Getting started

The TrendlineLabs Public API serves read-only prediction-market data across Polymarket, Kalshi, Limitless and predict.fun: events, markets, prices, order books, price history and trades, with every answer carrying its own freshness signal.

1. Get a key

API access is free, and our team approves each account.

Sign in at trendlinelabs.ai and open API keys from your account menu (trendlinelabs.ai/developer).
Choose Request API access. You can add a short note about what you are building.
Once we approve it, the same page shows the key manager. Choose Create key, pick its scopes and copy the key.

Keys look like tl_live_ plus a secret. The secret is shown once, at creation, so store it somewhere safe. You can list and revoke your keys on the same page. Until access is granted, creating a key answers 403 access_not_granted.

2. Make your first request

Every request sends the key as a bearer token. Set it once:

export TRENDLINE_API_KEY=...            # your key
export TRENDLINE_API_BASE=https://systems.trendlinelabs.ai

Read your own key back, which needs no scope:

curl: examples/getKey.sh
Python: examples/getKey.py
JavaScript (Node 18+, an ES module): examples/getKey.mjs

The answer is examples/getKey.response.json: the key’s id, scopes, tier, and its limit per window_s seconds.

3. Walk from an event to a book

List events: examples/listEvents.sh (.py, .mjs). Each event carries its universal_id.
Read one event: examples/getEvent.sh. Its markets list carries each market’s universal_id.
Read a market’s order book on one venue: examples/getOrderbook.sh.

Every example reads TRENDLINE_API_BASE and TRENDLINE_API_KEY from the environment, so the same file runs against any base you point it at.

4. What every answer carries

X-Request-Id: this request’s id. Send your own X-Request-Id and it is echoed; the error envelope’s request_id is the same value. Quote it when you ask for help.
Cache-Control: no-store on every operation’s answer (not on the reference document itself).
X-RateLimit-Limit, X-RateLimit-Remaining and X-RateLimit-Reset once your key has passed the rate limiter (see Rate limits).

Next: Authentication, Errors, Freshness.

Examples on this page

getKey

#!/bin/sh
# getKey: Get the calling key. Needs TRENDLINE_API_KEY; TRENDLINE_API_BASE overrides the base.
curl -sS "${TRENDLINE_API_BASE:-https://systems.trendlinelabs.ai}/public/v1/key" \
  -H "Authorization: Bearer $TRENDLINE_API_KEY"

"""getKey: Get the calling key. Needs TRENDLINE_API_KEY; TRENDLINE_API_BASE overrides the base."""
import os

import requests

BASE = os.environ.get("TRENDLINE_API_BASE", "https://systems.trendlinelabs.ai")
KEY = os.environ["TRENDLINE_API_KEY"]

r = requests.get(f"{BASE}/public/v1/key", params={},
                 headers={"Authorization": f"Bearer {KEY}"}, timeout=10)
r.raise_for_status()
print(r.json())

// getKey: Get the calling key. Needs TRENDLINE_API_KEY; TRENDLINE_API_BASE overrides the base.
const BASE = process.env.TRENDLINE_API_BASE ?? "https://systems.trendlinelabs.ai";
const KEY = process.env.TRENDLINE_API_KEY;
const r = await fetch(`${BASE}/public/v1/key`, { headers: { Authorization: `Bearer ${KEY}` } });
console.log(r.status, await r.json());

Response

{
  "key_id": "6720f0c1a2b3c4d5e6f70812",
  "name": "research-bot",
  "prefix": "tl_live_",
  "last4": "Qx7k",
  "scopes": [
    "market:read"
  ],
  "tier": "FREE",
  "limit": 100,
  "window_s": 60,
  "created_at": "2026-10-01T09:00:00+00:00",
  "expires_at": "2027-10-01T09:00:00+00:00",
  "last_used_at": "2026-10-06T05:59:58+00:00"
}

listEvents

#!/bin/sh
# listEvents: List active events. Needs TRENDLINE_API_KEY; TRENDLINE_API_BASE overrides the base.
curl -sS "${TRENDLINE_API_BASE:-https://systems.trendlinelabs.ai}/public/v1/events?limit=1" \
  -H "Authorization: Bearer $TRENDLINE_API_KEY"

"""listEvents: List active events. Needs TRENDLINE_API_KEY; TRENDLINE_API_BASE overrides the base."""
import os

import requests

BASE = os.environ.get("TRENDLINE_API_BASE", "https://systems.trendlinelabs.ai")
KEY = os.environ["TRENDLINE_API_KEY"]

r = requests.get(f"{BASE}/public/v1/events", params={"limit": "1"},
                 headers={"Authorization": f"Bearer {KEY}"}, timeout=10)
r.raise_for_status()
print(r.json())

