14. Extensibility

Note: the extension points below (createTools, custom processors, custom providers) belong to roadmap modules (§6–§9). The implemented core’s extension points are ParseOptions.cleaner, wrapper, onAttachment, and threadIdResolver (§12.1).

14.1 Custom AI Tools

import { createTools } from "@mvrx/mail/tools";

const myTools = createTools({
  extractTicketId: (email) => {
    const match = email.metadata.subject?.match(/\[TICKET-(\d+)\]/);
    return match ? { ticketId: match[1] } : null;
  },
});

14.2 Custom Compose Strategy

import { createCompose } from "@mvrx/mail/compose";

const myCompose = createCompose({
  systemPrompt: "You are a terse, no-nonsense email assistant. Use plain English. No filler phrases.",
  defaultTone: "casual",
  defaultLength: "concise",
});

const draft = await myCompose.draft("Follow up with Alice about invoices.", ai);

14.3 Custom Attachment Processor

import type { AttachmentProcessor } from "@mvrx/mail/attachments";

const calendarProcessor: AttachmentProcessor = {
  accepts: (att) => att.contentType === "text/calendar",
  process: async (att) => {
    const text = new TextDecoder().decode(await att.content());
    att.extractedText = parseIcalSummary(text);
  },
};

14.4 Extending NormalizedEmail

interface AppEmail extends NormalizedEmail {
  x_ticket_id:  string | null;
  x_category:   string | null;
}

const email = await parse(message) as AppEmail;
email.x_ticket_id = myTools.extractTicketId(email)?.ticketId ?? null;

Custom fields must use the x_ prefix per AECS-1 §9.

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