# Checking my eth validator's sync committee duties

## :fast\_forward: Quick steps guide

{% hint style="info" %}
The following steps align with our [mainnet guide](/spanish/coins/overview-eth/guide-or-how-to-setup-a-validator-on-eth2-mainnet.md). You may need to adjust file names and directory locations where appropriate. The core concepts remain the same.
{% endhint %}

### :dagger: Why do I want to check my sync committee duties ?

* Since the Altair Hard Fork, checking sync committee membership is a must before performing any maintenance. This will give you up to [\~27 hours of advanced notice](https://github.com/ethereum/consensus-specs/pull/2453) in case your validators have been selected for sync committee duties.
* Understanding the schedule of your validator's duties better, you can find the best time to plan consensus/execution client updates, system reboots or outages.

### :robot: Pre-requisites

* Linux bash shell or command line
* Assumes you will be running this script on the beacon node. If running remotely, you might need to change your beacon node's http API to bind from localhost to 0.0.0.0
* Your ETH validator index number(s) -- Enter your validator's public key on [https://beaconcha.in/](https://beaconcha.in) or [https://beaconscan.com/](https://beaconscan.com) Example of Validator index # 12345 is shown below.

<figure><img src="/files/cNzZQvp0q9elSSyDc7st" alt=""><figcaption><p>Given your validator's public key, the index number is shown. Example of Validator 12345 from <a href="https://beaconcha.in/validator/12345">https://beaconcha.in/validator/12345</a></p></figcaption></figure>

{% hint style="success" %}
:sparkles: Kudos to [**2038**](https://www.reddit.com/user/2038/) on Reddit for [authoring this process.](https://www.reddit.com/r/ethstaker/comments/qjlfsf/how_to_check_upcoming_sync_committee_membership/)
{% endhint %}

### :construction: How to Check Sync Committee Duties script

1\. Create a `check_sync_committee.sh` script with a text editor, nano.

```
nano check_sync_committee.sh
```

2\. Paste the following script content and then save your file. CTRL+O, enter, then CTRL+X.

```
#!/bin/sh

BEACON_NODE="http://localhost:5052"
VALIDATOR_LIST=$(echo "$@" | tr ' ' '|')

epoch_to_time(){
    expr 1606824000 + \( $1 \* 384 \)
    }

time_to_epoch(){
    expr \( $1 - 1606824000 \) / 384
    }

get_committee(){
    URLSTEM="${BEACON_NODE}/eth/v1/beacon/states/finalized"
    curl -X GET "${URLSTEM}/sync_committees?epoch=$1" 2> /dev/null \
    | sed -e 's/["]/''/g' | cut -d'[' -f2 | cut -d']' -f1 | tr ',' '\n'
    }

search_committee(){
    get_committee $2 | grep -Ex $VALIDATOR_LIST \
    | awk -v c=$1 '{print "validator:", $1, "found in", c, "sync committee"}'
    }

display_epoch(){
    echo "epoch: $1 : $(date -d@$(epoch_to_time $1)) <-- $2"
    }

CURR_EPOCH=$(time_to_epoch $(date +%s))
CURR_START_EPOCH=`expr \( $CURR_EPOCH / 256 \) \* 256`
NEXT_START_EPOCH=`expr $CURR_START_EPOCH + 256`
NEXTB1_START_EPOCH=`expr $NEXT_START_EPOCH + 256`

echo
display_epoch $CURR_START_EPOCH   "current sync committee start"
display_epoch $CURR_EPOCH         "now"
display_epoch $NEXT_START_EPOCH   "next sync committee start"
display_epoch $NEXTB1_START_EPOCH "next-but-one sync committee start"
echo

if [ "$#" -gt 0 ]
then
    search_committee "current" $CURR_EPOCH
    search_committee "next"    $NEXT_START_EPOCH
fi
```

3\. Add execute permissions to the script.

```
 chmod +x check_sync_committee.sh
```

4\. Enter your validator index numbers as parameters to the script.

```bash
./check_sync_committee.sh <validator index number(s)>
# Example
# ./check_sync_committee.sh 1000 1001 1002 1003
```

Sample Output of the script:

> ```
> ./check_sync_committee.sh 123511 124216 
>
> epoch: 75008 : Sat 30 Oct 21:51:12 BST 2021 <-- current sync committee start
> epoch: 75115 : Sun 31 Oct 08:16:00 GMT 2021 <-- now
> epoch: 75264 : Mon  1 Nov 00:09:36 GMT 2021 <-- next sync committee start
> epoch: 75520 : Tue  2 Nov 03:28:00 GMT 2021 <-- next-but-one sync committee start
>
> validator: 123511 found in current sync committee
> validator: 124216 found in next sync committee
> ```

This output indicates the following:

* it is currently epoch 75115
* and validator #123511 is in current sync committee from epoch 75008 to epoch 75263
* and validator #124216 is in next sync committee from epoch 75264 to epoch 75520

If there is no output, then no validators are scheduled for current or next sync committee.

{% hint style="info" %}
:question:**Troubleshooting:**

* The python script calls the `http API`
* Ensure the `http API` is enabled for your consensus layer client.
  * teku: `--rest-api-enabled=true`
* Teku by default uses port 5051, rather than 5052. Replace the port number before using.
  * example: BEACON\_NODE="<http://localhost:5051>"
    {% endhint %}

{% hint style="warning" %}
:fire: **Script Usage Caveats**:

* Sync committee duties are only known for the current AND next sync committee period.
  {% endhint %}


---

# Agent Instructions: Querying This Documentation

If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter:

```
GET https://www.coincashew.com/spanish/coins/overview-eth/guide-or-how-to-setup-a-validator-on-eth2-mainnet/part-ii-maintenance/checking-my-eth-validators-sync-committee-duties.md?ask=<question>
```

The question should be specific, self-contained, and written in natural language.
The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.