A2Agent compatibility testing: custom catalog validation #3

Hi Copilot maintainers,

I represent A2Agent, an OpenAI- and Anthropic-compatible API gateway. We'd like to verify compatibility with your existing provider configuration and contribute a focused PR.

Copilot already accepts any OpenAI-compatible baseUrl through OpenAiAdapter. listModels currently casts the response and stringifies each id/name without runtime shape checks, so missing IDs can become the literal model name "undefined", while null entries can throw. I would propose a small validation change and actionable catalog errors, keeping manually entered models available.

• A minimal configuration recipe using existing settings and placeholder credentials.
• Offline null/primitive rows, missing/numeric IDs, duplicates and valid custom model IDs, without applying the official-OpenAI name filter to custom providers.
• If you are interested, we can agree a small live compatibility check after the offline scope is reviewed.

Would you prefer a documentation/test-only PR or a broader integration?

Separately, after successful verification, would you consider including A2Agent wherever you document tested providers? We'll follow your preferred wording and placement, without implying endorsement.

We can privately provide a test key with US$10 in one-time API credits, plus technical support. This support is not conditional on merging, endorsement, or listing.

Thanks!