polymarket-us 0.6.0

Unofficial Rust SDK for the Polymarket US Retail API
Documentation
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# polymarket-us

[![Crates.io](https://img.shields.io/crates/v/polymarket-us.svg)](https://crates.io/crates/polymarket-us)
[![Docs.rs](https://docs.rs/polymarket-us/badge.svg)](https://docs.rs/polymarket-us)
[![License: MIT](https://img.shields.io/badge/license-MIT-blue.svg)](LICENSE)
[![Rust](https://img.shields.io/badge/rust-2021-orange.svg)](https://www.rust-lang.org)
[![CI](https://github.com/mbordash/polymarket-us/actions/workflows/ci.yml/badge.svg)](https://github.com/mbordash/polymarket-us/actions/workflows/ci.yml)

Unofficial Rust SDK for the Polymarket US Retail API.

## Features

- **Resource-based API** — Organized into focused clients (`client.markets()`, `client.orders()`, `client.events()`, etc.)
- **Ed25519 request signing** — Automatic X-PM-* authentication headers
- **Typed async REST client** — Markets, events, orders, portfolio, account, and search endpoints
- **Async WebSocket streaming** — Separate market-data and private account sockets, with automatic reconnect and keepalive
- **Order book & pricing data** — Get order books, best bid/offer, settlement prices
- **Builder-based configuration** — Base URLs, timeouts, custom HTTP client
- **Automatic retries** — Exponential backoff with jitter on idempotent requests, honouring `Retry-After`; `POST` is never retried, so orders can't be duplicated
- **rustls throughout** — No OpenSSL dependency

## Installation

```sh
cargo add polymarket-us tokio --features tokio/macros,tokio/rt-multi-thread
```

Or in `Cargo.toml`:

```toml
[dependencies]
polymarket-us = "0.6"
tokio = { version = "1", features = ["macros", "rt-multi-thread"] }
```

Requires Rust 1.86 or newer. TLS is provided by [rustls](https://github.com/rustls/rustls),
so no OpenSSL installation is needed. Root certificates come from the platform
verifier, which means the trust store the rest of the machine already uses — no
bundled root set to go stale.

## Authentication

Authenticated endpoints require:

- `POLYMARKET_US_KEY_ID`
- `POLYMARKET_US_SECRET_KEY`

`POLYMARKET_US_SECRET_KEY` must be Base64 that decodes to either:

- 64 bytes (keypair format, first 32 bytes are used as signing seed), or
- 32 bytes (raw Ed25519 seed).

Example:

```bash
export POLYMARKET_US_KEY_ID="your-key-id"
export POLYMARKET_US_SECRET_KEY="your-base64-secret"
```

## Quick start

```rust
use polymarket_us::{PolymarketUsClient, PolymarketUsError};

#[tokio::main]
async fn main() -> Result<(), PolymarketUsError> {
    let client = PolymarketUsClient::builder().build()?;

    // Health check
    let health = client.health().await?;
    println!("status: {}", health.status);

    // List markets
    let markets = client.markets().list().await?;
    println!("markets: {}", markets.markets.len());

    // Get order book for a market
    let book = client.markets().order_book("BTC-USD").await?;
    println!("bid/ask: {} orders", book.bids.len() + book.asks.len());

    Ok(())
}
```

## Resource-Based API

The SDK is organized into focused resource clients for better discoverability and maintainability:

### Markets
Market discovery, order books, and pricing data.

```rust
// List markets
let markets = client.markets().list().await?;

// List with filters
let query = [("limit", "10"), ("category", "politics")];
let page = client.markets().list_with_query(&query).await?;

// Order book and pricing
let book = client.markets().order_book("BTC-USD").await?;
let bbo = client.markets().bbo("BTC-USD").await?;           // Best bid/offer
let settlement = client.markets().settlement_price("BTC-USD").await?;
```

