If you are building trading bots or analytics for prediction markets (Polymarket, Kalshi, etc.), you generally have two infrastructure choices: a commercial SaaS wrapper or an open-source library.

DomeApi is the leading commercial solution. It’s a robust "Stripe-like" SaaS that handles node management and data normalization for a fee. It is excellent for enterprise teams that need SLAs and managed infrastructure.

pmxt is the free, open-source alternative. It is a Python library designed for developers who prefer local execution, zero fees, and full control over their order flow.

Feature, DomeApi.io, pmxt (Open Source)
Model, Commercial SaaS (B2B), Open Source Library (MIT)
Cost, Paid / Credit-based, Free
Execution, Via 3rd-party API, Local / Direct-to-Exchange
Privacy, Middleman sees trades, Private (You own the keys)
Best For, "Startups, Apps", "Traders, Researchers, Devs"

Why use pmxt?
For many individual developers and algorithmic traders, a SaaS layer adds unnecessary latency and cost. pmxt is modeled after ccxt, unifying the fragmented APIs of various prediction markets into a single, consistent class structure.

Zero Latency Overhead: You connect directly to the exchange APIs (Polymarket, Kalshi, etc.) from your own machine or server.

No Rate Limits (from us): You are only bound by the exchange's own limits.

Unified Interface: Switch between exchanges without rewriting your entire codebase.

Code Example
Here is how to fetch markets and place a trade using pmxt:
`
import pmxt

api = pmxt.Exchange()

1. Search for the broad Event

events = api.fetch_events(query='Who will Trump nominate as Fed Chair?')
fed_event = events[0] # first event (by volume)

2. Filter for the specific Market within that event

warsh = api.filter_markets(fed_event.markets, 'Kevin Warsh')[0] # first market match

print(f"Price: {warsh.yes.price}")
`

Get Started
If you need a reliable, free alternative to commercial prediction market APIs, check out the repo.

Documentation: https://pmxt.dev/docs
GitHub: https://github.com/pmxt-dev/pmxt