DpExchangeGemini

⚠️ EXPERIMENTAL — read this before depending on it

This package has never run in production. It is published early and openly so it can be used and reported on, not because it is finished.

• The API may change without a major version. Pin three-part (~> 0.2.106 or later).
• Verification is uneven, and the gaps are on the expensive side. The conformance suite passes against a fake, and against Gemini's live public endpoints. Order placement and authenticated flows are thinly covered. No test in this repo spends money.
• Maturity is declared per endpoint. Read capabilities/0, not this banner.

Report a divergence.

Gemini for the DpExchange family: market data, trading and streaming behind the same facade every venue in the family exposes.

What this package covers

88 callbacks, of which 64 are declared :experimental and 24 :unsupported. None is :proven — that requires a consumer trading live, and this package has never run in production (D15).

Placing an order: place_order(credentials, %{symbol: "BTC-USD", side: :buy, order_type: :limit, time_in_force: :gtc, quantity: Decimal.new("1"), price: Decimal.new("100")}, opts). Nothing is defaulted, an unknown request key is refused, and a placement that may have reached the venue is {:error, {:order_unconfirmed, client_order_id_or_nil, reason}} - reconcile before placing again. See usage-rules.md.

Asset classes: crypto. Streamed kinds: quotes, top of book, trades (:trades is opt-in via Feed's channels:) — everything else pulls only.

Of the 24 unsupported endpoints, 22 are the venue's own absence, not this package's backlog — see venue_does_not_serve/0 and docs/reference/gemini/negative-claims.md, which records the source and date behind every one.

Installation

def deps do
  [
    {:dp_exchange_gemini, "~> 0.2.106"}
  ]
end

Usage

# In your supervision tree. Nothing starts itself.
children = [{DpExchange.Gemini, []}]

{:ok, last_trade} = DpExchange.Gemini.get_price("BTC-USD", [])

:ok = DpExchange.Gemini.subscribe(["BTC-USD"], to: self())

# Credentials are an argument to the call that needs them. The child keeps none: they sign
# that one request and are not stored.
{:ok, balances} = DpExchange.Gemini.get_balances(my_credentials(), [])

Streamed data arrives in the subscriber's mailbox as {:dp_exchange, :gemini, payload}, where payload is a Quote, TopOfBook or (with channels: [..., :trades]) a Trade. Link and data-quality conditions arrive separately, as the same message shape carrying a DpExchange.Core.Notice, to processes that called DpExchange.Gemini.subscribe_notices/1. Quote.venue_time and TopOfBook.venue_time are nil from REST (the venue states no quote time); observed_at states freshness.

DpExchange.Gemini is the entire public API. Everything else — transport, signing, session handling, supervision — is internal, and the conformance suite asserts it.

See dp_exchange_core for the contract, and this package's usage-rules.md for what is specific to Gemini.

License

MIT. See LICENSE.