app.json

<p><code>app.json</code> is a manifest format for describing web apps. It declares environment variables, addons, and other information required to run an app on Heroku. This document describes the schema in detail.</p> <h2 id="example-app-json">Example app.json</h2> <pre><code class="lang-json">{ "name": "Small Sharp Tool", "description": "This app does one little thing, and does it well.", "keywords": [ "productivity", "HTML5", "scalpel" ], "website": "https://small-sharp-tool.com/", "repository": "https://github.com/jane-doe/small-sharp-tool", "logo": "https://small-sharp-tool.com/logo.svg", "success_url": "/welcome", "scripts": { "postdeploy": "bundle exec rake bootstrap" }, "env": { "BUILDPACK_URL": "https://github.com/stomita/heroku-buildpack-phantomjs", "SECRET_TOKEN": { "description": "A secret key for verifying the integrity of signed cookies.", "generator": "secret" }, "WEB_CONCURRENCY": { "description": "The number of processes to run.", "value": "5" } }, "addons": [ "openredis", "mongolab:shared-single-small" ] } </code></pre> <h2 id="schema-reference">Schema Reference</h2> <h3 id="name">name</h3> <p><em>(string, optional)</em> A clean and simple name to identify the template (30 characters max).</p> <pre><code class="lang-json">{ "name": "Small Sharp Tool" } </code></pre> <h3 id="description">description</h3> <p><em>(string, optional)</em> A brief summary of the app: what it does, who it's for, why it exists, etc.</p> <pre><code class="lang-json">{ "description": "This app does one little thing, and does it well." } </code></pre> <h3 id="keywords">keywords</h3> <p><em>(array, optional)</em> An array of strings describing the app.</p> <pre><code class="lang-json">{ "keywords": [ "productivity", "HTML5", "scalpel" ] } </code></pre> <h3 id="website">website</h3> <p><em>(string, optional)</em> The project's website.</p> <pre><code class="lang-json">{ "website": "https://small-sharp-tool.com/" } </code></pre> <h3 id="repository">repository</h3> <p><em>(string, optional)</em> The location of the application's source code, such as a Git URL, GitHub URL, Subversion URL, or Mercurial URL.</p> <pre><code class="lang-json">{ "repository": "https://github.com/jane-doe/small-sharp-tool" } </code></pre> <h3 id="logo">logo</h3> <p><em>(string, optional)</em> The URL of the application's logo image. Dimensions should be square. Format can be SVG, PNG, or JPG.</p> <pre><code class="lang-json">{ "logo": "https://small-sharp-tool.com/logo.svg" } </code></pre> <h3 id="success_url">success_url</h3> <p><em>(string, optional)</em> A URL specifying where to redirect the user once their new app is deployed. If value is a fully-qualified URL, the user should be redirected to that URL. If value begins with a slash <code>/</code>, the user should be redirected to that path in their newly deployed app.</p> <pre><code class="lang-json">{ "success_url": "/welcome" } </code></pre> <h3 id="scripts">scripts</h3> <p><em>(object, optional)</em> A key-value object specifying scripts or shell commands to execute at different stages in the build/release process. Currently, <code>postdeploy</code> is the only supported script.</p> <pre><code class="lang-json">{ "scripts": { "postdeploy": "bundle exec rake bootstrap" } } </code></pre> <h3 id="env">env</h3> <p><em>(object, optional)</em> A key-value object for environment variables, or <a href="https://devcenter.heroku.com/articles/config-vars">config vars</a> in Heroku parlance. Keys are the names of the environment variables. Values can be strings or objects. If the value is a string, it will be used. If the value is an object, it defines specific requirements for that variable:</p> <ul> <li><code>description</code>: a human-friendly blurb about what the value is for and how to determine what it should be</li> <li><code>value</code>: a default value to use. This should always be a string.</li> <li><code>required</code>: A boolean indicating whether the given value is required for the app to function (default: <code>true</code>).</li> <li><code>generator</code>: a string representing a function to call to generate the value. Currently the only supported generator is <code>secret</code>, which generates a pseudo-random string of characters.</li> </ul> <pre><code class="lang-json">{ "env": { "BUILDPACK_URL": "https://github.com/stomita/heroku-buildpack-phantomjs", "SECRET_TOKEN": { "description": "A secret key for verifying the integrity of signed cookies.", "generator": "secret" }, "WEB_CONCURRENCY": { "description": "The number of processes to run.", "value": "5" } } } </code></pre> <h3 id="addons">addons</h3> <p><em>(array, optional)</em> An array of strings specifying Heroku addons to provision on the app before deploying. Each addon should be in the format <code>addon:plan</code> or <code>addon</code>. If plan is omitted, that addon's default plan will be provisioned.</p> <pre><code class="lang-json">{ "addons": [ "openredis", "mongolab:shared-single-small" ] } </code></pre>