Documentation for --checkpoint-sync-url

docs/get-started/checkpoint-start.md

@@ -14,17 +14,19 @@ When starting from a recent checkpoint, Teku downloads historic chain data in th
 
 You need access to a beacon node with [REST API enabled] (for example, Teku) to download the finalized checkpoint state file.
 
+Alternatively, you can use a Checkpointz endpoint from [this community-maintained list of checkpoint state endpoints](https://eth-clients.github.io/checkpoint-sync-endpoints/).
+
 :::
 
 The following command downloads a recent finalized checkpoint state from a beacon node, and starts Teku:
 
 ```bash
 teku --eth1-endpoint=http://localhost:8545 \
 --validator-keys=/Users/me/mainnet/validator/keys:/Users/me/mainnet/validator/passwords \
---initial-state=http://other-node:5051/eth/v2/debug/beacon/states/finalized
+--checkpoint-sync-url=https://beaconstate.ethstaker.cc
 ```
 
-The command uses the [`--initial-state`](../reference/cli/index.md#initial-state) option to download the finalized checkpoint state from the [`/eth/v2/debug/beacon/states/`](https://consensys.github.io/teku/#operation/getEthV1DebugBeaconStatesWithState_id) endpoint on the beacon node (for example, Teku).
+The command uses the [`--checkpoint-sync-url`](../reference/cli/index.md#checkpoint-sync-url) option to download the finalized checkpoint state.
 
 :::note
 
@@ -34,11 +36,12 @@ You can also download a finalized checkpoint state file, and specify the locatio
 curl -o state.ssz -H 'Accept: application/octet-stream' http://other-node:5051/eth/v2/debug/beacon/states/finalized
 ```
 
-:::
-
-:::tip
-
-See [this community-maintained list of checkpoint state endpoints](https://eth-clients.github.io/checkpoint-sync-endpoints/).
+And to start Teku:
+```bash
+teku --eth1-endpoint=http://localhost:8545 \
+--validator-keys=/Users/me/mainnet/validator/keys:/Users/me/mainnet/validator/passwords \
+--initial-state=state.ssz
+```
 
 :::
 

docs/reference/cli/index.md

@@ -811,6 +811,46 @@ See [this community-maintained list of checkpoint state endpoints](https://eth-c
 
 :::
 
+### checkpoint-sync-url
+
+<!--tabs-->
+
+# Syntax
+
+```bash
+--checkpoint-sync-url=<URL>
+```
+
+# Example
+
+```bash
+--checkpoint-sync-url="https://beaconstate.ethstaker.cc"
+```
+
+# Environment variable
+
+```bash
+TEKU_CHECKPOINT_SYNC_URL="https://beaconstate.ethstaker.cc"
+```
+
+# Configuration file
+
+```bash
+checkpoint-sync-url: "https://beaconstate.ethstaker.cc"
+```
+
+<!--/tabs-->
+
+URL of a Checkpointz endpoint used to boostrap the node.
+
+By default, Teku will try to download the finalized state from the endpoint. If it can't download the finalized state, it will try to download the genesis state.
+
+:::tip
+
+See [this community-maintained list of checkpoint state endpoints](https://eth-clients.github.io/checkpoint-sync-endpoints/).
+
+:::
+
 ### logging
 
 <!--tabs-->