amir20/dozzle · error

failed to parse arguments

Error message

failed to parse arguments: %w

What it means

executeFindContainers optionally unmarshals its JSON arguments into findContainersArgs. Empty arguments are allowed (lists all containers), but if non-empty arguments are invalid JSON or contain wrong-typed fields, json.Unmarshal fails and the error is wrapped with this message.

Solutions

1. Either omit arguments entirely (valid: lists all containers) or send a well-formed JSON object.
2. Check the wrapped json error for the offending field/type and correct it.
3. Log the exact argsJSON at the caller side to spot encoding problems before dispatch.

Example fix

// before
find_containers("my-app") // not a JSON object
// after
find_containers({"name":"my-app"})

// omit args to list everything, or validate before sending
const argsJSON = filter ? JSON.stringify({ name: filter }) : "";

try {
  return await callTool("find_containers", argsJSON);
} catch (e) {
  if (String(e).includes("failed to parse arguments")) {
    // fall back to calling with no arguments to list all containers
    return await callTool("find_containers", "");
  }
  throw e;
}

When it happens

Trigger: Calling the find_containers tool with a filter/name argument that is malformed JSON or of the wrong type (e.g. name as a number, or a JSON array instead of an object).

Common situations: Agent-generated payloads with unescaped characters; passing a JSON-escaped string instead of an object; template interpolation producing invalid JSON.

Understand the failure class

Background: "failed to unmarshal" / json.Unmarshal errors: why parsing a response into a Go struct fails and how to fix it — this error's family across 23 libraries.

• Parsing and encoding errors: unexpected token, malformed input — why parsers reject input and how to find the real culprit.

Related errors

• failed to parse arguments
• failed to parse arguments
• failed to parse arguments
• notifications are not configured on this host
• failed to parse arguments

AI-assisted analysis of amir20/dozzle@d9463cbe21 (2026-09-07). Data as JSON: /api/errors/b428cefee26734dc. Report an issue: GitHub.

Appendix: source

Thrown at internal/cloud/tools_containers.go:49

			NCpu:          int32(h.NCPU),
			MemTotal:      h.MemTotal,
			DockerVersion: h.DockerVersion,
			AgentVersion:  h.AgentVersion,
			Type:          h.Type,
			Available:     h.Available,
		}
	}
	return &pb.CallToolResponse{
		Success: true,
		Result:  &pb.CallToolResponse_ListHosts{ListHosts: &pb.ListHostsResult{Hosts: result}},
	}, nil
}

func executeFindContainers(argsJSON string, deps ToolDeps) (*pb.CallToolResponse, error) {
	var args findContainersArgs
	if argsJSON != "" {
		if err := json.Unmarshal([]byte(argsJSON), &args); err != nil {
			return nil, fmt.Errorf("failed to parse arguments: %w", err)
		}
	}

	containers, errs := deps.HostService.ListAllContainers(deps.Labels)
	logHostErrors(errs)
	hostNames := buildHostNameMap(deps.HostService)

	result := make([]*pb.ContainerInfo, 0, len(containers))
	for _, c := range containers {
		if args.Name != "" && !containsIgnoreCase(c.Name, args.Name) {
			continue
		}
		if args.Image != "" && !containsIgnoreCase(c.Image, args.Image) {
			continue
		}
		if args.State != "" && !strings.EqualFold(c.State, args.State) {
			continue
		}

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