# POST /signal/decision/report changes: unknown client_transaction_id fails

Calls to POST /signal/decision/report, body parameter client_transaction_id on Plaid API stopped working on September 1, 2025.

- API: Plaid API (production.plaid.com)
- Kind: Behaviour change
- Announced: August 6, 2025
- Takes effect: September 1, 2025
- Calls after that day: fail
- Calls it hits: `POST /signal/decision/report`, `body parameter client_transaction_id`
- Source: [Changelog](https://plaid.com/docs/changelog/)
- Verified: November 6, 2026, against Plaid API's own pages
- Page: https://www.okapi.bot/providers/plaid-api/breaking-changes/post-signal-decision-report-changes-unknown-client-transaction-id-fails/

## Plaid API's words

> Beginning September 1, 2025, when /signal/decision/report or /signal/return/report is called with an unknown client_transaction_id (one that was never submitted to /signal/evaluate ), these endpoints will return an error instead of a success response.

Okapi finds the calls this change hits in your repo and opens the pull request with the fix: https://github.com/apps/okapi-agent