Skillshub castai-hello-world

install

source · Clone the upstream repo

git clone https://github.com/ComeOnOliver/skillshub

Claude Code · Install into ~/.claude/skills/

T=$(mktemp -d) && git clone --depth=1 https://github.com/ComeOnOliver/skillshub "$T" && mkdir -p ~/.claude/skills && cp -r "$T/skills/jeremylongshore/claude-code-plugins-plus-skills/castai-hello-world" ~/.claude/skills/comeonoliver-skillshub-castai-hello-world && rm -rf "$T"

manifest: skills/jeremylongshore/claude-code-plugins-plus-skills/castai-hello-world/SKILL.md

CAST AI Hello World

Overview

First API calls against the CAST AI REST API: list connected clusters, retrieve the savings report, and inspect node inventory. All examples use

curl

with the

X-API-Key

header -- no SDK required.

Prerequisites

Completed
```
castai-install-auth
```
setup
```
CASTAI_API_KEY
```
environment variable set
At least one cluster connected to CAST AI

Instructions

Step 1: List Connected Clusters

curl -s -H "X-API-Key: ${CASTAI_API_KEY}" \
  https://api.cast.ai/v1/kubernetes/external-clusters \
  | jq '.items[] | {id, name, status, providerType}'

Expected output:

{
  "id": "abc123-def456",
  "name": "production-eks",
  "status": "ready",
  "providerType": "eks"
}

Step 2: Get Cluster Savings Report

export CASTAI_CLUSTER_ID="your-cluster-id"

# Current month savings
curl -s -H "X-API-Key: ${CASTAI_API_KEY}" \
  "https://api.cast.ai/v1/kubernetes/clusters/${CASTAI_CLUSTER_ID}/savings" \
  | jq '{
    monthlySavings: .monthlySavings,
    savingsPercentage: .savingsPercentage,
    currentCost: .currentMonthlyCost,
    optimizedCost: .optimizedMonthlyCost
  }'

Step 3: List Cluster Nodes

curl -s -H "X-API-Key: ${CASTAI_API_KEY}" \
  "https://api.cast.ai/v1/kubernetes/external-clusters/${CASTAI_CLUSTER_ID}/nodes" \
  | jq '.items[] | {
    name: .name,
    instanceType: .instanceType,
    lifecycle: .lifecycle,
    cpu: .allocatableCpu,
    memory: .allocatableMemory,
    zone: .zone
  }'

Step 4: Check Autoscaler Policies

curl -s -H "X-API-Key: ${CASTAI_API_KEY}" \
  "https://api.cast.ai/v1/kubernetes/clusters/${CASTAI_CLUSTER_ID}/policies" \
  | jq '{
    enabled: .enabled,
    unschedulablePods: .unschedulablePods.enabled,
    nodeDownscaler: .nodeDownscaler.enabled,
    spotInstances: .spotInstances.enabled
  }'

Output

List of connected clusters with IDs and status
Monthly savings report with before/after cost
Node inventory with instance types and lifecycle (spot vs on-demand)
Autoscaler policy status

Error Handling

Error	Cause	Solution
`401 Unauthorized`	Bad API key	Regenerate at console.cast.ai
`404 Not Found`	Wrong cluster ID	List clusters first to get correct ID
Empty `items` array	No clusters connected	Run `castai-install-auth` to onboard
`agentStatus: offline`	Agent not running	Check `kubectl get pods -n castai-agent`

Resources

Next Steps

Proceed to

castai-local-dev-loop

to set up a development workflow.