1 Bundle Requirements & Eligibility

• Single Seller Rule: A bundle can only contain items listed by the same seller. You cannot combine listings from multiple distinct sellers into one bundle offer.
• Packable Items Only: Only items flagged as packable (is_packable = true) are eligible to be included in a bundle. Non-packable or oversized items cannot be added.
• Offer Merging: Creating a new bundle offer with a seller who already has an active live offer will automatically merge the new items into the existing active bundle draft.

2 Turn-Based Negotiation & Expiry

• Strict Turn-Based Acceptance: Accepting an offer is strictly turn-based. When an offer is in "Pending" status, only the seller can accept or counter. When in "Countered" status, only the buyer can accept.
• 48-Hour Hardcoded Lifetime: Bundle offers remain active for exactly 48 hours. Offer expiration is evaluated lazily when accessing or interacting with the offer (there is no automated background cron job).

3 Pro-Rata Price Allocation & Checkout

When a custom bundle price is accepted, total item costs are distributed across all bundle items on a pro-rata basis according to their original listing prices. Any fractional rounding adjustment is absorbed by the final line item so that total line items match the exact agreed bundle price.