// listEvents: List active events. Needs TRENDLINE_API_KEY; TRENDLINE_API_BASE overrides the base.
const BASE = process.env.TRENDLINE_API_BASE ?? "https://systems.trendlinelabs.ai";
const KEY = process.env.TRENDLINE_API_KEY;
const r = await fetch(`${BASE}/public/v1/events?limit=1`, { headers: { Authorization: `Bearer ${KEY}` } });
console.log(r.status, await r.json());

Response

{
  "events": [
    {
      "universal_id": "ev-btc-100k-2026",
      "title": "Bitcoin price at year end",
      "category_group": "crypto",
      "categories": [
        "crypto",
        "bitcoin"
      ],
      "platform_count": 2,
      "venues": [
        "kalshi",
        "polymarket"
      ],
      "kalshi_event_ticker": "KXBTC-26DEC31",
      "poly_event_slug": "bitcoin-above-100k-on-december-31",
      "limitless_event_id": null,
      "predictfun_event_id": null,
      "image_url": null,
      "resolution_date": "2026-12-31T23:59:59.000Z",
      "first_seen_at": "2026-09-01T12:00:00.000Z",
      "last_seen_at": "2026-10-06T05:59:30.000Z"
    }
  ],
  "next_cursor": "eyJ2IjoxLCJhZnRlciI6ImV2LWJ0Yy0xMDBrLTIwMjYiLCJmcCI6IjAwMDAwMDAwMDAwMDAwMDAifQ==",
  "universe_last_seen_at": "2026-10-06T05:59:30.000Z",
  "universe_age_s": 30
}

getEvent

#!/bin/sh
# getEvent: Get one event with its markets. Needs TRENDLINE_API_KEY; TRENDLINE_API_BASE overrides the base.
curl -sS "${TRENDLINE_API_BASE:-https://systems.trendlinelabs.ai}/public/v1/events/ev-btc-100k-2026" \
  -H "Authorization: Bearer $TRENDLINE_API_KEY"

"""getEvent: Get one event with its markets. Needs TRENDLINE_API_KEY; TRENDLINE_API_BASE overrides the base."""
import os

import requests

BASE = os.environ.get("TRENDLINE_API_BASE", "https://systems.trendlinelabs.ai")
KEY = os.environ["TRENDLINE_API_KEY"]

r = requests.get(f"{BASE}/public/v1/events/ev-btc-100k-2026", params={},
                 headers={"Authorization": f"Bearer {KEY}"}, timeout=10)
r.raise_for_status()
print(r.json())

// getEvent: Get one event with its markets. Needs TRENDLINE_API_KEY; TRENDLINE_API_BASE overrides the base.
const BASE = process.env.TRENDLINE_API_BASE ?? "https://systems.trendlinelabs.ai";
const KEY = process.env.TRENDLINE_API_KEY;
const r = await fetch(`${BASE}/public/v1/events/ev-btc-100k-2026`, { headers: { Authorization: `Bearer ${KEY}` } });
console.log(r.status, await r.json());

