Plugin Capabilities Model

Every plugin declares its required capabilities in its EngineDescriptor.

Capability Enum

type Capability string

const (
    // Host function capabilities (what the plugin can call)
    CapSQL           Capability = "host:sql"         // Execute SQL via core's connection manager
    CapHTTP          Capability = "host:http"         // Make HTTP calls via core's connection manager
    CapStoreRead     Capability = "host:store:read"   // Read from core's plugin_data store
    CapStoreWrite    Capability = "host:store:write"  // Write to core's plugin_data store
    CapCryptoEncrypt Capability = "host:crypto"       // Request encryption from core
    CapAuditEmit     Capability = "host:audit"        // Emit audit events through core

    // Engine type capabilities (what kind of engine this is)
    CapDynamicCreds  Capability = "engine:dynamic_credentials"  // Create/revoke credentials
    CapRootRotation  Capability = "engine:root_rotation"        // Rotate root credentials
    CapCrypto        Capability = "engine:crypto"               // Encrypt/decrypt (transit engine)
    CapCertificates  Capability = "engine:certificates"         // Sign/revoke certificates (PKI/SSH)
)

Plugins declare capabilities in their descriptor. The core only exposes the host functions the plugin declared. A plugin that declares CapSQL but not CapHTTP cannot make HTTP calls — the host function simply does not exist in its sandbox.

Security Property

Plugins have NO direct access to network, filesystem, or core memory. All external access is mediated through host functions that the core controls.

Capability Grant Rules

Plugin Tier	Capability Grant
Official (signed by GetArcan)	All declared capabilities auto-granted
Enterprise (activation key)	All declared + enterprise-only capabilities
Community (user-signed, future)	User must explicitly approve each capability on install

The core checks capabilities before forwarding requests to plugins. A plugin that declares CapDynamicCreds but not CapCrypto will receive PermissionDenied if an Encrypt() call is routed to it.