Update Event

Instructions

Implementation Reference

• src/calendar/tools.ts:298-311 (handler)

  Handler function for update_event tool - receives event id and optional fields (summary, startDate, endDate, location, description), runs automation via Swift or JXA, returns MutationResult.

  async ({ id, summary, startDate, endDate, location, description }) => {
    try {
      const result = await runAutomation<MutationResult>({
        swift: {
          command: "update-event",
          input: { id, title: summary, startDate, endDate, location, notes: description },
        },
        jxa: () => updateEventScript(id, { summary, startDate, endDate, location, description }),
      });
      return ok(result);
    } catch (e) {
      return errJxaFor("update event", e);
    }
  },

• src/calendar/tools.ts:273-312 (registration)

  Registration of update_event tool with MCP server, including title, description, input schema (id required, rest optional), and annotations (destructive, idempotent).

  server.registerTool(
    "update_event",
    {
      title: "Update Event",
      description:
        "Update event properties. Only specified fields are changed. Attendees and recurrence rules cannot be modified via automation.",
      inputSchema: {
        id: z.string().max(500).describe("Event UID"),
        summary: z.string().max(500).optional().describe("New title"),
        startDate: z
          .string()
          .max(64)
          .optional()
          .describe("New start date/time (ISO 8601, e.g. '2026-03-15T09:00:00Z')"),
        endDate: z.string().max(64).optional().describe("New end date/time (ISO 8601, e.g. '2026-03-15T10:00:00Z')"),
        location: z.string().max(5000).optional().describe("New location"),
        description: z.string().max(5000).optional().describe("New notes/description"),
      },
      annotations: {
        readOnlyHint: false,
        destructiveHint: true,
        idempotentHint: true,
        openWorldHint: false,
      },
    },
    async ({ id, summary, startDate, endDate, location, description }) => {
      try {
        const result = await runAutomation<MutationResult>({
          swift: {
            command: "update-event",
            input: { id, title: summary, startDate, endDate, location, notes: description },
          },
          jxa: () => updateEventScript(id, { summary, startDate, endDate, location, description }),
        });
        return ok(result);
      } catch (e) {
        return errJxaFor("update event", e);
      }
    },
  );

• src/calendar/scripts.ts:173-196 (helper)

  JXA helper that generates an AppleScript/JXA string to update a calendar event by UID. Finds the event across all calendars, then applies only the provided fields.

  export function updateEventScript(
    id: string,
    updates: { summary?: string; startDate?: string; endDate?: string; location?: string; description?: string },
  ): string {
    const lines: string[] = [];
    if (updates.summary !== undefined) lines.push(`ev.summary = '${esc(updates.summary)}';`);
    if (updates.startDate !== undefined) lines.push(`ev.startDate = new Date('${esc(updates.startDate)}');`);
    if (updates.endDate !== undefined) lines.push(`ev.endDate = new Date('${esc(updates.endDate)}');`);
    if (updates.location !== undefined) lines.push(`ev.location = '${esc(updates.location)}';`);
    if (updates.description !== undefined) lines.push(`ev.description = '${esc(updates.description)}';`);
  
    return `
      const Calendar = Application('Calendar');
      const cals = Calendar.calendars();
      let ev = null;
      for (const cal of cals) {
        const events = cal.events.whose({uid: '${esc(id)}'})();
        if (events.length > 0) { ev = events[0]; break; }
      }
      if (!ev) throw new Error('Event not found: ${esc(id)}');
      ${lines.join("\n    ")}
      JSON.stringify({id: ev.uid(), summary: ev.summary()});
    `;
  }

• src/calendar/tools.ts:279-290 (schema)

  Input schema for update_event - id required, all other fields optional. Uses Zod validation with max length constraints.

  inputSchema: {
    id: z.string().max(500).describe("Event UID"),
    summary: z.string().max(500).optional().describe("New title"),
    startDate: z
      .string()
      .max(64)
      .optional()
      .describe("New start date/time (ISO 8601, e.g. '2026-03-15T09:00:00Z')"),
    endDate: z.string().max(64).optional().describe("New end date/time (ISO 8601, e.g. '2026-03-15T10:00:00Z')"),
    location: z.string().max(5000).optional().describe("New location"),
    description: z.string().max(5000).optional().describe("New notes/description"),
  },