> ## Documentation Index
> Fetch the complete documentation index at: https://docs.powerhq.co/llms.txt
> Use this file to discover all available pages before exploring further.

# Using the playground

> What the free playground can run, its limits, and how to call it from code or an AI agent without a key.

The [playground](/playground) is backed by a public endpoint that needs no API key, no signup and no
browser. Anything you can run in the playground, you can run from a script or an AI coding assistant.

<Info>
  **10 free calls per IP.** Loading the playground and browsing the schema are free — only real
  queries count against it. It is a one-time allowance, not a daily one, so it is meant for
  evaluating the data rather than running a workload. [Request an API key](mailto:support@powerhq.co)
  to call production directly with no cap.
</Info>

## What you can run

| Query                                                | What it answers                                               |
| ---------------------------------------------------- | ------------------------------------------------------------- |
| [`residentialPlans`](/queries/residential-plans)     | Residential plans, rates, fees and enrollment links for a ZIP |
| [`businessPlans`](/queries/business-plans)           | Commercial plans for a ZIP and annual usage                   |
| [`utilities`](/queries/utilities)                    | Which utilities serve a ZIP code                              |
| [`nextStartDate`](/queries/next-start-date)          | Earliest available service start date                         |
| [`energyInfoByState`](/queries/energy-info-by-state) | State average rate and generation mix                         |

## What it will not run

`utilityAccounts` is **not available** in the public playground. It looks up real customer service
accounts by street address, so it stays behind an issued API key. The playground is read-only:
mutations and subscriptions are rejected.

## Calling it from code

```bash theme={null}
curl -s -X POST https://powerhq-playground-api.powerhq.workers.dev/graphql \
  -H "Content-Type: application/json" \
  -d '{"query": "{ utilities(zipCode: \"75231\") { id name } }"}'
```

Responses carry `X-RateLimit-Limit` and `X-RateLimit-Remaining` so a client can see what it has left.
Once the allowance is used up the endpoint returns `429` with a GraphQL-shaped error, and it does not
refill — an API key is the way forward from there.

## For AI agents

**Schema introspection is enabled and does not count against the limit**, so an agent can discover the
whole API before writing a single query:

```bash theme={null}
curl -s -X POST https://powerhq-playground-api.powerhq.workers.dev/graphql \
  -H "Content-Type: application/json" \
  -d '{"query": "{ __schema { queryType { fields { name } } } }"}'
```

That returns every available query with its arguments and return types. From there, build a normal
GraphQL query and post it to the same endpoint.

## Moving to your own key

With an issued key you skip the playground and call production directly, with no per-day cap:

```bash theme={null}
curl -s -X POST https://eapi.prod.powerhq.co/graphql \
  -H "x-api-key: YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"query": "{ utilities(zipCode: \"75231\") { id name } }"}'
```