### Events
Event-level metadata and context.

```rust
// List all events
let events = client.events().list().await?;

// Get event by ID or slug
let event = client.events().retrieve("event-123").await?;
let event = client.events().retrieve_by_slug("2024-us-election").await?;
```

### Orders
Complete order lifecycle management. All operations are authenticated.

```rust
use polymarket_us::types;

let order_req = types::PlaceOrderRequest {
    symbol: "BTC-USD".to_string(),
    action: types::OrderAction::Buy,
    outcome_side: types::OrderSide::Long,
    order_type: types::OrderType::Limit,
    price: types::Money { value: "0.50".to_string(), currency: "USD".to_string() },
    quantity: 100,
    tif: types::TimeInForce::GoodTillCancel,
    client_order_id: Some("my-order-1".to_string()),
    post_only: false,
    expires_at: None,
};

// Place order
let order = client.orders().create(&order_req).await?;

// Get open orders
let open = client.orders().open(None::<&()>).await?;

// Modify, cancel, preview
client.orders().modify(&order.order_id, &modify_req).await?;
client.orders().cancel(&order.order_id, &types::CancelOrderParams { quantity: None }).await?;
let estimate = client.orders().preview(&preview_req).await?;

// Close position
client.orders().close_position(&types::ClosePositionRequest {
    symbol: "BTC-USD".to_string(),
    quantity: 50,
}).await?;
```

### Account
Account balances and buying power (authenticated).

```rust
let balances = client.account().balances().await?;
for balance in balances.balances {
    println!("{}; balance={}, buying_power={}",
        balance.currency,
        balance.current_balance,
        balance.buying_power
    );
}
```

### Portfolio
Holdings and activity history (authenticated).

```rust
// Get positions
let positions = client.portfolio().positions().await?;

// Get activity with pagination
let query = [("limit", "50")];
let activities = client.portfolio().activities(&query).await?;
```

### Search
Full-text search across markets and events.

```rust
let query = [("q", "bitcoin")];
let results = client.search().search(&query).await?;

// Search specific resource
let markets = client.search().markets(&query).await?;
let events = client.search().events(&query).await?;
```

## Advanced market queries

Use `list_with_query()` for filters, cursors, and pagination:

```rust
use polymarket_us::{PolymarketUsClient, PolymarketUsError};
use serde::Serialize;

#[derive(Serialize)]
struct MarketsQuery<'a> {
    category: Option<&'a str>,
    limit: Option<u32>,
    cursor: Option<&'a str>,
}

async fn load_filtered_markets(client: &PolymarketUsClient) -> Result<(), PolymarketUsError> {
    let query = MarketsQuery {
        category: Some("politics"),
        limit: Some(25),
        cursor: None,
    };

    let page = client.markets().list_with_query(&query).await?;
    println!("filtered markets: {}", page.markets.len());
    Ok(())
}
```

If your account tier requires authenticated access for some filters, use
`list_authenticated_with_query()`, which takes the same query argument.

## Streaming

The venue splits its WebSocket surface across two sockets on the **API** host
(not the gateway host used for public REST traffic), and the SDK mirrors that
split rather than multiplexing them:

| Data | Endpoint | Client | Subscriptions |
|---|---|---|---|
| Books, trades, best-bid/offer | `wss://api.polymarket.us/v1/ws/markets` | `MarketStreamClient` | `MarketSubscription` |
| Orders, positions, balances | `wss://api.polymarket.us/v1/ws/private` | `PrivateStreamClient` | `PrivateSubscription` |

Because the two subscription families are distinct types, subscribing to an
order feed on the market socket is a compile error rather than a server
rejection.

