crypto-publicdata

Real-time multi-exchange market data service written in OCaml. Connects to crypto exchanges in public-data-only mode (no API keys), aggregates per-symbol ticker data into a single in-memory cache, stores realtime kline (OHLCV) history for a curated subset of venues, and re-broadcasts everything over a WebSocket + REST API at the root path.

Status: early scaffolding. The architecture and wire protocol are described in CLAUDE.md; code is still landing.

Prerequisites

• macOS or Linux
• A recent OCaml toolchain (5.x) installed via opam

Install opam

macOS (Homebrew):

brew install opam

Linux (Debian/Ubuntu):

sudo apt-get install opam

Or follow the official installer.

Initialize opam (first time only)

opam init --bare -a -y

Set up the project switch

From the repo root, create a local switch pinned to OCaml 5.2 and install the dev tools:

opam switch create . 5.2.0 --deps-only --yes
eval "$(opam env --switch=. --set-switch)"

opam install --yes \
  dune \
  ocaml-lsp-server \
  ocamlformat \
  utop

Add the eval line to your shell profile (or use direnv with use opam) so the switch activates automatically when you cd into the repo.

Common commands (once the project is scaffolded)

dune build            # build all
dune runtest          # run tests
dune exec bin/main.exe # run the service
dune fmt              # format via ocamlformat
dune build @check     # type-check without linking

Dependencies for runtime libraries (HTTP server, WebSocket client, JSON, async runtime, storage backend, ...) will be pinned in the project's *.opam files as they land. Re-run opam install --deps-only --with-test . after pulling to stay in sync.