Polymarket Client¶

The Polymarket client provides access to both the Gamma (markets) and CLOB (trading) APIs.

Import¶

import "github.com/grokify/polymarket-go/internal/polymarket"

Creating a Client¶

// Default client
client := polymarket.NewClient()

// With options
client := polymarket.NewClient(
    polymarket.WithCLOBURL("https://clob.polymarket.com"),
    polymarket.WithGammaURL("https://gamma-api.polymarket.com"),
    polymarket.WithHTTPClient(customHTTPClient),
)

Markets API (Gamma)¶

GetMarkets¶

Fetch active prediction markets with optional filters.

func (c *Client) GetMarkets(ctx context.Context, params GetMarketsParams) ([]Market, error)

Parameters:

Field	Type	Description
`Active`	*bool	Filter by active status
`Closed`	*bool	Filter by closed status
`Limit`	int	Maximum results to return
`Cursor`	string	Pagination cursor
`TagSlug`	string	Category filter
`Order`	string	Sort field (e.g., "liquidity")
`Ascending`	bool	Sort direction
`LiqMin`	float64	Minimum liquidity filter
`LiqMax`	float64	Maximum liquidity filter
`TextQuery`	string	Search query

Example:

active := true
markets, err := client.GetMarkets(ctx, polymarket.GetMarketsParams{
    Active: &active,
    Limit:  10,
    Order:  "liquidity",
    LiqMin: 50000,
})
if err != nil {
    log.Fatal(err)
}

for _, m := range markets {
    fmt.Printf("%s - $%.0f liquidity\n", m.Question, m.LiquidityNum)
}

GetMarket¶

Fetch a single market by condition ID.

func (c *Client) GetMarket(ctx context.Context, conditionID string) (*Market, error)

Market Type¶

type Market struct {
    ID              string  `json:"id"`
    Question        string  `json:"question"`
    Slug            string  `json:"slug"`
    Description     string  `json:"description"`
    ConditionID     string  `json:"conditionId"`
    QuestionID      string  `json:"questionID"`
    EndDateISO      string  `json:"endDateIso"`
    Active          bool    `json:"active"`
    Closed          bool    `json:"closed"`
    LiquidityNum    float64 `json:"liquidityNum"`
    VolumeNum       float64 `json:"volumeNum"`
    Volume24hr      float64 `json:"volume24hr"`
    Outcomes        string  `json:"outcomes"`        // JSON array
    OutcomePrices   string  `json:"outcomePrices"`   // JSON array
    ClobTokenIDs    string  `json:"clobTokenIds"`    // JSON array
    BestBid         float64 `json:"bestBid"`
    BestAsk         float64 `json:"bestAsk"`
    Spread          float64 `json:"spread"`
    LastTradePrice  float64 `json:"lastTradePrice"`
}

Order Book API (CLOB)¶

GetOrderBook¶

Fetch the order book for a token.

func (c *Client) GetOrderBook(ctx context.Context, tokenID string) (*OrderBook, error)

Example:

book, err := client.GetOrderBook(ctx, tokenID)
if err != nil {
    log.Fatal(err)
}

fmt.Printf("Bids: %d, Asks: %d\n", len(book.Bids), len(book.Asks))
if len(book.Bids) > 0 {
    fmt.Printf("Best bid: %s @ %s\n", book.Bids[0].Size, book.Bids[0].Price)
}

OrderBook Type¶

type OrderBook struct {
    Market string           `json:"market"`
    Asset  string           `json:"asset_id"`
    Hash   string           `json:"hash"`
    Bids   []OrderBookLevel `json:"bids"`
    Asks   []OrderBookLevel `json:"asks"`
}

type OrderBookLevel struct {
    Price string `json:"price"`
    Size  string `json:"size"`
}

Price APIs¶

GetPrice¶

func (c *Client) GetPrice(ctx context.Context, tokenID string) (*Price, error)

GetMidPrice¶

func (c *Client) GetMidPrice(ctx context.Context, tokenID string) (*MidPrice, error)

GetSpread¶

func (c *Client) GetSpread(ctx context.Context, tokenID string) (*Spread, error)

Example:

mid, _ := client.GetMidPrice(ctx, tokenID)
spread, _ := client.GetSpread(ctx, tokenID)

fmt.Printf("Mid: %.4f, Spread: %.4f\n", mid.Mid, spread.Spread)

Constants¶

const (
    DefaultCLOBURL  = "https://clob.polymarket.com"
    DefaultGammaURL = "https://gamma-api.polymarket.com"
)

Error Handling¶

All methods return errors for:

Network failures
Non-200 HTTP responses
JSON decoding failures

markets, err := client.GetMarkets(ctx, params)
if err != nil {
    // Handle error - check for context cancellation, network issues, etc.
    log.Printf("Failed to fetch markets: %v", err)
}