Introduction
What are the CRX tools?
Four surfaces, each answering a different question about the venue. CRX is an on-chain venue for non-deliverable FX forwards (NDFs). The tools let you read it, trade it, and feed it to an agent — without asking a person.
| Surface | Answers | Reach for it when |
|---|---|---|
| Relayer API | "How do I get a quote and bind a trade?" | You are building a desk, a bot, or any client that quotes or trades |
| On-chain reads | "What is actually settled on-chain?" | You need the ground truth — balances, positions, marks — independent of any service |
| Explorer | "What is the venue doing right now?" | You want venue metrics — flow, makers, settlement — without writing code |
| LLM endpoints | "How do I point an agent at CRX?" | You are wiring an AI agent and need a machine-readable map |
Why two layers — off-chain and on-chain?
Because they tell you different truths. The relayer is a courier, not a custodian. It brokers requests for quote, prices them, and anchors the agreed quote on-chain — but it never holds your money and never decides the trade. The binding happens between two firms, on-chain.
So the off-chain API is fast and convenient; the on-chain reads are authoritative. When the two disagree, the chain wins.
- Off-chain (relayer): the RFQ workflow, margin estimates, the maker and taker registries. Low latency, session-light.
- On-chain (the core contract): balances, master agreements, positions, the mark, settlement state. Read it directly over RPC when you need certainty.
Where do I start?
By the surface that matches your goal.
- Build a client or bot → CRX API → Get started (~4 min). The base URL, auth, and the full endpoint set.
- Read pairs, sessions, and live marks → Pairs & Marks API (~3 min).
- Read positions and settlement for an address → Positions & Settlement API (~3 min).
- Use a client library → SDKs → Get started (~2 min).
- Watch the venue live → Explorer & On-chain Reads (~3 min).
- Wire an agent → Using LLMs (~2 min).
What can the tools not do?
State the limits before you build against them.
No custody endpoint. The relayer never holds funds. Deposits, withdrawals, and binds are on-chain calls you sign yourself.
No order book. CRX is request-for-quote and direct-bilateral. There is no resting book to stream; you ask a maker, the maker answers.
No central counterparty. Each trade is firm-to-firm. The tools never net one party's relationship against another's.
The model behind all of this is one page: How CRX works (~6 min).
Next: CRX API → Get started (~4 min) — the relayer base URL, auth, and the core endpoints.