> ## Documentation Index
> Fetch the complete documentation index at: https://developer.upsun.com/llms.txt
> Use this file to discover all available pages before exploring further.

# This week in new features - Build-time variables

> Discover the benefits of project-level variables available at build time on Platform.sh and explore their use cases, including private composer repositories.

export const PostMeta = ({data = {}}) => {
  const {author, date, image} = data;
  const authors = Array.isArray(author) ? author : author ? [author] : [];
  const resolveAuthor = slug => {
    const entry = AUTHOR_MAP[slug] || ({});
    const name = entry.name || slug;
    const github = entry.github || null;
    const linkedin = entry.linkedin || null;
    const url = github ? `https://github.com/${github}` : linkedin || null;
    const avatarUrl = github ? `https://github.com/${github}.png?size=64` : null;
    return {
      name,
      url,
      avatarUrl
    };
  };
  const formattedDate = date ? new Date(date).toLocaleDateString('en-US', {
    year: 'numeric',
    month: 'long',
    day: 'numeric'
  }) : null;
  if (!image && authors.length === 0 && !formattedDate) return null;
  const AUTHOR_MAP = {
    "aaron-collier": {
      "name": "Aaron Collier"
    },
    "aaron-dudenhofer": {
      "name": "Aaron Dudenhofer"
    },
    "aaron-porter": {
      "name": "Aaron Porter"
    },
    "adriaan-odendaal": {
      "name": "Adriaan Odendaal"
    },
    "ajmal": {
      "name": "Ajmal Siddiqui"
    },
    "akalipetis": {
      "name": "Antonis Kalipetis"
    },
    "alexander-varwijk": {
      "name": "Alexander Varwijk"
    },
    "alicia-bevilacqua": {
      "name": "Alicia Bevilacqua"
    },
    "amelie-deguerry": {
      "name": "Amelie Deguerry"
    },
    "anacidre": {
      "name": "Ana Cidre",
      "linkedin": "https://www.linkedin.com/in/ana-cidre"
    },
    "andoni": {
      "name": "Andoni Auzmendi"
    },
    "andrei-taranu": {
      "name": "Andrei (Alex) Taranu",
      "linkedin": "https://www.linkedin.com/in/andrei-alex-taranu/"
    },
    "andrew-baxter": {
      "name": "Andrew Baxter"
    },
    "andrew-melck": {
      "name": "Andrew Melck"
    },
    "antoine-crochet-damais": {
      "name": "Antoine Crochet Damais"
    },
    "augustin-delaporte": {
      "name": "Augustin Delaporte",
      "linkedin": "https://www.linkedin.com/in/augustindelaporte/"
    },
    "branislav-bujisic": {
      "name": "Branislav Bujisic"
    },
    "carl-smith": {
      "name": "Carl Smith"
    },
    "caroline-leroy": {
      "name": "Caroline Leroy"
    },
    "cati-mayer": {
      "name": "Cati Mayer"
    },
    "catplat": {
      "name": "C Trinkwon"
    },
    "ceelolulu": {
      "name": "Celeste van der Watt"
    },
    "chadwcarlson": {
      "name": "Chad Carlson",
      "github": "chadwcarlson",
      "linkedin": "https://www.linkedin.com/in/chadwcarlson"
    },
    "chris-ward": {
      "name": "Chris Ward"
    },
    "chris-yates": {
      "name": "Chris Yates"
    },
    "christian-sieber": {
      "name": "Christian Sieber"
    },
    "christopher-lockheardt": {
      "name": "Christopher Lockheardt"
    },
    "christopher-skene": {
      "name": "Christopher Skene"
    },
    "chuck-morgan": {
      "name": "Chuck Morgan"
    },
    "corey-dockendorf": {
      "name": "Corey Dockendorf"
    },
    "crell": {
      "name": "Crell"
    },
    "damz": {
      "name": "Damz"
    },
    "dan-morrison": {
      "name": "Dan Morrison"
    },
    "davidbonachera": {
      "name": "David Bonachera",
      "github": "davidbonachera",
      "linkedin": "https://www.linkedin.com/in/davidbonachera"
    },
    "dereliahmet1": {
      "name": "Ahmet Faruk Dereli"
    },
    "devicezero": {
      "name": "Jonas Kröger",
      "github": "devicezero",
      "linkedin": "https://www.linkedin.com/in/jonaskroeger/"
    },
    "doug-goldberg": {