### Wire format

A subscription serializes to the server's `subscribe` envelope:

```json
{
  "subscribe": {
    "requestId": "md-sub-1",
    "subscriptionType": "SUBSCRIPTION_TYPE_MARKET_DATA",
    "marketSlugs": ["btc-100k-2025"]
  }
}
```

and unsubscribing echoes the same `requestId`:

```json
{ "unsubscribe": { "requestId": "md-sub-1" } }
```

`MarketSubscription::frame()` / `PrivateSubscription::frame()` return exactly
what will be sent, which is the quickest way to check a subscription against the
docs. Note that the endpoint rejects a frame it cannot parse — including one
carrying a field it does not define — so the SDK sends only the three documented
fields. `insert_extra` adds more when the docs call for it.

Subscription types map to `SubscriptionType`, whose wire form is the
fully-qualified enum name:

| Constructor | `subscriptionType` |
|---|---|
| `MarketSubscription::market_data(slugs)` | `SUBSCRIPTION_TYPE_MARKET_DATA` |
| `MarketSubscription::market_data_lite(slugs)` | `SUBSCRIPTION_TYPE_MARKET_DATA_LITE` |
| `MarketSubscription::trades(slugs)` | `SUBSCRIPTION_TYPE_TRADE` |
| `PrivateSubscription::orders()` | `SUBSCRIPTION_TYPE_ORDER` |
| `PrivateSubscription::positions()` | `SUBSCRIPTION_TYPE_POSITION` |
| `PrivateSubscription::account_balances()` | `SUBSCRIPTION_TYPE_ACCOUNT_BALANCE` |

A type the SDK does not model yet can still be used via `custom()`, which sends
the string verbatim.

### Market data

```rust
use polymarket_us::{
    MarketSubscription, PolymarketUsClient, PolymarketUsError, StreamDataEvent,
    StreamMessageKind,
};

async fn watch_market(client: &PolymarketUsClient) -> Result<(), PolymarketUsError> {
    let mut stream = client
        .market_stream()
        .connect(vec![
            MarketSubscription::market_data_lite(["btc-100k-2025"]),
            MarketSubscription::trades(["btc-100k-2025"]),
        ])
        .await?;

    // Add and remove subscriptions at runtime.
    let extra = MarketSubscription::market_data(["eth-10k-2025"]);
    let request_id = extra.request_id().to_string();
    stream.subscribe(extra).await?;
    stream.unsubscribe(&request_id).await?;

    while let Some(message) = stream.next().await {
        match message.kind {
            StreamMessageKind::Data(StreamDataEvent::Trade(payload)) => {
                println!("trade: {payload}");
            }
            StreamMessageKind::Data(StreamDataEvent::MarketDataLite(payload)) => {
                println!("bbo: {payload}");
            }
            _ => {}
        }
    }

    Ok(())
}
```

### Private account events

`private_stream()` fails with `MissingAuth` if the client has no credentials,
since the endpoint rejects an unauthenticated upgrade.

```rust
use polymarket_us::{PolymarketUsClient, PolymarketUsError, PrivateSubscription};

async fn watch_account(client: &PolymarketUsClient) -> Result<(), PolymarketUsError> {
    let mut stream = client
        .private_stream()?
        .connect(vec![
            PrivateSubscription::orders(),
            PrivateSubscription::positions(),
            PrivateSubscription::account_balances(),
        ])
        .await?;

    while let Some(message) = stream.next().await {
        println!("{:?}", message.kind);
    }

    Ok(())
}
```

### Staying connected

Both streams reconnect automatically and replay their subscriptions each time.

A connection that goes quiet for `StreamConnectConfig::idle_timeout` (60s by
default) is torn down and reconnected. This matters because a TCP connection can
die without a FIN or RST — common behind NAT and load balancers — in which case
the socket never reports an error and the stream would otherwise wait forever.

