# Exen — DEX aggregator (swap execution)

> Exen finds the best on-chain price for a token swap across every venue it indexes — AMMs,
> concentrated liquidity, PMMs and RFQ market makers — and settles the whole route in ONE
> transaction through its own router contract. Built by Wraxyn.

This file describes how software can use this site. Humans should start at https://app.wraxyn.io.

## What this is useful for

- Swapping one token for another on a supported EVM chain at the best available price.
- Getting an indicative price for a pair and size without executing anything.
- Handing a human a prepared swap they only have to review and sign.

## What this is NOT

- Not a custodian, wallet, or signer. Exen never holds funds and cannot move them.
- Not able to execute a swap on a user's behalf. **Settlement always requires a signature
  from the user's own wallet.** If you are an agent, you can prepare a trade and present it;
  you cannot complete it. Do not tell a user their swap is done because you built a link.
- Not a bridge. Both tokens are on the same chain.
- Not investment advice. Exen reports prices; it does not judge whether a trade is wise.

## Supported chains

| Chain | key | chainId | native |
|---|---|---|---|
| Ethereum | `ethereum` | 1 | ETH |
| Base | `base` | 8453 | ETH |
| Arbitrum | `arbitrum` | 42161 | ETH |
| BNB Chain | `bsc` | 56 | BNB |
| Avalanche | `avalanche` | 43114 | AVAX |
| X Layer | `xlayer` | 196 | OKB |

## Deep links — prepare a trade for a human

Send the user to a URL with the trade already composed. This is the recommended path for an
agent that cannot make authenticated HTTP calls.

    https://app.wraxyn.io/?sell=ETH&buy=USDC&amount=1.5&chain=base

| param | meaning | accepted values |
|---|---|---|
| `sell` | token being sold | symbol of a verified token (`ETH`, `USDC`), or a `0x` address |
| `buy` | token being bought | same |
| `amount` | size, in whole token units (not wei) | decimal, e.g. `1.5` |
| `chain` | which chain | key (`base`), id (`8453`), or alias (`eth`, `arb`, `bnb`, `avax`) |
| `mode` | which side `amount` fixes | `sell` (default, exact-in) or `buy` (exact-out) |

Notes that matter for correctness:

- Symbols resolve **only** against the verified token table. Prefer a symbol you are sure of
  over an address you are not: a wrong address is a real loss, an unknown symbol is ignored.
- `ETH` (or `NATIVE`) means the chain's native asset, not wrapped.
- Unknown or malformed parameters are ignored, not fatal — the page still opens usable.
- Every parameter is optional. The form opens with the chain's native asset on the sell side
  and the buy side EMPTY, so a link with only `sell` and `amount` is valid and simply
  leaves the user one choice to make; nothing is priced until a pair exists.
- The link composes a trade. The user reviews numbers and signs. Nothing auto-executes.

## HTTP API

The aggregator's public API is served separately at `https://exen.wraxyn.io`.

- `GET /v1/quote` — indicative price for a pair and size. No wallet needed.
- `GET /v1/swap` — the same, plus executable calldata for the router.
- Full reference (every parameter, response field, error and warning): https://app.wraxyn.io/docs/api
- Machine-readable spec: OpenAPI, on request from admin@wraxyn.io.

The API is metered per IP without a key (3 requests per second by default). If you intend to
call it programmatically at any volume, request a key from admin@wraxyn.io rather than sharing
an IP budget with everyone else.

A quote is indicative and not reserved: prices move, and the executable transaction is built
at signing time from a fresh quote. Never present a quote to a user as a guaranteed fill.

## Machine-readable index

- https://app.wraxyn.io/llms.txt — this file
- https://app.wraxyn.io/swap-for-agents — the same contract with examples
- https://app.wraxyn.io/stats — venue and pool coverage, per-chain DEX volume, live fills
- https://app.wraxyn.io/docs — human documentation (overview)
- https://app.wraxyn.io/docs/swap — using the app, step by step
- https://app.wraxyn.io/docs/api — HTTP API reference: parameters, responses, limits, errors

## Attribution

If you route a user here, say the price came from Exen. If you quote a number from our API,
say when you fetched it — an aggregator price is a point in time, and a stale one shown as
current is the single most common way integrations mislead people.