multica-ai/multica · error

download file: %w

Error message

download file: %w

What it means

Once the command has the signed download_url, it fetches the bytes with client.DownloadFile under a 60s timeout. This error wraps any failure of that fetch: expired signed URL, DNS/network failure to the storage host, or a 403 from object storage.

Source

Thrown at server/cmd/multica/cmd_attachment.go:157

	var att map[string]any
	if err := client.GetJSON(ctx, "/api/attachments/"+args[0], &att); err != nil {
		return fmt.Errorf("get attachment: %w", err)
	}

	downloadURL := strVal(att, "download_url")
	if downloadURL == "" {
		return fmt.Errorf("attachment has no download URL")
	}

	filename := filepath.Base(strVal(att, "filename"))
	if filename == "" || filename == "." {
		filename = args[0]
	}

	// Download the file content.
	data, err := client.DownloadFile(ctx, downloadURL)
	if err != nil {
		return fmt.Errorf("download file: %w", err)
	}

	// Write to the output directory, creating it if needed so `-o` works
	// against a directory that does not exist yet (the help example's
	// `-o ./attachments` in a clean workdir).
	outputDir, _ := cmd.Flags().GetString("output-dir")
	if outputDir != "" {
		if err := os.MkdirAll(outputDir, 0o755); err != nil {
			return fmt.Errorf("create output directory: %w", err)
		}
	}
	destPath := filepath.Join(outputDir, filename)

	if err := os.WriteFile(destPath, data, 0o644); err != nil {
		return fmt.Errorf("write file: %w", err)
	}

	// Print the absolute path so agents can reference the file.

View on GitHub (pinned to 2c0912b6ec)

Solutions

1. Retry the download — a fresh run gets a newly signed URL
2. Allow egress to the storage/host serving download_url in firewall/proxy rules
3. For large files on slow links, download from a machine with better bandwidth or increase the CLI timeout env if supported
4. Check system clock (significant skew can invalidate signatures)

Example fix

# retry pattern in shell (fresh signed URL each attempt)
for i in 1 2 3; do multica attachment download "$id" -o ./attachments && break; sleep 5; done

# signed URLs are freshly minted per run — one retry fixes expiry
for i in 1 2; do multica attachment download "$id" -o ./attachments && exit 0; sleep 2; done; exit 1

When it happens

Trigger: Metadata was fetched but the signed URL expired before the download started (long queue, paused terminal); egress blocked to the storage domain (air-gapped agent sandbox, firewall); clock skew invalidating the signature; storage outage.

Common situations: Agent containers with restricted egress allowing only the API host; slow links where the 60s timeout is exceeded for large files; sitting on the metadata too long before downloading.

Related errors

• get attachment: %w
• upload attachment: %w
• attachment has no download URL
• create output directory: %w
• write file: %w

AI-assisted analysis of multica-ai/multica@2c0912b6ec (2026-08-15). Data as JSON: /api/errors/f69def951bb9cc38. Report an issue: GitHub.