t8y2/dbx · error

Unexpected management API response for vhost listing

Error message

Unexpected management API response for vhost listing

What it means

listNamespaces calls the RabbitMQ management API endpoint /api/vhosts and expects the JSON response to decode into a JSON array. This error is thrown when the decoded response is not an []any (e.g. the management API returned an object such as {"error":"..."}, an error payload, or an unexpected shape) instead of a vhost array. It indicates the management API responded successfully at the HTTP layer but with data the driver cannot interpret as a vhost listing.

Solutions

1. Verify the connection points at the RabbitMQ management HTTP port (default 15672), not the AMQP port, and that the management plugin is enabled (rabbitmq-plugins enable rabbitmq_management).
2. Check management credentials: log in with the same user via curl -u user:pass http://host:15672/api/vhosts and confirm a JSON array is returned.
3. Inspect any proxy/load balancer in front of the management API that may rewrite or block /api/vhosts.
4. Log the raw managementGet response body when this occurs to see what the server actually returned, then update the driver's decoding if the API shape changed.

Example fix

// before
array, ok := vhosts.([]any)
if !ok {
    return nil, errors.New("Unexpected management API response for vhost listing")
}
// after
array, ok := vhosts.([]any)
if !ok {
    return nil, fmt.Errorf("Unexpected management API response for vhost listing: got %T: %v", vhosts, vhosts)
}

// Pre-check management API reachability/shape before calling listNamespaces
resp, err := http.Get("http://host:15672/api/vhosts") // with auth in practice
if err != nil || resp.StatusCode != 200 {
    return fmt.Errorf("management API not healthy: status %v", resp.StatusCode)
}

func isVhostArray(v any) bool {
    arr, ok := v.([]any)
    if !ok { return false }
    for _, item := range arr {
        if _, ok := item.(map[string]any); !ok { return false }
    }
    return true
}

namespaces, err := agent.Call("listNamespaces", params)
if err != nil {
    if strings.Contains(err.Error(), "Unexpected management API response") {
        // log raw response, check management port/plugin/credentials, retry after fix
        return fmt.Errorf("management API returned non-array payload; verify port 15672 and rabbitmq_management plugin: %w", err)
    }
    return err
}

When it happens

Trigger: managementGet(connection, "/api/vhosts") returns a decoded value that fails the type assertion vhosts.([]any) — typically because the management endpoint returned a JSON object (auth error body, HTML/plain-text error page, proxy response, or a non-standard management plugin response) instead of an array of vhosts.

Common situations: Wrong management API port or reverse proxy returning an error page; management credentials valid for HTTP but the endpoint path changed across RabbitMQ versions; a load balancer or management UI returning JSON error objects; pointing the agent at the AMQP port instead of the management HTTP port.

Understand the failure class

Background: "invalid response format", "malformed payload", "missing data field": when an API returns 200 but the response shape is wrong — this error's family across 23 libraries.

Related errors

• Unexpected management API response for cluster overview
• Unexpected management API response for list endpoint
• Unexpected management API response for node listing
• No management API endpoint candidates
• RabbitMQ Management API URL is required when AMQP uses…

AI-assisted analysis of t8y2/dbx@c0390bff16 (2026-09-05). Data as JSON: /api/errors/f1bafd6634583462. Report an issue: GitHub.

Appendix: source

Thrown at agents/drivers/rabbitmq/operations.go:310

			entry["prefetch"] = *prefetch
		}
		consumers = append(consumers, entry)
	}
	return consumers
}

func (s *server) listNamespaces(params jsonObject) (any, error) {
	connection, err := s.requireConnectionConfig(params)
	if err != nil {
		return nil, err
	}
	vhosts, err := managementGet(connection, "/api/vhosts")
	if err != nil {
		return nil, err
	}
	array, ok := vhosts.([]any)
	if !ok {
		return nil, errors.New("Unexpected management API response for vhost listing")
	}
	namespaces := make([]jsonObject, 0, len(array))
	for _, value := range array {
		vhost, ok := value.(map[string]any)
		if ok {
			namespaces = append(namespaces, jsonObject{"name": stringOrEmpty(jsonObject(vhost), "name")})
		}
	}
	return jsonObject{"namespaces": namespaces}, nil
}

func (s *server) createNamespace(params jsonObject) (any, error) {
	namespace, err := namespaceName(params)
	if err != nil {
		return nil, err
	}
	connection, err := s.requireConnectionConfig(params)
	if err != nil {

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