RPC errors · eth_call, eth_getBalance, eth_getBlockByNumber
header not found
What it means
The node could not find the block header for the block you named. In our sweep it came back for state reads at block 1 on nodes that do not keep that history: the node does not have the header, so it cannot load the state behind it.
The same message appears for blocks that are too new for the node that answered: a request for the latest block, routed to a node a block or two behind the others, can briefly fail this way on a load-balanced endpoint.
The exact messages, and where we saw them
Returned by real upstream nodes when we triggered this error on 2026-09-24 through our endpoint on each chain we serve.
header not foundHow to fix it
- For old blocks, the fix is the same as for pruned state: an archive node, or reconstructing history from events.
- For new blocks, use a tag the node resolves itself (
latest,safe,finalized) instead of a number you read from a different request, or retry briefly on this error.