can1357/oh-my-pi · error · ToolError

imageSelectorMessage = "The ':img' selector only supports lo

Error message

imageSelectorMessage = "The ':img' selector only supports local .svg and .svgz files."

What it means

The ':img' selector asks ReadTool to render an image, but it is only implemented for local SVG/SVGZ files. When the parsed selector is kind 'image' and the target URL's scheme is not 'local', the tool throws immediately rather than attempting remote rendering.

Source

Thrown at packages/coding-agent/src/tools/read.ts:1172

			? await this.#tryReadDelimitedPaths(readPath, signal, entry => internalRouter.canResolve(entry))
			: null;
		if (delimitedInternalResult) return delimitedInternalResult;

		// Peel malformed selectors through the internal-URL-aware parser before routing.
		let promotedSelector: string | undefined;
		if (internalRouter.canResolve(readPath)) {
			const internalTarget = splitInternalUrlSel(readPath);
			const parsed = parseSel(internalTarget.sel);
			if (internalTarget.sel !== undefined && parsed.kind === "none") {
				throw new ToolError(
					`Invalid selector ':${internalTarget.sel}' on '${internalTarget.path}'. Use :N, :N-M, :N+K, :N- (open-ended), a comma-separated list of ranges, :raw, :img for SVG rendering, or a range combined with raw (e.g. :raw:50-100).`,
				);
			}
			const urlMeta = parseInternalUrl(internalTarget.path);
			const scheme = urlMeta.protocol.replace(/:$/, "").toLowerCase();
			const imageSelectorMessage = "The ':img' selector only supports local .svg and .svgz files.";
			if (parsed.kind === "image" && scheme !== "local") {
				throw new ToolError(imageSelectorMessage);
			}
			if (scheme === "local") {
				const localFile = await resolveLocalUrlToFile(urlMeta, {
					cwd: this.session.cwd,
					settings: this.session.settings,
					signal,
					localProtocolOptions: this.session.localProtocolOptions,
					skills: this.session.skills,
				});
				if (localFile) {
					readPath = localFile.path;
					// Preserve a local:// selector separately so a sibling literal file
					// cannot shadow the URL's selector semantics during filesystem routing.
					promotedSelector = internalTarget.sel;
				} else {
					if (parsed.kind === "image") throw new ToolError(imageSelectorMessage);
					return this.#handleInternalUrl(internalTarget.path, parsed, signal);
				}

View on GitHub (pinned to 9690622007)

Solutions

Use a local:// URL pointing at an actual .svg or .svgz file when using ':img'.
Drop the ':img' selector and read the resource as text/raw instead.
Copy or download the SVG to a local file first, then read it with ':img'.

Example fix

// before
read("agent://diagram:img")
// after
read("local:///tmp/diagram.svg:img")

Defensive patterns

Strategy: validation

Validate before calling

if (sel === 'img' && !url.startsWith('local://')) throw new Error(':img requires a local:// .svg/.svgz target');

Type guard

function canUseImgSelector(url) { return url.startsWith('local://') && /\.svgz?$/i.test(url.split(':img')[0]); }

Try / catch

try { return await read(url) } catch (e) { if (String(e.message).includes(':img')) { return await read(url.replace(':img','')); } throw e; }

Prevention

Attach :img only to local:// URLs ending in .svg or .svgz
Check the URL scheme before adding render selectors
Fall back to :raw for non-local resources

When it happens

Trigger: Reading an internal-scheme URL (e.g. agent://, https-like internal resources) or any non-local:// target with an ':img' suffix, e.g. 'agent://skill/foo:img'.

Common situations: Trying to get a rendered view of a remote or generated SVG via an internal URL scheme, or appending ':img' by habit to any URL the agent reads.

Related errors

AI-assisted analysis of can1357/oh-my-pi@9690622007 (2026-08-31). Data as JSON: /api/errors/1c1b8d36ab8b7eba. Report an issue: GitHub.