Authentication and runtime configuration

hf_hub_ex is a library: it does not read operating-system environment variables directly from runtime modules. The host application owns that boundary and passes configuration through options or application config.

Recommended host setup

For an application or script, read secrets in config/runtime.exs or an equivalent config provider:

import Config

if token = System.get_env("HF_TOKEN") do
  config :hf_hub, token: token
end

cache_dir = System.get_env("HF_HUB_CACHE") || System.get_env("HF_HOME")
if cache_dir, do: config(:hf_hub, cache_dir: cache_dir)

case System.get_env("HF_HUB_OFFLINE") do
  value when value in ["1", "true", "TRUE", "yes", "YES"] ->
    config :hf_hub, offline: true

  _ ->
    :ok
end

For one-off IEx usage, passing token: explicitly is also fine:

token = System.fetch_env!("HF_TOKEN")
{:ok, repo} = HfHub.Repo.create("my-org/my-dataset", repo_type: :dataset, token: token)

Library defaults

• HfHub.Auth.get_token/0 reads Application.get_env(:hf_hub, :token).
• HfHub.Config.cache_dir/0 reads Application.get_env(:hf_hub, :cache_dir) and defaults to ~/.cache/huggingface.
• HfHub.offline_mode?/0 reads Application.get_env(:hf_hub, :offline).

Local development

Use your preferred shell secret manager (direnv, a private wrapper script, or your deployment platform's secret manager) to set HF_TOKEN before starting the host app. Do not commit tokens to config files.