For agents

Documentation

Exen is a DEX aggregator. It prices a swap against every venue it indexes on a chain — AMMs, concentrated liquidity, proprietary market makers and RFQ desks — splits the trade across whichever combination pays best, and settles the whole route in one transaction through its own router contract. It is built by Wraxyn.

Two ways to use it

They are the same engine and the same prices. Pick by who is doing the swapping.

The app

Use it if: A person is doing the swap and will sign it in their own wallet.
Start at: Swapping in the app

The HTTP API

Use it if: Software is pricing or building the swap — a wallet, a bot, another aggregator, a solver.
Start at: HTTP API

	Use it if	Start at
The app	A person is doing the swap and will sign it in their own wallet.	Swapping in the app
The HTTP API	Software is pricing or building the swap — a wallet, a bot, another aggregator, a solver.	HTTP API

The app is a client of the API and gets no private endpoint, no reserved liquidity and no better price than you would get calling it yourself.

Supported chains

Ethereum

Chain ID: 1
Native: ETH
Key: ethereum

Base

Chain ID: 8453
Native: ETH
Key: base

Arbitrum

Chain ID: 42161
Native: ETH
Key: arbitrum

BNB Chain

Chain ID: 56
Native: BNB
Key: bsc

Avalanche

Chain ID: 43114
Native: AVAX
Key: avalanche

X Layer

Chain ID: 196
Native: OKB
Key: xlayer

Polygon

Chain ID: 137
Native: POL
Key: polygon

Robinhood

Chain ID: 4663
Native: ETH
Key: robinhood

Chain	Chain ID	Native	Key
Ethereum	1	ETH	`ethereum`
Base	8453	ETH	`base`
Arbitrum	42161	ETH	`arbitrum`
BNB Chain	56	BNB	`bsc`
Avalanche	43114	AVAX	`avalanche`
X Layer	196	OKB	`xlayer`
Polygon	137	POL	`polygon`
Robinhood	4663	ETH	`robinhood`

Both tokens are always on the same chain — Exen routes, it does not bridge. Live pool and venue coverage per chain is on the stats page, and GET /v1/{chain}/sources returns the machine-readable list.

Four things worth knowing before either path

A quote is not a reservation. Nothing is held. Quotes are stateless: the transaction you eventually sign is built from a fresh solve at that moment, which is why the number in the review step can differ from the one you were reading.
The floor is what is enforced, not the quote. A sell carries a minimum-received amount derived from your slippage tolerance; the transaction reverts below it. An exact-output buy delivers the target amount to the wei or reverts. Everything between the quote and the floor is ordinary market movement.
Exen never holds your funds. The router moves tokens within a single transaction that you sign; it has no custody, no balance of yours between transactions, and nothing here can move funds without a signature from your own wallet.
Amounts are integers, in base units. Every amount on the wire is a decimal string of wei — 1500000 is 1.5 USDC. Token decimals vary by chain and are not guessable (BSC stables are 18 decimals, not 6).

Reference material

API base URL

https://exen.wraxyn.io

OpenAPI specification

/openapi.yaml · /openapi.json — the published contract, for client generators and API tools.

The whole API as one file

/api.md — every endpoint, parameter, response field, error and warning as flat Markdown. Built for an LLM or an agent: one fetch, no navigation.

API access

https://exen.wraxyn.io is open with no key at 3 req/s. Need a rate budget of your own? Add an API key — same URL; ask admin@wraxyn.io.

Agent / LLM contract

/llms.txt and /swap-for-agents — deep links that compose a trade for a human to sign.

Coverage and live activity

/stats

Terms and privacy

/terms · /privacy

What	Where
API base URL	`https://exen.wraxyn.io`
OpenAPI specification	/openapi.yaml · /openapi.json — the published contract, for client generators and API tools.
The whole API as one file	/api.md — every endpoint, parameter, response field, error and warning as flat Markdown. Built for an LLM or an agent: one fetch, no navigation.
API access	`https://exen.wraxyn.io` is open with no key at 3 req/s. Need a rate budget of your own? Add an API key — same URL; ask admin@wraxyn.io.
Agent / LLM contract	/llms.txt and /swap-for-agents — deep links that compose a trade for a human to sign.
Coverage and live activity	/stats
Terms and privacy	/terms · /privacy

Fees

Swaps in the app carry a fee on the token you receive. It is already included in every figure you are shown — the quote, the minimum received, and the amount you sign — so the number in the app is the number you get, not a number to subtract from.

Wrapping or unwrapping the native coin

Fee: None
What counts: ETH↔WETH, BNB↔WBNB and the equivalent on every chain. No fee at all — the swap is 1:1 by contract.

Between major assets

Fee: 5 bps (0.05%)
What counts: Fiat stablecoins, Ether, and the chain’s own gas coin in either form — on both sides of the trade.

Everything else

Fee: 10 bps (0.10%)
What counts: Any trade with at least one endpoint outside the list above.

Trade	Fee	What counts
Wrapping or unwrapping the native coin	None	ETH↔WETH, BNB↔WBNB and the equivalent on every chain. No fee at all — the swap is 1:1 by contract.
Between major assets	5 bps (0.05%)	Fiat stablecoins, Ether, and the chain’s own gas coin in either form — on both sides of the trade.
Everything else	10 bps (0.10%)	Any trade with at least one endpoint outside the list above.

Calling the API without a key is priced separately: 10 bps (0.10%) on the buy token, stated in the fee block of every response. That is a property of being anonymous rather than of any particular trade — a key of your own carries whatever we agree with you. See Add an API key.

[ subject to change ]

These rates are a starting point and we expect to revise them. They are not a commitment, and a trade is always priced at the rate in force when you request the quote — which is the rate shown to you at that moment.

If a rate does not work for what you are building — high volume, a fee split, an integration where the economics need to look different — we would rather hear about it than lose the use case. Write to admin@wraxyn.io and tell us what you are doing.

Getting in touch

[ contact ]

API keys, higher rate limits, integration help, listing a venue, or anything these pages do not answer: admin@wraxyn.io. Tell us what you are building and the chains you care about — that is enough to issue a key.