: {
@@ -76,10 +156,10 @@ describe('GitHub Action tests', () => {
     };
     const apiClient = new MablApiClient('test');
     const requestBody = apiClient.buildRequestBody(
-      'app',
-      '',
-      '',
-      'uri',
+
+      ['chrome', 'firefox'],
+      ['alpha', 'beta'],
+      ['Header-Uno:value-uno', 'Header-Dos:value-dos'],
       false,
       false,
 
@@ -97,6 +177,9 @@ describe('GitHub Action tests', () => {
         repository_pull_request_merged_at: '2019',
         repository_pull_request_created_at: '2019',
       },
+      'app',
+      '',
+      'uri',
       'abcs',
     );
     expect(expected).toStrictEqual(requestBody);