Introduction

spool is a launchpad and AMM on Solana where every pool pulls each swap through its own line of Knots.

A knot is one rule with one job: tax early buys, raise the fee on a hard pull, burn a share, pay the LPs. You tie up to eight of them onto a pool when it opens. From then on every swap meets them in the same order, and nobody can retie them, the creator included.

Why knots

Most launches pick their rules after the fact, in a tweet. On spool the rules are part of the pool. A trader reads them before the first swap, a quote shows what each knot will take, and the receipt lands on chain.

What is in these docs

• How a swap runs: the three stages and the order knots fire in.
• Knots: every knot with its parameters and bounds, read live from lib/spool.js.
• Builder and Scan: the two tools on this site and what they check.
• spool.js: the client, its functions and formats.
• Limits: what spool protects against and what it cannot.

Quick start

Price a swap through a line of knots in five lines of code.

Import spool.js

The client is one ES module with no dependencies. Import it straight from this site.

import * as spool from "https://spoolliq.vercel.app/lib/spool.js";

const line = spool.fromPreset("recommended");
console.log(spool.quote(line));     // { buy: [3.3, 15.3], sell: [0.3, 2.3] }
console.log(spool.check(line).ok);  // true
console.log(spool.moneyMap(line));  // where every fee of a buy lands

<script type="module">
  import { fromPreset, quote } from "https://spoolliq.vercel.app/lib/spool.js";
  document.body.textContent = JSON.stringify(quote(fromPreset("fair")));
</script>

# the call scanMint() makes, by hand
curl -s https://solana-rpc.publicnode.com -H 'content-type: application/json' \
  -d '{"jsonrpc":"2.0","id":1,"method":"getAccountInfo","params":["EPjFWdd5AufqSSqeM2qN1xzybapC8G4wEGGkZwyTDt1v",{"encoding":"jsonParsed"}]}'

Try it

Pick a line and run it through the real module, loaded from this site.

Next

Read How a swap runs, then tie your own line in the builder.

How a swap runs

One swap, one transaction, three stages. Knots fire in the order they sit on the line.

The three stages

Anti-Snipe sits in two stages: its slot cap is a guard, its decaying tax is a fee. The builder files it under before, because that is where it can refuse a buy.

Order

Within a stage, knots run in the order they were tied. The order is part of the pool and cannot change. spool.js sorts a line by stage the same way the pool does, so line() always returns the order a swap meets.

The quote

A quote names every charge separately: the base LP fee, then one row per knot. charges(line, side, at) returns those rows for a buy or a sell, at the calmest swap or at every knot's ceiling.

All knots

Thirteen knots in three groups. This table is built from KNOTS in spool.js, so it is always what the builder uses.

Bounds

Every parameter has a minimum and a maximum. A value outside them is clamped when a line is built, so a shared link cannot smuggle in a 90% tax.

Protection knots

Four knots that decide who can buy, how much and when.

Anti-Snipe

For the guard length after launch, every buy pays a tax that starts at the top rate and decays to zero, slot by slot. Each slot also has a buy cap as a share of supply. Sells never pay it. Defaults: 10% tax, 150 slots (about a minute), 0.5% cap per slot.

Wallet Cap

While the guard lasts, no wallet buys more than a set share of supply. The cap counts one wallet across all pools of the same launch, so splitting a buy between pools does not get around it. It charges nothing.

Launch Window

Buys can open a few seconds late, so the first slot is nobody's. Sells can stay shut until the pools have filled. It charges nothing.

Sandwich Guard

Each slot window remembers its opening price. A swap that moves price back toward it pays a fee on that move, up to the cap. The back leg of a sandwich always does. With a Holder Pot on the line, the charges fill the pot; without one, they go to LPs.

Fee knots

Four knots that set what a swap pays beyond the base fee.

Drag Fee

Named after the drag on a reel: the harder the pull, the more it resists. The fee grows with how far the swap pushes price from its recent reference, at the slope you set, up to the cap. A swap toward the reference pays the base fee only.

drag = min(cap, slope × |move %|)     // only when the move is away from the reference
// slope 0.08, a 2% push → +0.16%

Storm Fee

Volatility over the last 64 slots places the fee between a floor and a ceiling. Calm water, low fee.

Exit Clock

Sells pay a rate that runs from the top down to the floor over the horizon, by how long the tokens sat in the seller's wallet. It never blocks a sell.

Creator Cut

A flat rate on both sides, paid to the creator in the same transaction. It cannot be raised later.

Reward knots

Knots that run after the swap fills and send value somewhere.

Auto Burn

A share of the tokens a buy receives is burned in the same instruction. Supply only goes down.

LP Rewards

An extra fee on buys, kept by the liquidity that was in range when the buy filled. LPs who lock longer earn a larger weight.

Holder Pot

Sandwich Guard fills it. Once per period it pays every holder by balance times time held. It charges nothing by itself.

Biggest Catch

A trophy for the biggest single buy of each round.

Rounds

Rounds align to UTC, from 15 minutes to a day. The biggest single buy holds the trophy until a bigger one lands. Several small buys from one wallet do not add up.

The prize

At the close the holder takes the prize share of the pot, 50% by default. The rest streams to LPs over the next round. The pot is filled by Arb Recapture, so Biggest Catch needs it on the same line.

