wavetermdev/waveterm · warning

Invalid VDOM URL format

Error message

Invalid VDOM URL format

What it means

handleVDom in pkg/web/webvdomproto.go:24 rejects URLs that do not contain at least one path segment after the /vdom/ prefix. In practice strings.Split never returns fewer than 1 element, so this guard fires only for malformed routing setups where the request reaches the handler without a usable path. It returns HTTP 400.

Source

Thrown at pkg/web/webvdomproto.go:24

import (
	"fmt"
	"io"
	"log"
	"net/http"
	"strings"

	"github.com/wavetermdev/waveterm/pkg/wshrpc"
	"github.com/wavetermdev/waveterm/pkg/wshrpc/wshclient"
	"github.com/wavetermdev/waveterm/pkg/wshrpc/wshserver"
	"github.com/wavetermdev/waveterm/pkg/wshutil"
)

// Add the new handler function
func handleVDom(w http.ResponseWriter, r *http.Request) {
	// Extract UUID and path from URL
	pathParts := strings.Split(strings.TrimPrefix(r.URL.Path, "/vdom/"), "/")
	if len(pathParts) < 1 {
		http.Error(w, "Invalid VDOM URL format", http.StatusBadRequest)
		return
	}

	uuid := pathParts[0]
	// Simple UUID validation
	if len(uuid) != 36 {
		http.Error(w, "Invalid UUID format", http.StatusBadRequest)
		return
	}

	// Reconstruct the remaining path
	path := "/" + strings.Join(pathParts[1:], "/")
	if r.URL.RawQuery != "" {
		path += "?" + r.URL.RawQuery
	}

	// Read request body if present
	var body []byte

View on GitHub (pinned to a4447c1563)

Solutions

1. Check the request URL that reached the server; it must look like /vdom/<36-char-uuid>/<resource-path>.
2. Fix the reverse proxy or router config so the /vdom/ prefix and the UUID survive the rewrite.
3. Correct the client-side fetch/URL construction to include the UUID path segment.
4. Verify the handler registration in the web server routing table points at the right prefix.

Example fix

// before (client)
fetch("/vdom/")

// after
fetch(`/vdom/${blockId}/render`) // blockId is a 36-char UUID

function validateVdomUrl(blockId, resourcePath) {
  if (!blockId) throw new Error("vdom block id required");
  return `/vdom/${blockId}/${resourcePath.replace(/^\//, "")}`;
}

const resp = await fetch(url);
if (resp.status === 400) {
  const msg = await resp.text();
  throw new Error(`vdom request rejected: ${msg}`);
}

When it happens

Trigger: A request hits the /vdom/ route whose URL path, after trimming the prefix, yields no segments — e.g. a proxy or router rewrites the path away, or a misconfigured reverse proxy forwards an empty path to the vdom endpoint.

Common situations: Reverse-proxy strip-prefix rules (nginx 'proxy_pass' with trailing slash) consuming the UUID segment, a webserver route registered with a non-capturing pattern, or manually constructed fetch() calls to /vdom/ with no UUID.

Understand the failure class

Background: "Invalid URL" errors: why new URL(), URI.parse, and reqwest::Url reject your string — missing scheme, whitespace, and bad path format — this error's family across 39 libraries.

Related errors

• wcloud endpoint not set
• wcloud ping endpoint not set
• dropping text/plain file with URL (must be fetched and conve
• failed to copy from file: %v
• failed to copy from reader: %v

AI-assisted analysis of wavetermdev/waveterm@a4447c1563 (2026-09-01). Data as JSON: /api/errors/4077e7356c52aca7. Report an issue: GitHub.