How are teams handling the Assistants API → Responses API migration in large codebases?

I’m working through the Assistants API deprecation and the migration guide covers the API surface well, but not the part I’m stuck on: finding every affected call site across a codebase that’s grown organically.

In our case the calls are spread across several services, some behind wrappers, and a plain grep for client.beta.threads misses the indirect ones. So far I’ve been doing it manually and I’m not confident I’ve found everything.

For those who’ve already done this migration:

  • How did you inventory the affected code — grep, AST tooling, or manual review?
  • Roughly how long did it take end to end?
  • Did anything slip through and only surface later in staging or production?

Interested in what actually worked rather than what the docs recommend.