Trading - Bison API

Overview

The SDK provides high-level methods for trading on Kalshi markets:

executeBuyFlow / executeSellFlow - Place buy/sell orders with automatic signature generation
executeCancelOrderFlow - Cancel existing orders
executeMintFlow / executeBurnFlow - Create/destroy position tokens
getUserOrders / getUserPositions - Query user’s orders and positions

To avoid ambiguity, we denote the smallest possible multiple of USDC (0.000001 USDC) as one uusdc, which stands for µUSDC (micro-USDC), and denote the smallest possible multiple of a contract (0.01 contract) as one ccontract (centicontract).User-facing USDC balances are specified as fixed-point strings (e.g. "1.2625" for USDC). Contract quantities in the API and SDK are specified as integer ccontracts strings (e.g. "1050" for 10.50 contracts at precision 2).

Developer Accounts

If you have a developer account, you can set it at the client level to automatically apply it to all orders:

const client = createBisonClient({ 
  baseUrl: 'https://api.bison.markets',
  devAccountId: 'your-dev-account-id'
});

// All orders automatically include your dev account ID
await client.executeBuyFlow({
  walletClient,
  publicClient,
  userAddress: '0xf39Fd6e51aad88F6F4ce6aB8827279cffFb92266',
  chain: 'base',
  marketId: 'KXFEDDECISION-26JAN-T425',
  side: 'yes',
  ccontracts: '1000', // 10.00 contracts * 100
  priceUusdc: '650000',
});

You can also override the dev account for specific orders when using the lower-level placeOrder method:

await client.placeOrder({
  chain: 'base',
  marketId: 'KXFEDDECISION-26JAN-T425',
  ccontracts: '1000', // 10.00 contracts * 100
  priceUusdc: '650000',
  action: 'buy',
  side: 'yes',
  userAddress: '0xf39Fd6e51aad88F6F4ce6aB8827279cffFb92266',
  signature: '0x...',
  expiry: 1234567890,
  devAccountId: 'different-dev-account' // Overrides client default
});

See the Developer Accounts guide for more information on how to get a dev account and earn from trading fees.

Placing Orders

Place limit orders on Kalshi markets. The SDK handles EIP-712 signature generation automatically.

`executeBuyFlow`

async executeBuyFlow(params: {
  walletClient: WalletClient;
  publicClient: PublicClient;
  userAddress: `0x${string}`;
  chain: string;
  marketId: string;
  side: 'yes' | 'no';
  ccontracts: string;
  priceUusdc: string;
  onEvent?: (event: BisonEvent) => void;
  onError?: (error: Error) => void;
}): Promise<{ disconnect: () => void; txHash: `0x${string}` | null }>

Parameters

walletClient

WalletClient

required

Viem wallet client for signing messages

publicClient

PublicClient

required

Viem public client for reading contract state

userAddress

string

required

User’s Ethereum address

chain

string

required

Chain identifier ("base" or "bsc"). Vault address is automatically resolved from the /info endpoint.

marketId

string

required

Kalshi market ticker (e.g., "KXFEDDECISION-26JAN-T425")

side

string

required

Position side: "yes" or "no"

ccontracts

string

required

Number of ccontracts as an integer string (e.g., "1050" for 10.50 contracts at precision 2)

Tip: use contractsToCcontracts("10.50", 2).toString() from the SDK to convert a fixed-point contracts string.

priceUusdc

string

required

Limit price in µUSDC as an integer string

onEvent

function

Optional callback for order events (placed, filled, etc.)

onError

function

Optional callback for WebSocket errors

Returns

Object containing:

disconnect - Function to stop listening for events
txHash - Transaction hash (currently always null for off-chain orders)

Example

import { createBisonClient } from '@bison-markets/sdk-ts';
import { createWalletClient, createPublicClient, http, custom } from 'viem';
import { base } from 'viem/chains';

const client = createBisonClient({ 
  baseUrl: 'https://api.bison.markets' 
});

const walletClient = createWalletClient({
  chain: base,
  transport: custom(window.ethereum!),
});

const publicClient = createPublicClient({
  chain: base,
  transport: http(),
});

// Buy 10 YES contracts at 65 cents each
const result = await client.executeBuyFlow({
  walletClient,
  publicClient,
  userAddress: '0xf39Fd6e51aad88F6F4ce6aB8827279cffFb92266',
  chain: 'base',
  marketId: 'KXFEDDECISION-26JAN-T425',
  side: 'yes',
  ccontracts: '1000', // 10.00 contracts * 100
  priceUusdc: '650000', // $0.65 * 10^6
  onEvent: (event) => {
    if (event.type === 'order_placed') {
      console.log('Order placed successfully:', event.orderId);
    } else if (event.type === 'order_filled') {
      console.log('Order filled:', event.orderId);
    }
  },
  onError: (error) => {
    console.error('WebSocket error:', error);
  },
});