Feeding that check is `keepalive_interval` (20s by default): the SDK pings the
server, and the pong counts as traffic. That distinction is what keeps a market
with nothing to report from being mistaken for a dead socket. Pass `None` to
either to switch it off.

```rust
use std::time::Duration;
use polymarket_us::StreamConnectConfig;

let config = StreamConnectConfig::default()
    .with_idle_timeout(Some(Duration::from_secs(30)))
    .with_keepalive_interval(Some(Duration::from_secs(10)));
```

Inbound events arrive as `StreamMessageKind::Data(StreamDataEvent::…)`:
`MarketData`, `MarketDataLite`, `OrderBookDelta`, `Trade`, `OrderSnapshot`,
`OrderUpdate`, `PositionSnapshot`, `PositionUpdate`, `BalanceSnapshot`,
`BalanceUpdate`, `Heartbeat`, and `Other` for anything not yet modelled.
`StreamMessage::request_id` carries the `requestId` the server echoed, matching
the subscription that produced it.

## Endpoint coverage

**Markets** (`client.markets()`):
- `list()` — List all markets
- `list_with_query(q)` — List markets with filters/pagination
- `list_authenticated()` — Authenticated market listing
- `list_authenticated_with_query(q)` — Authenticated with filters
- `order_book(symbol)` — Get market order book
- `bbo(symbol)` — Get best bid/offer
- `settlement_price(symbol)` — Get settlement price

**Events** (`client.events()`):
- `list()` — List all events
- `list_with_query(q)` — List events with filters
- `retrieve(id)` — Get event by ID
- `retrieve_by_slug(slug)` — Get event by slug

**Orders** (`client.orders()`):
- `create(req)` — Create order
- `place(req)` — Place order (alternative endpoint)
- `place_batch(req)` — Place multiple orders atomically
- `open(q)` — Get open orders
- `retrieve(id)` — Get order by ID
- `cancel(id, params)` — Cancel order
- `cancel_trading(id)` — Cancel via trading endpoint
- `cancel_all(params)` — Cancel all orders
- `modify(id, req)` — Modify open order
- `preview(req)` — Preview order estimate
- `close_position(req)` — Close position

**Account** (`client.account()`):
- `balances()` — Get account balances and buying power

**Portfolio** (`client.portfolio()`):
- `positions()` — Get positions
- `activities(q)` — Get activity with pagination

**Search** (`client.search()`):
- `search(q)` — Full-text search across markets/events
- `markets(q)` — Search markets
- `events(q)` — Search events

**Streaming** (`client.market_stream()` / `client.private_stream()`):
- Two endpoint-specific clients mirroring the server's `/v1/ws/markets` and `/v1/ws/private` split
- Typed subscription types via `SubscriptionType`, with `custom()` for unmodelled ones
- Dynamic `subscribe(...)` / `unsubscribe(...)` by `requestId`
- Automatic reconnect with subscription replay, keepalive pings, and idle-connection teardown

## Migrating to 0.5

**The streaming API in 0.4 did not work against the live venue.** It sent a flat
frame — `{"channel": "market_data", "trackingId": ..., "symbol": ...}` — that the
server never parsed as a subscribe request, so every subscription came back as
`{"error":"invalid_message"}`. It also derived its URL from the gateway host,
which does not serve WebSockets. 0.5 replaces that layer; there is no compatible
upgrade path, but the mapping is mechanical.

**One client became two**, matching the server's own split:

```rust
// 0.4 — one client, one socket, derived from the gateway host
let stream = client.streaming();

// 0.5 — wss://api.polymarket.us/v1/ws/markets
let markets = client.market_stream();
// 0.5 — wss://api.polymarket.us/v1/ws/private
let private = client.private_stream()?;
```

**`StreamSubscription` became `MarketSubscription` and `PrivateSubscription`**,
and takes market slugs rather than a symbol:

```rust
// 0.4
StreamSubscription::market_data("BTC-USD")
StreamSubscription::trades("BTC-USD")
StreamSubscription::order_snapshot("BTC-USD")
StreamSubscription::order_update()
StreamSubscription::position_snapshot()   // and position_update()
StreamSubscription::balance_snapshot()    // and balance_update()

// 0.5
MarketSubscription::market_data(["btc-100k-2025"])
MarketSubscription::trades(["btc-100k-2025"])
PrivateSubscription::orders()
PrivateSubscription::positions()
PrivateSubscription::account_balances()
```

The snapshot/update split is gone from the *subscribe* side — the server has one
subscription type per family — but survives on the receive side, where
`StreamDataEvent::OrderSnapshot` and `OrderUpdate` are still distinct.

