Estimate a fee target.
Authorizations
ApiKeyAuthApiKeyAuthapi-key string
NOWNodes API key passed in the api-key header.
Modified between 0.5.0 and 0.6.0: new mempoolspacemedian alternative fee estimation option (PR #1233, server configuration); fee estimates lower than 1 sat/vB can be returned (PR #1335). Response shape unchanged. Documented as it exists in 0.6.0.
Returns backend fee estimation for the requested confirmation target.
Load estimate: Low; a small backend fee estimate lookup.
Parameters
blocksinteger>= 1requiredpathConfirmation target in blocks.
conservativebooleantruequeryUse conservative smart fee estimation where supported.
Response
HTTP 200 EthereumPoW Blockbook response for estimateFee.
Domain or validation error. live-verified: JSON body {"error": "..."} (unknown block/transaction, invalid address, malformed broadcast hex, missing filter parameters).
Unauthorized: missing or invalid api-key header. The NOWNodes gateway returns the plain-text body "Unknown API_key".
Method Not Allowed: gateway-level response for unknown routes (and for the v1 GET broadcast route on this instance).
Internal Server Error. live-verified on the deployed instance: JSON body {"error":"Internal server error"} (observed on /api/rawtx and invalid XPUB lookups).