// Stop listening for events when done
// result.disconnect();

`executeSellFlow`

Works identically to executeBuyFlow but places a sell order.

async executeSellFlow(params: {
  walletClient: WalletClient;
  publicClient: PublicClient;
  userAddress: `0x${string}`;
  chain: string;
  marketId: string;
  side: 'yes' | 'no';
  ccontracts: string;
  priceUusdc: string;
  onEvent?: (event: BisonEvent) => void;
  onError?: (error: Error) => void;
}): Promise<{ disconnect: () => void; txHash: `0x${string}` | null }>

Example

// Sell 5 NO contracts at 40 cents each
const result = await client.executeSellFlow({
  walletClient,
  publicClient,
  userAddress: '0xf39Fd6e51aad88F6F4ce6aB8827279cffFb92266',
  chain: 'base',
  marketId: 'KXFEDDECISION-26JAN-T425',
  side: 'no',
  ccontracts: '500', // 5.00 contracts * 100
  priceUusdc: '400000', // $0.40 * 10^6
});

Cancelling Orders

Cancel an existing open order.

`executeCancelOrderFlow`

async executeCancelOrderFlow(params: {
  walletClient: WalletClient;
  userAddress: `0x${string}`;
  chain: string;
  orderId: string;
}): Promise<void>

Parameters

walletClient

WalletClient

required

Viem wallet client for signing messages

userAddress

string

required

User’s Ethereum address

chain

string

required

Chain identifier ("base" or "bsc"). Vault address is automatically resolved from the /info endpoint.

orderId

string

required

ID of the order to cancel (from order event or getUserOrders)

Example

await client.executeCancelOrderFlow({
  walletClient,
  userAddress: '0xf39Fd6e51aad88F6F4ce6aB8827279cffFb92266',
  chain: 'base',
  orderId: 'abc123-order-id',
});

console.log('Order cancellation requested');

Querying Orders & Positions

`getUserOrders`

Get orders for a user with optional filtering and pagination.

async getUserOrders(
  userId: string,
  params?: GetUserOrdersParams
): Promise<GetUserOrdersResponse>

Parameters

userId

string

required

User’s Ethereum address

params

object

Optional filtering and pagination parameters

Show params properties

status

string

Filter by order status: "pending", "filled", "cancelled", or "closed" (filled OR cancelled)

marketId

string

Filter by market ticker

action

string

Filter by action: "buy" or "sell"

side

string

Filter by side: "yes" or "no"

createdAfter

number

Orders created after this timestamp (milliseconds)

createdBefore

number

Orders created before this timestamp (milliseconds)

sortBy

string

Sort by field: "createdAt" (default) or "updatedAt"

sortOrder

string

Sort direction: "desc" (default) or "asc"

limit

number

Max orders per page (default: 50, max: 200)

cursor

string

Pagination cursor from previous response

Response

The response includes an orders array and a pagination object:

{
  orders: Order[];
  pagination: {
    total: number;      // Total matching orders
    hasMore: boolean;   // More pages available
    nextCursor?: string; // Cursor for next page
  };
}

Examples

Get all pending orders:

const { orders } = await client.getUserOrders(
  '0xf39Fd6e51aad88F6F4ce6aB8827279cffFb92266',
  { status: 'pending' }
);

console.log('Open orders:');
orders.forEach(order => {
  const requestedContracts = Number(order.requestedCcontracts) / 100;
  const price = Number(order.priceUusdc) / 1_000_000;
  console.log(`${order.action} ${requestedContracts} ${order.side} @ $${price}`);
  console.log(`  Market: ${order.marketId}`);
  console.log(`  Order ID: ${order.kalshiOrderId}`);
});

Get order history with pagination:

// First page of completed orders
const result = await client.getUserOrders(
  '0xf39Fd6e51aad88F6F4ce6aB8827279cffFb92266',
  { 
    status: 'closed',
    sortBy: 'updatedAt',
    sortOrder: 'desc',
    limit: 10 
  }
);

console.log(`Showing ${result.orders.length} of ${result.pagination.total} orders`);

// Fetch next page if available
if (result.pagination.hasMore) {
  const nextPage = await client.getUserOrders(
    '0xf39Fd6e51aad88F6F4ce6aB8827279cffFb92266',
    { 
      status: 'closed',
      sortBy: 'updatedAt',
      sortOrder: 'desc',
      limit: 10,
      cursor: result.pagination.nextCursor
    }
  );
}

Filter by market:

const { orders } = await client.getUserOrders(
  '0xf39Fd6e51aad88F6F4ce6aB8827279cffFb92266',
  { marketId: 'KXFEDDECISION-26JAN-T425' }
);

