API.md

Blockchair.com API

API v.2 documentation

• English: API_DOCUMENTATION_EN.md (up to v.2.0.37)
• Russian: API_DOCUMENTATION_RU.md (up to v.2.0.10)

Please apply for an API key first

tl;dr:

• If you use our API occasionally a key is not required
• Non-commercial and academic projects constantly using our API should apply for a free Public API key
• Commercial projects should apply for a key to Premium API

Since the introduction of our API more than two years ago it has been free to use in both non-commercial and commercial cases with a limit of 30 requests per minute. Obtaining an API key has been required only for those who were hitting this limit.

Beginning July 19th, 2019 we require all applications using our API to obtain an API key.

If you develop a non-commercial project (e.g. a website showing some stats) or conducting academic research, please apply for a free key to our Public API (info@blockchair.com).

If you develop a commercial project (e.g. a web wallet showing ads), please apply for a key to our Premium API (info@blockchair.com).

While we still allow making requests without a key, services which make too many resource-consuming requests may automatically be banned (the API will return HTTP Error 430 in this case).

The key is applied to the end of the request string like this: api.blockchair.com/bitcoin/blocks?key=MYSECRETKEY. Please remember that your key is a secret -- don't disclose it to client-side applications as unauthorized users may start to use your key.

Changelog

• v.2.0.37 - Oct 9th, 2019

  • {:chain}/dashboards/address/{:address} endpoint now has an optional parameter ?transaction_details=true which allows you to retrieve transaction details in the transactions array instead of just transaction hashes. Each transactions array element contains the following values:
    • hash - transaction hash
    • time - transaction timestamp (UTC)
    • balance_change - how the transaction affected the balance of {:address}

  Appending a request with ?transaction_details=true makes it count as 2 separate requests in the matter of API limits (including Premium API).

  Usage example: https://api.blockchair.com/bitcoin/dashboards/address/12cbQLTFMXRnSzktFkuoG3eHoMeFtpTu3S?transaction_details=true

  This option is supported for Bitcoin, Bitcoin Cash, Litecoin, Dash, Bitcoin SV, Dogecoin, and Groestlcoin only.

• v.2.0.36 - Sep 17th, 2019

  • We begin a public beta test of ERC-20 support on our platform. Over 100.000 tokens are available to explore!

    • New ERC-20 endpoints:
      • ERC-20 tokens infinitable: https://api.blockchair.com/ethereum/erc-20/tokens
      • ERC-20 transactions infinitable: https://api.blockchair.com/ethereum/erc-20/transactions (example: https://api.blockchair.com/ethereum/erc-20/transactions?q=token_address({:token_address}) - filter transactions by a specific token). These two infinitables act as other infinitables in our API, i.e. it's possible to sort and filter by many params, to paginate, etc.
      • ERC-20 token stats dashboard: https://api.blockchair.com/ethereum/erc-20/{:token_address}/stats - returns some basic stats about a token
      • ERC-20 token holder dashboard: https://api.blockchair.com/ethereum/erc-20/{:token_address}/dashboards/address/{:address} - returns info about a token holder (the balance, list of latest transactions, etc.)
    • New options and changes to the existing Ethereum dashboards:
      • Ethereum transaction dashboard: https://api.blockchair.com/ethereum/dashboards/transaction/{:transaction_hash}?erc_20=true - returns info about a transaction including ERC-20 transfers
      • Ethereum address dashboard: https://api.blockchair.com/ethereum/dashboards/address/{:address}?erc_20=true - returns info about an address including its ERC-20 token balances (tip: addresses and hashes should start with 0x)
      • Ethereum stats dashboards (https://api.blockchair.com/ethereum/stats) now have data.layer_2.erc_20 key yielding basic stats on ERC-20's: the total number of tokens, the total number of transactions, and the number of new tokens and transactions over the last 24 hours.
      • For all Ethereum endpoints there's a new key context.state_layer_2 which yields the latest processed block number. It can be different from context.state as it takes some time to process second layer transactions.

    Please note these endpoints are in beta, so there may be some unannounced compatibility-breaking changes. More detailed documentation will come later this month. Appending ?erc_20=true to requests makes it counted as 2 separate requests in the matter of API limits (including Premium API).

