bourse

Elixir client library for ten provider-authored exchange integrations generated from owned JSON specs via compile-time macros.

Status: first public release — the runtime support contract is the ten venues listed below.

Installation

def deps do
  [
    {:bourse, "~> 0.1"}
  ]
end

Lighter private signing

Lighter private endpoints use a host-native helper compiled from the packaged Go and C sources. Install Go 1.23.1 and a C compiler, then build the helper in the consuming Mix project before making private Lighter calls or assembling a release:

mix ccxt.build_lighter_signer

Public Lighter market-data calls do not require the helper. The package does not ship prebuilt native binaries.

Quick Start

# Public market data (no credentials)
{:ok, exchange} = Bourse.Exchange.new("bybit")
{:ok, ticker} = Bourse.fetch_ticker(exchange, "BTC/USDT")

# Authenticated private call
{:ok, exchange} =
  Bourse.Exchange.new("bybit",
    api_key: System.fetch_env!("BYBIT_API_KEY"),
    secret: System.fetch_env!("BYBIT_API_SECRET")
  )

{:ok, balance} = Bourse.fetch_balance(exchange)

Supported Exchanges

Runtime support is closed and invariant across builds. Every supported venue loads one complete owned spec; the version-pinned CCXT corpus retained in the source repository is reference material for authoring and compatibility tests, not runtime support.

Bourse.Registry.exchanges()
#=> ["alpaca", "binance", "binancecoinm", "binanceusdm", "bybit",
#=>  "deribit", "derive", "hyperliquid", "lighter", "okx"]

Bourse.Exchange.new("kraken")
#=> {:error, {:unsupported_exchange, "kraken"}}

Migrating from ccxt_client

bourse is the breaking rename of the former ccxt_client package. Change the dependency name to :bourse, replace the CCXT module prefix with Bourse, move application configuration from :ccxt_client to :bourse, and rename app-specific CCXT_* environment variables to BOURSE_*.

Consumers that cannot migrate in the same release can remain on the final CCXT-namespaced line with {:ccxt_client, "~> 0.6.1"} until their namespace change lands. Every ccxt_client release is retired as renamed, so that dependency resolves with a deprecation warning and receives no further updates.

Two Contracts

bourse exposes two API surfaces with different stability guarantees.

Raw Endpoints — Stable

Per-exchange generated functions that pass through to the exchange API unchanged. Signing, rate limiting, circuit breakers, and transport are handled; the response body is returned as-is.

{:ok, exchange} = Bourse.Exchange.new("bybit", api_key: key, secret: secret)
{:ok, response} = Bourse.Bybit.public_get_v5_market_tickers(exchange, %{category: "spot"})

Recommended for agents, automated trading, and any consumer that wants to interpret exchange responses directly.

Unified API — Evolving

Standardized cross-exchange methods return the unified structs declared by each owned venue spec where that method is supported.

{:ok, ticker} = Bourse.fetch_ticker(exchange, "BTC/USDT")

Capability and routing introspection are available through Bourse.Exchange.has?/2 and each generated module's __unified_endpoints__/0.

WebSocket — Early

{:ok, ws} = Bourse.WS.connect(exchange, :public)
:ok = Bourse.WS.subscribe(ws, ["tickers.BTCUSDT"])
# Messages arrive at the calling process as {:websocket_message, decoded_map}
Bourse.WS.close(ws)

Thin wrapper over zen_websocket driven by authored per-exchange subscription and auth patterns. Callers pass exchange-native channel strings.

Known Caveats

Consumer-facing gotchas not obvious from the API signatures. Full context in CLAUDE.md and ROADMAP.md.

• has?/2 is support introspection, while endpoint mapping is the dispatch gate. Cross-check a venue's generated __unified_endpoints__/0 when choosing among multiple native endpoint families.

• Signing is a closed authored contract. HMAC venues execute their authored deterministic recipes. Derive, Hyperliquid, and Lighter use bundled first-party signers. Consumers cannot register a reference-only exchange or inject a long-tail signer. Derive and Hyperliquid expect the EVM private key in credentials.secret; Lighter uses its documented API signing key.

• Every supported venue resolves a sandbox, but sandbox semantics differ.Exchange.new(id, sandbox: true) succeeds for all ten venues; what it selects is venue-specific. Some venues swap the host (Alpaca paper trading), some add a header to the production host (OKX simulated trading), and some change signed payload material (Lighter also switches chain id). A venue's sandbox may additionally be read-only or region-restricted for signed writes, which surfaces as a business error rather than a transport failure. Check the venue's own sandbox documentation before treating a sandbox pass as production-equivalent.

Discovery

Bourse.describe()                      # Library overview
Bourse.describe(Bourse, :fetch_ticker) # Method signature + params + errors + return shape
Bourse.MCP.tools()                     # MCP tool definitions for agent autodiscovery
Bourse.Registry.exchanges()            # List the ten runtime exchange ids

Per-exchange introspection (generated on every exchange module):

Bourse.Bybit.__spec__()               # Raw spec map (describe output)
Bourse.Bybit.__endpoints__()          # List of %{path, method, authenticated, weight, ...}
Bourse.Bybit.__signing__()            # %{pattern: :hmac_sha256_headers, config: %{...}}
Bourse.Bybit.__unified_endpoints__()  # Unified-method → endpoint-config mapping

Documentation

• ROADMAP.md — active work, priorities, upstream dependencies
• CHANGELOG.md — completed tasks and known limitations
• CLAUDE.md — architecture, design decisions, internal conventions
• CONTRIBUTING.md — how to land code and authored-spec fixes

Authoring Exchange Changes

This section is for work inside the source repository. The authoring and audit Mix tasks named below are repo-internal and are not part of the published package; only mix ccxt.build_lighter_signer ships to consumers.

For a supported venue, author the owned spec or normalization slice against the provider's API behavior and provider-owned documentation. Register the applicable live recording, accepted-request golden, or recorded exchange error and keep the ccxt.oracle_gate Mix task green. CCXT and ccxt-distill remain reference/bootstrap material only; they do not establish venue semantics.

An unsupported venue enters through the ccxt.promote_venue Mix task; copying a reference spec into the repository does not make it runtime-supported. See CONTRIBUTING.md and docs/authored-specs.md.

Development

Checks for work inside the source repository:

mix deps.get
mix test.json --quiet
mix dialyzer.json --quiet
mix credo --strict --format json

License

MIT — see LICENSE.