error marshaling ChaincodeActionPayload: proto: Marshal call

Error message

error marshaling ChaincodeActionPayload: proto: Marshal called with nil

What it means

GetBytesChaincodeActionPayload serializes a *peer.ChaincodeActionPayload. A nil pointer cannot be marshaled by proto.Marshal, so the function returns this explicit error naming the message type. Callers use the result when assembling signed transactions.

Source

Thrown at protoutil/proputils.go:165

	}
	resBytes, err := proto.Marshal(res)
	return resBytes, errors.Wrap(err, "error marshaling Response")
}

// GetBytesChaincodeEvent gets the bytes of ChaincodeEvent
func GetBytesChaincodeEvent(event *peer.ChaincodeEvent) ([]byte, error) {
	if event == nil {
		return nil, errors.New("error marshaling ChaincodeEvent: proto: Marshal called with nil")
	}
	eventBytes, err := proto.Marshal(event)
	return eventBytes, errors.Wrap(err, "error marshaling ChaincodeEvent")
}

// GetBytesChaincodeActionPayload get the bytes of ChaincodeActionPayload from
// the message
func GetBytesChaincodeActionPayload(cap *peer.ChaincodeActionPayload) ([]byte, error) {
	if cap == nil {
		return nil, errors.New("error marshaling ChaincodeActionPayload: proto: Marshal called with nil")
	}
	capBytes, err := proto.Marshal(cap)
	return capBytes, errors.Wrap(err, "error marshaling ChaincodeActionPayload")
}

// GetBytesProposalResponse gets proposal bytes response
func GetBytesProposalResponse(pr *peer.ProposalResponse) ([]byte, error) {
	if pr == nil {
		return nil, errors.New("error marshaling ProposalResponse: proto: Marshal called with nil")
	}
	respBytes, err := proto.Marshal(pr)
	return respBytes, errors.Wrap(err, "error marshaling ProposalResponse")
}

// GetBytesHeader get the bytes of Header from the message
func GetBytesHeader(hdr *common.Header) ([]byte, error) {
	if hdr == nil {
		return nil, errors.New("error marshaling Header: proto: Marshal called with nil")

View on GitHub (pinned to 2736b63f8f)

Solutions

Nil-check the ChaincodeActionPayload before calling GetBytesChaincodeActionPayload.
Verify the earlier GetProposalResponsePayload/UnmarshalChaincodeActionPayload step succeeded and produced a non-nil result.
Ensure each ProposalResponse passed to CreateSignedTx has a valid Payload.
In tests, construct &peer.ChaincodeActionPayload{...} before invoking.

Example fix

// before
capBytes, err := protoutil.GetBytesChaincodeActionPayload(cap)
// after
if cap == nil {
    return nil, errors.New("missing ChaincodeActionPayload for transaction")
}
capBytes, err := protoutil.GetBytesChaincodeActionPayload(cap)

Defensive patterns

Strategy: validation

Validate before calling

if cap == nil {
    return nil, errors.New("cannot build transaction: ChaincodeActionPayload is nil")
}

Type guard

func hasActionPayload(pResp *peer.ProposalResponse) bool {
    return pResp != nil && pResp.Payload != nil
}

Try / catch

capBytes, err := protoutil.GetBytesChaincodeActionPayload(cap)
if err != nil {
    return nil, errors.Wrap(err, "ChaincodeActionPayload serialization failed")
}

Prevention

Verify GetPayloadResponses/UnmarshalChaincodeActionPayload succeeded before building the tx.
Validate every ProposalResponse has a non-nil Payload before CreateSignedTx.
Reject endorsement sets with missing actions early instead of at serialization time.

When it happens

Trigger: Calling protoutil.GetBytesChaincodeActionPayload(nil), or passing cap extracted from a Transaction action that is missing/nil (as in CreateSignedTx, prepareTransaction, createSignedTxTwoActions when actions are absent).

Common situations: Building a signed transaction from proposal responses where the payload action was never populated, or a ProposalResponse.Payload failed to unmarshal into ChaincodeActionPayload earlier in the flow.

Related errors

AI-assisted analysis of hyperledger/fabric@2736b63f8f (2026-09-04). Data as JSON: /api/errors/8a2d0c00cac3ae94. Report an issue: GitHub.