fix(beacon): forward Content-Type header from upstream responses#806
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fix(beacon): forward Content-Type header from upstream responses#806
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Add Content-Type to the beacon chain response headers whitelist. Without this, REST endpoints returning SSZ binary data (e.g. /eth/v2/debug/beacon/states) are mislabeled as application/json by dproxy, breaking client-side parsing. Companion fix: drpcorg/dproxy#2348
msizov
approved these changes
Mar 20, 2026
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Summary
Content-Typeto beacon chain response headers whitelist inBeaconChainSpecific.getResponseHeadersToForward()RestHttpReader.extractResponseHeaders()drops the Content-Type from upstream beacon nodesapplication/jsonfor all REST responses, causing SSZ binary data to be mislabeledProblem
GET /eth/v2/debug/beacon/states/{slot}withAccept: application/octet-streamreturns SSZ binary butContent-Type: application/json. Clients fail with:Observed from multiple providers (zero1node, nodesguru, kukisglobal). Actively used endpoint (~80+ req/hour).
Root cause
BeaconChainSpecific.getResponseHeadersToForward()only whitelistedEth-Consensus-*headers.Content-Typewas filtered out byRestHttpReader.extractResponseHeaders()before reaching the gRPCresponse_headersfield.Companion PR
drpcorg/dproxy#2348 — dproxy side: use upstream Content-Type when present instead of hardcoded
application/json