# Limitless API

REST and WebSocket for markets, books, candles and trading on Base.

*https://predictionmarkets.tools/tools/limitless-api · Prediction Market Data APIs*

## Facts

### At a glance

| Field | Value |
| --- | --- |
| Vendor | Limitless |
| Category | Prediction Market Data APIs |
| Job | realtime |
| Website | https://docs.limitless.exchange/developers/introduction |
| Pricing model | commission |
| Free tier | true |
| Open source | false |
| Licence | none |
| Self-hosted | false |
| Tested hands-on | false |
| Last updated | 2026-09-19 |

### Availability

| Field | Value |
| --- | --- |
| Jurisdictions | global |
| Open to US persons | false |
| KYC required | false |

### Markets

| Field | Value |
| --- | --- |
| Subjects | crypto, business, macro, politics, sports |
| Settlement | crypto |
| Resolved by | Pyth Network resolves most markets automatically, a Chainlink time-weighted average price resolves short crypto markets, and the Limitless team resolves custom event markets by hand. |

### Economics

| Field | Value |
| --- | --- |
| Taker fee | 1.5 |
| Maker fee | 0 |
| Liquidity model | clob |
| Platforms | library |
| AI features | none |

### Interfaces

| Field | Value |
| --- | --- |
| API | true |
| WebSocket | true |
| Scripting | none |
| Python | true |
| MCP server | true |
| Export | json |

### Capabilities

Yes: order_book, automation, live_trading, portfolio_tracking

No: charting, screening, backtesting, paper_trading, calibration_scoring, cross_venue, alerts, news, tax_reporting

*Verified: pricing 2026-09-19; availability 2026-09-19; economics 2026-09-19; markets 2026-09-19.*

## What it is

The API of an on-chain prediction market on Base, and the broadest surface in this category for its size: markets and search, order books, historical prices, oracle candlesticks, a trading feed, leaderboards, positions and portfolio history, plus order placement, cancellation and cancel-replace. REST lives at `api.limitless.exchange` with a Scalar explorer beside it; real time is a Socket.IO WebSocket at `ws.limitless.exchange` on the `/markets` namespace.

Two features are unusual here. There are official SDKs in four languages — TypeScript, Python, Go and Rust — each documented endpoint by endpoint rather than as a single quick start. And Limitless runs a first-party MCP server at `api.limitless.exchange/mcp`, which lets an assistant search markets, read books and price history and prepare orders that a human then approves in the browser; it is non-custodial and holds no keys.

The catalogue is mostly sport, which the venue's reputation for minute-scale crypto markets does not suggest. Of 522 active markets on 19 September 2026, the first 300 the endpoint returned were 240 football, other sports and esports questions against 17 crypto or commodity up-or-down markets and 13 equity ones; the 5-minute and 15-minute products were two apiece.

## Availability

The terms, last updated 15 September 2026, are the document to read. Limitless is operated by Street Chow Inc., a Panamanian company, and **is not available for trading to users from the United States, the Republic of China, or the Canadian provinces of Ontario and Alberta**. A separate clause blocks access entirely from Russia, Belarus, Cuba, Iran, North Korea, Syria and the Crimea, Donetsk and Luhansk regions.

There is no KYC step: an account is a connected wallet, and eligibility is asserted by you rather than checked at signup, though the company reserves the right to demand proof of age, identity or eligibility at any time.

The API layer carries none of that. The public endpoints are a single global host with no regional mirrors and no region selection, and they answered from this machine without credentials. As everywhere in this category, reading is not permission to trade.

## Pricing

No charge for the API. Fees are taken out of fills, and only from takers — a resting limit order that gets filled pays nothing, which the docs state twice.

The curve is the thing to plan against, and it runs the opposite way from Polymarket's. On order-book markets the buy fee starts at **3.00% at prices from 1 cent to 50 cents** and falls as the price rises: 1.51% at 70 cents, 0.85% at 85 cents, 0.42% at 99 cents. The sell fee peaks at the midpoint instead — 1.50% at 50 cents, 0.78% at 90 cents, 0.42% at the extremes. AMM markets are a flat 0.40%. Buy fees are paid in outcome tokens, sell fees in USDC.

Limitless says outright that the curve is not published as a closed-form formula and that the tables list representative prices only. The honest way to read a fee here is from the execution response, which carries `effectiveFeeBps`, the charged `usdFee` or `contractsFee`, and the market's configured base rate. Those published percentages are shares of what the fill costs, not of the dollar it pays out - the execution response applies the same rate to `usdGross` and `contractsGross` alike, and a 3.00% fee on a 1-cent contract could not be anything else. This card's figure converts the worst case to the catalogue's common measure: 3.00% of a 50-cent fill is 1.5 cents a contract, or 1.5% of the dollar at stake, against 1.25% on [polymarket-clob-api](https://predictionmarkets.tools/tools/polymarket-clob-api) and 1.75% on [kalshi-api](https://predictionmarkets.tools/tools/kalshi-api). An AMM market is a flat 0.40% of the fill instead.

Redemption after resolution is not a trade and carries no trading fee — but selling into the book just before resolution does, which is where the sell curve costs the most.

## Markets & resolution

Resolution is mostly automatic and mostly not human. Pyth Network resolves the majority of markets at the deadline; short-cadence crypto up-or-down markets are moving to a Chainlink time-weighted average price, where both the price to beat and the closing value come from the same averaged stream, so a single spike at the boundary does not decide the market; custom event markets (sports, politics) are resolved by the Limitless team, typically 24 to 72 hours after the deadline.

