Worked on the vercel/ai repository to enhance OpenAI compatibility by addressing data fidelity issues related to usage tracking. Focused on API development and testing using TypeScript, the developer updated the openaiCompatibleTokenUsageSchema from z.object() to z.looseObject(), allowing the system to retain non-standard usage fields from OpenAI-compatible providers. This change ensured that additional provider-specific fields were preserved in usage.raw, improving interoperability and supporting more accurate billing and analytics. The work included updating tests and documentation, manual verification of preserved fields, and creating a patch changeset, resulting in more robust handling of diverse usage data across providers.