Response validation

The SDK checks resource responses against the data shape expected by the installed version. This can reveal an upstream API change before it becomes a hard-to-find bug in your application.

Default behavior

The default policy is warn. When validation fails, the client writes a warning and still returns the API data.

Choose a policy

Pass the policy when you create a client:

const ignored = new RankedClient({ validation: "ignore" });
const warned = new RankedClient({ validation: "warn" });
const strict = new RankedClient({ validation: "error" });

Policy	Behavior when data does not match
ignore	Skips validation and returns the data
warn	Reports the issue and returns the data
error	Reports the issue and throws INVALID_RESPONSE

Use error when your application cannot work safely with an unexpected response. Keep warn when showing partial data is better than failing the whole request.

Collect issues yourself

Use onIssue to send validation problems to your logger:

import { RankedClient, type ValidationIssue } from "mcsrranked-sdk";

function reportValidationIssue(issue: ValidationIssue) {
  console.warn(issue.route, issue.url, issue.problems);
}

const ranked = new RankedClient({
  validation: {
    policy: "warn",
    onIssue: reportValidationIssue,
  },
});

Each issue contains the SDK route, request URL, and a list of problems. A problem has a property path when one can be identified and a validation message.

If onIssue throws, the SDK logs that callback failure and continues its normal validation policy.

Low-level requests

request<T>() and fetch() do not use the resource response schemas. The generic passed to request<T>() is a compile-time assertion, not runtime validation.