Custom session fields

import { createKavach } from 'kavachos';
import { customSession } from 'kavachos/auth';

const kavach = await createKavach({
  database: { provider: 'sqlite', url: 'kavach.db' },
  auth: {
    session: { secret: process.env.SESSION_SECRET },
  },
  plugins: [
    customSession({
      // Merged into every session automatically
      defaultFields: { theme: 'system', beta: false },
      // Called once per session creation to compute dynamic fields
      onSessionCreate: async (userId) => ({
        createdAt: Date.now(),
        plan: await fetchUserPlan(userId),
      }),
    }),
  ],
});

import type { CustomSessionModule } from 'kavachos/auth';

const mod = kavach.plugins.getContext().customSession as CustomSessionModule;

// Read custom fields
const fields = await mod.getSessionFields(session.id);
// => { theme: 'system', beta: false, createdAt: 1234567890, plan: 'pro' }

// Update fields on an existing session
await mod.updateSessionFields(session.id, { beta: true, lastPage: '/dashboard' });

GET /auth/session/fields?sessionId=sess_abc123

{ "fields": { "theme": "dark", "plan": "pro" } }

PATCH /auth/session/fields
Content-Type: application/json

{
  "sessionId": "sess_abc123",
  "fields": { "theme": "light" }
}

{ "updated": true }

interface CustomSessionConfig {
  defaultFields?: Record<string, unknown>;
  onSessionCreate?: (userId: string, request?: Request) => Promise<Record<string, unknown>>;
}