Does Polymarket have an API?

Three APIs, one platform

Polymarket does not expose a single endpoint that answers every question. It splits its public surface across three services, and most of the confusion developers run into comes from reaching for the wrong one. Polymarket documents all three at docs.polymarket.com, and its help center notes that the client libraries it links from its GitHub are open source and free to use.

The Gamma API is the catalogue. It answers questions about what markets exist: their titles, slugs, categories, end dates, current outcome prices, volume, and liquidity. The Data API is the ledger. It answers questions about who holds what: positions keyed by wallet address, trade history, and holder counts per market. The CLOB API is the exchange itself. It serves the live order book and price endpoints publicly, and behind an API key it accepts, cancels, and manages orders.

The three Polymarket APIs, side by side

The table below compares the three services on the attributes that usually decide which one a project needs. Rows marked as of 2026 describe arrangements that can change; the authentication and cost lines in particular are worth re-checking against the official documentation before you rely on them.

What free actually means here

The read side of Polymarket is free in the strongest sense of the word. There is no signup, no key, no quota dashboard, and no billing relationship standing between a request and a response on the Gamma and Data APIs. A plain HTTPS request to gamma-api.polymarket.com returns market records to anyone. This is unusual. Most venues that produce price data of this quality meter it, and several of the paid Polymarket data products advertised online are reselling the same public endpoints with a cache and a nicer schema in front.

Where money can enter is the authenticated half of the CLOB API. Placing and cancelling orders requires credentials tied to a funded wallet, and the taker fees that apply to some categories are described in Polymarket fees explained. Reading is separate from transacting, and everything Cent Signals does lives entirely on the reading side.

The historical data problem

The single sharpest edge people hit is history. The public APIs are built to describe the present: what a market is worth now, what the book looks like now, what a wallet holds now. The CLOB API does expose a prices-history endpoint, which takes a token id along with either an interval or an explicit start and end timestamp, plus a fidelity parameter that controls the spacing between returned points.

In practice its resolution has limits. Developers working against it have reported that once a market has resolved, granularity finer than roughly twelve hours stops coming back reliably, even for markets whose prices plainly moved minute to minute while they were live. The consequence is simple: if a long, fine-grained price series matters to a project, that series has to be recorded as it happens rather than requested afterwards. This is why Cent Signals commits a dated snapshot on every ingest run. The snapshot is the archive, and the methodology page states exactly what each run captures and how long it is kept.

Rate limits, and why the honest answer is be polite

Search for Polymarket rate limits and you will find confident numbers quoted per ten-second window, per minute, and per hour, from sources that contradict one another. Polymarket's API reference introduction does not publish a rate limit table, so none of those figures should be treated as load-bearing. Anyone building against a free, unauthenticated endpoint is a guest on infrastructure someone else pays for.

The approach that has worked here is unglamorous. The Cent Signals ingest script waits 350 milliseconds between calls, fetches each endpoint once per run rather than polling, and treats a slow response as a reason to back off rather than to retry harder. Requests are often throttled and queued before anything returns an error status, so a script that keeps firing simply makes itself slower while adding load. Reading the data once, carefully, is enough for editorial coverage.

What the API makes visible about wallets

Because Polymarket settles on-chain through smart contracts on Polygon, the Data API can return position and trade records keyed by wallet address, and it does so for anyone who asks, without credentials. That single fact is what makes independent coverage of this market possible at all. Large transactions are not leaked or scraped; they are a public property of how the exchange is built, described further in what is a Polymarket whale.

Cent Signals reads exactly those two public services, Gamma and Data, with no key and no privileged access, and renders what comes back on the whale trades feed and the traders leaderboard. Addresses are reported as addresses. We do not connect them to real-world identities, and the presence of a large position in the feed is an observation about public data, never an indication of what any reader should do.

Reading the numbers the API returns

An API response is only as useful as the reader's grasp of what the fields mean. A price field of 0.08 is an implied probability of about 8 percent, not a discount, and a volume field and a liquidity field measure two genuinely different things that are easy to conflate. Those distinctions are unpacked in how to read implied probability on Polymarket and volume vs liquidity on Polymarket, and the field names themselves are defined in the glossary. The API hands over numbers. What those numbers are evidence of, and how much weight any one of them deserves, is the part no endpoint answers.

Frequently asked questions