Arb Recapture

When a pool drifts from its reference price, the swap that closes the gap pays most of the profit back.

The split

Ordinary swaps never pay it. It only applies to the part of a swap that closes a gap.

Pool terms and caps

Two terms tied with every pool, and the caps every line must fit.

Terms

Caps

Caps are checked at every knot's ceiling, not at the calmest swap. A line that could ever charge too much does not open.

Money map

Where every fee of one swap lands, as a share of the swap.

Recipients

Example

The recommended line at a buy's ceiling: base 0.3% to LPs, Anti-Snipe 10%, Drag Fee 2%, Auto Burn 1%, LP Rewards 2%, spool share 20%. LPs get 11.5%, the burn 0.8%, spool 3%.

Multi-pool launch

One token, up to eight pools, one transaction.

A launch creates the token and opens one pool per quote asset: SOL, USDC, USDT and so on. Each pool has its own liquidity, its own base fee and its own line of knots. If any pool fails a check, the whole launch fails and nothing opens.

Dev buy lock

A creator can buy inside the launch transaction. The pools' liquidity then stays locked for the term they set, while fees stay collectable.

LP lock boost

LPs who lock a position for longer earn a larger share of LP Rewards and of the Catch pot's remainder.

Fee lines

Turn a pool's fee right into a token whose stakers share the income.

Minting

The fee right is locked behind a fixed-supply token. No owner, no second mint. Every swap in the pool then pays the token's stakers, released over up to 14 days and claimable whenever they like.

Terms that end

A fee line can run for good or for a term. When a term ends, the fee right reels back to its owner.

Builder

Tie knots into a line and see, as you go, whether a pool would open with it.

How to use it

1. Start from a ready-made line, or blank.
2. Say whether the token is new or already trades. Launch-only knots go away for the second.
3. Tap knots in the catalog to tie them on. Open one to set its parameters.
4. Read Checks, What a swap pays and the Money map on the right.
5. Copy the link, or copy the PoolParams.

What Checks means

Errors stop a pool from opening: too many knots, a ceiling over a cap, a floor above its top. Notes do not: a pot with nothing to fill it, a cap named at launch. Meters show each cap at every knot's maximum.

Open the builder

Scan

Read any Solana token or pool before you trade.

What it reads

• The mint account, through getAccountInfo with jsonParsed: mint and freeze authority, supply, decimals, program.
• Token-2022 extensions: transfer fee, transfer hook, permanent delegate, non-transferable, default account state.
• Every Solana pool DexScreener has indexed, with venue, liquidity and volume.

Paste a pool address and Scan looks up its base token first.

Verdicts

Flagged lines: a live mint authority, a live freeze authority, a non-zero transfer fee, a non-empty transfer hook, a permanent delegate, non-transferable tokens, a default frozen state.

spool.js reference

One ES module at /lib/spool.js. No dependencies, no keys, it signs nothing.

Lines

Fee math

Formats

Chain

import { scanMint, pools } from "https://spoolliq.vercel.app/lib/spool.js";
const r = await scanMint("DezXAZ8z7PnrnRJjz3wXBoRgixCa6xjnB7YaB1pPB263");
console.log(r.verdict, r.lines.map(l => l.label + ": " + l.value));
console.log((await pools(r.address))[0]);

Share links

The whole line in one URL fragment.

The builder keeps its state in #h=. The value is URL-safe base64 of a short text: terms first, then one knot per segment with its parameters in catalog order.

0.3,20;antisnipe:10,150,0.5;drag:0.08,2;burn:1;lprewards:2
// base fee, spool share ; id:params ; id:params …

decode() clamps every value to its bounds and drops unknown ids, so a hand-edited link can only produce a valid line.

PoolParams

The object a launch carries for each line.

Example

Methodology

How the figures on the main page are counted.

Until a figure has been read it shows a dash, never a zero.

Errors

Threat model and limits

What knots protect

• Snipers in the first slots: Anti-Snipe, Wallet Cap, Launch Window.
• Sandwiches: Sandwich Guard makes the back leg pay.
• Outside arbitrage bots: Arb Recapture keeps most of the gap in the pool.
• Retuning after launch: knots are tied with the pool, nobody can change them.

What they cannot

• A token whose mint authority is still live. Read it in Scan.
• Pools of the same token on other venues. Their swaps never meet spool knots.
• A creator who sells. Knots price a sell; they do not forbid it.
• Fake tokens with the same ticker. A token is its address.

$SPOOL

The token of the spool line.

The contract above comes from the same settings line as the main page. Scan it like any other token: Scan.

FAQ

Can a creator change the knots later?

No. Knots are tied when the pool opens. A new line means a new pool.

Does a knot ever block a sell?

Only Launch Window can, and only for the lock time you set at launch, at most an hour. Exit Clock prices a sell, it never blocks it.

Why does my quote show a range?

Drag Fee, Storm Fee, Sandwich Guard and Anti-Snipe depend on the moment. The range runs from the calmest swap to every knot's ceiling. Your swap lands somewhere inside it.

Does spool take part of the base fee?

No. The base fee goes to LPs in full. spool's share comes only from knot fees.

Can I use spool.js in my own app?

Yes. Import it from this site or save the file. MIT.