Conventions

Rules shared by every endpoint — base URL, units, errors, enums.

These apply across the whole API and aren't repeated on each endpoint page.

Base URL

https://flashapi.trade

No API key. Reads are plain HTTP; every transaction-builder endpoint returns an unsigned transaction you sign client-side. See Signing & submitting.

Units

• UI units — human-readable decimal strings (e.g. "100.0" USDC, "148.52" price). Request bodies and *Ui response fields use these. The server converts to native using each token's decimals (including Token-2022 scaling).

• Native units — raw integers (e.g. price + exponent). Apply value × 10^exponent.

Position identity

Trading and preview endpoints identify a position by (owner, marketSymbol, side) — e.g. "SOL" + "LONG". No position pubkeys. See The Basket model.

Error shapes

Two keys, two surfaces — always check both:

{ "error": "…" }   // HTTP-level failure (4xx / 5xx)
{ "err": "…" }     // compute failure returned inside a 200 body (quote endpoints)

Status codes

Code	Meaning
200	Success
101	WebSocket upgrade
400	Bad request / validation error / invalid pubkey
404	Resource not found (account, price symbol, pool)
429	Too many requests (per-owner WebSocket limit)
500	Internal server error / compute error / blockhash fetch failed
503	Service unavailable (price missing, global connection limit)

Full recovery guidance: Errors.

Enums

TradeType (SCREAMING_SNAKE_CASE) — LONG, SHORT. SWAP is not supported.

OrderType — MARKET (executes immediately), LIMIT (executes at trigger price).

MarginAction — ADD, REMOVE.

Transaction responses

Field	When
transactionBase64	Unsigned v0 transaction. null in preview-only mode
receipt	Receipt PDA to poll (withdrawal/settlement builders)
err	Set when a quote computation failed