unowned-contract

The wrapped thing changed seam

Somebody else's contract moved. A vendor API, a firmware build, a warehouse dialect, a model provider: whatever the adapter wrapped changed its payload, its authentication or its meaning out of band, and the adapter that trusted the old shape broke. The fix is almost always to handle the new shape, not to restore the old behaviour.

Symptom

An integration that has worked for a long time starts failing, and nothing shipped on our side. Or the call still succeeds and the data it carries no longer matches what the code reads: a field that is now absent, a type that flipped, an identifier that is now a string, a list that became an object.

Authentication is the other common face of it. Requests that used to be accepted now come back as a redirect, a login page, or a rejection with a shape the adapter does not recognise.

What Crumbtrail can see

For every request the browser made, including calls to external hosts, a session carries the method, the URL, the status, the timing, the headers when header capture is enabled, and the request and response bodies subject to the capture size limit and the redaction policy. Where the backend integration is installed, backend spans carry the same for calls that integration instruments, and a response body when it reports one. getLinkedRequestContext returns the joined frontend and backend view of one request id.

Several named detector signals point straight at this archetype when they fire: content_type_body_mismatch, api_route_returned_document (a document arriving where structured data was expected, which is what an expired session or a moved authentication endpoint looks like), response_count_mismatch, backend_http_error, backend_http_client_error and invalid_webhook_signature_accepted.

It does not see a call your backend makes to a vendor unless the backend integration is installed and instruments that call. It does not see the vendor's changelog, deprecation notice or status page, and it never will, because none of that is in the running application. A body larger than the configured maximum is summarised rather than stored, and fields the redaction policy classifies as sensitive are replaced with non recoverable shape metadata. When the field that changed is a redacted one you can see that its shape moved and you cannot see its value.