epsilon-exchange

Python SDK for Epsilon — non-custodial limit, stop-loss, and DCA orders on Robinhood Chain, via the Epsilon /v1 API.

Your private key never leaves your machine: orders are built and EIP-712 signed locally, and the API only ever sees the signed payload. The signing implementation is pinned byte-for-byte against the TypeScript SDK and the Go verifier by a shared golden fixture.

Install

pip install epsilon-exchange

Get an API key at developers.epsilon.exchange/dashboard.

Place a limit order

from epsilon_exchange import (
    EpsilonClient, build_and_sign_order, parse_units, calculate_trigger_price,
)

client = EpsilonClient(api_key="eps_...")
private_key = "0x..."   # the wallet that holds the tokens
wallet = "0x..."        # its address

# 1. Find tokens (symbol → address + decimals)
eth = client.search_tokens("WETH")["tokens"][0]
usd = client.search_tokens("USDG")["tokens"][0]

# 2. Route — request it with the order_type you will submit; its feeLegs carry
#    that fee cell and are exact-matched on submit. Pass them through unmodified.
amount_in = parse_units("0.5", eth["decimals"])
route = client.order_route(eth["address"], usd["address"], amount_in,
                           slippage_ppm=10_000, wallet=wallet, order_type="limit")

# 3. Build + sign locally (sell 0.5 WETH at 3000 USDG/WETH or better)
signed = build_and_sign_order(
    private_key,
    token_in=eth["address"],
    token_out=usd["address"],
    amount_in=amount_in,
    trigger_price=calculate_trigger_price("3000", usd["decimals"]),
    token_in_decimals=eth["decimals"],
    fee_legs=route.get("feeLegs"),
    kind="limit",
)

# 4. Submit
res = client.submit_order(signed, "limit")
print(res["orderHash"])

The router must be approved to spend token_in first (a plain ERC-20 approve to the router — address in epsilon_exchange.ROUTER_ADDRESS).

Modules

• EpsilonClient — /v1 API: search_tokens, quote, order_route, submit_order, get_order, list_orders, cancel_order
• build_and_sign_order / sign_cancel — local EIP-712 signing (eth-account)
• parse_units / format_units / calculate_trigger_price — decimal helpers
• chain — chain id, router address, EIP-712 domain and types

Also available

• TypeScript: @epsilon-exchange/sdk
• AI agents (Claude/Cursor): @epsilon-exchange/mcp
• Docs: developers.epsilon.exchange