Swapping and quoting

The swap instruction

Swap takes four arguments: side (0 buy: quote in, base out; 1 sell), mode (0 exact-in, 1 exact-out), amount, and limit, which is the minimum output for exact-in and the maximum input for exact-out. A swap that can't meet its limit fails with SlippageExceeded and moves nothing.

There is no router contract: a swap is one instruction against one pool. To split a trade across a launch's pools, put several Swap instructions in one transaction.

Quote first

quoteSwap runs the program's pipeline in TypeScript against a decoded pool at a given time and slot, and returns the input, the output, every charge and the pool afterwards.

import { Connection, PublicKey } from "@solana/web3.js"
import { decodePool, ix, minOut, poolRef, quoteSwap } from "@/sdk/src"

const info = await connection.getAccountInfo(poolAddress)
const pool = decodePool(info!.data)
const slot = BigInt(await connection.getSlot())
const now = BigInt(Math.floor(Date.now() / 1000))

const q = quoteSwap(pool, 1_000_000_000n, { now, slot, buy: true }) // 1 SOL in
const swap = ix.swap({
  user, pool: poolRef(poolAddress, pool), userBase, userQuote,
  side: 0, mode: 0, amount: 1_000_000_000n, limit: minOut(q.output, 50), // 0.5%
})

Quote close to sending: the dynamic fee, the Storm level, the Snipe tax and the LP stream all move with time. maxIn does the same job for exact-out.

Accounts a swap may need

Every optional account slot is filled with the reel program id when unused. With the SDK, pass the ones the pool's blocks need in extra; anything you leave out is filled for you.

When the base mint is a reel-launched token, the seven reel-hook accounts follow, in this order: reel-hook, extra metas, mint guard, reel program, source holder, destination holder, destination agent. ix.swap appends them for a hooked pool, and hookExtras(mint, srcOwner, dstOwner) returns them for your own builders.

Rules that refuse a swap

Market Guard's feed check

Market Guard reads the Pyth PriceUpdateV2 account pinned at PoolInit and checks its feed_id on every read. A missing or stale feed refuses every swap, sells too. So who can write that account matters: a creator-written PriceUpdateV2 lets its writer halt the pool by not posting, while Pyth's sponsored push feed can be refreshed by anyone with a verified update.

A Market Guard pool's Details tab reads the pinned account when it opens (and again when you come back to the browser tab), and shows its write authority (bytes 8..40):

• "Market Guard reads a Pyth sponsored feed" (info) when all three hold: the account is owned by the Pyth receiver (rec5EKMG…), its write authority is the account itself, and its address is the Pyth Push Oracle's (pythWSns…) shard-0 PDA for the pool's feed_id. Pyth's SOL/USD sponsored feed, 7UVimffxr9ow1uXYxsr4LHAcV58mLzhmwaeKvJ1pjLiE, is that PDA for its feed id.
• "Check Market Guard's feed writer" (warning) otherwise, naming the writer. Only shard 0 is recognised, so a push-oracle feed on another shard gets the warning too.
• "Market Guard feed not readable" (warning) when the account is missing or can't be read.

The check doesn't read the price's age: oracle_max_age is enforced by the program at swap time. Pin the sponsored feed for the pair when you open a Market Guard pool.

Exact-out, SOL and rounds

• Exact-out is solved by inverting the charges at their ceilings, then running the swap forward. You receive at least what you asked for, sometimes a few atoms more, and pay at most limit. A swap that closes a recapture gap usually fails as exact-out: use exact-in.
• SOL trades as wrapped SOL. wrapSolIxs creates and funds the account before a buy, unwrapSolIx closes it after a sell, in the same transaction.
• King of the Pool rounds are closed by KotpSettle, which anyone may send. Put it before the first swap after a round ends (ix.kotpSettle) so the round settles as trading goes on.