Microsoft has launched Dev Proxy v2.0, a major update that introduces improved accuracy in API simulations, smarter telemetry handling, and support for .NET 10. While the release includes a few small breaking changes, it significantly enhances reliability for developers building and testing applications that integrate with Microsoft Graph, OpenAI APIs, and other cloud services.

Download Dev Proxy v2.0.

A key update corrects how mocked Microsoft Graph responses handle date formatting. Dev Proxy now uses culture-invariant, standards-aligned formats—RFC 1123 for HTTP headers and ISO 8601 for error payloads—ensuring consistent behavior across environments and better emulation of real Graph responses. Telemetry recording has also been improved: plugins now generate output only when relevant data exists, reducing clutter and aligning with standard Dev Proxy recording behavior.

Developers working with AI workloads gain deeper visibility into token efficiency thanks to enhanced telemetry that tracks cached tokens, enabling clearer insight into cost savings and model optimization strategies. The release also includes compatibility with .NET 10, ensuring access to the latest runtime performance and security features. A corresponding update to the Dev Proxy Toolkit for VS Code (v1.10.0) brings updated JSON snippets aligned to the new v2.0 schemas.

Dev Proxy v2.0 offers greater consistency, cleaner workflows, and improved cost transparency for AI applications—making it a recommended upgrade for all current users.