---
title: "Transactions"
description: "Endpoint for looking up a previously-processed write by its rid in the OneStream compatibility dialect."
---

# Transactions

Every write in the OneStream dialect carries an `rid` (request identifier). The endpoint in this group lets you check whether a given `rid` has already been processed and, if so, replay the original response verbatim. Use it before retrying a `POST` that timed out — it prevents accidental double-writes without depending on the panel-side idempotency window alone.

## Endpoints

| Endpoint | Method and path | What it does |
|---|---|---|
| [Look up a transaction](/docs/?page=os-ref-transaction) | `GET /ext/transaction/{rid}` | Returns the cached response for a previously-processed rid, or 404 if the rid was never seen. |