      "name": "Doug Goldberg"
    },
    "duncan-naves": {
      "name": "Duncan Naves",
      "github": "duncannaves",
      "linkedin": "https://www.linkedin.com/in/duncan-naves-a94423aa"
    },
    "erika-bustamante": {
      "name": "Erika Bustamante"
    },
    "fabpot": {
      "name": "Fabien Potencier"
    },
    "flovntp": {
      "name": "Florent Huck",
      "github": "flovntp",
      "linkedin": "https://www.linkedin.com/in/florenthuck"
    },
    "fred-plais": {
      "name": "Fred Plais"
    },
    "gauthier-garnier": {
      "name": "Gauthier Garnier"
    },
    "gilzow": {
      "name": "Paul Gilzow"
    },
    "gmoigneu": {
      "name": "Guillaume Moigneu",
      "github": "gmoigneu",
      "linkedin": "https://www.linkedin.com/in/guillaumemoigneu/"
    },
    "gregqualls": {
      "name": "Greg Qualls"
    },
    "guguss": {
      "name": "Augustin Delaporte"
    },
    "haylee-millar": {
      "name": "Haylee Millar"
    },
    "ivana-kotur": {
      "name": "Ivana Kotur"
    },
    "jackrabbithanna": {
      "name": "Mark Hanna"
    },
    "jared-wright": {
      "name": "Jared Wright",
      "github": "jww-sh",
      "linkedin": "https://www.linkedin.com/in/jaredwaynewright"
    },
    "jessica-orozco": {
      "name": "Jessica Orozco"
    },
    "joey-stanford": {
      "name": "Joey Stanford"
    },
    "john-grubb": {
      "name": "John Grubb"
    },
    "jonas-kruger": {
      "name": "Jonas Kruger"
    },
    "kathryn-frazer": {
      "name": "Kathryn Frazer"
    },
    "kemiojo": {
      "name": "Kemi Elizabeth Ojogbede"
    },
    "kieronsambrook-smith": {
      "name": "Kieronsambrook Smith"
    },
    "laurent-arnoud": {
      "name": "Laurent Arnoud"
    },
    "letoya-boyne": {
      "name": "Letoya Boyne"
    },
    "lolautruche": {
      "name": "Jérôme Vieilledent"
    },
    "lyly-lepinay": {
      "name": "Lyly Lepinay"
    },
    "manauwar-alam": {
      "name": "Manauwar Alam"
    },
    "marc-antoine-porri": {
      "name": "Marc Antoine Porri"
    },
    "maria-antinkaapo": {
      "name": "Maria Antinkaapo"
    },
    "maria-de-anton": {
      "name": "Maria De Anton"
    },
    "mark-dorison": {
      "name": "Mark Dorison"
    },
    "markus-hausammann": {
      "name": "Markus Hausammann"
    },
    "mary-thomas": {
      "name": "Mary Thomas"
    },
    "mathias-bolt-lesniak": {
      "name": "Mathias Bolt Lesniak"
    },
    "mathieu-strauch": {
      "name": "Mathieu Strauch"
    },
    "matthias-van-woensel": {
      "name": "Matthias Van Woensel",
      "linkedin": "https://www.linkedin.com/in/matthias-van-woensel-267a069"
    },
    "michael-sharp": {
      "name": "Michael Sharp"
    },
    "mupsi": {
      "name": "Marine Gandy"
    },
    "natalie-harper": {
      "name": "Natalie Harper"
    },
    "ngommenginger": {
      "name": "Nicolas Gommenginger",
      "linkedin": "https://www.linkedin.com/in/nicolas-gommenginger"
    },
    "nicholas-bennison": {
      "name": "Nicholas Bennison"
    },
    "nicholas-vahalik": {
      "name": "Nicholas Vahalik"
    },
    "nick-hardiman": {
      "name": "Nick Hardiman"
    },
    "nickanderegg": {
      "name": "Nickanderegg"
    },
    "nicolas-grekas": {
      "name": "Nicolas Grekas",
      "github": "nicolas-grekas",
      "linkedin": "https://www.linkedin.com/in/nicolasgrekas/"
    },
    "niti-malwade": {
      "name": "Niti Malwade"
    },
    "opensocialteam": {
      "name": "Opensocialteam"
    },
    "ori-pekelman": {
      "name": "Ori Pekelman"
    },
    "otavio-santana": {
      "name": "Otavio Santana"
    },
    "palwandi": {
      "name": "Pawan Alwandi",
      "github": "pawpy",
      "linkedin": "https://www.linkedin.com/in/pawanalwandi"
    },
    "patrick-boest": {
      "name": "Patrick Boest"
    },
    "patrick-dawkins": {
      "name": "Patrick Dawkins",
      "github": "pjcdawkins",
