(RuntimeError) environment variable WOLFRAM_APP_ID is missing

You need to set an environment variable that’s visible to your BEAM process. How to do that depends on your operating system.

If you use linux/mac with a sh compatible shell, then it’s export, for fish and windows it’s set.

I have a Mac OS Mojave

Yeah just see my edited post.

It’s export then (under the assumption that you use bash or zsh, which both are the default shells in Mac, depending on the version, but as I’m not a Mac user by myself I have no clue when the change happened)

Hi,

echo $SHELL

Mojave: /bin/bash → .bash_profile
Catalina: /bin/zsh → .zprofile

https://forum.elixirforum.com/t/programming-phoenix-could-not-fetch-application-environment-wolfram/26584

I’d not hardcode it into any of those…

I use zsh.
So I put in the ~/.zshrc file?

I readed before this post, but it’s not my case.

defmodule InfoSys.Wolfram do
  import SweetXml
  alias InfoSys.Result

  @behaviour InfoSys.Backend

  @base "http://api.wolframalpha.com/v2/query"

  @impl true
  def name, do: "wolfram"

  @impl true
  def compute(query_str, _opts) do
    query_str
    |> fetch_xml()
    |> xpath(~x"/queryresult/pod[contains(@title, 'Result') or
                                 contains(@title, 'Definitions')]
                            /subpod/plaintext/text()")
    |> build_results()
  end

  defp build_results(nil), do: []

  defp build_results(answer) do
    [%Result{backend: __MODULE__, score: 95, text: to_string(answer)}]
  end

  defp fetch_xml(query) do
    {:ok, {_, _, body}} = :httpc.request(String.to_charlist(url(query)))

    body
  end

  defp url(input) do
    "#{@base}?" <>
    URI.encode_query(appid: id(), input: input, format: "plaintext")
  end

  defp id, do: Application.fetch_env!(:info_sys, :wolfram)[:app_id]
end

As I said, I’d not hardcode it there for several reasons, but use a .env or .envrc for the project (not comitted into source control) and source it before working with the project.

direnv is a nice tool for such setups. It will automatically “execute” .envrc files when entering a directory, if that directory is “trusted”.

Just for help if someone stopped like me in this part of the book, I’ll share what I do for run correctly.
I create inside the config folder a .env file and then add:
export WOLFRAM_APP_ID="XXXXXX-XXXXXXXXXX"
then after I run on terminal:
source config/.env
And then I try iex -S mix:

iex(1)> InfoSys.compute("what is elixir?")
[
  %Task{
    owner: #PID<0.366.0>,
    pid: #PID<0.368.0>,
    ref: #Reference<0.625303463.500432897.47893>
  }
]

and work’s.

Then I add in the .gitignore file:

# Ignore .env files 
/.env

for not share by git the WOLFRAM_APP_ID.
Is that correct what I’m doing?
Thank’s for Help @Nobbz and @fun2src.

This will only ignore .env from the repositories root. If you want to exclude config/.env, then you have to do /config/.env, assuming that git-root and project root are the same.

Other than that, the flow seems to be correct, though I prefer to have .env(rc) files in the project root for discoverability.