How to get the largest bitcoin transactions with Blockchair's API

2020-11-06 09:50:28

Guillaume Souillard

Today, we are going to see how to use Blockchair's API to index the biggest bitcoin transactions. ClankApp uses Blockchair since 1 year ago. The quality of the service is awesome and the team is always available.

What is Blockchair?

Today, we use blockchain explorers everyday in order to track our transactions or extract some stats about cryptocurrencies. Blockchair is the most advanced search engine for exploring 17 blockchains (and more in the future).


Blockchair keeps your personnal data secret and has a "Crypto-anarchist corner" allowing to use Blockchair through the Tor Browser for example. They aspire to become the DuckDuckGo for the blockchain community and act for the adoption of this technology.

It is for all these reasons that we decided to work with Blockchair.

Blockchair's API ❤️

Blockchair's API represents 40% of our data, mainly for bitcoin, ethereum and ERC 20 tokens.

But today we will focus on bitcoin and we will see how to index the biggest bitcoin transactions.

Api requirements, pricing and rate limit.

As you can see in the official documentation, you can use Blockchair API for free if you don't need a lot of charge (Up to 1440 requests a day for the Free Plan).

If you need more calls, consult Blockchair Plans here.

Blockchair's API plans

If you are a student, you can use your GitHub student account to get premium access for Blockchair's API ✌🏼✌🏼.

Blockchair Github Student program.

Have you made your choice? Let's see how to use the API

As a first step, it is important to keep the documentation open in order to understand everything. We're just going to focus on the infinitable endpoints (SQL-like queries) for the transactions part.

This endpoint will allow us to make requests with conditions to find bitcoin transactions.

Our first request

# Transactions endpoint

Remember the goal, here we want to recover bitcoin transactions with a total output value greater than $1,000,000. For that, we will replace {:btc_chain} by bitcoin and we will construct our query logic like this: q=output_total_usd(1000000..).

Which gives that:


If you run this request in Postman for example, you will get this result:

    "data": [
            "block_id": 656595,
            "id": 586132324,
            "hash": "5efb8d3b2e67fb7984872bff49103fe59419a068cb0b9fec3c0196d699715a7a",
            "date": "2020-11-12",
            "time": "2020-11-12 14:37:46",
            "size": 3003,
            "weight": 9729,
            "version": 1,
            "lock_time": 656594,
            "is_coinbase": false,
            "has_witness": true,
            "input_count": 3,
            "output_count": 61,
            "input_total": 25000841362,
            "input_total_usd": 3923410,
            "output_total": 25000619406,
            "output_total_usd": 3923370,
            "fee": 221956,
            "fee_usd": 34.8318,
            "fee_per_kb": 73911.4,
            "fee_per_kb_usd": 11.599,
            "fee_per_kwu": 22813.9,
            "fee_per_kwu_usd": 3.5802,
            "cdd_total": 22.899962184847
    "context": {
        "code": 200,
        "source": "A+T",
        "limit": 1,
        "offset": 0,
        "rows": 1,
        "pre_rows": 1,
        "total_rows": 2065884,
        "state": 656595,
        "cache": {
            "live": true,
            "duration": 60,
            "since": "2020-11-12 14:54:27",
            "until": "2020-11-12 14:55:27",
            "time": null
        "api": {
            "version": "2.0.68",
            "last_major_update": "2020-07-19 00:00:00",
            "next_major_update": null,
            "documentation": "",
            "notice": "Beginning July 19th, 2020 we start enforcing request cost formulas, see the changelog for details"
        "time": 2.0017759799957275,
        "render_time": 0.01679706573486328,
        "full_time": 2.018573045730591,
        "request_cost": 1

data contains an array of database rows. Each row is in the following format:

Column Type Description
block_id int The height (id) of the block containing the transaction
id int Internal Blockchair transaction id (not related to the blockchain, used for internal purposes)
hash string [0-9a-f]{64} Transaction hash
date string YYYY-MM-DD The date of the block containing the transaction (UTC)
time string YYYY-MM-DD HH:ii:ss Timestamp of the block containing the transaction (UTC)
size int Transaction size in bytes
weight † int Weight of transaction in weight units
version int Transaction version field
lock_time int Lock time — can be either a block height, or a unix timestamp
is_coinbase boolean Is it a coinbase (generating new coins) transaction? (For such a transaction input_count is equal to 1 and means there's a synthetic coinbase input)
has_witness † boolean Is there a witness part in the transaction (using SegWit)?
input_count int Number of inputs
output_count int Number of outputs
input_total int Input value in satoshi
input_total_usd float Input value in USD
output_total int Output value in satoshi
output_total_usd float Total output value in USD
fee int Fee in satoshi
fee_usd float Fee in USD
fee_per_kb float Fee per kilobyte (1000 bytes) of data in satoshi
fee_per_kb_usd float Fee for kilobyte of data in USD
fee_per_kwu † float Fee for 1000 weight units of data in satoshi
fee_per_kwu_usd † float Fee for 1000 weight units of data in USD
cdd_total float The number of destroyed coindays

More info about data fields here

Now, we want to adjust our request in order to have transactions, with output total value greater than $1,000,000, and total output wich is equal to 1 and let it be ordered on the time field in the ASC order.


I'll let you try 😉

To conclude

We only reviewed a tiny fraction of what Blockchair's API is able to do, I will let you make your proposed opinion. Be curious, and consult the official documentation for more information.

Disclaimer: This article is for informational purposes only and you should not construe any such information as investment or other advise. ClankApp services do not engage in any trading activities. We urge everyone to do their own research and draw their own conclusions.

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* A whale is a transaction worth more than is worth more than a certain value relative to the volume of the asset.
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