Kupo

Kupo is a very fast and lightweight chain-index for the Cardano blockchain. It is like a lightweight version of db-sync. Chain indexers are useful to developers and service providers in that they process and organize raw blockchain data to suit developer needs.

Similar to ogmios, we are going to grab a pre-compiled static kupo binary a server.

cd /tmp

wget https://github.com/CardanoSolutions/kupo/releases/download/v2.11/kupo-v2.11.0-aarch64-linux.zip

Unzip it

unzip kupo-v2.11.0-aarch64-linux.zip

Copy it to our bin directory

cp /tmp/bin/kupo /home/n(x)/preview/bin/

Again, make sure we have it in the right place

which kupo

kupo --version

Let's create a startup script.

nano /home/n(x)/preview/scripts/kupo_start.sh

Copy the follwing into the kupo_start.sh file.

#!/bin/bash

# Kupo configuration:
# - Using local Ogmios instance on port 1337
# - Matching all patterns with "*"
# - Starting from specific block
# - Deferring DB indexes for faster startup
# - Working directory in user's home
# - Listening on all interfaces on port 1442

/home/n(x)/preview/bin/kupo \
--ogmios-port 1337 \
--match "*" \
--since "54412148.656e903c510441032ad566d26fecf7be98882bdefde6a1ed961cd8e7bfa9d18a" \
--defer-db-indexes \
--workdir /home/n(x)/preview/kupo-db \
--ogmios-host 127.0.0.1 \
--host 0.0.0.0 \
--port 1442

Save and exit, ctrl + o and ctrl + x.

Make it executable and start it.

chmod +x /home/n(x)/preview/scripts/kupo_start.sh

cd /home/n(x)/preview/scripts/

./kupo_start.sh

You should see output of kupo syncing.

Exit the process ctrl + c

Now let's make another service file in the scripts directory.

nano /home/n(x)/preview/scripts/kupo.service

Copy the following into your service file.

[Unit]
Description       = Kupo
Wants             = network-online.target
After             = network-online.target  
  
[Service]
User              = n(x)
Type              = simple
WorkingDirectory  = /home/n(x)/preview
ExecStart         = /bin/bash -c '/home/n(x)/preview/scripts/kupo_start.sh'
KillSignal        = SIGINT
RestartKillSignal = SIGINT
LimitNOFILE       = 24000
Restart           = always
RestartSec        = 7
SyslogIdentifier  = kupo
  
[Install]
WantedBy          = multi-user.target

Copy the service file to your system directory.

sudo cp /home/n(x)preview/scripts/kupo.service /etc/systemd/system/

Give it the correct permissions.

sudo chmod 0644 /etc/systemd/system/kupo.service

Reload daemons.

sudo systemctl daemon-reload

Start the service.

sudo systemctl start kupo.service

Check the status.

sudo systemctl status kupo.service

It should say "active"

If active, enable the service.

sudo systemctl enable kupo.service

Now lets allow connections to port 1442 for queries.

sudo ufw allow 1442/tcp

Reload.

sudo ufw reload

Now let's see if it is working!

From a local terminal session on your machine (meaning not logged into your server).

We are going to curl health metrics from your kupo endpoint.

curl "http://yourserverip:1442/health"

If everything is correctly configured, you will see output similar to this.

The documentation for kupo can be found here. See what other endpoints and data you can grab from your chain indexer!