What causes "received nil proposal response" in hyperledger/fabric?

Check network/TLS connectivity to the peer; re-run the command to rule out a transient empty response

received nil proposal response

Error message

received nil proposal response

What it means

CommittedQuerier.Query checks that the endorser returned a non-nil proposal response after ProcessProposal succeeds. A nil response despite a nil error would violate the gRPC contract and indicates a broken/unexpected endorser client implementation, so the client defends against it explicitly.

Source

Thrown at internal/peer/lifecycle/chaincode/querycommitted.go:129

	}

	proposal, err := c.createProposal()
	if err != nil {
		return errors.WithMessage(err, "failed to create proposal")
	}

	signedProposal, err := signProposal(proposal, c.Signer)
	if err != nil {
		return errors.WithMessage(err, "failed to create signed proposal")
	}

	proposalResponse, err := c.EndorserClient.ProcessProposal(context.Background(), signedProposal)
	if err != nil {
		return errors.WithMessage(err, "failed to endorse proposal")
	}

	if proposalResponse == nil {
		return errors.New("received nil proposal response")
	}

	if proposalResponse.Response == nil {
		return errors.New("received proposal response with nil response")
	}

	if proposalResponse.Response.Status != int32(cb.Status_SUCCESS) {
		return errors.Errorf("query failed with status: %d - %s", proposalResponse.Response.Status, proposalResponse.Response.Message)
	}

	if strings.ToLower(c.Input.OutputFormat) == "json" {
		return c.printResponseAsJSON(proposalResponse)
	}
	return c.printResponse(proposalResponse)
}

func (c *CommittedQuerier) printResponseAsJSON(proposalResponse *pb.ProposalResponse) error {
	if c.Input.Name != "" {

View on GitHub (pinned to 2736b63f8f)

Solutions

Check network/TLS connectivity to the peer; re-run the command to rule out a transient empty response
If using a custom or proxying endorser client, fix it to return an error when no response is produced
Inspect gRPC interceptor/proxy configuration that might drop the response message
Verify you are connecting to a genuine Fabric peer endorser endpoint

Example fix

// before: assuming response is always present
proposalResponse, err := c.EndorserClient.ProcessProposal(context.Background(), signedProposal)
if err != nil {
	return errors.WithMessage(err, "failed to endorse proposal")
}
// after (client-side defensive check)
proposalResponse, err := c.EndorserClient.ProcessProposal(context.Background(), signedProposal)
if err != nil {
	return errors.WithMessage(err, "failed to endorse proposal")
}
if proposalResponse == nil || proposalResponse.Response == nil {
	return errors.New("endorser returned nil or empty proposal response")
}

Defensive patterns

Strategy: type-guard

Validate before calling

if proposalResponse == nil || proposalResponse.Response == nil {
	return errors.New("endorser returned no usable proposal response")
}

Type guard

func hasUsableResponse(resp *pb.ProposalResponse) bool {
	return resp != nil && resp.Response != nil && len(resp.Response.Payload) > 0
}

Try / catch

proposalResponse, err := endorser.ProcessProposal(ctx, signedProposal)
if err != nil {
	return errors.WithMessage(err, "failed to endorse proposal")
}
if !hasUsableResponse(proposalResponse) {
	return errors.New("received nil or empty proposal response")
}

Prevention

Always nil-check both proposalResponse and proposalResponse.Response before use
Use the official Fabric EndorserClient, not stubs, in production paths
Audit gRPC interceptors/proxies that could swallow response messages
Retry transient empty responses with backoff before failing permanently

When it happens

Trigger: Calling Query (peer lifecycle chaincode querycommitted) with an EndorserClient whose ProcessProposal returns (nil, nil) — e.g. a faulty mock, misconfigured gRPC interceptor, or custom transport returning an empty result.

Common situations: Testing with stubbed endorser clients that return nil without an error, network middlewares/proxies that swallow responses, or gRPC misconfiguration where the connection reports success but no message arrives.

Related errors

AI-assisted analysis of hyperledger/fabric@2736b63f8f (2026-09-04). Data as JSON: /api/errors/de26b52cf726b2dd. Report an issue: GitHub.