• v.2.0.35 - Sep 11th, 2019

  • api.blockchair.com/{:chain}/nodes endpoint now also returns the heights array showing distribution of the latest block numbers among nodes. See a visualisation on our web interface as an example: https://blockchair.com/bitcoin/nodes
  • There's a new endpoint api.blockchair.com/nodes showing some aggregated node stats across 7 networks (Bitcoin, Bitcoin Cash, Bitcoin SV, Litecoin, Dash, Dogecoin, and Groestlcoin).
  • Our database dumps now also feature daily balances snapshot, see Bitcoin for example: https://gz.blockchair.com/bitcoin/addresses/ (please note that the download speed is limited for non-premium users). The format is address<TAB>balance.

• v.2.0.34 - Aug 7th, 2019

  • It's now possible to retrieve raw block data directly from our nodes. The endpoint is api.blockchair.com/{:chain}/raw/block/{:hash}|{:id}. This endpoint supports all chains except for ripple.

    • For Bitcoin-like chains the data array returns two elements:
      • raw_block - contains hex representation of the block
      • decoded_raw_block - contains json representation of the block that is generated by our node
    • For Ethereum only decoded_raw_block is available

    Please note that these endpoints are for development usage only. The result is returned directly from our nodes, so we can't guarantee backward compatibility in case we upgrade our nodes. For production, please use the api.blockchair.com/{:chain}/dashboards/block/{:hash}|{:id} endpoint - it pulls data from our databases.

  • Ethereum uncles now have an id property (previously they only had parent_block_id, index, and hash properties as identifiers). This affects api.blockchair.com/ethereum/dashboards/uncle/{:hash} and api.blockchair.com/ethereum/uncles?{:params} endpoints. Please note that id is not a unique identifier for an uncle (use hash or parent_block_id:index instead).

  • Fixed a bug where api.blockchair.com/{:chain}/dashboards/addresses/{:address},{:address},... endpoint returned 500 if ?limit=0 was applied

  • context.state doesn't return the latest block number anymore in case API returns an error (400, 402, 404, etc.)

• v.2.0.33 - Jul 23rd, 2019

  • According to the Bitcoin SV roadmap we've upgraded our nodes to support the Quasar upgrade
  • BREAKING CHANGE: Upon popular request (#161, #162, #193, #196, #211, and others), starting July 29th 00:00:00+0000 we're switching to the legacy address format for Bitcoin SV. This will affect the output of the following endpoints:
    • api.blockchair.com/bitcoin-sv/dashboards/transaction/{:hash}
    • api.blockchair.com/bitcoin-sv/dashboards/transactions/{:hash},{:hash},...
    • api.blockchair.com/bitcoin-sv/dashboards/address/{:address} (it will be still possible to use CashAddr in the query string)
    • api.blockchair.com/bitcoin-sv/dashboards/addresses/{:address},{:address},... (the same)
    • api.blockchair.com/bitcoin-sv/dashboards/xpub/{:[xyz]pub}
    • api.blockchair.com/bitcoin-sv/outputs?{:params}
    • api.blockchair.com/bitcoin-sv/mempool/outputs?{:params}
    • api.blockchair.com/bitcoin-sv/addresses?{:params}
    • api.blockchair.com/bitcoin-sv/state/changes/block/{:block_id)
    • api.blockchair.com/bitcoin-sv/state/changes/mempool

• v.2.0.32 - Jul 15th, 2019

  • We're launching Bitcoin Testnet support for developers! All the functions available for Bitcoin are now available for Bitcoin Testnet as well, including:

    • Filtering and sorting blockchain data using infinitables (api.blockchair.com/bitcoin/testnet/blocks, api.blockchair.com/bitcoin/testnet/transactions, api.blockchair.com/bitcoin/testnet/outputs, api.blockchair.com/bitcoin/testnet/mempool/transactions, api.blockchair.com/bitcoin/testnet/mempool/outputs, and api.blockchair.com/bitcoin/testnet/addresses), including aggregation capabilities
    • Dashboards (api.blockchair.com/bitcoin/testnet/dashboards/block/{:id|hash}, api.blockchair.com/bitcoin/testnet/dashboards/blocks/{:id|hash},{:id|hash},..., api.blockchair.com/bitcoin/testnet/dashboards/transaction/{:hash}, api.blockchair.com/bitcoin/testnet/dashboards/transactions/{:hash},{:hash},...), api.blockchair.com/bitcoin/testnet/dashboards/address/{:address}, api.blockchair.com/bitcoin/testnet/dashboards/addresses/{:address},{:address},..., api.blockchair.com/bitcoin/testnet/dashboards/xpub/{:[xyz]pub}
    • Broadcasting transactions (api.blockchair.com/bitcoin/testnet/push/transaction)
    • State changes (api.blockchair.com/bitcoin/testnet/state/changes/block/{:block_id) and api.blockchair.com/bitcoin/testnet/state/changes/mempool)
    • Stats (api.blockchair.com/bitcoin/testnet/stats)

