Polymarket API & backtesting guides
Reference material we needed and could not find: exact rate limits, the errors that are missing from the official docs, and what prediction market data can and cannot tell you. Every number is sourced and every command is reproducible.
The Polymarket Spot-Lag Edge Is Real. It Is Also About $100 Deep.
Buy the side that spot has already confirmed, before Polymarket reprices. Unlike most strategies people claim, this one survives contact with the data — with a z-score of 15. The reason it hasn't made everyone rich is sitting in the order book.
A 97.7% Win Rate That Loses Money: Buying Favorites, Backtested
Buy the side that's clearly winning, collect the near-certain payout, repeat. It produces a win rate that looks extraordinary on a screenshot. Across 17,002 trades on real order book data it also loses money, and the reason is arithmetic rather than luck.
Entry Timing Is Worth More Than Your Signal
Most strategy discussion is about what to buy. On five-minute markets, when you buy turns out to matter more — the identical signal moves from statistical noise to a 15-sigma edge depending only on the clock. With one important exception.
How to Build a Polymarket Trading Bot
Most Polymarket bot tutorials are built on SDKs that no longer exist. This is the current path end to end — what to install in 2026, how auth actually works, where the data gaps are, and the failure modes that kill bots in week one.
Polymarket API Rate Limits: The Complete Reference
Polymarket publishes its rate limits across several pages, in two completely different systems, using a 10-second window almost nobody expects. This is all of it in one table set — plus what actually happens when you cross a limit.
Polymarket API Errors: Every Code, Decoded
Polymarket's error messages are terse, and the ones that break your bot at 3am are usually the ones missing from the documentation entirely. Here is the full reference — documented errors, undocumented ones, and what to actually do about each.
Polymarket WebSockets: Real-Time Data That Does Not Drop
Polling the order book is the most common way to burn a rate limit budget for no benefit. Here are the four streams, the subscription options nobody documents, and the failure mode where your bot receives silence and calls it calm.
The Polymarket Python SDK in 2026 (and Migrating off py-clob-client)
If your code still imports ClobClient from py_clob_client, it is built on a superseded package — and so is most of the Polymarket code an AI assistant will write for you. Here is the current SDK and how to move.
The Polymarket API, Mapped: Gamma vs CLOB vs Data API
Newcomers lose a day to the same problem: Polymarket does not have an API, it has four of them, and the endpoint you want is rarely on the one you tried first. This is the complete map.
Does Polymarket Have a Testnet?
Short answer: no. Polymarket has never shipped a public testnet, and there is no sandbox environment or demo API. Your first real order is a real order, with real money, against real counterparties. Here is how experienced builders work around that.
Polymarket Up/Down Markets: Slugs, Resolution and the Order Book Cliff
Polymarket's crypto Up/Down markets are the highest-frequency instruments on the platform, and among the most misunderstood. Here is how to decode a slug, what determines resolution, and exactly what Polymarket keeps once a market closes.
How to Choose a Polymarket Data API
Every provider markets a big number. Almost none of them market the number that matters. Here is what to actually test before you commit, including the cases where you do not need a paid provider at all.
Backtest against the order books Polymarket doesn’t keep
240M+ point-in-time snapshots of Polymarket crypto Up/Down markets, with 8 levels of order book depth and sub-second timestamps — including markets that have already resolved.