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---
title: "Adjacent API"
icon: rocket
description: "Use prediction market data, indices, reference rates, and news in your own tools."
"og:image": "https://adjacent.markets/api/og?name=Adjacent+API&type=index&eyebrow=API+DOCS&subtitle=API+for+prediction+market+data%2C+indices%2C+reference+rates+and+news&variant=forest"
"twitter:image": "https://adjacent.markets/api/og?name=Adjacent+API&type=index&eyebrow=API+DOCS&subtitle=API+for+prediction+market+data%2C+indices%2C+reference+rates+and+news&variant=forest"
---

Adjacent gives you one place to work with prediction-market data from Kalshi
and Polymarket. Use it to build research tools, track markets, compare prices,
or give an AI agent reliable market data.

You can start with delayed public data or use an API key for realtime data and
the full catalog.

<CardGroup cols={2}>
  <Card title="Start with the API reference" icon="code" href="/api/get-api-v1-public-markets">
    Browse every endpoint with schemas, examples, and a live cURL request.
  </Card>

  <Card title="Pricing" icon="tag" href="/pricing">
    Compare data access, quotas, and plan limits.
  </Card>
</CardGroup>

## Choose what you need

**Market data.** Find markets and events, then read prices, trades, quotes,
and candles. Start with [Market data](/explore/market-data).

**Indices.** Use an index when you need a single measure built from many
prediction markets. Start with [Indices](/explore/indices).

**Reference rates.** Compare the same market across venues or across rolling
contracts with one price series. Start with
[Reference rates](/explore/reference-rates).

**News.** Find stored articles and connect them to markets, indices, and
filings. Start with [News](/explore/news).

**Filings.** Browse CFTC industry filings and follow status changes,
attachments, and related markets. Start with [Filings](/explore/filings).

**AI agents.** Connect an agent through MCP instead of teaching it every REST
endpoint. Start with [MCP server](/explore/mcp).

## Base URL

```
https://api.adjacent.markets
```

All endpoints use the `/api/v1/` prefix.

## Authentication

The anonymous `/api/v1/public/*` tier needs no token and returns data delayed by
15 minutes.

Realtime endpoints require a bearer token. Use a session token from the app or
an **API key** with the read scope for the resource you are calling.

```bash
curl -H "Authorization: Bearer YOUR_TOKEN" \
  https://api.adjacent.markets/api/v1/rates
```

### API keys

Create and manage keys in the app under **Settings → API keys**. Choose scopes
that your account can grant, then copy the secret because it appears only once.

Send the key as a bearer token:

```bash
curl -H "Authorization: Bearer ak_your_key" \
  https://api.adjacent.markets/api/v1/rates
```

…or as an `api_key` query parameter:

```bash
curl "https://api.adjacent.markets/api/v1/rates?api_key=ak_your_key"
```

A key can reach only the endpoints covered by its scopes. Other requests return
`403`.

## Need help choosing?

Start with the public tier if you are exploring the data or building a
prototype. Use an API key when you need realtime values, deeper history, news,
or higher request limits. If you are not sure which endpoint fits your use
case, [contact support](mailto:lucas@adjacentresearch.xyz).