    See documentation for Bitcoin for more details. Please note that USD countervalue for testnet coins is always 0. In the future we also plan to launch support for Bitcoin Cash and Ethereum testnets.

  • outputs.type column for SegWit-coins can now yield witness_unknown type

  • blocks.generation column for Bitcoin-like coins can now yield negative values in case there are transaction fees, but the output for the coinbase transaction is less than the sum of the fees

  • The utxo array in the {:chain}/dashboards/xpub/{[xyz]pub} dashboard now shows which utxo belongs to which addresses (now it's identical to {:address1}[,{:address2}…])

• v.2.0.31 - Jul 5th, 2019

  • Added two new keys to bitcoin/stats and litecoin/stats calls:

    • next_retarget_time_estimate yields an estimated timestamp of the next difficulty retarget
    • next_difficulty_estimate yeilds an estimated next difficulty value

    These keys are available for Bitcoin and Litecoin as other cryptos we support recalculate difficulty every block.

• v.2.0.30 - Jul 4th, 2019

  • We're adding a new table called addresses containing the list of all addresses and their confirmed balances to all Bitcoin-like coins (Bitcoin, Bitcoin Cash, Litecoin, Dash, Bitcoin SV, Dogecoin, Groestlcoin). Unlike other "infinitables" (blocks, transactions, outputs) this table isn't live, it's automatically updated every 5 minutes, thus we're classifying it as an "infiniview", meaning it's not really a table, but a view over the outputs table. See the documentation for this table. Here are some examples of how it can be used:

    • api.blockchair.com/bitcoin/addresses - show Bitcoin addresses with biggest balances (i.e. the rich list)
    • api.blockchair.com/bitcoin/addresses?q=balance(100000000) - show Bitcoin addresses having exactly 1 BTC on their balance
    • api.blockchair.com/bitcoin/addresses?a=count() - count the number of addresses with a non-zero balance
    • api.blockchair.com/bitcoin/addresses?a=count()&q=balance(100000000..) - count the number of addresses holding at least 1 BTC
    • api.blockchair.com/bitcoin/addresses?a=sum(balance)&q=balance(100000000..) - calculate how many bitcoins do the addresses from the previous example hold
    • api.blockchair.com/bitcoin/addresses?a=median(balance) - calculate the median balance

    Using this table makes it trivial to build various sorts of rich lists. It's now also possible to retrieve a full list of addresses and balances in one file (available only in our Private API solution). Please note that this table shouldn't be used for retrieving balances for a particular set of addresses, please use the api.blockchair.com/{:chain}/dashboards/addresses/{:addr1}[,{:addr2}...] dashboard endpoint instead.

• v.2.0.29 - Jun 30th, 2019

  • The State changes feature now supports requesting potential state changes caused by mempool transactions. The endpoint is https://api.blockchair.com/{:chain}/state/changes/mempool. It's now possible to easily build an app watching for transactions incoming/outgoing to/from millions of addresses, see an example.

• v.2.0.28 - Jun 28th, 2019

  • Added support for Groestlcoin nodes. The endpoint is https://api.blockchair.com/groestlcoin/nodes. The stats endpoint (https://api.blockchair.com/groestlcoin/stats) now also shows the node count.

