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

# Modes: Historical, Realtime, and Hybrid

> A recipe runs in one of three modes. The mode decides whether the sink backfills past history, tails live blocks, or does both. Here's how to pick.

# Modes

Every recipe runs in one of three modes. The mode is a single setting, but it decides the shape of your
whole setup: whether the sink fills in **past history**, follows **new blocks** as they arrive, or does
**both**. Pick the mode from what your product needs to show, then size the backfill window to match.

## The three modes

> **Most production setups want hybrid: backfill the history you need, then stay live automatically.**

### historical

Backfill a fixed window of past blocks, then stop. The sink indexes everything from your start block
(`MORALIS_HISTORICAL_FROM_BLOCK`) up to the chain tip at the time it runs, and finishes. Use it for
one-off loads, analytics snapshots, or to seed a table you will keep current another way.

### realtime

Tail live blocks from now on, with no backfill. The sink starts at the current tip and writes each new
block as it arrives. Use it when you only care about activity going forward, for example a live trade tape
or a transfer alert, and you do not need any history.

### hybrid

Backfill first, then hand off to live with no gap. The sink indexes your history window, then continues
straight into realtime tailing. This is the default for most recipes because it gives you a complete table
that also stays current. Use it whenever you want both history and live data, which is most of the time.

## Quick reference

| Mode         | What the sink does                       | Use when                                                       |
| ------------ | ---------------------------------------- | -------------------------------------------------------------- |
| `historical` | Backfill a window, then stop             | One-off load, analytics snapshot, seed-then-maintain-elsewhere |
| `realtime`   | Tail new blocks from now, no backfill    | You only need activity going forward                           |
| `hybrid`     | Backfill, then continue live with no gap | You want history **and** live data (most cases)                |

## How the mode relates to backfill

The mode is only half the decision. The other half is **how far back** to set your start block, and that
depends on whether your answer is current state or an event list, covered in
[History & backfill](./history-and-backfill). In short:

* **Current-state answers** (balances, holders, approvals) must backfill from the beginning of the relevant
  history to be correct, so they run `historical` or `hybrid` with the start block set accordingly.
* **Event-list answers** (swaps, transfers, logs, prices) are correct at any window, so the start block is
  purely a product choice, and `realtime` with no backfill is a valid option.

## How to set it

The mode is set in the recipe's sink config, alongside the start block:

```yaml theme={null}
mode: hybrid
source:
  filters:
    - "blockNumber >= ${MORALIS_HISTORICAL_FROM_BLOCK}"   # e.g. tip-50000, or a token's deploy block
cutoff:
  auto: true        # let the sink choose the historical/realtime handoff point
```

<Note>
  **Realtime and hybrid run best on ClickHouse.** ClickHouse corrects chain reorgs at the block level
  automatically (see [Reorgs](./reorgs)), so it is the recommended destination for any live mode. The Postgres
  and MySQL recipe variants ship in `historical` mode for backfill loads. See [Destinations](./destinations)
  for the full trade-off.
</Note>