Where the rules cannot be applied to the real-world result, Limitless treats the market as misresolved and refunds under its refund policy — **the amount staked, not the dollar a winning share would have paid**. That is a different failure mode from a disputed oracle vote, and worth encoding in any strategy that relies on a payout.

One API-shaped caveat: a market can read as resolved before the on-chain payout has been posted, so a redemption call may have to wait even after the status flips. NegRisk category markets add the constraint that exactly one outcome in a group can win.

## Integrations

REST plus Socket.IO, with SDKs in four languages and an MCP server. Authentication is a scoped API token (token ID plus secret) generated in the UI, signed per request with HMAC-SHA256 into `lmts-api-key`, `lmts-timestamp` and `lmts-signature`; the WebSocket signs a fixed canonical handshake string the same way. Static API-key headers are deprecated and no longer issued.

Orders are EIP-712 signatures against the market's venue `exchange` address, which you fetch once per market and cache, in GTC or FOK form. An optional receive window rejects stale signed orders with HTTP 425. Partners who place orders for other people's accounts need an application, and get sub-accounts and delegated signing on approval.

## Limitations

- **No US trading**, and the same for Ontario, Alberta and the Republic of China.
- **No test environment at all** — no sandbox, no testnet, no mock mode. Every rehearsal is real USDC on Base.
- **No published rate limits.** The docs describe 429 handling and invite you to write in for a quota; there is no number to design against.
- **No historical order book.** Past activity has to be reassembled from price history, feed events and your own fills.
- **History cannot outlive the market.** For the hourly and minute-scale crypto products, that is a very short series per slug.
- **The fee curve is undocumented as a formula**, so the only exact figure is the one returned after the trade.
- **One market per order-book request.** There is no batched book endpoint; following several markets means the WebSocket.

## Alternatives

For a bigger book with a flatter fee and the same wallet-based access, the [Polymarket CLOB API](https://predictionmarkets.tools/tools/polymarket-clob-api) is the obvious comparison, with the [Polymarket Gamma API](https://predictionmarkets.tools/tools/polymarket-gamma-api) alongside it for discovery. If the requirement is a US-accessible regulated venue with a demo environment and published rate limits, that is the [Kalshi API](https://predictionmarkets.tools/tools/kalshi-api).

## FAQ

### Do I need an API key to read Limitless market data?

No. Market browsing, order books, historical prices and the public portfolio endpoints answer unauthenticated requests — a call to the active-markets endpoint returned live records on 19 September 2026 with no headers. The public WebSocket channels for prices and market lifecycle are open too.

### What does trading through the Limitless API require?

A scoped API token issued from the web UI, HMAC-SHA256 signing on every request, and orders signed with EIP-712 against the market's venue contract on Base. Accounts are wallets, so there is no identity check — and the terms bar trading from the United States.

### Is there a Limitless test environment?

No. The documentation is explicit that there is no sandbox, testnet, mock mode or Base Sepolia deployment, and suggests rehearsing with minimum-size live orders on a low-volume market instead.

### How far back does Limitless price history go?

Only as far as the market itself. History is clipped to each market's own lifespan, so a 15-minute crypto market returns about 15 minutes. A longer series for a recurring product has to be stitched together across the separate markets that made it up.

## Also from Limitless

- [limitless-sdk](https://predictionmarkets.tools/tools/limitless-sdk.md)
- [Limitless](https://predictionmarkets.tools/tools/limitless.md)

## Background

- [Where weather data comes from and what you may do with it](https://predictionmarkets.tools/guides/where-weather-data-comes-from.md) — Observations, model output and archives are three products with three licences. The forecast is the cheap half; a clean observation history is not.

- [Why the same contract costs two different prices on two venues](https://predictionmarkets.tools/guides/why-the-same-contract-costs-two-prices.md) — Two venues quoting one outcome are quoting two contracts. What the gap between the prices is made of - rules, fallbacks, fees, collateral, exits, eligibility.
- [What a trade actually costs on a prediction market](https://predictionmarkets.tools/guides/what-a-trade-actually-costs.md) — Venues publish trading fees in four incompatible units, so 3.00% on one can be cheaper than 1.75% on another. How to convert them, and what else takes a cut.

## Also worth comparing

- [Futuur API](https://predictionmarkets.tools/tools/futuur-api.md) — One question, two order books — play money and real money, selected per request.
- [Polymarket CLOB API](https://predictionmarkets.tools/tools/polymarket-clob-api.md) — Order books, prices and order placement on Polymarket's matching engine.
- [Polymarket Gamma API](https://predictionmarkets.tools/tools/polymarket-gamma-api.md) — Polymarket's read-only catalogue of events, markets, series and tags.
- [Kalshi API](https://predictionmarkets.tools/tools/kalshi-api.md) — REST, WebSocket and FIX access to a CFTC-regulated event exchange.
- [Manifold API](https://predictionmarkets.tools/tools/manifold-api.md) — Every read is keyless, the server is MIT-licensed, and the currency is play money.
- [Polymarket US API](https://predictionmarkets.tools/tools/polymarket-us-api.md) — A keyless public gateway for reading, and a signed key behind KYC for trading.