Filter by date range:

const oneWeekAgo = Date.now() - 7 * 24 * 60 * 60 * 1000;

const { orders } = await client.getUserOrders(
  '0xf39Fd6e51aad88F6F4ce6aB8827279cffFb92266',
  { 
    status: 'filled',
    createdAfter: oneWeekAgo 
  }
);

`getUserPositions`

Get all positions for a user.

async getUserPositions(userId: string): Promise<GetUserPositionsResponse>

Example

const { positions } = await client.getUserPositions(
  '0xf39Fd6e51aad88F6F4ce6aB8827279cffFb92266'
);

console.log('Current positions:');
positions.forEach(position => {
  console.log(`Market: ${position.marketId}`);
  const contracts = Number(position.ccontracts) / 100;
  console.log(`  ${position.side.toUpperCase()}: ${contracts} contracts`);
});

Position Token Utilities

Get token addresses and balances for position tokens.

`getPositionTokenAddress`

async getPositionTokenAddress(params: {
  publicClient: PublicClient;
  chain: 'base' | 'bsc';
  marketId: string;
  side: 'yes' | 'no';
}): Promise<`0x${string}` | null>

Returns the ERC20 token address for a position, or null if not yet created. The vault address is automatically resolved from the /info endpoint.

`getTokenBalance`

async getTokenBalance(params: {
  publicClient: PublicClient;
  tokenAddress: `0x${string}`;
  userAddress: `0x${string}`;
}): Promise<bigint>

Returns the token balance for a user.

`addTokenToWallet`

async addTokenToWallet(params: {
  tokenAddress: `0x${string}`;
  marketId: string;
  side: 'yes' | 'no';
}): Promise<boolean>

Prompts the user to add a position token to their wallet (MetaMask, etc.).

Example

// Get token address
const tokenAddress = await client.getPositionTokenAddress({
  publicClient,
  chain: 'base',
  marketId: 'KXFEDDECISION-26JAN-T425',
  side: 'yes',
});

if (tokenAddress) {
  // Get user's balance
  const balance = await client.getTokenBalance({
    publicClient,
    tokenAddress,
    userAddress: '0xf39Fd6e51aad88F6F4ce6aB8827279cffFb92266',
  });
  
  console.log('Token balance:', balance.toString());
  
  // Add to wallet
  const added = await client.addTokenToWallet({
    tokenAddress,
    marketId: 'KXFEDDECISION-26JAN-T425',
    side: 'yes',
  });
  
  if (added) {
    console.log('Token added to wallet');
  }
}

Error Handling

try {
  await client.executeBuyFlow({
    walletClient,
    publicClient,
    userAddress: '0xf39Fd6e51aad88F6F4ce6aB8827279cffFb92266',
    chain: 'base',
    marketId: 'KXFEDDECISION-26JAN-T425',
    side: 'yes',
    ccontracts: '1000', // 10.00 contracts * 100
    priceUusdc: '650000',
  });
} catch (error) {
  if (error instanceof Error) {
    if (error.message.includes('insufficient balance')) {
      console.error('Not enough USDC deposited');
    } else if (error.message.includes('User rejected')) {
      console.error('User cancelled signature request');
    } else {
      console.error('Failed to place order:', error.message);
    }
  }
}

Important Notes

All order prices are in µUSDC (1 USD = 1,000,000 µUSDC, so $0.65 = 650000 µUSDC)
Order signatures expire after 10 minutes
Minting withdraws positions from the exchange to your wallet as ERC-20 tokens
Burning deposits ERC-20 tokens from your wallet back to the exchange as tradeable positions
The SDK automatically handles EIP-712 signature generation
WebSocket connection is automatically established for buy/sell flows
Always call disconnect() to clean up WebSocket connections
Developer account IDs set at the client level are automatically applied to all orders

TypeScript SDK

​Overview

​Developer Accounts

​Placing Orders

​executeBuyFlow

​Parameters

​Returns

​Example

​executeSellFlow

​Example

​Cancelling Orders

​executeCancelOrderFlow

​Parameters

​Example

​Querying Orders & Positions

​getUserOrders

​Parameters

​Response

​Examples

​getUserPositions

​Example

​Position Token Utilities

​getPositionTokenAddress

​getTokenBalance

​addTokenToWallet

​Example

​Error Handling

​Important Notes

Overview

Developer Accounts

Placing Orders

`executeBuyFlow`

Parameters

Returns

Example

`executeSellFlow`

Example

Cancelling Orders

`executeCancelOrderFlow`

Parameters

Example

Querying Orders & Positions

`getUserOrders`

Parameters

Response

Examples

`getUserPositions`

Example

Position Token Utilities

`getPositionTokenAddress`

`getTokenBalance`

`addTokenToWallet`

Example

Error Handling

Important Notes