Massive Crypto API

What it is

A REST, websocket and flat-file API for crypto spot prices, sold by Massive — the company that was called Polygon.io until 30 October 2025. One clarification first, because the old name collides with something else entirely: this vendor has never had anything to do with the Polygon blockchain or MATIC, and the rename ended that confusion rather than starting it.

The other thing to know before comparing prices is that there is no crypto product any more. The pricing page still answers to a crypto URL, but the plan behind it is called Currencies and it covers forex and crypto together — about 1,200 currency pairs and about 600 crypto pairs by the vendor's own count, each with its own websocket cluster and channel names. You cannot buy the crypto half separately, and if you only want crypto you are paying for a forex feed you will not call.

What you get for that is a normalised tape rather than a research terminal. Aggregate bars at second, minute and day granularity, tick trades with nanosecond exchange and receive timestamps, snapshots, four technical indicators computed server-side, and the reference endpoints that map exchange ids and trade conditions. Daily S3 flat files carry the same day bars, minute bars and trades in bulk for anyone who would rather not paginate ten years out of a REST endpoint.

Pricing

Two self-serve tiers and a quoted one, and the gap between the first two is wider than the fifty dollars suggests.

Currencies Basic is free and is end-of-day only. Five API calls a minute, two years of history, no websockets, no flat files, no tick trades, no snapshots. It is enough to check the response shape and not much else.

Currencies Starter is 49 USD a month, or 470 USD if you pay for a year up front. That is where real-time data, unlimited calls, ten-plus years of history, tick trades, the S3 flat files and the websocket clusters live. Concurrency rather than call volume is the limit that binds: all plans include up to three concurrent websocket connections, plus one for each data expansion.

Currencies Business is not on the self-serve page and has no published price — every plan in the public pricing payload is personal-licence and self-serve, and the business plan appears only in the docs' per-endpoint access tables. It is quoted by sales. The one crypto feature reserved for it is the Fair Market Value stream.

One detail that is unusually in the buyer's favour here: unlike the stocks, options, indices and futures tiers, the Currencies plans carry no professional/non-professional qualification. There is no form to sign saying what you do for a living.

Data & coverage

Crypto prices come from five exchanges. The vendor says "five named exchanges" on its own FAQ and then does not name them anywhere public — the list is returned by the reference endpoint, which needs a key, so a prospective buyer cannot see which five before paying. Trades carry an integer exchange id and you resolve it against that same endpoint.

Every trade record carries two timestamps: when the exchange generated it and when Massive received it. That pair is the most useful thing in the schema, because it is what lets you measure the vendor's own ingestion delay instead of trusting the words "real time" on the pricing page.

Crypto trades 24/7 and everything is stamped UTC, so the market-status and market-holiday endpoints that the crypto docs inherit from the equities side will tell you nothing you did not already know.

History is advertised as "10+ years" for the Currencies plan as a whole. That figure covers forex and crypto together and the vendor publishes no crypto-specific coverage start date, so treat it as a plan attribute rather than a promise about BTC bars from 2016. The coverage-start table on the product page lists stocks, options, indices and futures — and not currencies.

Integrations

First-party client libraries in Python, JavaScript, Go and Java. The Python import is now massive rather than polygon; both packages are maintained in parallel and point at the two API bases respectively.

There is a remote MCP server at mcp.massive.com, announced in September 2026 and authenticated over OAuth rather than with an API key. An unauthenticated request to it answers 401, so it is genuinely running. What it covers is less clear than it should be: the announcement's summary calls it US market data, while its body says access follows your plan and you can query any asset class your subscription includes. Nobody has published a tool list, so if crypto over MCP is the reason you are buying, ask before you pay.

Data comes back as JSON or CSV from REST, and the flat files are CSV on S3.

Limitations

There is no crypto order book, at any price. No Level 2 endpoint, no depth snapshot, nothing in the docs index and a 404 on the old book path. Quotes exist as a websocket channel only. If you need book depth, this is the wrong vendor and no tier fixes it.

There is no crypto news. The product page advertises "news on popular currencies", but the only news endpoints in the documentation are under Stocks, keyed by equity ticker, and the Benzinga partner feed is the same. The Currencies plan buys prices.

Crypto here means spot. No perpetuals, no funding rates, no open interest, no options. The futures product line is CME, CBOT, NYMEX and COMEX — traditional futures, not crypto derivatives.

Five exchanges is a small number for crypto, and you cannot find out which five without a key. For comparison, aggregators in this category routinely index dozens of venues; whether five well-connected feeds beat forty polled ones is a real argument, but you should at least be able to see the five.

The free tier is not a small version of the paid one, it is a different product. End-of-day bars at five calls a minute cannot be used to evaluate a real-time feed, so budget for a month of Starter as the actual trial.

The old API base is on borrowed time. api.polygon.io still works, but the vendor has said it plans to phase the old endpoints out and has not named a date. Anything written against the old host is on a clock nobody has shown you.

Alternatives

The absence of any order book at any price is what decides this one. Tardis.dev is the direct answer — tick-by-tick books and trades from 64 exchange feeds — at 350 dollars a month against 49 here, and with no hosted real-time data at all. CoinAPI covers 400-plus venues under one symbol scheme and meters you in credits and gigabytes; Amberdata and Kaiko are the institutional versions, the first with an 18-month cap on REST order-book history and the second with nothing self-serve about it.

If five spot exchanges and daily bars are genuinely enough, CoinGecko API and CoinMarketCap API do that for less, and a single venue's own feed — Binance API, OKX API — does it for nothing.