---
title: experimental.chain() function
description: >
  `experimental.chain()` runs two queries in a single Flux script sequentially and outputs the
  results of the second query.
menu:
  flux_0_x_ref:
    name: experimental.chain
    parent: experimental
    identifier: experimental/chain
weight: 101

introduced: 0.68.0
---

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`experimental.chain()` runs two queries in a single Flux script sequentially and outputs the
results of the second query.

Flux typically executes multiple queries in a single script in parallel.
Running the queries sequentially ensures any dependencies the second query
has on the results of the first query are met.

##### Applicable use cases
- Write to a bucket and query the written data in a single Flux script.
- Execute queries sequentially in testing scenarios.

##### Function type signature

```js
(first: stream[A], second: stream[B]) => stream[B] where A: Record, B: Record
```

{{% caption %}}For more information, see [Function type signatures](/flux/v0.x/function-type-signatures/).{{% /caption %}}

## Parameters

### first
({{< req >}})
First query to execute.



### second
({{< req >}})
Second query to execute.




## Examples

### Write to a bucket and query the written data

```js
import "experimental"

downsampled_max =
    from(bucket: "example-bucket-1")
        |> range(start: -1d)
        |> filter(fn: (r) => r._measurement == "example-measurement")
        |> aggregateWindow(every: 1h, fn: max)
        |> to(bucket: "downsample-1h-max", org: "example-org")

average_max =
    from(bucket: "downsample-1h-max")
        |> range(start: -1d)
        |> filter(fn: (r) => r.measurement == "example-measurement")
        |> mean()

experimental.chain(first: downsampled_max, second: average_max)

```