Security logic result is unavailable to tools forcing a second header read

Hello, I run an MCP server that proxies an internal HTTP API: every tool forwards the caller's bearer token upstream, so the token is both the gate and an input to each tool.

prependSecurity handles the gate well. But per docs/server/transport.md#security:

The result of the security logic does not reach the tool logic. If a tool needs data from the caller, read the request headers with handleWithHeaders (or serverLogic with headers).

So each tool re-reads the Authorization header and re-handles the missing-token case the gate already rejected (unreachable branch in every tool), and header parsing lives in two places that can drift apart.

Tapir's serverSecurityLogic covers this by deriving a typed principal once and handing it to the main logic. Do you think it would make sense to add an equivalent for Chimp, or is there a recommended pattern I've missed?

Start with docs/server/transport.md#security and compare prependSecurity with the documented handleWithHeaders and serverLogic patterns. Determine how a typed result from security logic could reach tool logic without a second Authorization-header read. Done means the supported pattern or API is documented and the redundant missing-token handling is no longer required.