Common troubleshooting and recipes

When generating Terraform providers from OpenAPI documents, you might encounter cases where your API’s structure doesn’t naturally fit Terraform’s resource-oriented approach. These differences typically occur because APIs aren’t always designed with Terraform’s infrastructure management style in mind.

Speakeasy’s generator identifies these design differences and offers extensions and customization options to address them. This enables you to produce effective Terraform providers, even when your API doesn’t initially match Terraform’s requirements, simplifying what might otherwise be challenging configuration tasks.

Fixing common API issues

Impedance mismatch errors

An impedance mismatch error happens when Speakeasy’s generator finds properties with different data types that need to be combined into one. This error means the data types don’t match up correctly across API operations (such as between request and response data or across different operations for the same entity), which can cause problems in the Terraform provider being created.

A typical impedance mismatch scenario occurs in the following situation:

A request takes a UUID string for task assignment:
request.json
```
{
  "taskId": "12345",
  "assignee": "user-uuid-1"
}
```

The response returns a full user object for that assignee:

response.json


{
  "taskId": "12345",
  "assignee": {
    "id": "user-uuid-1",
    "name": "Alice Johnson"
  }
}

When the generator attempts to merge these properties, it detects that it cannot reconcile the different data types (string vs object) and yields an impedance mismatch error.

How to fix an impedance mismatch error

Speakeasy includes built-in extensions to help fix impedance mismatch errors. You can use these solutions to adjust either the request or the response data:

Option 1: Override the property name

Use x-speakeasy-name-override to give the mismatched properties different names so they no longer attempt to merge:

openapi.yaml


TaskRequest:
  type: object
  x-speakeasy-entity: Task
  properties:
    taskId:
      type: string
    assignee:
      type: string
      x-speakeasy-name-override: assigneeId # Override the name to avoid merging

With this approach, the additional data (stored in the assignee response field) is still available to Terraform consumers. However, there may be a loss of drift detection when Terraform updates the resource’s state during the read operation.

Note: You can also use x-speakeasy-name-override to rename the conflicting property (in this case, “assignee”) in the response schema to achieve the same effect. The key is to prevent a type collision between request and response.

Option 2: Ignore the mismatched property

Use x-speakeasy-ignore to exclude the problematic property from generation:

openapi.yaml


TaskResponse:
  type: object
  x-speakeasy-entity: Task
  properties:
    taskId:
      type: string
    assignee:
      type: object
      properties:
        id:
          type: string
        name:
          type: string
      x-speakeasy-ignore: true # Ignore this property in the response

This approach resolves the impedance mismatch by removing the conflicting property altogether. However, this also means that the property is no longer tracked in Terraform state.

Last updated on September 16, 2025