The API is storing table rows and transaction traces for a number of smart contracts and provides a way for searching and retrieving the data.

The API accepts HTTP GET and POST requests, so it's up to you to choose the right one. Many SSE libraries are not allowing to send anything but GET requests.

The API output is a stream of Server-Sent Events (SSE). It allows transporting large chunks of data without much overhead, and there's support in browsers and javascript libraries.

The output is a number of events, such as row, rowupd, tx, followed by end event.

Presence of end event indicates that the whole output has been delivered. The event also contains the total count of events preceding it.

Data field in each event is a JSON object.

block_num and block_timestamp attributes in most of the output are informational and indicate the latest block that updated a specific data element (in case of contracts request, they indicate the moment when the contract was added to the database).

• https://HOST/strack/networks lists the EOSIO blockchains known to the API, their actual head block status and irreversible block number.

• https://HOST/strack/tokens?network=NETWORK&account=ACCOUNT lists all NFT assets belonging to the account. The rowval field in the data JSON represents a table row in corresponding smart contract. contract_type field indicates the type of a smart contract, such as "token:simpleassets" or "token:dgoods" or "token:atomicassets", and the client software has to interpret the row contents according to the type of a contract.

For AtomicAssets objects, the client needs to retrieve the encoding schema in order to be able to display them. The schemas are contained in "schemas" table, and collection name is the scope:

https://HOST/strack/table_rows?network=NETWORK&code=ACCOUNT&table=schemas&scope=COLLNAME

• https://HOST/strack/contracts?network=NETWORK lists smart contract accounts that are being tracked by the API. The following attributes are of importance:

  • account_name specifies the EOSIO account name;

  • contract_type specifies the type of contract. It is used in other queries.

  • track_tables: if present and set to true, contract table contents are tracked and returned by the API.

  • track_tx: if present and set to true, transaction history of this account is stored and retyurned by the API.

• https://HOST/strack/contract_tables?network=NETWORK&code=ACCOUNT lists names of tables in the smart contract, in tblname attribute.

• https://HOST/strack/table_scopes?network=NETWORK&code=ACCOUNT&table=TABLE lists the scopes of a table in scope attribute.

• https://HOST//strack/table_rows?network=NETWORK&code=ACCOUNT&table=TABLE&scope=SCOPE lists table rows. First come rows that are updated by irreversible transactions, in row events in undefined order. Then rowupd events follow in chronological order. They have an additional attribute added which is set to true if the row is added or modified, and false of a row is deleted. Attributes in every event are as follows:

  • primary_key is the table primary index value in numeric notation;

  • rowval is the value of a row as a JSON object.

• https://HOST//strack/table_row_by_pk?network=NETWORK&code=ACCOUNT&table=TABLE&scope=SCOPE&pk=N' returns a single or none row` event comprising of one table row value.

• https://HOST//strack/table_rows_by_scope?network=NETWORK&table=TABLE&scope=SCOPE&contract_type=CTYPE allows searching for a specific scope in tables across multiple smart contracts. This is useful if you need to find all NFT tokens belonging to an account. The result is in the same format as for table_rows request.

https://HOST//strack/account_history?network=NETWORK&account=ACCOUNT returns transaction traces relevant for the account in reverse order. Without additional parameters, it returns 100 latest transactions.

Additional HTTP request parameters:

• maxrows indicates the maximum entries to return. The output length may potentially be double of this number if there are so many speculative transactions.

• start_block indicates the lowest block number in the output.

• end_block indicates the highest block in the output.

The result is a number of tx events with the following attributes:

• id is a concatenation of the word 'tx', network name, and transaction ID, separated by colons.

• block_num and block_timestamp indicate the block of transaction.

• irreversible: true or false indicates whether the transaction is found in an irreversible or speculative block.

• trace contains a full transaction trace object as returned by Chronicle.

There are two ways how accounts are marked for tracking: by manual insertion in the database, and by having an entry in tokenconfigs table.

A list of public API endpoints is served by IPFS. It shares the same endpoints JSON as LightAPI, listing the endpoints under "state-track-endpoints" section. The list is available with the following links:

• https://endpoints.light.xeos.me/endpoints.json (served by Cloudflare)

• https://ipfs.io/ipns/QmTuBHRokSuiLBiqE1HySfK1BFiT2pmuDTuJKXNganE52N/endpoints.json

• GetScatter: funding the software development;

• EOS Amsterdam: hosting of public endpoints.

Source code repository: https://github.com/GetScatter/EOSIO-State-Track

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