Cross-Language SDKs for a Single Agent Capability Standard

In most real-world systems, “AI agents” sit on top of a polyglot stack:

If your capability model only really exists in one language, you end up with: A more sustainable pattern is to treat the capability protocol as the primary artifact and the language SDKs as implementations.

Concretely:

Now a capability implemented in Rust can be:

…without reinventing validation, approvals, or tracing.

If you are designing your own internal runtime, consider starting with the protocol and tests first, and only then layering language-specific ergonomics on top. It is slower upfront but pays off when your stack inevitably becomes polyglot.