async execute()

in packages/core/src/tools/web-fetch.ts [217:356]
119 lines of code
27 McCabe index (conditional complexity)

  async execute(
    params: WebFetchToolParams,
    signal: AbortSignal,
  ): Promise<ToolResult> {
    const validationError = this.validateParams(params);
    if (validationError) {
      return {
        llmContent: `Error: Invalid parameters provided. Reason: ${validationError}`,
        returnDisplay: validationError,
      };
    }

    const userPrompt = params.prompt;
    const urls = extractUrls(userPrompt);
    const url = urls[0];
    const isPrivate = isPrivateIp(url);

    if (isPrivate) {
      return this.executeFallback(params, signal);
    }

    const geminiClient = this.config.getGeminiClient();

    try {
      const response = await geminiClient.generateContent(
        [{ role: 'user', parts: [{ text: userPrompt }] }],
        { tools: [{ urlContext: {} }] },
        signal, // Pass signal
      );

      console.debug(
        `[WebFetchTool] Full response for prompt "${userPrompt.substring(
          0,
          50,
        )}...":`,
        JSON.stringify(response, null, 2),
      );

      let responseText = getResponseText(response) || '';
      const urlContextMeta = response.candidates?.[0]?.urlContextMetadata;
      const groundingMetadata = response.candidates?.[0]?.groundingMetadata;
      const sources = groundingMetadata?.groundingChunks as
        | GroundingChunkItem[]
        | undefined;
      const groundingSupports = groundingMetadata?.groundingSupports as
        | GroundingSupportItem[]
        | undefined;

      // Error Handling
      let processingError = false;

      if (
        urlContextMeta?.urlMetadata &&
        urlContextMeta.urlMetadata.length > 0
      ) {
        const allStatuses = urlContextMeta.urlMetadata.map(
          (m) => m.urlRetrievalStatus,
        );
        if (allStatuses.every((s) => s !== 'URL_RETRIEVAL_STATUS_SUCCESS')) {
          processingError = true;
        }
      } else if (!responseText.trim() && !sources?.length) {
        // No URL metadata and no content/sources
        processingError = true;
      }

      if (
        !processingError &&
        !responseText.trim() &&
        (!sources || sources.length === 0)
      ) {
        // Successfully retrieved some URL (or no specific error from urlContextMeta), but no usable text or grounding data.
        processingError = true;
      }

      if (processingError) {
        return this.executeFallback(params, signal);
      }

      const sourceListFormatted: string[] = [];
      if (sources && sources.length > 0) {
        sources.forEach((source: GroundingChunkItem, index: number) => {
          const title = source.web?.title || 'Untitled';
          const uri = source.web?.uri || 'Unknown URI'; // Fallback if URI is missing
          sourceListFormatted.push(`[${index + 1}] ${title} (${uri})`);
        });

        if (groundingSupports && groundingSupports.length > 0) {
          const insertions: Array<{ index: number; marker: string }> = [];
          groundingSupports.forEach((support: GroundingSupportItem) => {
            if (support.segment && support.groundingChunkIndices) {
              const citationMarker = support.groundingChunkIndices
                .map((chunkIndex: number) => `[${chunkIndex + 1}]`)
                .join('');
              insertions.push({
                index: support.segment.endIndex,
                marker: citationMarker,
              });
            }
          });

          insertions.sort((a, b) => b.index - a.index);
          const responseChars = responseText.split('');
          insertions.forEach((insertion) => {
            responseChars.splice(insertion.index, 0, insertion.marker);
          });
          responseText = responseChars.join('');
        }

        if (sourceListFormatted.length > 0) {
          responseText += `

Sources:
${sourceListFormatted.join('\n')}`;
        }
      }

      const llmContent = responseText;

      console.debug(
        `[WebFetchTool] Formatted tool response for prompt "${userPrompt}:\n\n":`,
        llmContent,
      );

      return {
        llmContent,
        returnDisplay: `Content processed from prompt.`,
      };
    } catch (error: unknown) {
      const errorMessage = `Error processing web content for prompt "${userPrompt.substring(
        0,
        50,
      )}...": ${getErrorMessage(error)}`;
      console.error(errorMessage, error);
      return {
        llmContent: `Error: ${errorMessage}`,
        returnDisplay: `Error: ${errorMessage}`,
      };
    }
  }