• v.2.0.27 - Jun 27th, 2019

  • Effective July 19th, there will be a new policy on using our Public API for both non-commercial and commercial projects. Please see Applying for an API key first and apply for an API key before July 19th! Since this is a major compatibility-breaking change, context.api.next_major_update is set to 2019-07-19 18:07:19 (see General Provisions)
  • Removed ethereum.uncles.total_difficulty column according to ethereum/go-ethereum#19024

• v.2.0.26 - Jun 20th, 2019

  • Added utxo array showing available unspent transaction outputs for Bitcoin-like coins to the following endpoints:

    • api.blockchair.com/{:chain}/dashboards/address/{:address}
    • api.blockchair.com/{:chain}/dashboards/addresses/{:address1}[,{:address2}…]
    • api.blockchair.com/{:chain}/dashboards/xpub/{:[xyz]pub}

    Each array element has the following structure:

    • block_id - block number (-1 for unconfirmed outputs)
    • transaction_hash - transaction hash
    • index - output index in the transaction (also known as the vout number)
    • value - output value in satoshi
    • address (only for addresses and xpub dashboards) - showing the output owner

    This new functionality DEPRECATES usage of an old method to retrieve the UTXO set for an address, namely api.blockchair.com/{:chain}/outputs?q=recipient({:address}),is_spent(false). See the discussion with some examples here: Blockchair#192

  • The 3 above listed endpoints now also have a new way to iterate through the transaction list and the UTXO set. It's now possible to use ?limit=A,B and ?offset=C,D sections in the query. The first number affects the transaction list, the second number affects the UTXO set. If only one number is set, it affects both. The default limit is 100. The maximum limit is 10000. The default offset is 0. The maximum offset is 1000000. Here are some examples:

    • api.blockchair.com/{:chain}/dashboards/address/{:address} - shows address data with an array of 100 latest transactions and 100 latest UTXOs
    • api.blockchair.com/{:chain}/dashboards/address/{:address}?limit=0 - if you require just some general stats like the address balance
    • api.blockchair.com/{:chain}/dashboards/address/{:address}?limit=0,100 - if you need just the general stats and the UTXO set
    • api.blockchair.com/{:chain}/dashboards/address/{:address}?limit=100,0 - if you need just the general stats and the transaction list
    • api.blockchair.com/{:chain}/dashboards/address/{:address}?limit=100,0&offset=100,0 - ... and to iterate it

  • The api.blockchair.com/{:chain}/dashboards/block/{:hash}|{:id} endpoint now also has an iterable set of transaction hashes included in the block. The default limit is 100. The maximum limit is 10000. The default offset is 0. The maximum offset is 1000000. This feature implements Blockchair#189

• v.2.0.25 - Jun 19th, 2019

  • Added Groestlcoin support (it has SegWit support, so all API functionality available for Bitcoin and Litecoin is available for Groestlcoin as well).
  • Added suggested_transaction_fee_per_byte_sat key to {:chain}/stats calls. This value shows a good enough approximation of an optimal fee value suggested by our engine based on the current mempool state (in satoshi per byte) to get into the next block. Please note that for transactions less important for you this fee suggestion may be too high, while for very important transactions it may not be enough if you'll get unlucky because of the lack of new blocks. Supported for all coins except for Ripple and Ethereum for which we'll have a separate value suggesting an appropriate gas price value.
  • Updated xpub support to v.b5 (see xpub support in the docs: two bugs have been fixed);

• v.2.0.24 - Jun 6th, 2019

  • Added an optional countdowns array to {:chain}/stats calls. If present, this array contains information about various upcoming events such as hard forks or reward halvings. There are two keys for each event: event which contains event description, and time_left showing how many seconds are left until the event occurs. Please note that the number of seconds is an approximate value because most events are triggered after a block at a specific height is mined, and since it's not possible to know for sure when a block becomes mined, we can only approximate that.

• v.2.0.23 - May 24th, 2019

  • Added support for Dash nodes. The endpoint is https://api.blockchair.com/dash/nodes. The stats endpoint (https://api.blockchair.com/dash/stats) now also shows the node count.
  • It's now possible to query Dash xpubs (see xpub support in the docs)
  • Dash is now out of beta on our platform

• v.2.0.22 - May 23rd, 2019

  • The state changes feature introduced in v.2.0.20 is now available for Ethereum. The endpoint is https://api.blockchair.com/ethereum/state/changes/block/{:block_id}. Please note that it shows only the balance changes caused by a block. Values are returned as strings because some wei values don't fit into int64.
  • Some optimizations to the Ethereum mempool processing - we now show a lot more unconfirmed transactions

