# Prismic Migration API Update: Changes to Error Format

**URL:** <https://community.prismic.io/t/prismic-migration-api-update-changes-to-error-format/20020>\
**Category:** Community Showcase & Announcements\
**Created:** [October 16, 2025, 3:18pm UTC](https://community.prismic.io/t/prismic-migration-api-update-changes-to-error-format/20020 "2025-10-16T15:18:25Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Ezekiel](https://avatars.discourse-cdn.com/v4/letter/e/848f3c/32.png) [@Ezekiel](https://community.prismic.io/u/Ezekiel)\
**Post date:** [October 16, 2025, 3:18pm UTC](https://community.prismic.io/t/prismic-migration-api-update-changes-to-error-format/20020/1 "2025-10-16T15:18:25Z")

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Hi there,

We’re making an update to the Prismic Migration API error format.

**👉 If your code doesn’t directly depend on the response body of errors, you don’t need to do anything.**

For most projects, that’s the case, success responses remain unchanged, and only the shape of error responses is affected.

### 🔄 What Changed

Previously, error responses could vary and sometimes returned inconsistent payloads.  
In some cases, responses were declared as `application/json` but returned plain text instead.

Going forward, **errors will always return proper JSON** following this type:

```auto
type ResponseError = {
message: string
details?: {
property?: string // (optional) the field that failed validation
value: unknown // the rejected value
error: string // a string explaining the failure
}[]
}

```

### 💡 Why the Change

This update both fixes a bug (errors incorrectly returned plain text while declaring `application/json`), and improves consistency. With the new format, error responses are always valid JSON and more actionable, making it easier to debug migrations quickly and reliably.

### 📅 When It Takes Effect

- The new format will go live on **November 3**.

#### ⚠ Action Required

If you’re using the **Prismic client** for migrations and rely on `error.response`, you’ll need to:

- **Upgrade to the latest Prismic client.**
- **Update your error handling logic** to account for the new shape.

_If you’re not handling errors directly, no action is needed._

If you have any questions about this, feel free to drop them below.