Everything else that changed:

- **`SubscriptionChannel` became `SubscriptionType`**, and its wire form is the
  fully-qualified enum name (`SUBSCRIPTION_TYPE_TRADE`, not `trade`). Unmodelled
  types go through `MarketSubscription::custom` / `PrivateSubscription::custom`.
- **`tracking_id` became `request_id`** throughout, matching the wire field.
  `StreamMessage::tracking_id` is now `StreamMessage::request_id`, and
  `unsubscribe` takes the `requestId` the subscription was created with.
- **`ManagedStream` became `MarketStream` and `PrivateStream`.** Each accepts
  only its own endpoint's subscription type, so the two sockets cannot be
  crossed.
- **`StreamSubscription::heartbeat()` is gone.** There is no heartbeat
  subscription type; keeping the connection warm is now the SDK's job, via
  `StreamConnectConfig::keepalive_interval`. If you subscribed to the heartbeat
  purely to feed `idle_timeout`, drop the subscription — that is handled.
- **`responses_debounced` is gone** from both `StreamSubscription` and
  `StreamConnectConfig`. It is not part of the documented subscribe object, and
  sending an undefined field risks the same `invalid_message` rejection.
- **`StreamConnectConfig::tracking_id` became `session_id`**, and is explicitly
  local — it identifies the connection in control events and is never sent.
- **`PolymarketUsStreamClient::from_gateway_base_url` is gone.** The sockets are
  not on the gateway host. `MarketStreamClient::with_base_url` and
  `PrivateStreamClient::with_base_url` take an explicit override for staging or
  local servers.

## Migrating to 0.4

The flat legacy methods deprecated in 0.3.0 have been removed. Each maps to a
resource client:

```rust
// Removed in 0.4
let markets = client.markets_list().await?;
let balances = client.account_balances().await?;
let order = client.place_order(&req).await?;

// Use instead
let markets = client.markets().list().await?;
let balances = client.account().balances().await?;
let order = client.orders().place(&req).await?;
```

The general rule: `client.<resource>_<verb>()` becomes `client.<resource>().<verb>()`.

Three other breaking changes:

- **`UsAuth` returns `PolymarketUsError`, not `anyhow::Error`.** `UsAuth::from_env()`
  and `UsAuth::from_parts()` now return `Result<UsAuth, PolymarketUsError>`, so
  credential failures can be matched on like every other SDK error. Bad Base64 or a
  wrong key length surfaces as `PolymarketUsError::InvalidCredentials`. If you were
  using `?` inside an `anyhow::Result` function, no change is needed.
- **`UsMarket::market_sides` is `Vec<MarketSide>`**, previously `Vec<serde_json::Value>`.
  Unmodelled keys are preserved in `MarketSide::extra`.
- **`League` and `Team` were removed.** They were unreachable placeholders that no
  endpoint returned; they will return with the endpoints that populate them.

## Configuration

```rust
use polymarket_us::{PolymarketUsClient, UsAuth};
use std::time::Duration;

fn build_client(auth: UsAuth) -> Result<PolymarketUsClient, polymarket_us::PolymarketUsError> {
    PolymarketUsClient::builder()
        .auth(auth)
        .gateway_base_url("https://gateway.polymarket.us")
        .api_base_url("https://api.polymarket.us")
        .timeout(Duration::from_secs(30))
        .build()
}
```