• v.2.0.21 - Apr 22nd, 2019

  • We've added an ability to query multiple addresses at once. The endpoint is https://api.blockchair.com/{:chain}/dashboards/addresses/{:addr1},{:addr2},... (supported for BTC, BCH, LTC, DASH, BSV, and DOGE). E.g., now, if you need to retrieve information about 3 different addresses, you wouldn't need to make 3 separate queries, you'd need to query just https://api.blockchair.com/bitcoin/dashboards/addresses/1A1zP1eP5QGefi2DMPTfTL5SLmv7DivfNa,12c6DSiU4Rq3P4ZxziKxzrL5LmMBrzjrJX,1HLoD9E4SDFFPDiYfNYnkBLQ85Y51J3Zb1. The response contains information on the set of addresses (total balance, total transaction count, etc.), information about each address, and the list of the latest 100 transactions for this set (iterable with &offset=N). The maximum number of addresses in one query is 100 (higher limits are available for our premium users). Querying multiple addresses at once works much faster (e.g. it's almost 95 times faster to query 100 addresses via the new endpoint compared to making separate requests).

• v.2.0.20 - Apr 19th, 2019

  • Now it's possible to query state changes caused by a block for all chains we support except for ETH. The endpoint is https://api.blockchair.com/{:chain}/state/changes/block/{:block_id}. The response contains an array where the keys are addresses which were affected by the block, and the values are balance changes. Example: https://api.blockchair.com/bitcoin/state/changes/block/1 returns 12c6DSiU4Rq3P4ZxziKxzrL5LmMBrzjrJX => 5000000000 which means that the only state change caused by this block was rewarding the miner with 50 bitcoins. This is useful if you need to track balance changes for a lot of addresses - you can now simply track state changes and find the needed addresses there instead of constantly retrieving information about the balances.

• v.2.0.19 - Apr 17th, 2019

  • Added alpha support for Ripple (see Ripple support in the docs)
  • Introducing Graph API for Ethereum (a possibility to find connections between two Ethereum addresses), see Ethereum graph in the docs) - it's in private alpha test mode
  • If you're constantly hitting Error 402 (i.e. by making too many requests per minute to our free API), you'll now receive Error 429 which means that your IP is banned for an hour. Not honoring our limits may result in a permanent ban
  • Fixed a couple of minor bugs in our Ethereum engine. We'll be rolling out an updated engine the next week, there shouldn't be any compatibility breaking changes

• v.2.0.18 - Apr 2nd, 2019

  • Added biggest transactions over the last 24h to https://api.blockchair.com/{chain}/stats calls (largest_transaction_24h key);
  • Updated xpub support to v.b3 (see xpub support in the docs, there are some breaking changes);
  • Updated aggregation support to v.b4 (see Data aggregation support in the docs)
  • We're DEPRECATING usage of unsupported parameters in GET and POST requests to our API endpoints (e.g. https://api.blockchair.com/stats?myarbitrarykey=1234 might result in a 400 Bad Request error);
  • Previously DEPRECATED API v.1 has been shut down
  • Previously DEPRECATED undocumented ?export= functionality now requires an API key (apply at <info@blockchair.com>) for everything except:
    • Aggregated results
    • blocks tables across all blockchains we support

• v.2.0.17 - Mar 14th, 2019

  • Added support for Bitcoin SV nodes, they are now separate from Bitcoin Cash nodes. Endpoint: https://api.blockchair.com/bitcoin-sv/nodes.

• v.2.0.16 - Mar 13th, 2019

  • Added support for ypub and zpub for Bitcoin and Litecoin in test mode. See xpub support in the docs.

