SendGrid MCP Server

Instructions

Implementation Reference

• src/tools/templates.ts:213-266 (handler)

  Handler function that performs PATCH request to SendGrid API to update the specified template version with provided parameters, including read-only check, input validation, and JSON parsing for test_data.

  handler: async ({ 
    template_id, 
    version_id, 
    name, 
    subject, 
    html_content, 
    plain_content, 
    active, 
    generate_plain_content, 
    test_data 
  }: { 
    template_id: string; 
    version_id: string; 
    name?: string; 
    subject?: string; 
    html_content?: string; 
    plain_content?: string; 
    active?: number; 
    generate_plain_content?: boolean; 
    test_data?: string; 
  }): Promise<ToolResult> => {
    const readOnlyCheck = checkReadOnlyMode();
    if (readOnlyCheck.blocked) {
      return { content: [{ type: "text", text: readOnlyCheck.message! }] };
    }
    
    const versionData: any = {};
    
    if (name !== undefined) versionData.name = name;
    if (subject !== undefined) versionData.subject = subject;
    if (html_content !== undefined) versionData.html_content = html_content;
    if (plain_content !== undefined) versionData.plain_content = plain_content;
    if (active !== undefined) versionData.active = active;
    if (generate_plain_content !== undefined) versionData.generate_plain_content = generate_plain_content;
    
    if (test_data) {
      try {
        versionData.test_data = JSON.parse(test_data);
      } catch (error) {
        return { content: [{ type: "text", text: "Error: test_data must be valid JSON" }] };
      }
    }
    
    if (Object.keys(versionData).length === 0) {
      return { content: [{ type: "text", text: "Error: Please provide at least one field to update" }] };
    }
    
    const result = await makeRequest(`https://api.sendgrid.com/v3/templates/${template_id}/versions/${version_id}`, {
      method: "PATCH",
      body: JSON.stringify(versionData),
    });
    
    return { content: [{ type: "text", text: JSON.stringify(result, null, 2) }] };
  },

• src/tools/templates.ts:198-212 (schema)

  Zod input schema defining parameters for updating a template version, including template_id, version_id, and optional fields like name, subject, html_content, etc.

  config: {
    title: "Update Template Version",
    description: "Update the content and settings of a template version",
    inputSchema: {
      template_id: z.string().describe("ID of the template"),
      version_id: z.string().describe("ID of the version to update"),
      name: z.string().optional().describe("New name for this version"),
      subject: z.string().optional().describe("Email subject line (supports Handlebars)"),
      html_content: z.string().optional().describe("HTML content of the email template"),
      plain_content: z.string().optional().describe("Plain text version"),
      active: z.number().optional().describe("Set as active version (1 = active, 0 = inactive)"),
      generate_plain_content: z.boolean().optional().describe("Auto-generate plain text from HTML"),
      test_data: z.string().optional().describe("JSON string of test data for Handlebars variables"),
    },
  },

• src/index.ts:20-23 (registration)

  Main MCP server registration loop that registers all tools from allTools, including update_template_version, using server.registerTool.

  // Register all tools
  for (const [name, tool] of Object.entries(allTools)) {
    server.registerTool(name, tool.config as any, tool.handler as any);
  }

• src/tools/index.ts:9-16 (registration)

  Aggregation of all tool sets into allTools object, including templateTools which contains update_template_version.

  export const allTools = {
    ...automationTools,
    ...campaignTools,
    ...contactTools,
    ...mailTools,
    ...miscTools,
    ...statsTools,
    ...templateTools,

• src/tools/templates.ts:197-267 (registration)

  Tool definition and registration within templateTools object export.

  update_template_version: {
    config: {
      title: "Update Template Version",
      description: "Update the content and settings of a template version",
      inputSchema: {
        template_id: z.string().describe("ID of the template"),
        version_id: z.string().describe("ID of the version to update"),
        name: z.string().optional().describe("New name for this version"),
        subject: z.string().optional().describe("Email subject line (supports Handlebars)"),
        html_content: z.string().optional().describe("HTML content of the email template"),
        plain_content: z.string().optional().describe("Plain text version"),
        active: z.number().optional().describe("Set as active version (1 = active, 0 = inactive)"),
        generate_plain_content: z.boolean().optional().describe("Auto-generate plain text from HTML"),
        test_data: z.string().optional().describe("JSON string of test data for Handlebars variables"),
      },
    },
    handler: async ({ 
      template_id, 
      version_id, 
      name, 
      subject, 
      html_content, 
      plain_content, 
      active, 
      generate_plain_content, 
      test_data 
    }: { 
      template_id: string; 
      version_id: string; 
      name?: string; 
      subject?: string; 
      html_content?: string; 
      plain_content?: string; 
      active?: number; 
      generate_plain_content?: boolean; 
      test_data?: string; 
    }): Promise<ToolResult> => {
      const readOnlyCheck = checkReadOnlyMode();
      if (readOnlyCheck.blocked) {
        return { content: [{ type: "text", text: readOnlyCheck.message! }] };
      }
      
      const versionData: any = {};
      
      if (name !== undefined) versionData.name = name;
      if (subject !== undefined) versionData.subject = subject;
      if (html_content !== undefined) versionData.html_content = html_content;
      if (plain_content !== undefined) versionData.plain_content = plain_content;
      if (active !== undefined) versionData.active = active;
      if (generate_plain_content !== undefined) versionData.generate_plain_content = generate_plain_content;
      
      if (test_data) {
        try {
          versionData.test_data = JSON.parse(test_data);
        } catch (error) {
          return { content: [{ type: "text", text: "Error: test_data must be valid JSON" }] };
        }
      }
      
      if (Object.keys(versionData).length === 0) {
        return { content: [{ type: "text", text: "Error: Please provide at least one field to update" }] };
      }
      
      const result = await makeRequest(`https://api.sendgrid.com/v3/templates/${template_id}/versions/${version_id}`, {
        method: "PATCH",
        body: JSON.stringify(versionData),
      });
      
      return { content: [{ type: "text", text: JSON.stringify(result, null, 2) }] };
    },
  },