## Error handling

```rust
use polymarket_us::{PolymarketUsClient, PolymarketUsError};

async fn check_health(client: &PolymarketUsClient) {
    match client.health().await {
        Ok(h) => println!("ok: {}", h.status),
        Err(PolymarketUsError::RateLimited { message, retry_after }) => {
            if let Some(d) = retry_after {
                eprintln!("rate limited (retry in {}s): {message}", d.as_secs());
            } else {
                eprintln!("rate limited: {message}");
            }
        }
        Err(PolymarketUsError::Authentication(msg)) => eprintln!("auth failed: {msg}"),
        Err(e) => eprintln!("request failed: {e}"),
    }
}
```

## Retries, Correlation IDs, and Rate Limits

### Automatic Retries

`GET` and `DELETE` requests are automatically retried with exponential backoff and jitter.
`POST` requests (order creation, placement, etc.) are **never** retried automatically to
prevent duplicate submissions.

```rust
use polymarket_us::{PolymarketUsClient, RetryConfig};
use std::time::Duration;

// Default: 3 retries, 200ms initial backoff, 10s cap, 25% jitter
let client = PolymarketUsClient::builder().build()?;

// Aggressive retry for high-availability workflows
let client = PolymarketUsClient::builder()
    .retry(RetryConfig::aggressive())
    .build()?;

// Disable retries entirely
let client = PolymarketUsClient::builder()
    .retry(RetryConfig::none())
    .build()?;

// Fine-grained control
let client = PolymarketUsClient::builder()
    .retry(RetryConfig {
        max_retries: 5,
        initial_backoff: Duration::from_millis(100),
        max_backoff: Duration::from_secs(30),
        jitter_factor: 0.3,
    })
    .build()?;
```

Retries occur on:
- HTTP 429 (respects `Retry-After` header if present)
- HTTP 500, 502, 503, 504
- Transport-level errors (connection refused, timeout)

### Correlation IDs

Every request automatically includes an `X-Correlation-ID` header (`pmrs-{uuid_v4}`) for
tracing requests across your logs and Polymarket support conversations.

```rust
// Custom prefix — useful to distinguish SDK requests by service/environment
let client = PolymarketUsClient::builder()
    .correlation_id_prefix("my-service-prod")
    .build()?;
// Sends: X-Correlation-ID: my-service-prod-550e8400-e29b-41d4-a716-446655440000
```

### Rate Limit Awareness

When Polymarket returns a `429`, the `Retry-After` header is parsed and surfaced in the
`RateLimited` error variant so your application can react precisely:

```rust
match client.markets().list().await {
    Err(PolymarketUsError::RateLimited { retry_after: Some(d), .. }) => {
        println!("backing off for {}s", d.as_secs());
        tokio::time::sleep(d).await;
    }
    _ => {}
}
```

For idempotent endpoints, the SDK already honors this automatically — the `Retry-After`
duration is used directly instead of the configured backoff.

## Testing

The SDK includes comprehensive unit tests for all resource clients and type serialization/deserialization:

```bash
# Run all tests
cargo test

# Run with output
cargo test -- --nocapture

# Run specific test module
cargo test resources::tests

# Run a single test
cargo test resources::tests::place_order_request_serializes
```

Current test coverage includes:
- ✅ Resource client creation and type checking (6 resources × 2 tests = 12 tests)
- ✅ Request/Response serialization for all order types (typed enums + wire compatibility)
- ✅ Type deserialization for markets, events, positions, balances
- ✅ Streaming wire format, endpoint routing, event parsing, and keepalive/idle behaviour
- ✅ Gateway quirks in market deserialization (double-encoded `outcomes` / `outcomePrices`)
- ✅ Retry/backoff policy tests and builder configuration tests

**Total: 93 tests plus 6 doc tests, all passing**

## Acknowledgements

Initial implementation originated in the DRADIS project and was extracted into this crate.

- Project link: `https://github.com/mbordash/DRADIS`
- Attribution is kept for provenance and maintenance history.