Response

{
  "universal_id": "ev-btc-100k-2026",
  "title": "Bitcoin price at year end",
  "category_group": "crypto",
  "categories": [
    "crypto",
    "bitcoin"
  ],
  "status": "active",
  "is_live": false,
  "first_seen_at": "2026-09-01T12:00:00.000Z",
  "last_seen_at": "2026-10-06T05:59:30.000Z",
  "resolution_date": "2026-12-31T23:59:59.000Z",
  "image_url": null,
  "total_volume_usd": 1834201.5,
  "liquidity_usd": 412000.0,
  "platform_count": 2,
  "source_lanes": [
    "kalshi",
    "polymarket"
  ],
  "kalshi_event_ticker": "KXBTC-26DEC31",
  "poly_event_slug": "bitcoin-above-100k-on-december-31",
  "limitless_event_id": null,
  "predictfun_event_id": null,
  "markets": [
    {
      "universal_id": "mk-btc-100k-2026",
      "title": "Bitcoin above $100k on December 31?",
      "status": "active",
      "yes_subject": "Bitcoin above $100k",
      "deadline_at": "2026-12-31T23:59:59.000Z",
      "kalshi_market_ticker": "KXBTC-26DEC31-B100000",
      "poly_market_slug": "bitcoin-above-100k-on-december-31",
      "limitless_market_id": null,
      "predictfun_market_id": null,
      "volume_usd": 1834201.5,
      "volume_24h_usd": 50211.0,
      "volume_by_platform": {
        "kalshi": 734201.5,
        "polymarket": 1100000.0
      },
      "volume_24h_by_platform": {
        "kalshi": 20211.0,
        "polymarket": 30000.0
      },
      "price_24h_change_by_platform": {
        "kalshi": 0.02,
        "polymarket": 0.01
      },
      "source_lanes": [
        "kalshi",
        "polymarket"
      ],
      "venue_details": {
        "kalshi": {
          "rules_primary": "Resolves YES if the reference price is above $100,000 at the close.",
          "rules_secondary": null,
          "open_time": "2026-09-01T12:00:00Z",
          "close_time": "2026-12-31T23:59:59Z",
          "yes_sub_title": "Above $100,000",
          "liquidity_raw": 152000.0,
          "volume_24h": 20211.0,
          "url": "https://kalshi.com/markets/kxbtc"
        },
        "polymarket": {
          "description": "Resolves YES if Bitcoin trades above $100,000 on December 31.",
          "resolution_source": "https://example.com/btc-index",
          "start_date": "2026-09-01T12:00:00Z",
          "end_date": "2026-12-31T23:59:59Z",
          "best_bid": 0.44,
          "liquidity": 260000.0,
          "volume_24h": 30000.0,
          "url": "https://polymarket.com/event/bitcoin-above-100k-on-december-31"
        },
        "limitless": null,
        "predictfun": null
      }
    }
  ]
}

getOrderbook

#!/bin/sh
# getOrderbook: Get a market's order book on one venue. Needs TRENDLINE_API_KEY; TRENDLINE_API_BASE overrides the base.
curl -sS "${TRENDLINE_API_BASE:-https://systems.trendlinelabs.ai}/public/v1/markets/mk-btc-100k-2026/orderbook?venue=kalshi&depth=2" \
  -H "Authorization: Bearer $TRENDLINE_API_KEY"

"""getOrderbook: Get a market's order book on one venue. Needs TRENDLINE_API_KEY; TRENDLINE_API_BASE overrides the base."""
import os

import requests

BASE = os.environ.get("TRENDLINE_API_BASE", "https://systems.trendlinelabs.ai")
KEY = os.environ["TRENDLINE_API_KEY"]

r = requests.get(f"{BASE}/public/v1/markets/mk-btc-100k-2026/orderbook", params={"venue": "kalshi", "depth": "2"},
                 headers={"Authorization": f"Bearer {KEY}"}, timeout=10)
r.raise_for_status()
print(r.json())

// getOrderbook: Get a market's order book on one venue. Needs TRENDLINE_API_KEY; TRENDLINE_API_BASE overrides the base.
const BASE = process.env.TRENDLINE_API_BASE ?? "https://systems.trendlinelabs.ai";
const KEY = process.env.TRENDLINE_API_KEY;
const r = await fetch(`${BASE}/public/v1/markets/mk-btc-100k-2026/orderbook?venue=kalshi&depth=2`, { headers: { Authorization: `Bearer ${KEY}` } });
console.log(r.status, await r.json());

Response

{
  "universal_id": "mk-btc-100k-2026",
  "venue": "kalshi",
  "venue_market_id": "KXBTC-26DEC31-B100000",
  "yes": {
    "bids": [
      {
        "price": 0.4,
        "size": 150
      },
      {
        "price": 0.39,
        "size": 400
      }
    ],
    "asks": [
      {
        "price": 0.41,
        "size": 310
      },
      {
        "price": 0.42,
        "size": 90
      }
    ]
  },
  "no": {
    "bids": [
      {
        "price": 0.59,
        "size": 310
      }
    ],
    "asks": [
      {
        "price": 0.6,
        "size": 150
      }
    ]
  },
  "no_source": "book",
  "ts_ms": 1791266398500,
  "age_ms": 1500,
  "max_age_s": 1200,
  "as_of_ms": 1791266400000
}

Get started

Concepts

Resources

1. Get a key

2. Make your first request

3. Walk from an event to a book

4. What every answer carries

Examples on this page

getKey

listEvents

getEvent

getOrderbook

​1. Get a key

​2. Make your first request

​3. Walk from an event to a book

​4. What every answer carries

​Examples on this page

​getKey

​listEvents

​getEvent

​getOrderbook

1. Get a key

2. Make your first request

3. Walk from an event to a book

4. What every answer carries

Examples on this page

getKey

listEvents

getEvent

getOrderbook