An Elixir client for OpenFeed — Australian Consumer Data Right banking and energy data.

OpenFeed implements the FAPI 2.0 Security Profile. This library's job is to make that a detail you do not think about: PAR, PKCE S256, DPoP proofs on every call, private_key_jwt client authentication, and the key management that implies.

Using Ash? See ash_openfeed, which builds on this and adds grant persistence, token refresh and an installer.

Where to look

Setting up

Generate a key and register its public half with OpenFeed:

mix openfeed.gen.key --path priv/openfeed.jwk
mix openfeed.jwks --path priv/openfeed.jwk

Build a config and add this module to your supervision tree, which starts the OIDC discovery worker so metadata is fetched once rather than per call:

config =
  OpenFeed.Config.new!(
    client_id: System.fetch_env!("OPENFEED_CLIENT_ID"),
    redirect_uri: "https://my.app/openfeed/callback",
    key_store: {OpenFeed.KeyStore.File, path: "priv/openfeed.jwk"}
  )

children = [{OpenFeed, config}, MyApp.Repo, MyAppWeb.Endpoint]

The consent flow

# 1. Starting out — keep all three values in the session.
flow = OpenFeed.Auth.new_flow()
{:ok, url} = OpenFeed.authorize_url(config, Enum.to_list(flow))
redirect(conn, external: url)

# 2. At your callback, having checked `state` matches.
{:ok, tokens} =
  OpenFeed.exchange_code(config, code,
    nonce: flow.nonce,
    pkce_verifier: flow.pkce_verifier
  )

# 3. Later, when the access token is close to expiry.
{:ok, tokens} = OpenFeed.refresh(config, tokens.refresh_token, tokens.sub)

Reading data

{:ok, accounts} = OpenFeed.Sharing.banking_accounts(config, tokens.access_token)

{:ok, transactions} =
  OpenFeed.Sharing.banking_transactions(
    config,
    tokens.access_token,
    account["accountId"],
    oldest_date: Date.add(Date.utc_today(), -365)
  )

Branch on OpenFeed.Error's :kind rather than on HTTP status — in particular, :grant_revoked means stop and ask the consumer to reconnect, while :subject_mismatch is also a 403 but means something has gone wrong on your side.