danny-avila/LibreChat · error · Error

This tool is only available for agents.

Error message

This tool is only available for agents.

What it means

Construction-time guard in createGeminiImageTool: the Gemini image tool is intentionally restricted to the agent execution path. If `fields.override` is false AND `fields.isAgent` is not truthy, the factory throws before building the tool. This prevents the tool from being registered for legacy (non-agent) request flows.

Source

Thrown at api/app/clients/tools/structured/GeminiImageGen.js:316

        promptTokens,
        completionTokens,
      },
    );
  } catch (error) {
    logger.error('[GeminiImageGen] Error recording token usage:', error);
  }
}

/**
 * Creates Gemini Image Generation tool
 * @param {Object} fields - Configuration fields
 * @returns {ReturnType<tool>} - The image generation tool
 */
function createGeminiImageTool(fields = {}) {
  const override = fields.override ?? false;

  if (!override && !fields.isAgent) {
    throw new Error('This tool is only available for agents.');
  }

  const { req, imageFiles = [], userId, fileStrategy, GEMINI_API_KEY, GOOGLE_KEY } = fields;

  const imageOutputType = fields.imageOutputType || EImageOutputType.PNG;

  const geminiImageGenTool = tool(
    async ({ prompt, image_ids, aspectRatio, imageSize }, runnableConfig) => {
      if (!prompt) {
        throw new Error('Missing required field: prompt');
      }

      logger.debug('[GeminiImageGen] Generating image', { aspectRatio, imageSize });

      let ai;
      try {
        ai = await initializeGeminiClient({
          GEMINI_API_KEY,

View on GitHub (pinned to 5ff282f900)

Solutions

1. Only construct this tool from the agent tool-loading path, which sets `isAgent: true` on fields.
2. For app/manifest initialization where no call will be made, pass `override: true`.
3. If you need image generation outside agents, use the dedicated non-agent image endpoint instead of this tool.
4. Audit the call site to confirm `fields` is being forwarded with isAgent intact from the request context.

Example fix

// before
const tools = createGeminiImageTool({ req }); // throws: not an agent

// after — agent path
const tools = createGeminiImageTool({ req, isAgent: true });
// or — bootstrap/manifest only
const tools = createGeminiImageTool({ override: true });

function assertAgentFactory(fields = {}) {
  if (!fields.override && !fields.isAgent) {
    throw new Error('createGeminiImageTool requires isAgent:true (or override:true for bootstrap).');
  }
}

function isAgentFactoryCall(fields) {
  return Boolean(fields?.override || fields?.isAgent);
}

When it happens

Trigger: Calling createGeminiImageTool() from a code path that does not pass `isAgent: true` and is not an app-bootstrap call (where override:true is expected). Typically a non-agent endpoint or a manual/programmatic instantiation.

Common situations: Wiring the Gemini image tool into a legacy assistant/non-agent tool registry; a refactor that lost the isAgent flag when forwarding fields; testing the factory directly without setting either flag; a custom route that tries to use the tool outside the agent controller.

Related errors

• This tool is only available for agents.
• Gemini Image Generation requires one of: user-provided API k
• Missing required field: prompt
• You no longer have access to subagent ${agentId}.
• User ID not found in blob path

AI-assisted analysis of danny-avila/LibreChat@5ff282f900 (2026-08-12). Data as JSON: /api/errors/0c360221fe652846. Report an issue: GitHub.