> ## Documentation Index
> Fetch the complete documentation index at: https://developer.fin.com/llms.txt
> Use this file to discover all available pages before exploring further.

# June 10, 2026

> Changelog for June 10, 2026

## ✨ New Features

### Pay-ins

1. **New Endpoint: `POST /v2/transactions/pay-ins`** Create a pay-in instruction for a customer. The customer makes a fiat payment before expiry using the returned deposit instructions and mandatory reference code, and receives USDC in their specified destination wallet.
   * `currency` — source currency. Currently supports `MXN` only.
   * `destination.rail` — blockchain rail for the destination wallet. Supports `POLYGON` and `SOLANA`.
   * `destination.currency` — destination currency. Currently supports `USDC` only.
   * `developer_fee` — optional object to apply a fixed and/or percentage fee to the pay-in.
   * `deposit_instruction` — returned in the response. Contains either `bank_details` (with CLABE, SPEI rail, and reference code) or `checkout_details`, depending on the `type` field.
   * `expire_at` — timestamp after which the pay-in can no longer be paid.
   * `X-Idempotency-Key` header is required on all requests.
   <Note>
     Pay-in instructions require separate configuration. Contact support to enable this feature for your account.
   </Note>
2. **New Endpoint: `GET /v2/transactions/pay-ins`** Returns a paginated list of pay-ins. Each item includes `id`, `status`, `source_amount`, `source_amount_in_major`, `currency`, and `created_at`. Supports `current_page` and `per_page` query parameters (max 100 per page).
3. **New Endpoint: `GET /v2/transactions/pay-ins/{payin_id}`** Returns full details for a single pay-in by ID, including status, amounts, fees, exchange rate, destination wallet, and deposit instructions. The `transaction_id` field is `null` until the pay-in is processed and a transaction is created.
   Pay-in statuses: `PENDING`, `PROCESSING`, `COMPLETED`, `EXPIRED`, `FAILED`.