Filecoin.StateLookupID - Filecoin

Example code for the Filecoin.StateLookupID JSON RPC method. Complete guide on how to use Filecoin.StateLookupID JSON RPC in GetBlock Web3 documentation.

This method returns the short ID address (f0...) for a given address at a tipset. ID addresses are compact and stable, and are used internally by the chain.

Many state methods take a tipset key as their final parameter: an array of block CIDs identifying the tipset to read. Pass an empty array [] to read against the current chain head.

Parameters

Parameter	Type	Required	Description
address	string	Yes	The address to resolve (f1/f2/f3/f4)
tipsetKey	array	Yes	Tipset key to read from; empty array for the chain head

Request

cURL

curl --location --request POST 'https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/' \
--header 'Content-Type: application/json' \
--data-raw '{"jsonrpc": "2.0", "method": "Filecoin.StateLookupID", "params": ["f1ne72cbn6r55wea7ifjv4ypyti7t2df5dumsjhzq", []], "id": "getblock.io"}'

JavaScript

example.js

const response = await fetch('https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/', {
    method: 'POST',
    headers: { 'Content-Type': 'application/json' },
    body: JSON.stringify({
        jsonrpc: '2.0',
        method: 'Filecoin.StateLookupID',
        params: ["f1ne72cbn6r55wea7ifjv4ypyti7t2df5dumsjhzq", []],
        id: 'getblock.io'
    })
});

const data = await response.json();
console.log(data.result);

Python

example.py

import requests

response = requests.post(
    'https://shared.eu-central-1.getblock.io/<ACCESS-TOKEN>/',
    headers={'Content-Type': 'application/json'},
    json={
        'jsonrpc': '2.0',
        'method': 'Filecoin.StateLookupID',
        'params': ["f1ne72cbn6r55wea7ifjv4ypyti7t2df5dumsjhzq", []],
        'id': 'getblock.io'
    }
)

print(response.json()['result'])

Response

{
    "jsonrpc": "2.0",
    "id": "getblock.io",
    "result": "f0123456"
}

Response Parameters

Field	Type	Description
result	string	The ID address (f0...) for the input address

Use Cases

• Address Normalization: Resolve any address to its ID form

• Indexing Keys: Use the stable ID address as a key

• Deduplication: Detect that two addresses are the same actor

• State Queries: Use ID addresses in downstream calls

Error Handling

Error Code	Message	Description
-32602	Invalid params	A parameter is missing or has the wrong type or format
1	Actor not found	The address or actor does not exist in the requested tipset
-32603	Internal error	The node failed to process the request