Get started in 5 minutes

Five minutes from now you’ll have a working API call against live prediction-market data. Then we’ll send you to the guide for your use case.

Step 1 — Get an API key

No credit card required. The free plan gives you 1,000 requests/month against the entire Data API — enough to evaluate everything.Open dashboard →

Copy your key

Your key starts with pk_ and goes in the x-api-key header of every request.

export PREDEXON_API_KEY="pk_..."

Step 2 — Make your first call

This call lists the top 5 trending markets on Polymarket. It works on the free plan with no setup.

curl -H "x-api-key: $PREDEXON_API_KEY" \
  "https://api.predexon.com/v2/polymarket/markets?status=open&sort=volume&limit=5"

You should see five live markets ranked by volume. If you got an error, see Troubleshooting below.

Step 3 — Pick your path

Now go to the guide for what you’re building.

Quant / data trader

Backtest with orderbook history, build smart-money models, stream live signals. Most of what you need is on the free tier.

App builder / platform

Architecture patterns, account models, fee monetization, and the full execution stack across every venue.

Active trader / fund

The combined data + execution loop. Discover, signal, size, execute, monitor.

AI agent developer

Drop the MCP server into Claude, Cursor, or Codex. Five recipes for common agent tasks.

Not sure which? Skim the Cookbook — five concrete end-to-end recipes for common tasks.

What’s on each surface

Surface	Base URL	When to reach for it
Data API	`api.predexon.com`	Markets, prices, candles, trades, wallets, smart money. Free on most endpoints.
Trading API	`trade.predexon.com`	Place orders across venues, manage accounts, fund/withdraw. Free on every endpoint.
WebSocket	`wss.predexon.com`	Live trades, orderbook, pending-trade signals. Dev plan and up.
MCP server	`npx predexon-mcp`	AI agents — same data through one drop-in package.

All four authenticate with the same API key.

Troubleshooting

401 / 403 errors

Verify your key is in the x-api-key header (lowercase, hyphenated).
Free plan can’t hit Smart Money, Cross-Venue Matching, Binance, or WebSocket — those need Dev or higher.
WebSocket connection rejected? Same gating — see Rate Limits.

429 Too Many Requests

You’ve hit your rate limit. Free is 1 req/s, Dev is 20 req/s, Pro is 100 req/s. Implement exponential backoff. See Best Practices for the pattern we recommend.

Empty results

Most list endpoints accept status, sort, limit parameters — try removing filters one at a time. Markets that were resolved more than a few weeks ago may be archived and need ?archived=true.

Where do I see all endpoints?

Every endpoint is documented under Data & Signals (data) and Unified Execution Infra (trading). Each page has an interactive playground.

Need help?

Discord

The fastest way to get unblocked. Engineering reads every message.

Email

team@predexon.com for anything that doesn’t fit Discord.

Documentation Index

​Step 1 — Get an API key

​Step 2 — Make your first call

​Step 3 — Pick your path