Overview
The AdaStat API is a free data service that lets developers pull Cardano blockchain records into their own apps, websites and scripts. An API (application programming interface) is a set of web addresses that a program can ask for data, a bit like a library catalogue that answers in a standard format. Nobody needs to sign up or get an API key, the password-like code many data services require before answering requests1. The data covers epochs (Cardano's five-day time periods), blocks, transactions, stake pools, accounts, addresses and tokens1.
The API comes from the team behind the AdaStat explorer, an independent Cardano block explorer built by members of the Russian-speaking Cardano community2. A Cardano Foundation profile names Dmytro Stashenko as co-founder and lead developer of both the explorer and its API3. The documented server serves Cardano mainnet, the live public network1.
The Cardano treasury is a shared fund that Cardano's governance votes to spend. A withdrawal of 212,000 ADA from it, submitted through Intersect in 2025 and later enacted, set aside funding for 24 months of development and support of the AdaStat explorer. The proposal lists a fully free REST API (a common web-based style of API) for developers that provides Cardano data in JSON, a plain text format most programming languages read directly4.
Key Features
- Free, openly licensed data. The AdaStat API is free to use, and its data is offered under the Apache 2.0 license, which lets anyone copy, share and adapt it without paying1,5.
- Core chain records in one place. Separate endpoints, web addresses that each return one kind of record, cover network summaries, epochs, blocks, transactions, stake pools, accounts, addresses and tokens1.
- Extra detail when you ask for it. Pool, account, address and token lookups can return added lists, such as a pool's delegators and blocks, an account's reward history, or a token's holders1.
- Long lists in large pages. Results arrive in pages of up to 1,000 items, with a cursor, a bookmark marking where the next page starts, for fetching the rest1.
- Predictable units. Times come back in UTC, ADA amounts in lovelace (one millionth of an ADA), and percentages as numbers between 0 and 11.
What to Expect
Developers start at the documentation site, a single reference page that lists each endpoint and the options it accepts. Requests are ordinary web addresses, so anyone comfortable with a short script or a command line can try one. Developers comparing Cardano API providers can read the full specification before writing any code1.
The API is built for servers and scripts rather than web pages. It does not support cross-origin requests (CORS), which means a website cannot call it straight from a visitor's browser and needs its own server in between1. The documentation also asks callers to stay at about one request per second. Short bursts may pass, but heavier traffic eventually gets "429" too-many-requests errors1.
The team would appreciate a link or a "Powered by AdaStat API" mention in apps built on the API, and questions go to the support email listed in the documentation1. In a Cardano developer portal interview, Stashenko said community projects use the API to display charts and other data6. Readers who want the same records without writing code can browse them on the AdaStat explorer itself.
