> For clean Markdown of any page, append .md to the page URL.
> For a complete documentation index, see https://docs.itential.com/itential-platform/2023-2/release-notes/breaking-changes/broken-references/llms.txt.
> For AI client integration (Claude Code, Cursor, etc.), connect to the MCP server at https://docs.itential.com/_mcp/server.

# Broken references

> Breaking change notice that Itential Platform 2023.2 now fails to start applications or adapters that contain broken JSON Schema $ref expressions.

## Breaking change notice (2023.2.0)

Itential Platform 2023.2 introduces a breaking change that affects incorrectly defined applications and adapters.

## Broken references

An application or adapter typically defines a method in its `pronghorn.json` file with an input that refers to a JSON Schema by `id` via the `$ref` keyword. Itential discovered that in some cases the JSON Schema pointed to by the `$ref` expression was missing, forming a broken reference. Previously, the Itential Platform HTTP server would ignore the missing reference and allow any data type at that location.

With this breaking change, the 2023.2 HTTP server now fails to run the method and returns a broken schema reference error.

## What should I do?

### Identify broken references

Broken references can be identified by calling a method and examining the response. The error message will look similar to:

```
Broken $ref encountered while applying method input schemas: can't resolve reference my-missing-schema from id apiWithBrokenRef-inputOne
```

### Remediate broken references

If you encounter this issue in a custom application or adapter, make a code change to your application or adapter model. Ensure all `$ref` expressions point to schemas that exist in the associated `./json-schema` directory. These schemas are identified by the value of their `$id` property, not by their filename in the directory.

> Breaking change notice that Itential Platform 2023.2 now fails to start applications or adapters that contain broken JSON Schema $ref expressions.