Unexpected management API response for node listing

Error message

Unexpected management API response for node listing

What it means

listNodes calls GET /api/nodes and expects a JSON array of node objects. If the response is not an array, the library throws this error. This protects callers from processing a malformed or unexpected management API response (e.g. an error object instead of the node list).

Source

Thrown at agents/drivers/rabbitmq/operations.go:1348

	putIfPresent(info, "totalExchanges", nestedLongOrNull(overview, "object_totals", "exchanges"))
	putIfPresent(info, "totalConnections", nestedLongOrNull(overview, "object_totals", "connections"))
	putIfPresent(info, "totalChannels", nestedLongOrNull(overview, "object_totals", "channels"))
	putIfPresent(info, "totalConsumers", nestedLongOrNull(overview, "object_totals", "consumers"))
	return info
}

func (s *server) listNodes(params jsonObject) (any, error) {
	connection, err := s.requireConnectionConfig(params)
	if err != nil {
		return nil, err
	}
	nodes, err := managementGet(connection, "/api/nodes")
	if err != nil {
		return nil, err
	}
	array, ok := nodes.([]any)
	if !ok {
		return nil, errors.New("Unexpected management API response for node listing")
	}
	result := make([]jsonObject, 0, len(array))
	for _, value := range array {
		node, ok := value.(map[string]any)
		if ok {
			result = append(result, nodeInfoFromJSON(jsonObject(node)))
		}
	}
	sort.SliceStable(result, func(left, right int) bool {
		return stringOrEmpty(result[left], "name") < stringOrEmpty(result[right], "name")
	})
	return jsonObject{"nodes": result}, nil
}

func nodeInfoFromJSON(node jsonObject) jsonObject {
	info := jsonObject{
		"name":    stringOrEmpty(node, "name"),
		"running": boolOrDefault(node, "running", false),

View on GitHub (pinned to c0390bff16)

Solutions

curl -u user:pass http://host:15672/api/nodes and confirm the body is a JSON array
Check credentials and that the response is not an auth/error object
Verify the management plugin is enabled (rabbitmq-plugins enable rabbitmq_management)
Upgrade/align driver with the RabbitMQ server version

Defensive patterns

Strategy: type-guard

Validate before calling

const res = await fetch(managementUrl + "/api/nodes", { headers: authHeader });
const body = await res.json();
if (!Array.isArray(body)) throw new Error("/api/nodes did not return an array");

Type guard

function isNodeList(v) { return Array.isArray(v) && v.every(n => n != null && typeof n === "object"); }

Try / catch

try { await agent.dispatch("listNodes", {}); } catch (e) { if (/Unexpected management API response/.test(e.message)) { /* verify /api/nodes returns a JSON array */ } else throw e; }

Prevention

Verify /api/nodes with curl before automating
Ensure the management plugin is enabled
Check for auth middleware returning error objects
Pin compatible RabbitMQ/driver versions

When it happens

Trigger: Management API returns a JSON object (e.g. {"error":"..."}) or scalar instead of an array for /api/nodes.

Common situations: Proxy returning an error object; authentication failure producing a non-array body; management plugin version mismatch changing the response envelope; hitting the wrong endpoint path.

Related errors

AI-assisted analysis of t8y2/dbx@c0390bff16 (2026-09-05). Data as JSON: /api/errors/50840d710a9a1385. Report an issue: GitHub.