      "linkedin": "https://www.linkedin.com/in/patrickdawkins"
    },
    "patrick-klima": {
      "name": "Patrick Klima"
    },
    "pjcdawkins": {
      "name": "Pjcdawkins"
    },
    "prineet-kaurbhurji": {
      "name": "Prineet Kaurbhurji"
    },
    "quentin-sinig": {
      "name": "Quentin Sinig"
    },
    "ralt": {
      "name": "Florian Margaine",
      "github": "ralt",
      "linkedin": "https://www.linkedin.com/in/florian-margaine-43971136"
    },
    "ramanathanramakrishnamurthy": {
      "name": "Ramanathanramakrishnamurthy"
    },
    "remi-lejeune": {
      "name": "Rémi Lejeune"
    },
    "ribel": {
      "name": "Taras Kruts"
    },
    "robert-douglass": {
      "name": "Robert Douglass"
    },
    "rudy-weber": {
      "name": "Rudy Weber"
    },
    "ryan-hicks": {
      "name": "Ryan Hicks"
    },
    "sabri-helal": {
      "name": "Sabri Helal"
    },
    "savannah-bergeron": {
      "name": "Savannah Bergeron"
    },
    "shannon-vettes": {
      "name": "Shannon Vettes"
    },
    "shawn-ogasawara": {
      "name": "Shawn Ogasawara",
      "linkedin": "https://www.linkedin.com/in/shawn-ogasawara-83a9a0/"
    },
    "shawna-spoor": {
      "name": "Shawna Spoor"
    },
    "shedrack-akintayo": {
      "name": "Shedrack Akintayo"
    },
    "simon-ruggier": {
      "name": "Simon Ruggier"
    },
    "sophie-van-der-kindere": {
      "name": "Sophie Van Der Kindere"
    },
    "stefanos-thampis": {
      "name": "Stefanos Thampis"
    },
    "stephen-weinberg": {
      "name": "Stephen Weinberg"
    },
    "sukhman-virk": {
      "name": "Sukhman Virk"
    },
    "sumaira-nazir": {
      "name": "Sumaira Nazir"
    },
    "sumer": {
      "name": "Sümer Cip"
    },
    "syed-raza": {
      "name": "Syed Raza"
    },
    "tamara-bacchia": {
      "name": "Tamara Bacchia"
    },
    "tara-arnold": {
      "name": "Tara Arnold"
    },
    "theosakamg": {
      "name": "Mickael Gaillard",
      "github": "theosakamg"
    },
    "thomasdiluccio": {
      "name": "Thomas di Luccio"
    },
    "tim-anderson": {
      "name": "Tim Anderson"
    },
    "tom-helmer-hansen": {
      "name": "Tom Helmer Hansen"
    },
    "tylermills": {
      "name": "Tyler Mills"
    },
    "upsun": {
      "name": "Upsun"
    },
    "veronika-tolkachova": {
      "name": "Veronika Tolkachova",
      "linkedin": "https://www.linkedin.com/in/veronika-tolkachova-169167a2"
    },
    "vince-parker": {
      "name": "Vince Parker"
    },
    "vinnie-russo": {
      "name": "Vincenzo Russo"
    },
    "vrobert78": {
      "name": "Vincent Robert",
      "github": "vrobert78",
      "linkedin": "https://www.linkedin.com/in/vincent-robert-498a883"
    },
    "yuriy-babenko": {
      "name": "Yuriy Babenko"
    },
    "yuriy-gerasimov": {
      "name": "Yuriy Gerasimov"
    }
  };
  return <div className="post-meta">
      {(authors.length > 0 || formattedDate) && <div className="post-meta-info">
          {authors.length > 0 && <div className="post-meta-authors">
              {authors.map(slug => {
    const {name, url, avatarUrl} = resolveAuthor(slug);
    const inner = <>
                    {avatarUrl && <img src={avatarUrl} alt={name} className="post-meta-avatar" />}
                    <span className="post-meta-author-name">{name}</span>
                  </>;
    return url ? <a key={slug} href={url} target="_blank" rel="noopener noreferrer" className="post-meta-author">
                    {inner}
                  </a> : <span key={slug} className="post-meta-author">{inner}</span>;
  })}
            </div>}
          {authors.length > 0 && formattedDate && <span className="post-meta-separator" aria-hidden="true">·</span>}
          {formattedDate && <span className="post-meta-date">{formattedDate}</span>}
        </div>}
      {image && <img src={image} alt="" className="post-meta-image" aria-hidden="true" />}
    </div>;
};

