For AI agents: the documentation index is at /llms.txt, and this page is available as Markdown at /documentation/exchange-overview.md.
Exchange overview
The True Markets exchange is a central limit order book. Its matching engine fills each incoming order against resting orders in price-time priority: the best price first, and the earliest order at that price first.
The exchange settles in one designated stablecoin. Fiat and other stablecoins are converted to it on deposit, and every trading pair is quoted in it.
Order types
A limit order buys or sells a quantity at a price you set or better. Use it when the price matters more than filling right away.
A market order buys or sells a quantity at the best prices on the book. Use it when filling right away matters more than the price.
Time in force
Time in force (TIF) sets how long an order stays on the book.
- Good Till Canceled (GTC): the order rests until it fills completely or you cancel it.
- Immediate Or Cancel (IOC): the order fills what it can against the book right away, and the exchange cancels the rest.
A market order never rests on the book, whatever its time in force.
Order checks
- Price bands: the exchange rejects an incoming order priced too far from the current market. See Price bands.
- Increment sizes: every price and quantity must be a multiple of the minimum increment for its price range. See Increment sizes.
The Rulebook has the full trading rules.
Protocols
You reach the exchange over REST, WebSocket or FIX. REST and WebSocket are reachable over the internet. FIX runs over a private network connection that we set up with your firm.
| Protocol | Use it for | Authentication | Reference |
|---|---|---|---|
| REST | orders, balances, transfers, trade history and market data over HTTPS | an HMAC-SHA256 signature in request headers | CeFi direct REST |
| WebSocket | streaming order books, trades and instrument updates | an HMAC-SHA256 or ES256 signature in the subscription message; public channels need none | CeFi direct WebSocket |
| FIX | low-latency order entry, market data and drop copy | a signed Logon (35=A) that opens the session | CeFi direct FIX |
FIX (Financial Information eXchange) is the standard protocol for institutional order flow. Drop copy is a read-only FIX session that mirrors every execution on your account, for allocation, compliance and audit.
We issue credentials during onboarding. Access and credentials explains how to apply.
Support
- Discord: discord.gg/SC92xRUZqw, for general and integration questions.
- Email: [email protected], for onboarding, accounts and network access.