---
title: Forming calls with GraphQL
slug: data-platform/docs/forming-calls-with-graphql
docTags: 
createdAt: 2026-08-10T12:05:16.000Z
---

You can run queries on the Optimizely Data Platform (ODP) using GraphQL API and GraphQL Explorer.

## Authenticating with GraphQL

The GraphQL Explorer uses the same [authentication](docId\:LIy60XfaOOtW4DxUAxG_6) as ODP's REST APIs.

## GraphQL Explorer

Optimizely Data Platform (ODP) GraphQL Explorer is an instance of [GraphiQL](https://github.com/graphql/graphiql), which is a "graphical interactive in-browser GraphQL IDE." There is a public version (safe for your customers to explore) and a private version (for your eyes only).

- [Public Graph\_i\_QL](https://zaius-graphql-explorer.zaius.com/?apiUrl=https%3A%2F%2Fapi.us1.odp.optimizely.com%2Fv3%2Fgraphql): You can use this to explore both public and private schema based on the [authentication](docId\:LIy60XfaOOtW4DxUAxG_6) method you choose. It requires you to paste your public/private API token into the API Key box.
- [Private Graph\_i\_QL](https://app.zaius.com/app#/graphql): You can use this to explore your full schema and gain experience writing GraphQL queries

## GraphQL endpoint

The API has a single endpoint for each region (United States, Europe, and Asia-Pacific). More information about the different endpoints for the GraphQL API is available in the [GraphQL API reference](docId\:lJ5O4yHN9mRHJeErNwKll).

## GraphQL queries

GraphQL queries return only the data you specify. To form a query, you must specify fields until you return only [scalars](docId\:Nyyj-xUv_4Wbkf3GIPLvL). The following query looks up the customers dimension.

```graphql
query {
customers {
   edges {
     node {
        first_name
        email
        name
     }
   }
 }
}
```

## Handling errors

There are two general types of GraphQL operation errors:

- Parse or Validation errors
- Execution errors

### Parse/Validation errors

Making a query with invalid query syntax or against fields that do not exist will fail client-side. Ensure that the GraphQL Schema is up-to-date on GraphQL Explorer.

### Execution errors

Execution errors occur at the server while resolving the query operation. These errors may be the client's fault (like a bad request), others could be a server issue (like internal server errors).

Let us say the server could not find the customer with following query:

```graphql
{
  customer(vuid: "notreal") {
    customer_id
    email
  }
}
```

The error response will look like the following. It includes the `message` field to explain the issue, the`extensions.classification` field represents where the error happens during the execution cycle and the `extensions.code` is a machine-readable error code.

```graphql
{
    "errors": [
        {
            "message": "Exception while fetching data (/customer) : could not resolve vuid = notreal",
            "locations": [
                {
                    "line": 2,
                    "column": 5
                }
            ],
            "path": [
                "customer"
            ],
            "extensions": {
                "code": "INVALID_IDENTIFIER_EXCEPTION",
                "classification": "DataFetchingException"
            }
        }
    ],
    "data": {
        "customer": null
    }
}
```

### Error codes

| Code                           | Description                                                          |
| ------------------------------ | -------------------------------------------------------------------- |
| INVALID\_IDENTIFIER\_EXCEPTION | The identifier provided as an argument to the filter does not exist. |