<PostMeta data={{ author: ["crell"], date: "2016-12-20", image: "/images/posts/unknown/project-variables/project-variables.webp" }} />

<Tip>
  This post was originally published on the Platform.sh blog and reflects information from the time of publication.
</Tip>

As we [wrote about recently](/posts/how-it-works/repeatable-deployments), all of the inputs to an application running on Platform.sh are clearly defined, predictable, and with one exception entirely under your control as a user. We’re happy to announce that we’ve added one more input, and it’s also under user control: Project-level variables available at build time.

Project variables are, as the name implies, just like the [other variables](https://docs.platform.sh/development/variables.html) we already support but bound to a project rather than to a specific environment. That is, they become available for all environments in a project unconditionally rather than just selected environments/branches. If a given environment has a variable of the same name it will override the project variable, but otherwise a project-level variable will be available to all environments.

“So what?” you may say. Variables defined on the master environment already inherit that way, so what’s the big deal? The big deal is that ***project variables are available at build time, too.***

Environment variables are only available on a running container. That is, they’re available to the running application and can be used in a deploy hook, but not in a build hook. Project variables, by contrast, are also available during a build hook.

Why would you want build-time variables? Shouldn’t the build be controlled entirely by what’s in Git? Generally speaking yes, but just as you may need runtime values that are not stored in Git, such as API keys, you may need secret values for the build process, too. The most common use for that is for downloading non-public 3rd party dependencies. In other words, and at the risk of burying the lead:

***We now support private Composer repositories on Platform.sh***

That includes the newly-announced [Private Packagist](https://packagist.com/).

We’ve written up a tutorial to show how to use a [private Composer repository](https://docs.platform.sh/tutorials/composer-auth.html). Give it a try.

There are of course plenty of other things you can do with build-time variables. Let us know what else you are able to do with them.