Polymarket

CLOB prediction markets on Polygon. Connect with one line.

Polymarket is the largest non-US prediction market venue. Matching is off-chain CLOB; settlement is on-chain ERC-1155 conditional tokens. Orders are signed client-side with an Ethereum key (EIP-712).

Connect

python

import horizon as hz

ex = hz.connect("polymarket",
    private_key="0x...",          # EOA signing key (hot)
    funder="0x...",               # funder address (often same as signer)
    signature_type=0,             # 0 = EOA, 1 = email proxy, 2 = browser proxy
)
# market_id is the ERC-1155 token id for YES or NO on the condition.
ex.buy("<token_id>", qty=100, limit=0.55)
print(ex.balance())
ex.close()

Kwargs

Kwarg	Type	Default	Notes
`private_key`	`str \\| None`	`None`	0x-prefixed 32-byte hex. Falls back to `secrets.get("polymarket.private_key")`.
`funder`	`str \\| None`	`None`	Funder address. Defaults to signer address for signature_type 0.
`signature_type`	`int`	`0`	`0`=EOA, `1`=email proxy, `2`=browser proxy. Most programmatic users want `0`.
`chain_id`	`int`	`137`	Polygon mainnet.
`host`	`str`	`"https://clob.polymarket.com"`	CLOB REST host. No sandbox.
`api_key`, `api_secret`, `api_passphrase`	`str \\| None`	derived	Usually auto-derived from the signer by the SDK on first call.
`secrets`	`Secrets \\| None`	`None`	See Secrets.
`budget_usd`	`float`	`0.0`	Optional hard cap.

Install

bash

pip install horizon[prediction]
# or
pip install py-clob-client eth_account

Status

Order submit / cancel / fetch: shipped.
Position and fill polling: shipped.
WebSocket feed: horizon.data.live.polymarket_ws.
On-chain balance read (ERC-1155 direct): follow-up.

Symbology, signature-type semantics, resolution handler: Polymarket (professionals).