Skill Contract

MCP Public Self-Signup Tools

VaultCrux Sprint 8 adds two public MCP methods under POST /rpc/public.

• register_agent
• request_sponsor

Both methods are listed in GET /capabilities/public.

register_agent

Registers a constrained self-signup principal and returns:

• agentPrincipalId
• sessionToken (vcrx_self_<signed_token>)
• discoveryTenantId (selfreg:<principal>)
• credit and daily query limits
• sponsor upgrade URL

request_sponsor

Requires session_token and returns sponsor summary metadata for that principal:

• current registration type
• credits remaining
• daily query remaining
• upgradeUrl

Use this to drive an upgrade CTA/funnel before invoking frontdoor sponsor claim.