sifting/io
Developer / indie builder

Financial data APIs for developers

Build any product on real-time and historical market data with one credential, one JSON schema, and first-party SDKs for Go, Python, and TypeScript.

Freetier to build on
3 SDKsGo, Python, TypeScript
1 keyevery market
How it fits together

One feed in, your product out

Markets you need
CryptoForexStocksCommodities
SiftingIOOne JSON schema. One key. REST and WebSocket.
What you buildYour product

If you are a developer evaluating market data, the first hour decides a lot. You want to read the docs, make a request, and see real data come back before you commit to anything. Most of the friction in this space is incidental: inconsistent schemas, auth that fights you, and pricing that assumes you are a hedge fund. This page is about removing that friction so you can get to the part you actually care about.

The problem

Developers evaluating market data face a maze of per-source APIs, inconsistent schemas, and pricing built for institutions. They want one well-documented surface, a free tier to prototype on, and SDKs that just work.

How SiftingIO handles it

One REST and WebSocket surface covers every market under the same JSON schema and bearer token. A free tier on every product covers prototyping, first-party SDKs for Go, Python, and TypeScript wrap the data plane, and versioned endpoints keep client code stable as the platform grows.

One surface across every market

There is one REST and WebSocket API, one JSON schema, and one bearer token across crypto, forex, stocks, commodities, DEX, and fundamentals. You learn the shape once and it applies everywhere, so moving from a weekend crypto prototype to a multi-asset product does not mean learning a second API and rewriting your client.

SDKs that carry the types for you

First-party SDKs for Go, Python, and TypeScript wrap the data plane with native types for every field, so you get autocomplete and compile-time checks instead of hand-rolling a client and guessing at response shapes. The same auth and tier limits apply whether you reach for an SDK or call the endpoints directly with your own HTTP client.

A free tier you can actually build on

Every market has a free tier sized for real prototyping, not a token demo that runs out before you have shipped anything. When the app grows, pricing moves up per market on a predictable monthly quota, so the bill tracks usage in a line you can reason about instead of jumping at you when you cross some hidden threshold.

Start building

From zero to live data in three steps

  1. 1

    Create a free API key

    Sign up and generate a key. The free tier covers every market, with no sales call to get started.

  2. 2

    Subscribe to your markets

    Add the markets your product needs. Bundle discounts apply automatically once two or more Pro markets are active.

  3. 3

    Call REST or stream over WebSocket

    Pull snapshots and history over REST, or subscribe to live ticks over WebSocket. Same schema and key, in Go, Python, or TypeScript.

FAQ

Developer / indie builder: common questions

Is there a free tier to prototype on?

Yes. Every market has a free tier that covers prototyping and small projects, so you can build and evaluate before committing to a paid plan.

What languages have official SDKs?

First-party SDKs are available for Go, Python, and TypeScript. They wrap the REST data plane and WebSocket gateway with native types, so you do not hand-roll a client.

How quickly can I make a first request?

The quick start gets a working REST request running in a few minutes with a single credential. The same key works across every market and over WebSocket.

Will my client code keep working as the API evolves?

Endpoints are versioned under /v1 and changes are additive only, so pinned client code keeps returning the same shape. Fields are not removed or renamed underneath you.

How does cost scale as my app grows?

Pricing is per market and per tier on a predictable monthly quota, so an app moves from Free to Builder to Pro on the markets it uses, without re-architecting or surprise bills.

Same data, same SLA, same schema

Build this on SiftingIO.

Start on the free tier, mix asset classes when you need to, and reach out if you want a closer look at how a similar team set up their stack.