Polymarket and Kalshi Rust SDKs (2026): Clients and Examples

Does Polymarket have an official Rust SDK?

Yes. Polymarket's docs call polymarket_client_sdk_v2 "the current Rust SDK" and say "a unified Rust SDK is in progress". The crate is built from Polymarket's rs-clob-client-v2 repository, carries an MIT license, and targets the 2024 edition with Rust 1.88 or newer. Two crates on crates.io come from Polymarket's own repositories:

The older crate stopped at 0.4.4 in March 2026. On 28 April 2026 Polymarket moved to CLOB V2, with new exchange contracts, a new order struct and pUSD collateral, and its changelog said there would be no backward compatibility after go-live. New code belongs on the V2 crate.

Everything else is community-built. A crates.io search for "polymarket" returned 94 crates on 3 October 2026, so watch the names. rs-clob-client and rs-clob-client-v2 are published by a community developer, not Polymarket. polymarket-us describes itself as an unofficial SDK for Polymarket US, whose official SDKs cover Python and TypeScript only. If you choose a community crate, check that it has a release after 28 April 2026.

How do you install the Polymarket Rust SDK?

Polymarket's docs give this command, which turns on the clob feature for authentication and trading:

cargo add polymarket_client_sdk_v2@0.7.0 --features clob

What does a Polymarket Rust SDK example look like?

This read-only example is copied from the crate's README. It needs the gamma feature, and your own Cargo.toml needs tokio and anyhow, which the example uses directly:

use polymarket_client_sdk_v2::gamma::Client;
use polymarket_client_sdk_v2::gamma::types::request::{EventsRequest, SearchRequest};

#[tokio::main]
async fn main() -> anyhow::Result<()> {
    let client = Client::default();

    // Find active events
    let request = EventsRequest::builder().active(true).limit(5).build();
    let events = client.events(&request).await?;
    println!("Found {} events", events.len());

    // Search for markets
    let search = SearchRequest::builder().q("bitcoin").build();
    let results = client.search(&search).await?;
    println!("Search results: {:?}", results);
    Ok(())
}

For trading, Polymarket's docs say the crate supports the CLOB order path for an existing Deposit Wallet: pass the wallet as the funder and authenticate with SignatureType::Poly1271. It has no client for deploying Deposit Wallets or submitting wallet batches, which go through the direct API. The wallet types are explained in our Polymarket proxy wallet guide.

Which CLOB host should the Polymarket Rust SDK use?

Set it yourself. In both 0.7.0 and 0.8.0, the CLOB's Client::default() points at https://clob-v2.polymarket.com, and the examples in the README and the docs pass the same host. That was the test host before launch. Polymarket's changelog says that as of 28 April 2026, V2 runs on https://clob.polymarket.com.

In our checks on 3 October 2026, clob-v2.polymarket.com returned no DNS records, while clob.polymarket.com answered {"version":2} on GET /version. Build the client with Client::new and pass https://clob.polymarket.com as the host. The SDK reads /version to decide how to sign orders, so the live host gets you V2 signing.

Is there an official Kalshi Rust SDK?

No. Kalshi's SDK page lists kalshi_python_sync, kalshi_python_async and kalshi-typescript, and warns that SDKs "may lag the API". For production it recommends generating your own client from its specs, or integrating directly. REST is described in an OpenAPI file, at version 3.32.0 as of October 2026, and WebSockets in an AsyncAPI file.

The Rust crates for Kalshi are all community projects. These are the client crates on crates.io as of 3 October 2026:

Two things stand out. Kalshi now selects Ed25519 by default when you create an API key, and its official SDKs accept Ed25519 from version 3.31.0, yet none of these crates referenced Ed25519 in its latest source when we checked. Create an RSA key for them. And kalshi 0.9.0 logs in with an email and password, a flow Kalshi's current API reference no longer documents. Key setup is covered in how to get a Kalshi API key.

How do you call Kalshi from Rust without an SDK?

Public market data needs no key, so any HTTP client works:

curl -s "https://external-api.kalshi.com/trade-api/v2/markets?limit=2&status=open"

Authenticated requests carry three headers: KALSHI-ACCESS-KEY with the key ID, KALSHI-ACCESS-TIMESTAMP in milliseconds, and KALSHI-ACCESS-SIGNATURE, a base64 signature of the timestamp, the HTTP method and the path with its query string removed. RSA keys sign with RSA-PSS over SHA-256, and Ed25519 keys sign the text directly. Kalshi's spec models those three headers as plain header keys, so a client generated from it still needs your code to compute the signature on every request.

How do you query Polymarket and Kalshi from Rust with one API?

Two venues means two auth schemes, two sets of field names and, for Kalshi, a client you maintain yourself. The Predictefy API is plain REST at data.predictefy.com, so a Rust service calls it with the HTTP client it already has, and the same request shape covers Polymarket, Kalshi and the rest of its 15+ venues:

curl -s "https://data.predictefy.com/api/polymarket/fetchMarkets?limit=3&sort=volume" \
  -H "Authorization: Bearer pk_live_YOUR_KEY"

Frequently Asked Questions