Build the minimal HTML consent screen presented when a dynamically-registered
client (identified by its clientRedirectUri) has not yet been approved to be
forwarded to the upstream authorization server. The MCP authorization spec
(§Security Considerations > Confused Deputy Problem) requires a proxy using a
static upstream client_id to obtain user consent for EACH dynamically
registered client before forwarding it upstream. The screen offers a single
approval action: a <form method="POST"> targeting consentPath and carrying
the opaque proxy state as a hidden field. Posting it records consent and
resumes the upstream redirect. Using a form POST (rather than a hyperlink GET)
means link prefetch/preload cannot auto-fire the state-changing grant and the
opaque state is not carried in a URL that could leak via Referer/history/logs.
Build the minimal HTML consent screen presented when a dynamically-registered client (identified by its clientRedirectUri) has not yet been approved to be forwarded to the upstream authorization server. The MCP authorization spec (§Security Considerations > Confused Deputy Problem) requires a proxy using a static upstream client_id to obtain user consent for EACH dynamically registered client before forwarding it upstream. The screen offers a single approval action: a <form method="POST"> targeting consentPath and carrying the opaque proxy state as a hidden field. Posting it records consent and resumes the upstream redirect. Using a form POST (rather than a hyperlink GET) means link prefetch/preload cannot auto-fire the state-changing grant and the opaque state is not carried in a URL that could leak via Referer/history/logs.