Polymarket API Documentation

The PolyOrderbooks API gives you programmatic access to historical Polymarket crypto and sports markets: discovery metadata, outcome prices, liquidity metrics, and L2 order book snapshots. Data is collected continuously into our historical store and served with consistent latency.

Production base URL

https://api.polyorderbooks.com

Paths in this documentation are relative to that host. Every /v1 data route requires a valid API key.

Quick start

Authenticate and query the catalog and history. If you are new here: get an API key, check rate limits, and review error handling before querying at scale.

# 1. Discover markets (API key required)
curl -s -H "X-API-Key: $POLYORDERBOOKS_API_KEY" \
  "https://api.polyorderbooks.com/v1/markets?search=bitcoin&limit=5"

# 2. Order book history (250ms resolution, available on every plan)
curl -s -H "X-API-Key: $POLYORDERBOOKS_API_KEY" \
  "https://api.polyorderbooks.com/v1/markets/MARKET_SLUG/books" \
  --get \
  --data-urlencode "start_ts=2026-07-26T00:00:00Z" \
  --data-urlencode "end_ts=2026-07-26T06:00:00Z" \
  --data-urlencode "resolution=250ms"

Use the Try playground on endpoint pages after adding your X-API-Key header.

First time here?

Create an account, verify your email, generate an API key, and run your first historical query.

Want the data before you write any code? The free BTC 5-minute order book sample is a real slice of the archive — 1-second L2 bids, asks, spread, and depth in CSV or JSON, CC BY 4.0, no signup. The same snapshot is archived on Zenodo if you want to cite it.

What you can build

Market discovery

Search series, events, and markets with tags, status, volume, and date filters.

Price history

Outcome-level prices from 250ms native capture through daily aggregates.

Liquidity analytics

Volume, liquidity, and spread for execution-quality and microstructure research.

Order book depth

Historical L2 bid and ask ladders for slippage and depth analysis.

Coverage

We ingest and serve Polymarket crypto and sports markets. Pass category=crypto or category=sports to pin a request to one archive, or omit it to page across both. See Discovery overview for catalog scope.

Data model

Series  →  Events  →  Markets  →  Tokens (Yes / No / …)

Discover

Search with GET /v1/markets or browse series and events.

Resolve

Read GET /v1/markets/{id_or_slug} for outcome token identifiers and resolution state.

Query history

Request prices, metrics, or books over your time window.

Design principles

Principle	Detail
Read-local	Discovery and history query our data store only — not live Polymarket APIs.
Sparse → uniform	Captures are stored on change; the API materializes uniform buckets via last-value carry.
Stable identifiers	Markets accept source id, URL slug, or scoped public id (`polymarket:market:<id>`).
Cursor pagination	Large result sets paginate with opaque cursors — see Pagination.
Plan enforcement	Resolution floor, history window, and rate limits are enforced per API key — see Pricing.

Create account

Free Starter plan — no credit card.

Dashboard

API keys, usage, and account settings.

Python SDK (PyPI)

Official polyorderbooks client — pip install polyorderbooks.

Python examples

Runnable scripts for discovery, books, and backtests.

OpenAPI

Machine-readable specification (hosted with these docs).

Getting started

Discovery

Historical

Backtest AI

Reference

Polymarket API Documentation

Quick start

First time here?

What you can build

Market discovery

Price history

Liquidity analytics

Order book depth

Coverage

Data model

Design principles

Links

Create account

Dashboard

Python SDK (PyPI)

Python examples

OpenAPI

​Quick start

First time here?

​What you can build

Market discovery

Price history

Liquidity analytics

Order book depth

​Coverage

​Data model

​Design principles

​Links

Create account

Dashboard

Python SDK (PyPI)

Python examples

OpenAPI

Quick start

What you can build

Coverage

Data model

Design principles

Links