post https://eth-mainnet.g.alchemy.com/v2/
Creates a filter object, based on filter options, to notify when the state changes (logs).
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Unlike eth_newBlockFilter which notifies you of all new blocks, you can pass in filter options to track new logs matching the topics specified.
To check if the state has changed, call eth_getFilterChanges.
Note on Filters
- Filters expire after 5 minutes of inactivity (no queries).
A note on specifying topic filters:
Topics are order-dependent. A transaction with a log with topics [A, B] will be matched by the following topic filters:
[]“anything”[A]“A in first position (and anything after)”[null, B]“anything in first position AND B in second position (and anything after)”[A, B]“A in first position AND B in second position (and anything after)”[[A, B], [A, B]]“(A OR B) in first position AND (A OR B) in second position (and anything after)”