create_custom_field

Add custom fields to SendGrid contacts to store specific data like text, numbers, or dates for targeted email marketing and segmentation.

Instructions

Create a new custom field for contacts

Input Schema

TableJSON Schema

Name	Required	Description	Default
`name`	Yes	Name of the custom field
`field_type`	Yes	Type of the field

Implementation Reference

src/tools/contacts.ts:197-208 (handler)

The handler function that executes the tool logic: checks read-only mode and makes a POST request to SendGrid API to create the custom field.

handler: async ({ name, field_type }: { name: string; field_type: string }): Promise<ToolResult> => {
  const readOnlyCheck = checkReadOnlyMode();
  if (readOnlyCheck.blocked) {
    return { content: [{ type: "text", text: readOnlyCheck.message! }] };
  }
  
  const result = await makeRequest("https://api.sendgrid.com/v3/marketing/field_definitions", {
    method: "POST",
    body: JSON.stringify({ name, field_type }),
  });
  return { content: [{ type: "text", text: JSON.stringify(result, null, 2) }] };
},

src/tools/contacts.ts:189-196 (schema)

Tool configuration with input schema using Zod for name (string) and field_type (enum: Text, Number, Date).

config: {
  title: "Create Custom Field",
  description: "Create a new custom field for contacts",
  inputSchema: {
    name: z.string().describe("Name of the custom field"),
    field_type: z.enum(["Text", "Number", "Date"]).describe("Type of the field"),
  },
},

src/tools/contacts.ts:188-209 (registration)

The tool 'create_custom_field' is defined and registered within the contactTools object exported from this file.

create_custom_field: {
  config: {
    title: "Create Custom Field",
    description: "Create a new custom field for contacts",
    inputSchema: {
      name: z.string().describe("Name of the custom field"),
      field_type: z.enum(["Text", "Number", "Date"]).describe("Type of the field"),
    },
  },
  handler: async ({ name, field_type }: { name: string; field_type: string }): Promise<ToolResult> => {
    const readOnlyCheck = checkReadOnlyMode();
    if (readOnlyCheck.blocked) {
      return { content: [{ type: "text", text: readOnlyCheck.message! }] };
    }
    
    const result = await makeRequest("https://api.sendgrid.com/v3/marketing/field_definitions", {
      method: "POST",
      body: JSON.stringify({ name, field_type }),
    });
    return { content: [{ type: "text", text: JSON.stringify(result, null, 2) }] };
  },
},

src/tools/index.ts:12-12 (registration)
contactTools (including create_custom_field) is merged into the allTools export used for MCP tool registration.
```
...contactTools,
```

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