Browser Agent MCP

Instructions

Implementation Reference

• src/executor.ts:543-575 (handler)

  The handler function that executes the api_post tool: sends POST request with provided data and headers, retrieves response, and returns formatted result or error.

  async function handleApiPost(client: APIRequestContext, args: any): Promise<{ toolResult: CallToolResult }> {
    try {
      const options = {
        data: args.data,
        headers: args.headers || { 'Content-Type': 'application/json' }
      };
  
      const response = await client.post(args.url, options);
      const responseData = await getResponseData(response);
  
      return {
        toolResult: {
          content: [
            {
              type: "text",
              text: `POST ${args.url} - Status: ${response.status()}`,
            },
            ...responseData
          ],
          isError: false,
        },
      };
    } catch (error) {
      return {
        toolResult: {
          content: [{
            type: "text",
            text: `POST request failed: ${(error as Error).message}`,
          }],
          isError: true,
        },
      };
    }

• src/tools.ts:147-163 (schema)

  The Tool schema definition for api_post, including name, description, and inputSchema with required url and data.

  {
    name: "api_post",
    description: "Perform a POST request to an API endpoint",
    inputSchema: {
      type: "object",
      properties: {
        url: { type: "string", description: "API endpoint URL" },
        data: { type: "string", description: "Request body data (JSON string)" },
        headers: { 
          type: "object", 
          description: "Request headers",
          additionalProperties: { type: "string" }
        }
      },
      required: ["url", "data"]
    }
  },

• src/executor.ts:212-213 (registration)

  Switch case in executeToolCall that registers and dispatches the api_post tool call to its handler.

  case "api_post":
    return await handleApiPost(apiClient!, args);

• src/tools.ts:14-20 (helper)

  API_TOOLS constant listing api_post among API tools, used to identify and initialize API client in executor.

  export const API_TOOLS = [
    "api_get",
    "api_post",
    "api_put",
    "api_patch",
    "api_delete"
  ];

• src/executor.ts:144-161 (helper)

  Helper function getResponseData used by api_post handler to process and format API response body.

  async function getResponseData(response: any): Promise<TextContent[]> {
    const contentType = response.headers()['content-type'] || '';
    let responseText: string;
    if (contentType.includes('application/json')) {
      try {
        const json = await response.json();
        responseText = JSON.stringify(json, null, 2);
      } catch (e) {
        responseText = await response.text();
      }
    } else {
      responseText = await response.text();
    }
    return [{
      type: "text",
      text: `Response body:\n${responseText}`,
    } as TextContent];
  }