• v.2.0.15 - Mar 12th, 2019

  • Added Dash support in test mode. We're supporting all the features for DASH as we support for other Satoshi-like coins. Additional columns: blocks.cbtx, transactions.type (possible types: simple, proregtx, proupservtx, proupregtx, prouprevtx, cbtx, qctx, subtxregister, subtxtopup, subtxresetkey, subtxcloseaccount), transactions.is_instant_lock, transactions.is_special (true for all transaction types except simple), transactions.special_json (contains special transaction data encoded in json). E.g.: https://api.blockchair.com/dash/blocks

• v.2.0.14 - Mar 6th, 2019

  • Added xpub support in test mode. There's now support for retrieving info about multiple addresses using xpub keys. Use https://api.blockchair.com/{chain}/dashboards/xpub/{xpub}. See xpub support in the docs.
  • Extended data aggregation abilities (still in test mode), see Data aggregation support in the docs. Now it's possbile to find correlations with price, and use special functions (e.g. to calculate SegWit adoption).
  • We're DEPRECATING API v.1 and will be shutting it down on April 1st, 2019.
  • We're DEPRECATING undocumented ?export= functionality when exporting large datasets without an API key. This feature will be documented in one of the next updates.
  • Full support for CREATE2 in Ethereum (see https://blockchair.com/ethereum/calls?q=type(create2)#)
  • When using CSV/TSV API (undocumented ?export= functionality) amounts in USD are now shown as in the JSON API version (previously you had to divide them by 10000). bitcoin.outputs.type, ethereum.transaction.type, and ethereum.calls.type now yield strings (e.g. pubkeyhash instead of 2).

• v.2.0.13 - Feb 13th, 2019

  • Added support for Cyrillic characters in fulltext search, e.g. https://api.blockchair.com/bitcoin/outputs?q=script_bin(~привет)

• v.2.0.12 - Feb 12th, 2019

  • Fixed a bug in Ethereum where some contract creations were erroneously shown as failed (thanks Daniel Luca for noticing)

• v.2.0.11 - Feb 5th, 2019

  • We're changing behavior of our mempool tables (for all supported coins except for Ethereum): now they don't contain the contents of the latest block (it was quite a clumsy thing to have both mempool transactions and transactions from the latest block in this table, but we've rebuilt our engine, so now mempool tables contain mempool content only, and it finally makes sense!). That means:
    • {chain}/mempool/blocks is deprecated. Hint: if you used mempool/blocks to get info about the latest block you can simply switch to using blocks?limit=1, e.g. https://api.blockchair.com/bitcoin/blocks?limit=1
    • {chain}/mempool/transactions and {chain}/mempool/outputs now don't contain info from the latest block, while {chain}/transactions and {chain}/outputs do
    • Before this update when using (undocumented) export functionality there was no information about the latest block at all, now there is
    • The same change to Ethereum will come in one of the next updates
  • Dogecoin is out of beta.
  • Bitcoin SV is out of beta. Please note there's still a possibility that we won't be able to offer some functionality in the long term if blocks suddenly become larger than 1 exabyte, we're still waiting for a more clear development roadmap.

• v.2.0.10 - Jan 29th, 2019

  • Added Dogecoin support in test mode (see Dogecoin support in the docs)

• v.2.0.9 - Dec 13th, 2018

  • Added Bitcoin SV support in test mode (see Bitcoin SV support in the docs); updated aggregation abilities (see Data aggregation support in the docs)

• v.2.0.8 - Nov 26th, 2018

  • Added the ability to retrieve raw transaction data in hex, see Retrieving raw transactions in the docs

• v.2.0.7 - Nov 22th, 2018

  • Now it's possible to broadcast transactions using our API, see Broadcasting transactions in the docs

• v.2.0.6 - Oct 8th, 2018

  • Added data aggregation of blockchain data in beta mode, see Data aggregation support in the docs

• v.2.0.5 - Oct 8th, 2018

  • Fixed bug where balance and received for bitcoin[-cash]|litecoin addresses in the {chain}/dashboards/address/{address} call were calculated wrong if there were specific unconfirmed transactions

• v.2.0.4 - Oct 3rd, 2018

  • Added some new useful fields to {chain}/stats calls

• v.2.0.3 - Sep 18th, 2018

  • Added context.api.tested_features with the list of features our API supports, but with no guarantee for backward compatibility if updated. Added Omni Layer and Wormhole support in testing mode (see "Tested features changelog")

• v.2.0.2 - Sep 9th, 2018

  • Added address.contract_created to the ethereum/dashboards/address/{A} call

• v.2.0.1 - Sep 1st, 2018

  • Added Litecoin support

• v.2.0.0

  • Migrating from API v.1 to API v.2 (see the docs)

Support

• E-mail: info@blockchair.com
• Telegram chat: @Blockchair
• Twitter: @Blockchair