Trade

curl --request POST \
  --url https://api.simmer.markets/api/sdk/trade \
  --header 'Content-Type: application/json' \
  --data '
{
  "market_id": "<string>",
  "amount": 0,
  "shares": 0,
  "action": "buy",
  "venue": "sim",
  "execute": false,
  "reasoning": "<string>",
  "source": "<string>",
  "skill_slug": "<string>",
  "signal_data": {},
  "dry_run": false,
  "price": 123,
  "signed_order": {
    "salt": "<string>",
    "maker": "<string>",
    "signer": "<string>",
    "tokenId": "<string>",
    "makerAmount": "<string>",
    "takerAmount": "<string>",
    "side": "<string>",
    "signatureType": 123,
    "signature": "<string>",
    "taker": "<string>",
    "nonce": "<string>",
    "feeRateBps": "<string>",
    "timestamp": "<string>",
    "metadata": "<string>",
    "builder": "<string>",
    "expiration": "<string>"
  },
  "wallet_address": "<string>"
}
'

{
  "detail": [
    {
      "loc": [
        "<string>"
      ],
      "msg": "<string>",
      "type": "<string>",
      "input": "<unknown>",
      "ctx": {}
    }
  ]
}

Trading

Trade

Execute a trade via SDK.

Venues:

venue=“sim” (default): Execute on Simmer’s LMSR market with $SIM
venue=“polymarket”: Execute real trade on Polymarket via Dome API (requires wallet setup with allowances)
venue=“kalshi”: Execute real trade on Kalshi via DFlow (requires Solana wallet setup with SOL + USDC)

Options:

dry_run=True: Validate and calculate without executing. Returns the exact shares, projected price, and cost the live path would settle for. Supported on all venues: polymarket, kalshi, and sim (LMSR — closed-form cost-inversion guarantees dry_run.cost == live.cost within float precision). Useful for sizing budgets without committing the trade.

Deprecated: venue=“sandbox”/“simmer” are deprecated, use venue=“sim” instead.

Requires API key in Authorization header (rate limited: 120/minute).

POST

api

sdk

trade

Trade

curl --request POST \
  --url https://api.simmer.markets/api/sdk/trade \
  --header 'Content-Type: application/json' \
  --data '
{
  "market_id": "<string>",
  "amount": 0,
  "shares": 0,
  "action": "buy",
  "venue": "sim",
  "execute": false,
  "reasoning": "<string>",
  "source": "<string>",
  "skill_slug": "<string>",
  "signal_data": {},
  "dry_run": false,
  "price": 123,
  "signed_order": {
    "salt": "<string>",
    "maker": "<string>",
    "signer": "<string>",
    "tokenId": "<string>",
    "makerAmount": "<string>",
    "takerAmount": "<string>",
    "side": "<string>",
    "signatureType": 123,
    "signature": "<string>",
    "taker": "<string>",
    "nonce": "<string>",
    "feeRateBps": "<string>",
    "timestamp": "<string>",
    "metadata": "<string>",
    "builder": "<string>",
    "expiration": "<string>"
  },
  "wallet_address": "<string>"
}
'

{
  "detail": [
    {
      "loc": [
        "<string>"
      ],
      "msg": "<string>",
      "type": "<string>",
      "input": "<unknown>",
      "ctx": {}
    }
  ]
}

Multi-outcome markets (e.g., “Who will win the election?”) use a different contract type on Polymarket. This is auto-detected and handled server-side — no extra parameters needed.

Before selling, verify:

Market is active — resolved markets cannot be sold, use /redeem instead
Shares >= 5 — Polymarket minimum per sell order
Position exists on-chain — call GET /positions fresh before selling
Use shares (not amount) for sells

The source tag groups trades for P&L tracking and prevents accidental re-buys on markets you already hold. Use a consistent prefix like sdk:strategy-name.

Body

application/json

Request to execute a trade via SDK.

market_id

string

required

side

enum<string>

required

Available options:

yes,

no

amount

number

default:0

number

default:0

action

enum<string>

default:buy

Available options:

buy,

sell

venue

enum<string>

default:sim

Available options:

sim,

simmer,

sandbox,

polymarket,

kalshi

order_type

enum<string> | null

Available options:

GTC,

GTD,

FOK,

FAK

execute

boolean

default:false

deprecated

DEPRECATED. Legacy flag that returns Polymarket order params for client-side CLOB submission instead of executing the trade. YES side only — NO is not supported. Does not write to sim_trades and is incompatible with venue='sim'. Use venue='polymarket' for server-side execution (handles both managed and external wallets) or venue='sim' for sandbox trades.

reasoning

string | null

source

string | null

skill_slug

string | null

signal_data

Signal Data · object

dry_run

boolean

default:false

price

number | null

signed_order

SignedPolymarketOrder · object

Pre-signed Polymarket order from external wallet (client-side signing).

Supports both V1 and V2 order shapes via optional fields. The frontend populates V1-or-V2 depending on its VITE_POLYMARKET_V2_ENABLED flag; the /polymarket/place-order-external handler routes based on exchange_version hint on the parent ExternalWalletOrderRequest (or infers from which fields are present).

V1 uses: taker, expiration, nonce, feeRateBps (in signed hash) V2 uses: timestamp, metadata, builder (in signed hash); expiration retained in HTTP body at "0" (out of signed hash)

Show child attributes

which_side_to_close

enum<string> | null

Available options:

yes,

no

wallet_address

string | null

Response

Successful Response

Import Kalshi Market Batch Trades

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